display.cpp

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/*
    Copyright (C) 2003 - 2025
    by David White <dave@whitevine.net>
    Part of the Battle for Wesnoth Project https://www.wesnoth.org/
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY.
 
    See the COPYING file for more details.
*/
 
/**
 * @file
 * Routines to set up the display, scroll and zoom the map.
 */
 
#include "display.hpp"
 
#include "arrow.hpp"
#include "color.hpp"
#include "draw.hpp"
#include "draw_manager.hpp"
#include "fake_unit_manager.hpp"
#include "filesystem.hpp"
#include "floating_label.hpp"
#include "font/sdl_ttf_compat.hpp"
#include "font/text.hpp"
#include "global.hpp"
#include "gui/core/event/handler.hpp" // is_in_dialog
#include "preferences/preferences.hpp"
#include "halo.hpp"
#include "hotkey/command_executor.hpp"
#include "log.hpp"
#include "map/map.hpp"
#include "map/label.hpp"
#include "minimap.hpp"
#include "overlay.hpp"
#include "play_controller.hpp" //note: this can probably be refactored out
#include "reports.hpp"
#include "resources.hpp"
#include "serialization/chrono.hpp"
#include "synced_context.hpp"
#include "team.hpp"
#include "terrain/builder.hpp"
#include "time_of_day.hpp"
#include "tooltips.hpp"
#include "units/unit.hpp"
#include "units/animation_component.hpp"
#include "units/drawer.hpp"
#include "units/orb_status.hpp"
#include "utils/general.hpp"
#include "video.hpp"
#include "whiteboard/manager.hpp"
 
#include <boost/algorithm/string/trim.hpp>
 
#include <algorithm>
#include <array>
#include <cmath>
#include <iomanip>
#include <numeric>
#include <utility>
 
#ifdef _WIN32
#include <windows.h>
#endif
 
using namespace std::chrono_literals;
// Includes for bug #17573
 
static lg::log_domain log_display("display");
#define ERR_DP LOG_STREAM(err, log_display)
#define WRN_DP LOG_STREAM(warn, log_display)
#define LOG_DP LOG_STREAM(info, log_display)
#define DBG_DP LOG_STREAM(debug, log_display)
 
// These are macros instead of proper constants so that they auto-update if the game config is reloaded.
#define zoom_levels      (game_config::zoom_levels)
#define final_zoom_index (static_cast<int>(zoom_levels.size()) - 1)
#define DefaultZoom      (game_config::tile_size)
#define SmallZoom        (DefaultZoom / 2)
#define MinZoom          (zoom_levels.front())
#define MaxZoom          (zoom_levels.back())
 
namespace {
    int prevLabel = 0;
}
 
unsigned int display::zoom_ = DefaultZoom;
unsigned int display::last_zoom_ = SmallZoom;
 
// Returns index of zoom_levels which is closest match to input zoom_level
// Assumption: zoom_levels is a sorted vector of ascending tile sizes
static int get_zoom_levels_index(unsigned int zoom_level)
{
    zoom_level = std::clamp(zoom_level, MinZoom, MaxZoom);  // ensure zoom_level is within zoom_levels bounds
    auto iter = std::lower_bound(zoom_levels.begin(), zoom_levels.end(), zoom_level);
 
    // find closest match
    if(iter != zoom_levels.begin() && iter != zoom_levels.end()) {
        float diff = *iter - *(iter - 1);
        float lower = (zoom_level - *(iter - 1)) / diff;
        float upper = (*iter - zoom_level) / diff;
 
        // the previous element is closer to zoom_level than the current one
        if(lower < upper) {
            iter--;
        }
    }
 
    return std::distance(zoom_levels.begin(), iter);
}
 
void display::add_overlay(const map_location& loc, overlay&& ov)
{
    std::vector<overlay>& overlays = get_overlays()[loc];
    auto pos = std::find_if(overlays.begin(), overlays.end(),
        [new_order = ov.z_order](const overlay& existing) { return existing.z_order > new_order; });
 
    auto inserted = overlays.emplace(pos, std::move(ov));
    if(const std::string& halo = inserted->halo; !halo.empty()) {
        auto [x, y] = get_location_rect(loc).center();
        inserted->halo_handle = halo_man_.add(x, y, halo, loc);
    }
}
 
void display::remove_overlay(const map_location& loc)
{
    get_overlays().erase(loc);
}
 
void display::remove_single_overlay(const map_location& loc, const std::string& toDelete)
{
    utils::erase_if(get_overlays()[loc],
        [&toDelete](const overlay& ov) { return ov.image == toDelete || ov.halo == toDelete || ov.id == toDelete; });
}
 
display::display(const display_context* dc,
        std::weak_ptr<wb::manager> wb,
        reports& reports_object,
        const std::string& theme_id,
        const config& level)
    : dc_(dc)
    , halo_man_()
    , wb_(std::move(wb))
    , exclusive_unit_draw_requests_()
    , viewing_team_index_(0)
    , dont_show_all_(false)
    , viewport_origin_(0, 0)
    , view_locked_(false)
    , theme_(theme::get_theme_config(theme_id.empty() ? prefs::get().theme() : theme_id), video::game_canvas())
    , zoom_index_(0)
    , fake_unit_man_(new fake_unit_manager(*this))
    , builder_(new terrain_builder(level, (dc_ ? &context().map() : nullptr), theme_.border().tile_image, theme_.border().show_border))
    , minimap_renderer_(nullptr)
    , minimap_location_()
    , redraw_background_(false)
    , invalidateAll_(true)
    , diagnostic_label_(0)
    , invalidateGameStatus_(true)
    , map_labels_(new map_labels(nullptr))
    , reports_object_(&reports_object)
    , scroll_event_("scrolled")
    , reportLocations_()
    , reportSurfaces_()
    , reports_()
    , menu_buttons_()
    , action_buttons_()
    , invalidated_()
    , tod_hex_mask1(nullptr)
    , tod_hex_mask2(nullptr)
    , fog_images_()
    , shroud_images_()
    , selectedHex_()
    , mouseoverHex_()
    , keys_()
    , animate_map_(true)
    , animate_water_(true)
    , flags_()
    , playing_team_index_(0)
    , drawing_buffer_()
    , map_screenshot_(false)
    , reach_map_()
    , reach_map_old_()
    , reach_map_changed_(true)
    , reach_map_team_index_(0)
    , invalidated_hexes_(0)
    , drawn_hexes_(0)
    , redraw_observers_()
    , debug_flags_()
    , arrows_map_()
    , color_adjust_()
{
    //The following assertion fails when starting a campaign
    assert(singleton_ == nullptr);
    singleton_ = this;
 
    resources::fake_units = fake_unit_man_.get();
 
    blindfold_ctr_ = 0;
 
    read(level.child_or_empty("display"));
 
    fill_images_list(game_config::fog_prefix, fog_images_);
    fill_images_list(game_config::shroud_prefix, shroud_images_);
 
    unsigned int tile_size = prefs::get().tile_size();
    if(tile_size < MinZoom || tile_size > MaxZoom)
        tile_size = DefaultZoom;
    zoom_index_ = get_zoom_levels_index(tile_size);
    zoom_ = zoom_levels[zoom_index_];
    if(zoom_ != prefs::get().tile_size())   // correct saved tile_size if necessary
        prefs::get().set_tile_size(zoom_);
 
    init_flags();
 
    if(!menu_buttons_.empty() || !action_buttons_.empty()) {
        create_buttons();
    }
 
#ifdef _WIN32
    // Increase timer resolution to prevent delays getting much longer than they should.
    timeBeginPeriod(1u);
#endif
}
 
display::~display()
{
#ifdef _WIN32
    timeEndPeriod(1u);
#endif
 
    singleton_ = nullptr;
    resources::fake_units = nullptr;
}
 
void display::set_theme(const std::string& new_theme)
{
    theme_ = theme{theme::get_theme_config(new_theme), video::game_canvas()};
    builder_->set_draw_border(theme_.border().show_border);
    menu_buttons_.clear();
    action_buttons_.clear();
    create_buttons();
    rebuild_all();
    queue_rerender();
}
 
void display::init_flags()
{
    flags_.clear();
    if (!dc_) return;
    flags_.resize(context().teams().size());
 
    for(const team& t : context().teams()) {
        reinit_flags_for_team(t);
    }
}
 
void display::reinit_flags_for_team(const team& t)
{
    std::string flag = t.flag();
    std::string old_rgb = game_config::flag_rgb;
    std::string new_rgb = t.color();
 
    if(flag.empty()) {
        flag = game_config::images::flag;
    }
 
    LOG_DP << "Adding flag for side " << t.side() << " from animation " << flag;
 
    // Must recolor flag image
    animated<image::locator> temp_anim;
 
    for(const std::string& item : utils::square_parenthetical_split(flag)) {
        const std::vector<std::string> sub_items = utils::split(item, ':');
        std::string img_path = item;
        auto time = 100ms;
 
        if(sub_items.size() > 1) {
            img_path = sub_items.front();
            try {
                time = std::max(1ms, std::chrono::milliseconds{std::stoi(sub_items.back())});
            } catch(const std::invalid_argument&) {
                ERR_DP << "Invalid time value found when constructing flag for side " << t.side() << ": " << sub_items.back();
            }
        }
 
        image::locator flag_image(img_path, formatter{} << "~RC(" << old_rgb << ">" << new_rgb << ")");
        temp_anim.add_frame(time, flag_image);
    }
 
    animated<image::locator>& f = flags_[t.side() - 1];
    f = temp_anim;
    auto time = f.get_end_time();
    if (time > 0ms) {
        int start_time = randomness::rng::default_instance().get_random_int(0, time.count() - 1);
        f.start_animation(std::chrono::milliseconds{start_time}, true);
    } else {
        // this can happen if both flag and game_config::images::flag are empty.
        ERR_DP << "missing flag for side " << t.side();
    }
}
 
texture display::get_flag(const map_location& loc)
{
    for(const team& t : context().teams()) {
        if(t.owns_village(loc) && (!fogged(loc) || !viewing_team().is_enemy(t.side()))) {
            auto& flag = flags_[t.side() - 1];
            flag.update_last_draw_time();
 
            const image::locator& image_flag = animate_map_
                ? flag.get_current_frame()
                : flag.get_first_frame();
 
            return image::get_texture(image_flag, image::TOD_COLORED);
        }
    }
 
    return texture();
}
 
const team& display::playing_team() const
{
    return context().teams()[playing_team_index()];
}
 
const team& display::viewing_team() const
{
    return context().teams()[viewing_team_index()];
}
 
void display::set_viewing_team_index(std::size_t teamindex, bool show_everything)
{
    assert(teamindex < context().teams().size());
    viewing_team_index_ = teamindex;
    if(!show_everything) {
        labels().set_team(&context().teams()[teamindex]);
        dont_show_all_ = true;
    } else {
        labels().set_team(nullptr);
        dont_show_all_ = false;
    }
    labels().recalculate_labels();
    if(std::shared_ptr<wb::manager> w = wb_.lock()) {
        w->on_viewer_change(teamindex);
    }
}
 
void display::set_playing_team_index(std::size_t teamindex)
{
    assert(teamindex < context().teams().size());
    playing_team_index_ = teamindex;
    invalidate_game_status();
}
 
bool display::add_exclusive_draw(const map_location& loc, const unit& unit)
{
    if(!loc.valid()) return false;
    auto [iter, success] = exclusive_unit_draw_requests_.emplace(loc, unit.id());
    return success;
}
 
std::string display::remove_exclusive_draw(const map_location& loc)
{
    if(!loc.valid()) return {};
    std::string id = exclusive_unit_draw_requests_[loc];
    exclusive_unit_draw_requests_.erase(loc);
    return id;
}
 
bool display::unit_can_draw_here(const map_location& loc, const unit& unit) const
{
    auto request = exclusive_unit_draw_requests_.find(loc);
    return request == exclusive_unit_draw_requests_.end() || request->second == unit.id();
}
 
void display::update_tod(const time_of_day* tod_override)
{
    const time_of_day* tod = tod_override;
    if(tod == nullptr) {
        tod = &get_time_of_day();
    }
 
    const tod_color col = color_adjust_ + tod->color;
    image::set_color_adjustment(col.r, col.g, col.b);
 
    invalidate_all();
}
 
void display::adjust_color_overlay(int r, int g, int b)
{
    color_adjust_ = tod_color(r, g, b);
    update_tod();
}
 
void display::fill_images_list(const std::string& prefix, std::vector<std::string>& images)
{
    if(prefix == ""){
        return;
    }
 
    // search prefix.png, prefix1.png, prefix2.png ...
    for(int i=0; ; ++i){
        std::ostringstream s;
        s << prefix;
        if(i != 0)
            s << i;
        s << ".png";
        if(image::exists(s.str()))
            images.push_back(s.str());
        else if(i>0)
            break;
    }
    if (images.empty())
        images.emplace_back();
}
 
void display::rebuild_all()
{
    builder_->rebuild_all();
}
 
void display::reload_map()
{
    redraw_background_ = true;
    builder_->reload_map();
}
 
void display::change_display_context(const display_context * dc)
{
    dc_ = dc;
    builder_->change_map(&context().map()); //TODO: Should display_context own and initialize the builder object?
}
 
void display::blindfold(bool value)
{
    if(value == true)
        ++blindfold_ctr_;
    else
        --blindfold_ctr_;
}
 
bool display::is_blindfolded() const
{
    return blindfold_ctr_ > 0;
}
 
const rect& display::minimap_area() const
{
    return theme_.mini_map_location(video::game_canvas());
}
 
const rect& display::palette_area() const
{
    return theme_.palette_location(video::game_canvas());
}
 
const rect& display::unit_image_area() const
{
    return theme_.unit_image_location(video::game_canvas());
}
 
rect display::max_map_area() const
{
    rect max_area{0, 0, 0, 0};
 
    // hex_size() is always a multiple of 4
    // and hex_width() a multiple of 3,
    // so there shouldn't be off-by-one-errors
    // due to rounding.
    // To display a hex fully on screen,
    // a little bit extra space is needed.
    // Also added the border two times.
    max_area.w = static_cast<int>((context().map().w() + 2 * theme_.border().size + 1.0 / 3.0) * hex_width());
    max_area.h = static_cast<int>((context().map().h() + 2 * theme_.border().size + 0.5) * hex_size());
 
    return max_area;
}
 
rect display::map_area() const
{
    rect max_area = max_map_area();
 
    // if it's for map_screenshot, maximize and don't recenter
    if(map_screenshot_) {
        return max_area;
    }
 
    rect res = map_outside_area();
 
    if(max_area.w < res.w) {
        // map is smaller, center
        res.x += (res.w - max_area.w) / 2;
        res.w = max_area.w;
    }
 
    if(max_area.h < res.h) {
        // map is smaller, center
        res.y += (res.h - max_area.h) / 2;
        res.h = max_area.h;
    }
 
    return res;
}
 
rect display::map_outside_area() const
{
    if(map_screenshot_) {
        return max_map_area();
    } else {
        return theme_.main_map_location(video::game_canvas());
    }
}
 
bool display::outside_area(const rect& area, const int x, const int y)
{
    const int x_thresh = hex_size();
    const int y_thresh = hex_size();
    return (x < area.x || x > area.x + area.w - x_thresh || y < area.y || y > area.y + area.h - y_thresh);
}
 
// This function uses the screen as reference
map_location display::hex_clicked_on(int xclick, int yclick) const
{
    rect r = map_area();
    if(!r.contains(xclick, yclick)) {
        return map_location();
    }
 
    xclick -= r.x;
    yclick -= r.y;
 
    return pixel_position_to_hex(viewport_origin_.x + xclick, viewport_origin_.y + yclick);
}
 
// This function uses the rect of map_area as reference
map_location display::pixel_position_to_hex(int x, int y) const
{
    // adjust for the border
    x -= static_cast<int>(theme_.border().size * hex_width());
    y -= static_cast<int>(theme_.border().size * hex_size());
    // The editor can modify the border and this will result in a negative y
    // value. Instead of adding extra cases we just shift the hex. Since the
    // editor doesn't use the direction this is no problem.
    const int offset = y < 0 ? 1 : 0;
    if(offset) {
        x += hex_width();
        y += hex_size();
    }
    const int s = hex_size();
    const int tesselation_x_size = hex_width() * 2;
    const int tesselation_y_size = s;
    const int x_base = x / tesselation_x_size * 2;
    const int x_mod  = x % tesselation_x_size;
    const int y_base = y / tesselation_y_size;
    const int y_mod  = y % tesselation_y_size;
 
    int x_modifier = 0;
    int y_modifier = 0;
 
    if (y_mod < tesselation_y_size / 2) {
        if ((x_mod * 2 + y_mod) < (s / 2)) {
            x_modifier = -1;
            y_modifier = -1;
        } else if ((x_mod * 2 - y_mod) < (s * 3 / 2)) {
            x_modifier = 0;
            y_modifier = 0;
        } else {
            x_modifier = 1;
            y_modifier = -1;
        }
 
    } else {
        if ((x_mod * 2 - (y_mod - s / 2)) < 0) {
            x_modifier = -1;
            y_modifier = 0;
        } else if ((x_mod * 2 + (y_mod - s / 2)) < s * 2) {
            x_modifier = 0;
            y_modifier = 0;
        } else {
            x_modifier = 1;
            y_modifier = 0;
        }
    }
 
    return map_location(x_base + x_modifier - offset, y_base + y_modifier - offset);
}
 
display::rect_of_hexes::iterator& display::rect_of_hexes::iterator::operator++()
{
    if (loc_.y < rect_.bottom[loc_.x & 1])
        ++loc_.y;
    else {
        ++loc_.x;
        loc_.y = rect_.top[loc_.x & 1];
    }
 
    return *this;
}
 
// begin is top left, and end is after bottom right
display::rect_of_hexes::iterator display::rect_of_hexes::begin() const
{
    return iterator(map_location(left, top[left & 1]), *this);
}
display::rect_of_hexes::iterator display::rect_of_hexes::end() const
{
    return iterator(map_location(right+1, top[(right+1) & 1]), *this);
}
 
const display::rect_of_hexes display::hexes_under_rect(const rect& r) const
{
    if(r.w <= 0 || r.h <= 0) {
        // Dummy values giving begin == end (end is right + 1)
        return {0, -1, {0, 0}, {0, 0}};
    }
 
    // translate rect coordinates from screen-based to map_area-based
    auto [x, y] = viewport_origin_ - map_area().origin() + r.origin();
    // we use the "double" type to avoid important rounding error (size of an hex!)
    // we will also need to use std::floor to avoid bad rounding at border (negative values)
    double tile_width = hex_width();
    double tile_size = hex_size();
    double border = theme_.border().size;
 
    return {
        // we minus "0.(3)", for horizontal imbrication.
        // reason is: two adjacent hexes each overlap 1/4 of their width, so for
        // grid calculation 3/4 of tile width is used, which by default gives
        // 18/54=0.(3). Note that, while tile_width is zoom dependent, 0.(3) is not.
        static_cast<int>(std::floor(-border + x / tile_width - 0.3333333)),
 
        // we remove 1 pixel of the rectangle dimensions
        // (the rounded division take one pixel more than needed)
        static_cast<int>(std::floor(-border + (x + r.w - 1) / tile_width)),
 
        // for odd x, we must shift up one half-hex. Since x will vary along the edge,
        // we store here the y values for even and odd x, respectively
        {
            static_cast<int>(std::floor(-border + y / tile_size)),
            static_cast<int>(std::floor(-border + y / tile_size - 0.5))
        },
        {
            static_cast<int>(std::floor(-border + (y + r.h - 1) / tile_size)),
            static_cast<int>(std::floor(-border + (y + r.h - 1) / tile_size - 0.5))
        }
    };
 
    // TODO: in some rare cases (1/16), a corner of the big rect is on a tile
    // (the 72x72 rectangle containing the hex) but not on the hex itself
    // Can maybe be optimized by using pixel_position_to_hex
}
 
bool display::shrouded(const map_location& loc) const
{
    return is_blindfolded() || (dont_show_all_ && viewing_team().shrouded(loc));
}
 
bool display::fogged(const map_location& loc) const
{
    return is_blindfolded() || (dont_show_all_ && viewing_team().fogged(loc));
}
 
point display::get_location(const map_location& loc) const
{
    // Two possible regressions to be aware of when changing this code:
    // https://github.com/wesnoth/wesnoth/issues/10903 (faulty hex offset) and
    // https://github.com/wesnoth/wesnoth/issues/10676 (Grid overlay flickering)
    return {
        map_area().x - viewport_origin_.x + static_cast<int>(std::ceil((loc.x + theme_.border().size) * hex_width())),
        map_area().y - viewport_origin_.y + static_cast<int>(std::ceil((loc.y + theme_.border().size) * zoom_ + (is_odd(loc.x) ? zoom_ / 2.0 : 0.0)))
    };
}
 
rect display::get_location_rect(const map_location& loc) const
{
    // TODO: evaluate how these functions should be defined in terms of each other
    return { get_location(loc), point{hex_size(), hex_size()} };
}
 
map_location display::minimap_location_on(int x, int y)
{
    // TODO: don't return location for this,
    //  instead directly scroll to the clicked pixel position
 
    if(!minimap_area().contains(x, y)) {
        return map_location();
    }
 
    // we transform the coordinates from minimap to the full map image
    // probably more adjustments to do (border, minimap shift...)
    // but the mouse and human capacity to evaluate the rectangle center
    // is not pixel precise.
    int px = (x - minimap_location_.x) * context().map().w() * hex_width() / std::max(minimap_location_.w, 1);
    int py = (y - minimap_location_.y) * context().map().h() * hex_size() / std::max(minimap_location_.h, 1);
 
    map_location loc = pixel_position_to_hex(px, py);
    if(loc.x < 0) {
        loc.x = 0;
    } else if(loc.x >= context().map().w()) {
        loc.x = context().map().w() - 1;
    }
 
    if(loc.y < 0) {
        loc.y = 0;
    } else if(loc.y >= context().map().h()) {
        loc.y = context().map().h() - 1;
    }
 
    return loc;
}
 
surface display::screenshot(bool map_screenshot)
{
    if (!map_screenshot) {
        LOG_DP << "taking ordinary screenshot";
        return video::read_pixels();
    }
 
    if (context().map().empty()) {
        ERR_DP << "No map loaded, cannot create a map screenshot.";
        return nullptr;
    }
 
    // back up the current map view position and move to top-left
    point old_pos = viewport_origin_;
    viewport_origin_ = {0, 0};
 
    // Reroute render output to a separate texture until the end of scope.
    rect area = max_map_area();
    if (area.w > 1 << 16 || area.h > 1 << 16) {
        WRN_DP << "Excessively large map screenshot area";
    }
    LOG_DP << "creating " << area.w << " by " << area.h
           << " texture for map screenshot";
    texture output_texture(area.w, area.h, SDL_TEXTUREACCESS_TARGET);
    auto target_setter = draw::set_render_target(output_texture);
    auto clipper = draw::override_clip(area);
 
    map_screenshot_ = true;
 
    DBG_DP << "invalidating region for map screenshot";
    invalidate_locations_in_rect(map_area());
 
    DBG_DP << "drawing map screenshot";
    draw();
 
    map_screenshot_ = false;
 
    // Restore map viewport position
    viewport_origin_ = old_pos;
 
    // Read rendered pixels back as an SDL surface.
    LOG_DP << "reading pixels for map screenshot";
    return video::read_pixels();
}
 
std::shared_ptr<gui::button> display::find_action_button(const std::string& id)
{
    for(auto& b : action_buttons_) {
        if(b->id() == id) {
            return b;
        }
    }
    return nullptr;
}
 
std::shared_ptr<gui::button> display::find_menu_button(const std::string& id)
{
    for(auto& b : menu_buttons_) {
        if(b->id() == id) {
            return b;
        }
    }
    return nullptr;
}
 
void display::layout_buttons()
{
    DBG_DP << "positioning menu buttons...";
    for(const auto& menu : theme_.menus()) {
        if(auto b = find_menu_button(menu.get_id())) {
            const rect& loc = menu.location(video::game_canvas());
            b->set_location(loc);
            b->set_measurements(0,0);
            b->set_label(menu.title());
            b->set_image(menu.image());
        }
    }
 
    DBG_DP << "positioning action buttons...";
    for(const auto& action : theme_.actions()) {
        if(auto b = find_action_button(action.get_id())) {
            const rect& loc = action.location(video::game_canvas());
            b->set_location(loc);
            b->set_measurements(0,0);
            b->set_label(action.title());
            b->set_image(action.image());
        }
    }
}
 
namespace
{
gui::button::TYPE string_to_button_type(const std::string& type)
{
    if(type == "checkbox") {
        return gui::button::TYPE_CHECK;
    } else if(type == "image") {
        return gui::button::TYPE_IMAGE;
    } else if(type == "radiobox") {
        return gui::button::TYPE_RADIO;
    } else if(type == "turbo") {
        return gui::button::TYPE_TURBO;
    } else {
        return gui::button::TYPE_PRESS;
    }
}
} // namespace
 
void display::create_buttons()
{
    if(video::headless()) {
        return;
    }
 
    // Keep the old buttons around until we're done so we can check the previous state.
    std::vector<std::shared_ptr<gui::button>> menu_work;
    std::vector<std::shared_ptr<gui::button>> action_work;
 
    DBG_DP << "creating menu buttons...";
    for(const auto& menu : theme_.menus()) {
        if(!menu.is_button()) {
            continue;
        }
 
        auto b = std::make_shared<gui::button>(menu.title(), gui::button::TYPE_PRESS, menu.image(),
            gui::button::DEFAULT_SPACE, true, menu.overlay(), font::SIZE_BUTTON_SMALL);
 
        DBG_DP << "drawing button " << menu.get_id();
        b->set_id(menu.get_id());
        if(!menu.tooltip().empty()) {
            b->set_tooltip_string(menu.tooltip());
        }
 
        if(auto b_prev = find_menu_button(b->id())) {
            b->enable(b_prev->enabled());
        }
 
        menu_work.push_back(std::move(b));
    }
 
    DBG_DP << "creating action buttons...";
    for(const auto& action : theme_.actions()) {
        auto b = std::make_shared<gui::button>(action.title(), string_to_button_type(action.type()),
            action.image(), gui::button::DEFAULT_SPACE, true, action.overlay(), font::SIZE_BUTTON_SMALL);
 
        DBG_DP << "drawing button " << action.get_id();
        b->set_id(action.get_id());
        if(!action.tooltip(0).empty()) {
            b->set_tooltip_string(action.tooltip(0));
        }
 
        if(auto b_prev = find_action_button(b->id())) {
            b->enable(b_prev->enabled());
            if(b_prev->get_type() == gui::button::TYPE_CHECK) {
                b->set_check(b_prev->checked());
            }
        }
 
        action_work.push_back(std::move(b));
    }
 
    menu_buttons_ = std::move(menu_work);
    action_buttons_ = std::move(action_work);
 
    if (prevent_draw_) {
        // buttons start hidden in this case
        hide_buttons();
    }
 
    layout_buttons();
    DBG_DP << "buttons created";
}
 
void display::draw_buttons()
{
    // This is currently unnecessary because every GUI1 widget is a TLD.
    // They will draw themselves. Keeping code in case this changes.
    return;
 
    //const rect clip = draw::get_clip();
    //for(auto& btn : menu_buttons_) {
    //  if(clip.overlaps(btn->location())) {
    //      btn->set_dirty(true);
    //      btn->draw();
    //  }
    //}
 
    //for(auto& btn : action_buttons_) {
    //  if(clip.overlaps(btn->location())) {
    //      btn->set_dirty(true);
    //      btn->draw();
    //  }
    //}
}
 
void display::hide_buttons()
{
    for (auto& button : menu_buttons_) {
        button->hide();
    }
    for (auto& button : action_buttons_) {
        button->hide();
    }
}
 
void display::unhide_buttons()
{
    for (auto& button : menu_buttons_) {
        button->hide(false);
    }
    for (auto& button : action_buttons_) {
        button->hide(false);
    }
}
 
std::vector<texture> display::get_fog_shroud_images(const map_location& loc, image::TYPE image_type)
{
    std::vector<std::string> names;
    const auto adjacent = get_adjacent_tiles(loc);
 
    enum visibility { FOG = 0, SHROUD = 1, CLEAR = 2 };
    std::array<visibility, 6> tiles;
 
    const std::array image_prefix{&game_config::fog_prefix, &game_config::shroud_prefix};
 
    for(int i = 0; i < 6; ++i) {
        if(shrouded(adjacent[i])) {
            tiles[i] = SHROUD;
        } else if(!fogged(loc) && fogged(adjacent[i])) {
            tiles[i] = FOG;
        } else {
            tiles[i] = CLEAR;
        }
    }
 
    for(int v = FOG; v != CLEAR; ++v) {
        // Find somewhere that doesn't have overlap to use as a starting point
        int start{0};
        while(start < 6 && tiles[start] == v) {
            ++start;
        }
 
        if(start == 6) {
            // Completely surrounded by fog or shroud. This might have
            // a special graphic.
            const std::string name = *image_prefix[v] + "-all.png";
            if(image::exists(name)) {
                names.push_back(name);
                // Proceed to the next visibility (fog -> shroud -> clear).
                continue;
            }
            // No special graphic found. We'll just combine some other images
            // and hope it works out.
            start = 0;
        }
 
        // Find all the directions overlap occurs from
        for(int i = (start + 1) % 6, cap1 = 0; i != start && cap1 != 6; ++cap1) {
            if(tiles[i] == v) {
                std::ostringstream stream;
                std::string name;
                stream << *image_prefix[v];
 
                for(int cap2 = 0; v == tiles[i] && cap2 != 6; i = (i + 1) % 6, ++cap2) {
                    stream << "-" << map_location::write_direction(map_location::direction{i});
 
                    if(!image::exists(stream.str() + ".png")) {
                        // If we don't have any surface at all,
                        // then move onto the next overlapped area
                        if(name.empty()) {
                            i = (i + 1) % 6;
                        }
                        break;
                    } else {
                        name = stream.str();
                    }
                }
 
                if(!name.empty()) {
                    names.push_back(name + ".png");
                }
            } else {
                i = (i + 1) % 6;
            }
        }
    }
 
    // now get the textures
    std::vector<texture> res;
 
    for(const std::string& name : names) {
        if(texture tex = image::get_texture(name, image_type)) {
            res.push_back(std::move(tex));
        }
    }
 
    return res;
}
 
void display::get_terrain_images(const map_location& loc, const std::string& timeid, TERRAIN_TYPE terrain_type)
{
    terrain_image_vector_.clear();
 
    std::vector<image::light_adjust> lighting;
    const time_of_day& tod = get_time_of_day(loc);
 
    // get all the light transitions
    const auto adjs = get_adjacent_tiles(loc);
    std::array<const time_of_day*, adjs.size()> atods;
 
    for(std::size_t d = 0; d < adjs.size(); ++d) {
        atods[d] = &get_time_of_day(adjs[d]);
    }
 
    for(int d = 0; d < 6; ++d) {
        /*
        concave
          _____
         /     \
        / atod1 \_____
        \ !tod  /     \
         \_____/ atod2 \
         /  \__\ !tod  /
        /       \_____/
        \  tod  /
         \_____/
         */
 
        const time_of_day& atod1 = *atods[d];
        const time_of_day& atod2 = *atods[(d + 1) % 6];
 
        if(atod1.color == tod.color || atod2.color == tod.color || atod1.color != atod2.color) {
            continue;
        }
 
        if(lighting.empty()) {
            // color the full hex before adding transitions
            tod_color col = tod.color + color_adjust_;
            lighting.emplace_back(0, col.r, col.g, col.b);
        }
 
        // add the directional transitions
        tod_color acol = atod1.color + color_adjust_;
        lighting.emplace_back(d + 1, acol.r, acol.g, acol.b);
    }
 
    for(int d = 0; d < 6; ++d) {
        /*
        convex 1
          _____
         /     \
        / atod1 \_____
        \ !tod  /     \
         \_____/ atod2 \
         /  \__\  tod  /
        /       \_____/
        \  tod  /
         \_____/
         */
 
        const time_of_day& atod1 = *atods[d];
        const time_of_day& atod2 = *atods[(d + 1) % 6];
 
        if(atod1.color == tod.color || atod1.color == atod2.color) {
            continue;
        }
 
        if(lighting.empty()) {
            // color the full hex before adding transitions
            tod_color col = tod.color + color_adjust_;
            lighting.emplace_back(0, col.r, col.g, col.b);
        }
 
        // add the directional transitions
        tod_color acol = atod1.color + color_adjust_;
        lighting.emplace_back(d + 7, acol.r, acol.g, acol.b);
    }
 
    for(int d = 0; d < 6; ++d) {
        /*
        convex 2
          _____
         /     \
        / atod1 \_____
        \  tod  /     \
         \_____/ atod2 \
         /  \__\ !tod  /
        /       \_____/
        \  tod  /
         \_____/
         */
 
        const time_of_day& atod1 = *atods[d];
        const time_of_day& atod2 = *atods[(d + 1) % 6];
 
        if(atod2.color == tod.color || atod1.color == atod2.color) {
            continue;
        }
 
        if(lighting.empty()) {
            // color the full hex before adding transitions
            tod_color col = tod.color + color_adjust_;
            lighting.emplace_back(0, col.r, col.g, col.b);
        }
 
        // add the directional transitions
        tod_color acol = atod2.color + color_adjust_;
        lighting.emplace_back(d + 13, acol.r, acol.g, acol.b);
    }
 
    if(lighting.empty()){
        tod_color col = tod.color + color_adjust_;
        if(!col.is_zero()){
            // no real lightmap needed but still color the hex
            lighting.emplace_back(-1, col.r, col.g, col.b);
        }
    }
 
    const terrain_builder::TERRAIN_TYPE builder_terrain_type = terrain_type == FOREGROUND
        ? terrain_builder::FOREGROUND
        : terrain_builder::BACKGROUND;
 
    if(const terrain_builder::imagelist* const terrains = builder_->get_terrain_at(loc, timeid, builder_terrain_type)) {
        // Cache the offmap name. Since it is themeable it can change, so don't make it static.
        const std::string off_map_name = "terrain/" + theme_.border().tile_image;
        for(const auto& terrain : *terrains) {
            const image::locator& image = animate_map_ ? terrain.get_current_frame() : terrain.get_first_frame();
 
            // We prevent ToD coloring and brightening of off-map tiles,
            // We need to test for the tile to be rendered and
            // not the location, since the transitions are rendered
            // over the offmap-terrain and these need a ToD coloring.
            texture tex;
            const bool off_map = (image.get_filename() == off_map_name
                || image.get_modifications().find("NO_TOD_SHIFT()") != std::string::npos);
 
            if(off_map) {
                tex = image::get_texture(image, image::HEXED);
            } else if(lighting.empty()) {
                tex = image::get_texture(image, image::HEXED);
            } else {
                tex = image::get_lighted_texture(image, lighting);
            }
 
            if(tex) {
                terrain_image_vector_.push_back(std::move(tex));
            }
        }
    }
}
 
namespace
{
constexpr std::array layer_groups {
    drawing_layer::terrain_bg,
    drawing_layer::unit_first,
    drawing_layer::unit_move_default
};
 
enum {
    // you may adjust the following when needed:
 
    // maximum border. 3 should be safe even if a larger border is in use somewhere
    MAX_BORDER           = 3,
 
    // store x, y, and layer in one 32 bit integer
    // 4 most significant bits == layer group   => 16
    BITS_FOR_LAYER_GROUP = 4,
 
    // 10 second most significant bits == y     => 1024
    BITS_FOR_Y           = 10,
 
    // 1 third most significant bit == x parity => 2
    BITS_FOR_X_PARITY    = 1,
 
    // 8 fourth most significant bits == layer   => 256
    BITS_FOR_LAYER       = 8,
 
    // 9 least significant bits == x / 2        => 512 (really 1024 for x)
    BITS_FOR_X_OVER_2    = 9,
 
    SHIFT_LAYER          = BITS_FOR_X_OVER_2,
 
    SHIFT_X_PARITY       = BITS_FOR_LAYER    + SHIFT_LAYER,
 
    SHIFT_Y              = BITS_FOR_X_PARITY + SHIFT_X_PARITY,
 
    SHIFT_LAYER_GROUP    = BITS_FOR_Y        + SHIFT_Y
};
 
uint32_t generate_hex_key(const drawing_layer layer, const map_location& loc)
{
    // Start with the index of last group entry...
    uint32_t group_i = layer_groups.size() - 1;
 
    // ...and works backwards until the group containing the specified layer is found.
    while(layer < layer_groups[group_i]) {
        --group_i;
    }
 
    // the parity of x must be more significant than the layer but less significant than y.
    // Thus basically every row is split in two: First the row containing all the odd x
    // then the row containing all the even x. Since thus the least significant bit of x is
    // not required for x ordering anymore it can be shifted out to the right.
    const uint32_t x_parity = static_cast<uint32_t>(loc.x) & 1;
 
    uint32_t key = 0;
    static_assert(SHIFT_LAYER_GROUP + BITS_FOR_LAYER_GROUP == sizeof(key) * 8, "Bit field too small");
 
    key  = (group_i  << SHIFT_LAYER_GROUP) | (static_cast<uint32_t>(loc.y + MAX_BORDER) << SHIFT_Y);
    key |= (x_parity << SHIFT_X_PARITY);
    key |= (static_cast<uint32_t>(layer) << SHIFT_LAYER) | static_cast<uint32_t>(loc.x + MAX_BORDER) / 2;
 
    return key;
}
} // namespace
 
void display::drawing_buffer_add(const drawing_layer layer, const map_location& loc, decltype(draw_helper::do_draw) draw_func)
{
    drawing_buffer_.AGGREGATE_EMPLACE(generate_hex_key(layer, loc), std::move(draw_func), get_location_rect(loc));
}
 
void display::drawing_buffer_commit()
{
    DBG_DP << "committing drawing buffer"
           << " with " << drawing_buffer_.size() << " items";
 
    // std::list::sort() is a stable sort
    drawing_buffer_.sort();
 
    const auto clipper = draw::reduce_clip(map_area());
 
    /*
     * Info regarding the rendering algorithm.
     *
     * In order to render a hex properly it needs to be rendered per row. On
     * this row several layers need to be drawn at the same time. Mainly the
     * unit and the background terrain. This is needed since both can spill
     * in the next hex. The foreground terrain needs to be drawn before to
     * avoid decapitation a unit.
     *
     * This ended in the following priority order:
     * layergroup > location > layer > 'draw_helper' > surface
     */
    for(const draw_helper& helper : drawing_buffer_) {
        std::invoke(helper.do_draw, helper.dest);
    }
 
    drawing_buffer_.clear();
}
 
void display::draw_panel(const theme::panel& panel)
{
    // Most panels are transparent.
    if (panel.image().empty()) {
        return;
    }
 
    const rect& loc = panel.location(video::game_canvas());
 
    if (!loc.overlaps(draw::get_clip())) {
        return;
    }
 
    DBG_DP << "drawing panel " << panel.get_id() << ' ' << loc;
 
    texture tex(image::get_texture(panel.image()));
    if (!tex) {
        ERR_DP << "failed to load panel " << panel.get_id()
            << " texture: " << panel.image();
        return;
    }
 
    draw::tiled(tex, loc);
}
 
void display::draw_label(const theme::label& label)
{
    const rect& loc = label.location(video::game_canvas());
 
    if (!loc.overlaps(draw::get_clip())) {
        return;
    }
 
    const std::string& text = label.text();
    const color_t text_color = label.font_rgb_set() ? label.font_rgb() : font::NORMAL_COLOR;
    const std::string& icon = label.icon();
 
    DBG_DP << "drawing label " << label.get_id() << ' ' << loc;
 
    if(icon.empty() == false) {
        draw::blit(image::get_texture(icon), loc);
 
        if(text.empty() == false) {
            tooltips::add_tooltip(loc,text);
        }
    } else if(text.empty() == false) {
        font::pango_text& renderer = font::get_text_renderer();
        renderer.set_text(text, false);
        renderer.set_family_class(font::family_class::sans_serif);
        renderer.set_font_size(label.font_size());
        renderer.set_font_style(font::pango_text::STYLE_NORMAL);
        renderer.set_foreground_color(text_color);
        renderer.set_ellipse_mode(PANGO_ELLIPSIZE_END);
        renderer.set_maximum_width(loc.w);
        renderer.set_maximum_height(loc.h, true);
 
        auto t = renderer.render_and_get_texture();
        draw::blit(t, rect{ loc.origin(), t.draw_size() });
    }
}
 
bool display::draw_all_panels(const rect& region)
{
    bool drew = false;
    const rect game_canvas = video::game_canvas();
 
    for(const auto& panel : theme_.panels()) {
        if(region.overlaps(panel.location(game_canvas))) {
            draw_panel(panel);
            drew = true;
        }
    }
 
    for(const auto& label : theme_.labels()) {
        if(region.overlaps(label.location(game_canvas))) {
            draw_label(label);
            drew = true;
        }
    }
 
    return drew;
}
 
void display::draw_text_in_hex(const map_location& loc,
        const drawing_layer layer,
        const std::string& text,
        std::size_t font_size,
        color_t color,
        double x_in_hex,
        double y_in_hex)
{
    if (text.empty()) return;
 
    auto& renderer = font::get_text_renderer();
    renderer.set_text(text, false);
    renderer.set_font_size(font_size * get_zoom_factor());
    renderer.set_maximum_width(-1);
    renderer.set_maximum_height(-1, false);
    renderer.set_foreground_color(color);
    renderer.set_add_outline(true);
 
    drawing_buffer_add(layer, loc, [x_in_hex, y_in_hex, tex = renderer.render_and_get_texture()](const rect& dest) {
        draw::blit(tex, rect{ dest.point_at(x_in_hex, y_in_hex) - tex.draw_size() / 2, tex.draw_size() });
    });
}
 
void display::select_hex(map_location hex)
{
    invalidate(selectedHex_);
    selectedHex_ = hex;
    invalidate(selectedHex_);
    recalculate_minimap();
}
 
void display::highlight_hex(map_location hex)
{
    if(mouseoverHex_ == hex) {
        return;
    }
    invalidate(mouseoverHex_);
    mouseoverHex_ = hex;
    invalidate(mouseoverHex_);
}
 
void display::set_diagnostic(const std::string& msg)
{
    if(diagnostic_label_ != 0) {
        font::remove_floating_label(diagnostic_label_);
        diagnostic_label_ = 0;
    }
 
    if(!msg.empty()) {
        font::floating_label flabel(msg);
        flabel.set_font_size(font::SIZE_PLUS);
        flabel.set_color(font::YELLOW_COLOR);
        flabel.set_position(300, 50);
        flabel.set_clip_rect(map_outside_area());
 
        diagnostic_label_ = font::add_floating_label(flabel);
    }
}
 
const theme::action* display::action_pressed()
{
    for(auto i = action_buttons_.begin(); i != action_buttons_.end(); ++i) {
        if((*i)->pressed()) {
            const std::size_t index = std::distance(action_buttons_.begin(), i);
            if(index >= theme_.actions().size()) {
                assert(false);
                return nullptr;
            }
            return &theme_.actions()[index];
        }
    }
 
    return nullptr;
}
 
const theme::menu* display::menu_pressed()
{
    for(auto i = menu_buttons_.begin(); i != menu_buttons_.end(); ++i) {
        if((*i)->pressed()) {
            const std::size_t index = std::distance(menu_buttons_.begin(), i);
            if(index >= theme_.menus().size()) {
                assert(false);
                return nullptr;
            }
            return theme_.get_menu_item((*i)->id());
        }
    }
 
    return nullptr;
}
 
void display::announce(const std::string& message, const color_t& color, const announce_options& options)
{
    if(options.discard_previous) {
        font::remove_floating_label(prevLabel);
    }
    font::floating_label flabel(message);
    flabel.set_font_size(font::SIZE_FLOAT_LABEL);
    flabel.set_color(color);
    flabel.set_position(
        map_outside_area().x + map_outside_area().w / 2, map_outside_area().y + map_outside_area().h / 3);
    flabel.set_lifetime(options.lifetime);
    flabel.set_clip_rect(map_outside_area());
 
    prevLabel = font::add_floating_label(flabel);
}
 
void display::recalculate_minimap()
{
    if(video::headless()) {
        return;
    }
 
    const rect& area = minimap_area();
    if(area.empty()){
        return;
    }
 
    minimap_renderer_ = image::prep_minimap_for_rendering(
        context().map(),
        context().teams().empty() ? nullptr : &viewing_team(),
        nullptr,
        (selectedHex_.valid() && !is_blindfolded()) ? &reach_map_ : nullptr
    );
 
    redraw_minimap();
}
 
void display::redraw_minimap()
{
    draw_manager::invalidate_region(minimap_area());
}
 
void display::draw_minimap()
{
    const rect& area = minimap_area();
 
    if(area.empty() || !area.overlaps(draw::get_clip())) {
        return;
    }
 
    if(!minimap_renderer_) {
        return;
    }
 
    const auto clipper = draw::reduce_clip(area);
 
    // Draw the minimap background.
    draw::fill(area, 31, 31, 23);
 
    // Draw the minimap and update its location for mouse and units functions
    minimap_location_ = std::invoke(minimap_renderer_, area);
 
    draw_minimap_units();
 
    // calculate the visible portion of the map:
    // scaling between minimap and full map images
    double xscaling = 1.0 * minimap_location_.w / (context().map().w() * hex_width());
    double yscaling = 1.0 * minimap_location_.h / (context().map().h() * hex_size());
 
    // we need to shift with the border size
    // and the 0.25 from the minimap balanced drawing
    // and the possible difference between real map and outside off-map
    rect map_rect = map_area();
    rect map_out_rect = map_outside_area();
    double border = theme_.border().size;
    double shift_x = -border * hex_width() - (map_out_rect.w - map_rect.w) / 2;
    double shift_y = -(border + 0.25) * hex_size() - (map_out_rect.h - map_rect.h) / 2;
 
    int view_x = static_cast<int>((viewport_origin_.x + shift_x) * xscaling);
    int view_y = static_cast<int>((viewport_origin_.y + shift_y) * yscaling);
    int view_w = static_cast<int>(map_out_rect.w * xscaling);
    int view_h = static_cast<int>(map_out_rect.h * yscaling);
 
    rect outline_rect {
        minimap_location_.x + view_x - 1,
        minimap_location_.y + view_y - 1,
        view_w + 2,
        view_h + 2
    };
 
    draw::rect(outline_rect, 255, 255, 255);
}
 
void display::draw_minimap_units()
{
    if (!prefs::get().minimap_draw_units() || is_blindfolded()) return;
 
    double xscaling = 1.0 * minimap_location_.w / context().map().w();
    double yscaling = 1.0 * minimap_location_.h / context().map().h();
 
    for(const auto& u : context().units()) {
        if (fogged(u.get_location()) ||
            (viewing_team().is_enemy(u.side()) &&
             u.invisible(u.get_location())) ||
             u.get_hidden()) {
            continue;
        }
 
        int side = u.side();
        color_t col = team::get_minimap_color(side);
 
        if(!prefs::get().minimap_movement_coding()) {
            auto status = orb_status::allied;
            if(viewing_team().is_enemy(side)) {
                status = orb_status::enemy;
            } else if(viewing_team().side() == side) {
                status = context().unit_orb_status(u);
            } else {
                // no-op, status is already set to orb_status::allied;
            }
            col = game_config::color_info(orb_status_helper::get_orb_color(status)).rep();
        }
 
        double u_x = u.get_location().x * xscaling;
        double u_y = (u.get_location().y + (is_odd(u.get_location().x) ? 1 : -1)/4.0) * yscaling;
        // use 4/3 to compensate the horizontal hexes imbrication
        double u_w = 4.0 / 3.0 * xscaling;
        double u_h = yscaling;
 
        rect r {
                  minimap_location_.x + int(std::round(u_x))
                , minimap_location_.y + int(std::round(u_y))
                , int(std::round(u_w))
                , int(std::round(u_h))
        };
 
        draw::fill(r, col.r, col.g, col.b, col.a);
    }
}
 
bool display::scroll(const point& amount, bool force)
{
    if(view_locked_ && !force) {
        return false;
    }
 
    // No move offset, do nothing.
    if(amount == point{}) {
        return false;
    }
 
    point new_pos = viewport_origin_ + amount;
    bounds_check_position(new_pos.x, new_pos.y);
 
    // Camera position doesn't change, exit.
    if(viewport_origin_ == new_pos) {
        return false;
    }
 
    point diff = viewport_origin_ - new_pos;
    viewport_origin_ = new_pos;
 
    /* Adjust floating label positions. This only affects labels whose position is anchored
     * to the map instead of the screen. In order to do that, we want to adjust their drawing
     * coordinates in the opposite direction of the screen scroll.
     *
     * The check a few lines up prevents any scrolling from happening if the camera position
     * doesn't change. Without that, the label still scroll even when the map edge is reached.
     * If that's removed, the following formula should work instead:
     *
     * const int label_[x,y]_adjust = [x,y]pos_ - new_[x,y];
     */
    font::scroll_floating_labels(diff.x, diff.y);
 
    labels().recalculate_shroud();
 
    //
    // NOTE: the next three blocks can be removed once we switch to accelerated rendering.
    //
 
    if(!video::headless()) {
        rect dst = map_area();
        dst.shift(diff);
        dst.clip(map_area());
 
        rect src = dst;
        src.shift(-diff);
 
        // swap buffers
        std::swap(front_, back_);
 
        // Set the source region to blit from
        back_.set_src(src);
 
        // copy from the back to the front buffer
        auto rts = draw::set_render_target(front_);
        draw::blit(back_, dst);
 
        back_.clear_src();
 
        // queue repaint
        draw_manager::invalidate_region(map_area());
    }
 
    if(diff.y != 0) {
        rect r = map_area();
 
        if(diff.y < 0) {
            r.y = r.y + r.h + diff.y;
        }
 
        r.h = std::abs(diff.y);
        invalidate_locations_in_rect(r);
    }
 
    if(diff.x != 0) {
        rect r = map_area();
 
        if(diff.x < 0) {
            r.x = r.x + r.w + diff.x;
        }
 
        r.w = std::abs(diff.x);
        invalidate_locations_in_rect(r);
    }
 
    scroll_event_.notify_observers();
 
    redraw_minimap();
 
    return true;
}
 
bool display::zoom_at_max()
{
    return zoom_ == MaxZoom;
}
 
bool display::zoom_at_min()
{
    return zoom_ == MinZoom;
}
 
bool display::set_zoom(bool increase)
{
    // Ensure we don't try to access nonexistent vector indices.
    zoom_index_ = std::clamp(increase ? zoom_index_ + 1 : zoom_index_ - 1, 0, final_zoom_index);
 
    // No validation check is needed in the next step since we've already set the index here and
    // know the new zoom value is indeed valid.
    return set_zoom(zoom_levels[zoom_index_], false);
}
 
bool display::set_zoom(unsigned int amount, const bool validate_value_and_set_index)
{
    unsigned int new_zoom = std::clamp(amount, MinZoom, MaxZoom);
 
    LOG_DP << "new_zoom = " << new_zoom;
 
    if(new_zoom == zoom_) {
        return false;
    }
 
    if(validate_value_and_set_index) {
        zoom_index_ = get_zoom_levels_index (new_zoom);
        new_zoom = zoom_levels[zoom_index_];
    }
 
    if((new_zoom / 4) * 4 != new_zoom) {
        WRN_DP << "set_zoom forcing zoom " << new_zoom
            << " which is not a multiple of 4."
            << " This will likely cause graphical glitches.";
    }
 
    const rect outside_area = map_outside_area();
    const rect area = map_area();
 
    // Turn the zoom factor to a double in order to avoid rounding errors.
    double zoom_factor = static_cast<double>(new_zoom) / static_cast<double>(zoom_);
 
    // INVARIANT: xpos_ + area.w == xend where xend is as in bounds_check_position()
    //
    // xpos_: Position of the leftmost visible map pixel of the viewport, in pixels.
    // Affected by the current zoom: this->zoom_ pixels to the hex.
    //
    // xpos_ + area.w/2: Position of the center of the viewport, in pixels.
    //
    // (xpos_ + area.w/2) * new_zoom/zoom_: Position of the center of the
    // viewport, as it would be under new_zoom.
    //
    // (xpos_ + area.w/2) * new_zoom/zoom_ - area.w/2: Position of the
    // leftmost visible map pixel, as it would be under new_zoom.
    viewport_origin_.x = std::round(((viewport_origin_.x + area.w / 2) * zoom_factor) - (area.w / 2));
    viewport_origin_.y = std::round(((viewport_origin_.y + area.h / 2) * zoom_factor) - (area.h / 2));
    viewport_origin_ -= (outside_area.size() - area.size()) / 2;
 
    zoom_ = new_zoom;
    bounds_check_position(viewport_origin_.x, viewport_origin_.y);
    if(zoom_ != DefaultZoom) {
        last_zoom_ = zoom_;
    }
 
    prefs::get().set_tile_size(zoom_);
 
    labels().recalculate_labels();
    redraw_background_ = true;
    invalidate_all();
 
    return true;
}
 
void display::toggle_default_zoom()
{
    if (zoom_ != DefaultZoom) {
        last_zoom_ = zoom_;
        set_zoom(DefaultZoom);
    } else {
        // When we are already at the default zoom,
        // switch to the last zoom used
        set_zoom(last_zoom_);
    }
}
 
bool display::tile_fully_on_screen(const map_location& loc) const
{
    return map_area().contains(get_location_rect(loc));
}
 
bool display::tile_nearly_on_screen(const map_location& loc) const
{
    const auto [x, y] = get_location(loc);
    const rect area = map_area();
    int hw = hex_width(), hs = hex_size();
    return x + hs >= area.x - hw && x < area.x + area.w + hw &&
           y + hs >= area.y - hs && y < area.y + area.h + hs;
}
 
void display::scroll_to_xy(const point& screen_coordinates, SCROLL_TYPE scroll_type, bool force)
{
    if(!force && (view_locked_ || !prefs::get().scroll_to_action())) return;
    if(video::headless()) {
        return;
    }
 
    point expected_move = screen_coordinates - map_area().center();
 
    point new_pos = viewport_origin_ + expected_move;
    bounds_check_position(new_pos.x, new_pos.y);
 
    point move = new_pos - viewport_origin_;
 
    if(scroll_type == WARP || scroll_type == ONSCREEN_WARP || turbo_speed() > 2.0 || prefs::get().scroll_speed() > 99) {
        scroll(move, true);
        redraw_minimap();
        events::draw();
        return;
    }
 
    // Doing an animated scroll, with acceleration etc.
 
    point prev_pos;
    const double dist_total = std::hypot(move.x, move.y);
    double dist_moved = 0.0;
 
    using fractional_seconds = std::chrono::duration<double>;
    auto prev_time = std::chrono::steady_clock::now();
 
    double velocity = 0.0;
    while (dist_moved < dist_total) {
        events::pump();
 
        auto time = std::chrono::steady_clock::now();
        auto dt = fractional_seconds{time - prev_time};
 
        // Do not skip too many frames on slow PCs
        dt = std::min<fractional_seconds>(dt, 200ms);
        prev_time = time;
 
        const double dt_as_double = dt.count();
        const double accel_time = 0.3 / turbo_speed(); // seconds until full speed is reached
        const double decel_time = 0.4 / turbo_speed(); // seconds from full speed to stop
 
        double velocity_max = prefs::get().scroll_speed() * 60.0;
        velocity_max *= turbo_speed();
        double accel = velocity_max / accel_time;
        double decel = velocity_max / decel_time;
 
        // If we started to decelerate now, where would we stop?
        double stop_time = velocity / decel;
        double dist_stop = dist_moved + velocity*stop_time - 0.5*decel*stop_time*stop_time;
        if (dist_stop > dist_total || velocity > velocity_max) {
            velocity -= decel * dt_as_double;
            if (velocity < 1.0) velocity = 1.0;
        } else {
            velocity += accel * dt_as_double;
            if (velocity > velocity_max) velocity = velocity_max;
        }
 
        dist_moved += velocity * dt_as_double;
        if (dist_moved > dist_total) dist_moved = dist_total;
 
        point next_pos(
            std::round(move.x * dist_moved / dist_total),
            std::round(move.y * dist_moved / dist_total)
        );
 
        point diff = next_pos - prev_pos;
        scroll(diff, true);
        prev_pos += diff;
 
        redraw_minimap();
        events::draw();
    }
}
 
void display::scroll_to_tile(const map_location& loc, SCROLL_TYPE scroll_type, bool check_fogged, bool force)
{
    if(context().map().on_board(loc) == false) {
        ERR_DP << "Tile at " << loc << " isn't on the map, can't scroll to the tile.";
        return;
    }
 
    scroll_to_tiles({loc}, scroll_type, check_fogged, false, 0.0, force);
}
 
void display::scroll_to_tiles(map_location loc1, map_location loc2,
                              SCROLL_TYPE scroll_type, bool check_fogged,
                              double add_spacing, bool force)
{
    scroll_to_tiles({loc1, loc2}, scroll_type, check_fogged, false, add_spacing, force);
}
 
void display::scroll_to_tiles(const std::vector<map_location>& locs,
                              SCROLL_TYPE scroll_type, bool check_fogged,
                              bool only_if_possible, double add_spacing, bool force)
{
    // basically we calculate the min/max coordinates we want to have on-screen
    int minx = 0;
    int maxx = 0;
    int miny = 0;
    int maxy = 0;
    bool valid = false;
 
    for(const map_location& loc : locs) {
        if(context().map().on_board(loc) == false) continue;
        if(check_fogged && fogged(loc)) continue;
 
        const auto [x, y] = get_location(loc);
 
        if (!valid) {
            minx = x;
            maxx = x;
            miny = y;
            maxy = y;
            valid = true;
        } else {
            int minx_new = std::min<int>(minx,x);
            int miny_new = std::min<int>(miny,y);
            int maxx_new = std::max<int>(maxx,x);
            int maxy_new = std::max<int>(maxy,y);
            rect r = map_area();
            r.x = minx_new;
            r.y = miny_new;
            if(outside_area(r, maxx_new, maxy_new)) {
                // we cannot fit all locations to the screen
                if (only_if_possible) return;
                break;
            }
            minx = minx_new;
            miny = miny_new;
            maxx = maxx_new;
            maxy = maxy_new;
        }
    }
    //if everything is fogged or the location list is empty
    if(!valid) return;
 
    if (scroll_type == ONSCREEN || scroll_type == ONSCREEN_WARP) {
        int spacing = std::round(add_spacing * hex_size());
        rect r = map_area().padded_by(-spacing); // Shrink
        if (!outside_area(r, minx,miny) && !outside_area(r, maxx,maxy)) {
            return;
        }
    }
 
    // let's do "normal" rectangle math from now on
    rect locs_bbox;
    locs_bbox.x = minx;
    locs_bbox.y = miny;
    locs_bbox.w = maxx - minx + hex_size();
    locs_bbox.h = maxy - miny + hex_size();
 
    // target the center
    point target = locs_bbox.center();
 
    if (scroll_type == ONSCREEN || scroll_type == ONSCREEN_WARP) {
        // when doing an ONSCREEN scroll we do not center the target unless needed
        rect r = map_area();
        auto [map_center_x, map_center_y] = r.center();
 
        int h = r.h;
        int w = r.w;
 
        // we do not want to be only inside the screen rect, but center a bit more
        double inside_frac = 0.5; // 0.0 = always center the target, 1.0 = scroll the minimum distance
        w = static_cast<int>(w * inside_frac);
        h = static_cast<int>(h * inside_frac);
 
        // shrink the rectangle by the size of the locations rectangle we found
        // such that the new task to fit a point into a rectangle instead of rectangle into rectangle
        w -= locs_bbox.w;
        h -= locs_bbox.h;
 
        if (w < 1) w = 1;
        if (h < 1) h = 1;
 
        r.x = target.x - w/2;
        r.y = target.y - h/2;
        r.w = w;
        r.h = h;
 
        // now any point within r is a possible target to scroll to
        // we take the one with the minimum distance to map_center
        // which will always be at the border of r
 
        if (map_center_x < r.x) {
            target.x = r.x;
            target.y = std::clamp(map_center_y, r.y, r.y + r.h - 1);
        } else if (map_center_x > r.x+r.w-1) {
            target.x = r.x + r.w - 1;
            target.y = std::clamp(map_center_y, r.y, r.y + r.h - 1);
        } else if (map_center_y < r.y) {
            target.y = r.y;
            target.x = std::clamp(map_center_x, r.x, r.x + r.w - 1);
        } else if (map_center_y > r.y+r.h-1) {
            target.y = r.y + r.h - 1;
            target.x = std::clamp(map_center_x, r.x, r.x + r.w - 1);
        } else {
            ERR_DP << "Bug in the scrolling code? Looks like we would not need to scroll after all...";
            // keep the target at the center
        }
    }
 
    scroll_to_xy(target, scroll_type, force);
}
 
 
void display::bounds_check_position()
{
    zoom_ = std::clamp(zoom_, MinZoom, MaxZoom);
    bounds_check_position(viewport_origin_.x, viewport_origin_.y);
}
 
void display::bounds_check_position(int& xpos, int& ypos) const
{
    const int tile_width = hex_width();
 
    // Adjust for the border 2 times
    const int xend = static_cast<int>(tile_width * (context().map().w() + 2 * theme_.border().size) + tile_width / 3);
    const int yend = static_cast<int>(zoom_ * (context().map().h() + 2 * theme_.border().size) + zoom_ / 2);
 
    xpos = std::clamp(xpos, 0, xend - map_area().w);
    ypos = std::clamp(ypos, 0, yend - map_area().h);
}
 
double display::turbo_speed() const
{
    bool res = prefs::get().turbo();
    if(keys_[SDLK_LSHIFT] || keys_[SDLK_RSHIFT]) {
        res = !res;
    }
 
    res |= video::headless();
    if(res)
        return prefs::get().turbo_speed();
    else
        return 1.0;
}
 
void display::set_prevent_draw(bool pd)
{
    prevent_draw_ = pd;
    if (!pd) {
        // ensure buttons are visible
        unhide_buttons();
    }
}
 
bool display::get_prevent_draw()
{
    return prevent_draw_;
}
 
submerge_data display::get_submerge_data(const rect& dest, double submerge, const point& size, uint8_t alpha, bool hreverse, bool vreverse)
{
    submerge_data data;
    if(submerge <= 0.0) {
        return data;
    }
 
    // Set up blit destinations
    data.unsub_dest = dest;
    const int dest_sub_h = dest.h * submerge;
    data.unsub_dest.h -= dest_sub_h;
    const int dest_y_mid = dest.y + data.unsub_dest.h;
 
    // Set up blit src regions
    const int submersion_line = size.y * (1.0 - submerge);
    data.unsub_src = {0, 0, size.x, submersion_line};
 
    // Set up shader vertices
    const color_t c_mid(255, 255, 255, 0.3 * alpha);
    const int pixels_submerged = size.y * submerge;
    const int bot_alpha = std::max(0.3 - pixels_submerged * 0.015, 0.0) * alpha;
    const color_t c_bot(255, 255, 255, bot_alpha);
    const SDL_FPoint pML{float(dest.x), float(dest_y_mid)};
    const SDL_FPoint pMR{float(dest.x + dest.w), float(dest_y_mid)};
    const SDL_FPoint pBL{float(dest.x), float(dest.y + dest.h)};
    const SDL_FPoint pBR{float(dest.x + dest.w), float(dest.y + dest.h)};
    data.alpha_verts = {
        SDL_Vertex{pML, c_mid, {0.0, float(1.0 - submerge)}},
        SDL_Vertex{pMR, c_mid, {1.0, float(1.0 - submerge)}},
        SDL_Vertex{pBL, c_bot, {0.0, 1.0}},
        SDL_Vertex{pBR, c_bot, {1.0, 1.0}},
    };
 
    if(hreverse) {
        for(SDL_Vertex& v : data.alpha_verts) {
            v.tex_coord.x = 1.0 - v.tex_coord.x;
        }
    }
    if(vreverse) {
        for(SDL_Vertex& v : data.alpha_verts) {
            v.tex_coord.y = 1.0 - v.tex_coord.y;
        }
    }
 
    return data;
}
 
void display::fade_tod_mask(
    const std::string& old_mask,
    const std::string& new_mask)
{
    // TODO: hwaccel - this needs testing as it's not used in mainline
    tod_hex_mask1 = image::get_texture(old_mask, image::HEXED);
    tod_hex_mask2 = image::get_texture(new_mask, image::HEXED);
 
    auto duration = 300ms / turbo_speed();
    auto start = std::chrono::steady_clock::now();
    for(auto now = start; now < start + duration; now = std::chrono::steady_clock::now()) {
        uint8_t p = float_to_color(chrono::normalize_progress(now - start, duration));
        tod_hex_alpha2 = p;
        tod_hex_alpha1 = ~p;
        draw_manager::invalidate_region(map_outside_area());
        events::pump_and_draw();
    }
 
    tod_hex_mask1.reset();
    tod_hex_mask2.reset();
}
 
void display::fade_to(const color_t& c, const std::chrono::milliseconds& duration)
{
    auto start = std::chrono::steady_clock::now();
    color_t fade_start = fade_color_;
    color_t fade_end = c;
 
    // If we started transparent, assume the same colour
    if(fade_start.a == 0) {
        fade_start.r = fade_end.r;
        fade_start.g = fade_end.g;
        fade_start.b = fade_end.b;
    }
 
    // If we are ending transparent, assume the same colour
    if(fade_end.a == 0) {
        fade_end.r = fade_start.r;
        fade_end.g = fade_start.g;
        fade_end.b = fade_start.b;
    }
 
    // Smoothly blend and display
    for(auto now = start; now < start + duration; now = std::chrono::steady_clock::now()) {
        uint8_t p = float_to_color(chrono::normalize_progress(now - start, duration));
        fade_color_ = fade_start.smooth_blend(fade_end, p);
        draw_manager::invalidate_region(map_outside_area());
        events::pump_and_draw();
    }
    fade_color_ = fade_end;
    draw_manager::invalidate_region(map_outside_area());
    events::draw();
}
 
void display::set_fade(const color_t& c)
{
    fade_color_ = c;
}
 
void display::queue_rerender()
{
    if(video::headless())
        return;
 
    DBG_DP << "redrawing everything";
 
    // This is specifically for game_display.
    // It would probably be better to simply make this function virtual,
    // if game_display needs to do special processing.
    invalidateGameStatus_ = true;
 
    reportLocations_.clear();
    reportSurfaces_.clear();
    reports_.clear();
 
    bounds_check_position();
 
    tooltips::clear_tooltips();
 
    theme_.set_resolution(video::game_canvas());
 
    if(!menu_buttons_.empty() || !action_buttons_.empty()) {
        create_buttons();
    }
 
    if(resources::controller) {
        hotkey::command_executor* command_executor = resources::controller->get_hotkey_command_executor();
        if(command_executor != nullptr) {
            // This function adds button overlays,
            // it needs to be run after recreating the buttons.
            command_executor->set_button_state();
        }
    }
 
    if(!gui2::is_in_dialog()) {
        labels().recalculate_labels();
    }
 
    redraw_background_ = true;
 
    // This is only for one specific use, which is by the editor controller.
    // It would be vastly better if this didn't exist.
    for(std::function<void(display&)> f : redraw_observers_) {
        f(*this);
    }
 
    invalidate_all();
 
    draw_manager::invalidate_all();
}
 
void display::queue_repaint()
{
    // Could redraw a smaller region if the display doesn't use it all,
    // but when does that ever happen?
    draw_manager::invalidate_all();
}
 
void display::add_redraw_observer(const std::function<void(display&)>& f)
{
    redraw_observers_.push_back(f);
}
 
void display::clear_redraw_observers()
{
    redraw_observers_.clear();
}
 
void display::draw()
{
    if(video::headless()) {
        DBG_DP << "display::draw denied";
        return;
    }
    //DBG_DP << "display::draw";
 
    // I have no idea why this is messing with sync context,
    // but i'm not going to touch it.
    set_scontext_unsynced leave_synced_context;
 
    // This isn't the best, but also isn't important enough to do better.
    if(redraw_background_ && !map_screenshot_) {
        DBG_DP << "display::draw redraw background";
        render_map_outside_area();
        draw_manager::invalidate_region(map_outside_area());
        redraw_background_ = false;
    }
 
    if(!context().map().empty()) {
        if(!invalidated_.empty()) {
            draw_invalidated();
            invalidated_.clear();
        }
        drawing_buffer_commit();
    }
}
 
void display::update()
{
    //DBG_DP << "display::update";
    // Ensure render textures are correctly sized and up-to-date.
    update_render_textures();
 
    // Trigger cache rebuild if animated water preference has changed.
    if(animate_water_ != prefs::get().animate_water()) {
        animate_water_ = prefs::get().animate_water();
        builder_->rebuild_cache_all();
    }
 
    if(debug_flag_set(DEBUG_BENCHMARK)) {
        invalidate_all();
    }
}
 
void display::layout()
{
    //DBG_DP << "display::layout";
 
    // There's nothing that actually does layout here, it all happens in
    // response to events. This isn't ideal, but neither is changing that.
 
    // Post-layout / Pre-render
 
    if (!context().map().empty()) {
        if(redraw_background_) {
            invalidateAll_ = true;
        }
        if(invalidateAll_) {
            DBG_DP << "draw() with invalidateAll";
 
            // toggle invalidateAll_ first to allow regular invalidations
            invalidateAll_ = false;
            invalidate_locations_in_rect(map_area());
 
            redraw_minimap();
        }
    }
 
    // invalidate animated terrain, units and haloes
    invalidate_animations();
 
    // Update and invalidate floating labels as necessary
    font::update_floating_labels();
}
 
void display::render()
{
    // This should render the game map and units.
    // It is not responsible for halos and floating labels.
    //DBG_DP << "display::render";
 
    // No need to render if we aren't going to draw anything.
    if(prevent_draw_) {
        DBG_DP << "render prevented";
        return;
    }
 
    // Update our frametime values
    tracked_drawable::update_count();
 
    // render to the offscreen buffer
    auto target_setter = draw::set_render_target(front_);
    draw();
 
    // update the minimap texture, if necessary
    // TODO: highdpi - high DPI minimap
    const rect& area = minimap_area();
    if(!area.empty() && !minimap_renderer_) {
        recalculate_minimap();
    }
}
 
bool display::expose(const rect& region)
{
    if(prevent_draw_) {
        DBG_DP << "draw prevented";
        return false;
    }
 
    rect clipped_region = draw::get_clip().intersect(region);
 
    // Blit from the pre-rendered front buffer.
    if(clipped_region.overlaps(map_outside_area())) {
        front_.set_src(clipped_region);
        draw::blit(front_, clipped_region);
        front_.clear_src();
    }
 
    // Render halos.
    halo_man_.render(clipped_region);
 
    // Render UI elements.
    // Ideally buttons would be drawn as part of panels,
    // but they are currently TLDs so they draw themselves.
    // This also means they draw over tooltips...
    draw_all_panels(clipped_region);
    draw_reports(clipped_region);
    if(clipped_region.overlaps(minimap_area())) {
        draw_minimap();
    }
 
    // Floating labels should probably be separated by type,
    // but they aren't so they all get drawn here.
    font::draw_floating_labels();
 
    // If there's a fade, apply it over everything
    if(fade_color_.a) {
        draw::fill(map_outside_area().intersect(region), fade_color_);
    }
 
    DBG_DP << "display::expose " << region;
 
    // The display covers the entire screen.
    // We will always be drawing something.
    return true;
}
 
rect display::screen_location()
{
    assert(!map_screenshot_);
    // There's no good way to determine this, as themes can put things
    // anywhere. Just return the entire game canvas.
    return video::game_canvas();
}
 
void display::update_render_textures()
{
    if(video::headless()) {
        return;
    }
 
    // We ignore any logical offset on the underlying window buffer.
    // Render buffer size is always a simple multiple of the draw area.
    rect darea = video::game_canvas();
    rect oarea = darea * video::get_pixel_scale();
 
    // Check that the front buffer size is correct.
    // Buffers are always resized together, so we only need to check one.
    point size = front_.get_raw_size();
    point dsize = front_.draw_size();
    bool raw_size_changed = size.x != oarea.w || size.y != oarea.h;
    bool draw_size_changed = dsize.x != darea.w || dsize.y != darea.h;
    if (!raw_size_changed && !draw_size_changed) {
        // buffers are fine
        return;
    }
 
    if(raw_size_changed) {
        LOG_DP << "regenerating render buffers as " << oarea;
        front_ = texture(oarea.w, oarea.h, SDL_TEXTUREACCESS_TARGET);
        back_ = texture(oarea.w, oarea.h, SDL_TEXTUREACCESS_TARGET);
    }
    if(raw_size_changed || draw_size_changed) {
        LOG_DP << "updating render buffer draw size to " << darea;
        front_.set_draw_size(darea.w, darea.h);
        back_.set_draw_size(darea.w, darea.h);
    }
 
    // Fill entire texture with black, just in case
    for(int i = 0; i < 2; ++i) {
        auto setter = draw::set_render_target(i ? back_ : front_);
        draw::fill(0,0,0);
    }
 
    // Fill in the background area on both textures.
    render_map_outside_area();
 
    queue_rerender();
}
 
void display::render_map_outside_area()
{
    // This could be optimized to avoid the map area,
    // but it's only called on game creation or zoom anyway.
    const rect clip_rect = map_outside_area();
    texture bgtex = image::get_texture(theme_.border().background_image);
    for(int i = 0; i < 2; ++i) {
        auto setter = draw::set_render_target(i ? back_ : front_);
        if(bgtex) {
            draw::tiled(bgtex, clip_rect);
        } else {
            draw::fill(clip_rect, 0, 0, 0);
        }
    }
}
 
map_labels& display::labels()
{
    return *map_labels_;
}
 
const map_labels& display::labels() const
{
    return *map_labels_;
}
 
rect display::get_clip_rect() const
{
    return map_area();
}
 
void display::draw_invalidated()
{
    //  log_scope("display::draw_invalidated");
    rect clip_rect = get_clip_rect();
    const auto clipper = draw::reduce_clip(clip_rect);
 
    DBG_DP << "drawing " << invalidated_.size() << " invalidated hexes with clip " << clip_rect;
 
    // The unit drawer can't function without teams
    utils::optional<unit_drawer> drawer{};
    if(!context().teams().empty()) {
        drawer.emplace(*this);
    }
 
    for(const map_location& loc : invalidated_) {
        rect hex_rect = get_location_rect(loc);
        if(!hex_rect.overlaps(clip_rect)) {
            continue;
        }
 
        draw_hex(loc);
        drawn_hexes_ += 1;
 
        if(drawer) {
            const auto u_it = context().units().find(loc);
            if(u_it != context().units().end() && unit_can_draw_here(loc, *u_it)) {
                drawer->redraw_unit(*u_it);
            }
        }
 
        draw_manager::invalidate_region(hex_rect.intersect(clip_rect));
    }
 
    invalidated_hexes_ += invalidated_.size();
}
 
void display::draw_hex(const map_location& loc)
{
    const bool on_map = context().map().on_board(loc);
    const time_of_day& tod = get_time_of_day(loc);
 
    int num_images_fg = 0;
    int num_images_bg = 0;
 
    const bool is_shrouded = shrouded(loc);
 
    // unshrouded terrain (the normal case)
    if(!is_shrouded) {
        get_terrain_images(loc, tod.id, BACKGROUND); // updates terrain_image_vector_
        num_images_bg = terrain_image_vector_.size();
 
        drawing_buffer_add(drawing_layer::terrain_bg, loc, [images = std::exchange(terrain_image_vector_, {})](const rect& dest) {
            for(const texture& t : images) {
                draw::blit(t, dest);
            }
        });
 
        get_terrain_images(loc, tod.id, FOREGROUND); // updates terrain_image_vector_
        num_images_fg = terrain_image_vector_.size();
 
        drawing_buffer_add(drawing_layer::terrain_fg, loc, [images = std::exchange(terrain_image_vector_, {})](const rect& dest) {
            for(const texture& t : images) {
                draw::blit(t, dest);
            }
        });
 
        // Draw the grid, if that's been enabled
        if(prefs::get().grid()) {
            static const image::locator grid_top{game_config::images::grid_top};
            static const image::locator grid_bottom{game_config::images::grid_bottom};
 
            drawing_buffer_add(drawing_layer::grid_top, loc,
                [tex = image::get_texture(grid_top, image::TOD_COLORED)](const rect& dest) { draw::blit(tex, dest); });
 
            drawing_buffer_add(drawing_layer::grid_bottom, loc,
                [tex = image::get_texture(grid_bottom, image::TOD_COLORED)](const rect& dest) { draw::blit(tex, dest); });
        }
 
        // overlays (TODO: can we just draw all the overlays in one pass instead of per-hex?)
        draw_overlays_at(loc);
 
        // village-control flags.
        if(context().map().is_village(loc)) {
            drawing_buffer_add(drawing_layer::terrain_bg, loc,
                [tex = get_flag(loc)](const rect& dest) { draw::blit(tex, dest); });
        }
    }
 
    // Draw the time-of-day mask on top of the terrain in the hex.
    // tod may differ from tod if hex is illuminated.
    const std::string& tod_hex_mask = tod.image_mask;
    if(tod_hex_mask1 || tod_hex_mask2) {
        drawing_buffer_add(drawing_layer::terrain_fg, loc, [this](const rect& dest) mutable {
            tod_hex_mask1.set_alpha_mod(tod_hex_alpha1);
            draw::blit(tod_hex_mask1, dest);
 
            tod_hex_mask2.set_alpha_mod(tod_hex_alpha2);
            draw::blit(tod_hex_mask2, dest);
        });
    } else if(!tod_hex_mask.empty()) {
        drawing_buffer_add(drawing_layer::terrain_fg, loc,
            [tex = image::get_texture(tod_hex_mask, image::HEXED)](const rect& dest) { draw::blit(tex, dest); });
    }
 
    // Paint arrows
    if(auto arrows_in_hex = arrows_map_.find(loc); arrows_in_hex != arrows_map_.end()) {
        std::vector<texture> to_draw;
        for(const arrow* a : arrows_in_hex->second) {
            to_draw.push_back(image::get_texture(a->get_image_for_loc(loc)));
        }
 
        drawing_buffer_add(drawing_layer::arrows, loc, [to_draw = std::move(to_draw)](const rect& dest) {
            for(const texture& t : to_draw) {
                draw::blit(t, dest);
            }
        });
    }
 
    // Apply shroud, fog and linger overlay
 
    if(is_shrouded || fogged(loc)) {
        // TODO: better noise function
        const auto get_variant = [&loc](const std::vector<std::string>& variants) -> const auto& {
            return variants[std::abs(loc.x + loc.y) % variants.size()];
        };
 
        const std::string& img = get_variant(is_shrouded ? shroud_images_ : fog_images_);
        drawing_buffer_add(drawing_layer::fog_shroud, loc,
            [tex = image::get_texture(img, image::TOD_COLORED)](const rect& dest) { draw::blit(tex, dest); });
    }
 
    if(!is_shrouded) {
        drawing_buffer_add(drawing_layer::fog_shroud, loc, [images = get_fog_shroud_images(loc, image::TOD_COLORED)](const rect& dest) {
            for(const texture& t : images) {
                draw::blit(t, dest);
            }
        });
    }
 
    if(debug_flag_set(DEBUG_FOREGROUND)) {
        using namespace std::string_literals;
        drawing_buffer_add(drawing_layer::unit_default, loc,
            [tex = image::get_texture("terrain/foreground.png"s)](const rect& dest) { draw::blit(tex, dest); });
    }
 
    if(on_map) {
        // This might be slight overkill. Basically, we want to check that none of the
        // first three bits in the debug flag bitset are set so we can avoid creating
        // a stringstream, a temp string, and attempting to trim it for every hex even
        // when none of these flags are set. This gives us a temp object with all bits
        // past the first three zeroed out.
        if((std::as_const(debug_flags_) << (__NUM_DEBUG_FLAGS - DEBUG_FOREGROUND)).none()) {
            return;
        }
 
        std::ostringstream ss;
        if(debug_flag_set(DEBUG_COORDINATES)) {
            ss << loc << '\n';
        }
 
        if(debug_flag_set(DEBUG_TERRAIN_CODES) && (game_config::debug || !is_shrouded)) {
            ss << context().map().get_terrain(loc) << '\n';
        }
 
        if(debug_flag_set(DEBUG_NUM_BITMAPS)) {
            ss << (num_images_bg + num_images_fg) << '\n';
        }
 
        std::string output = ss.str();
        boost::trim(output);
 
        if(output.empty()) {
            return;
        }
 
        auto& renderer = font::get_text_renderer();
        renderer.set_text(output, false);
        renderer.set_font_size(font::SIZE_TINY);
        renderer.set_alignment(PANGO_ALIGN_CENTER);
        renderer.set_foreground_color(font::NORMAL_COLOR);
        renderer.set_maximum_height(-1, false);
        renderer.set_maximum_width(-1);
 
        drawing_buffer_add(drawing_layer::fog_shroud, loc, [tex = renderer.render_and_get_texture()](const rect& dest) {
            // Center text in dest rect
            const rect text_dest { dest.center() - tex.draw_size() / 2, tex.draw_size() };
 
            // Add a little padding to the bg
            const rect bg_dest = text_dest.padded_by(3);
 
            draw::fill(bg_dest, 0, 0, 0, 170);
            draw::blit(tex, text_dest);
        });
    }
}
 
void display::draw_overlays_at(const map_location& loc)
{
    auto it = get_overlays().find(loc);
    if(it == get_overlays().end()) {
        return;
    }
 
    std::vector<overlay>& overlays = it->second;
    if(overlays.empty()) {
        return;
    }
 
    const time_of_day& tod = get_time_of_day(loc);
    tod_color tod_col = tod.color + color_adjust_;
 
    std::vector lt{image::light_adjust{-1, tod_col.r, tod_col.g, tod_col.b}};
 
    for(const overlay& ov : overlays) {
        if(fogged(loc) && !ov.visible_in_fog) {
            continue;
        }
 
        if(dont_show_all_ && !ov.team_name.empty()) {
            const auto current_team_names = utils::split_view(viewing_team().team_name());
            const auto team_names = utils::split_view(ov.team_name);
 
            bool item_visible_for_team = std::find_first_of(team_names.begin(), team_names.end(),
                current_team_names.begin(), current_team_names.end()) != team_names.end();
 
            if(!item_visible_for_team) {
                continue;
            }
        }
 
        texture tex = ov.image.find("~NO_TOD_SHIFT()") == std::string::npos
            ? image::get_lighted_texture(ov.image, lt)
            : image::get_texture(ov.image, image::HEXED);
 
        // Base submerge value for the terrain at this location
        const double ter_sub = context().map().get_terrain_info(loc).unit_submerge();
 
        drawing_buffer_add(
            drawing_layer::terrain_bg, loc, [tex, ter_sub, ovr_sub = ov.submerge](const rect& dest) mutable {
                if(ovr_sub > 0.0 && ter_sub > 0.0) {
                    // Adjust submerge appropriately
                    double submerge = ter_sub * ovr_sub;
 
                    submerge_data data
                        = display::get_submerge_data(dest, submerge, tex.draw_size(), ALPHA_OPAQUE, false, false);
 
                    // set clip for dry part
                    // smooth_shaded doesn't use the clip information so it's fine to set it up front
                    // TODO: do we need to unset this?
                    tex.set_src(data.unsub_src);
 
                    // draw underwater part
                    draw::smooth_shaded(tex, data.alpha_verts);
 
                    // draw dry part
                    draw::blit(tex, data.unsub_dest);
                } else {
                    // draw whole texture
                    draw::blit(tex, dest);
                }
            });
    }
}
 
/**
 * Redraws the specified report (if anything has changed).
 * If a config is not supplied, it will be generated via
 * reports::generate_report().
 */
void display::refresh_report(const std::string& report_name, const config * new_cfg)
{
    const theme::status_item *item = theme_.get_status_item(report_name);
    if (!item) {
        // This should be a warning, but unfortunately there are too many
        // unused reports to easily deal with.
        //WRN_DP << "no report '" << report_name << "' in theme";
        return;
    }
 
    // Now we will need the config. Generate one if needed.
 
    utils::optional_reference<events::mouse_handler> mhb = utils::nullopt;
 
    if (resources::controller) {
        mhb = resources::controller->get_mouse_handler_base();
    }
 
    reports::context temp_context = reports::context(*dc_, *this, *resources::tod_manager, wb_.lock(), mhb);
 
    const config generated_cfg = new_cfg ? config() : reports_object_->generate_report(report_name, temp_context);
    if ( new_cfg == nullptr )
        new_cfg = &generated_cfg;
 
    rect& loc = reportLocations_[report_name];
    const rect& new_loc = item->location(video::game_canvas());
    config &report = reports_[report_name];
 
    // Report and its location is unchanged since last time. Do nothing.
    if (loc == new_loc && report == *new_cfg) {
        return;
    }
 
    DBG_DP << "updating report: " << report_name;
 
    // Mark both old and new locations for redraw.
    draw_manager::invalidate_region(loc);
    draw_manager::invalidate_region(new_loc);
 
    // Update the config and current location.
    report = *new_cfg;
    loc = new_loc;
 
    // Not 100% sure this is okay
    // but it seems to be working so i'm not changing it.
    tooltips::clear_tooltips(loc);
 
    if (report.empty()) return;
 
    // Add prefix, postfix elements.
    // Make sure that they get the same tooltip
    // as the guys around them.
    std::string str = item->prefix();
    if (!str.empty()) {
        config &e = report.add_child_at("element", config(), 0);
        e["text"] = str;
        e["tooltip"] = report.mandatory_child("element")["tooltip"];
    }
    str = item->postfix();
    if (!str.empty()) {
        config &e = report.add_child("element");
        e["text"] = str;
        e["tooltip"] = report.mandatory_child("element", -1)["tooltip"];
    }
 
    // Do a fake run of drawing the report, so tooltips can be determined.
    // TODO: this is horrible, refactor reports to actually make sense
    draw_report(report_name, true);
}
 
void display::draw_report(const std::string& report_name, bool tooltip_test)
{
    const theme::status_item *item = theme_.get_status_item(report_name);
    if (!item) {
        // This should be a warning, but unfortunately there are too many
        // unused reports to easily deal with.
        //WRN_DP << "no report '" << report_name << "' in theme";
        return;
    }
 
    const rect& loc = reportLocations_[report_name];
    const config& report = reports_[report_name];
 
    int x = loc.x, y = loc.y;
 
    // Loop through and display each report element.
    int tallest = 0;
    int image_count = 0;
    bool used_ellipsis = false;
    std::ostringstream ellipsis_tooltip;
    rect ellipsis_area = loc;
 
    for (config::const_child_itors elements = report.child_range("element");
         elements.begin() != elements.end(); elements.pop_front())
    {
        rect area {x, y, loc.w + loc.x - x, loc.h + loc.y - y};
        if (area.h <= 0) break;
 
        std::string t = elements.front()["text"];
        if (!t.empty())
        {
            if (used_ellipsis) goto skip_element;
 
            // Draw a text element.
            font::pango_text& text = font::get_text_renderer();
            bool eol = false;
            if (t[t.size() - 1] == '\n') {
                eol = true;
                t = t.substr(0, t.size() - 1);
            }
            // If stripping left the text empty, skip it.
            if (t.empty()) {
                // Blank text has a null size when rendered.
                // It does not, however, have a null size when the size
                // is requested with get_size(). Hence this check.
                continue;
            }
            text.set_link_aware(false)
                .set_text(t, true);
            text.set_family_class(font::family_class::sans_serif)
                .set_font_size(item->font_size())
                .set_font_style(font::pango_text::STYLE_NORMAL)
                .set_alignment(PANGO_ALIGN_LEFT)
                .set_foreground_color(item->font_rgb_set() ? item->font_rgb() : font::NORMAL_COLOR)
                .set_maximum_width(area.w)
                .set_maximum_height(area.h, false)
                .set_ellipse_mode(PANGO_ELLIPSIZE_END)
                .set_characters_per_line(0);
 
            point tsize = text.get_size();
 
            // check if next element is text with almost no space to show it
            const int minimal_text = 12; // width in pixels
            config::const_child_iterator ee = elements.begin();
            if (!eol && loc.w - (x - loc.x + tsize.x) < minimal_text &&
                ++ee != elements.end() && !(*ee)["text"].empty())
            {
                // make this element longer to trigger rendering of ellipsis
                // (to indicate that next elements have not enough space)
                //NOTE this space should be longer than minimal_text pixels
                t = t + "    ";
                text.set_text(t, true);
                tsize = text.get_size();
                // use the area of this element for next tooltips
                used_ellipsis = true;
                ellipsis_area.x = x;
                ellipsis_area.y = y;
                ellipsis_area.w = tsize.x;
                ellipsis_area.h = tsize.y;
            }
 
            area.w = tsize.x;
            area.h = tsize.y;
            if (!tooltip_test) {
                draw::blit(text.render_and_get_texture(), area);
            }
            if (area.h > tallest) {
                tallest = area.h;
            }
            if (eol) {
                x = loc.x;
                y += tallest;
                tallest = 0;
            } else {
                x += area.w;
            }
        }
        else if (!(t = elements.front()["image"].str()).empty())
        {
            if (used_ellipsis) goto skip_element;
 
            // Draw an image element.
            texture img(image::get_texture(t));
 
            if (!img) {
                ERR_DP << "could not find image for report: '" << t << "'";
                continue;
            }
 
            if (area.w < img.w() && image_count) {
                // We have more than one image, and this one doesn't fit.
                img = image::get_texture(game_config::images::ellipsis);
                used_ellipsis = true;
            }
 
            if (img.w() < area.w) area.w = img.w();
            if (img.h() < area.h) area.h = img.h();
            if (!tooltip_test) {
                draw::blit(img, area);
            }
 
            ++image_count;
            if (area.h > tallest) {
                tallest = area.h;
            }
 
            if (!used_ellipsis) {
                x += area.w;
            } else {
                ellipsis_area = area;
            }
        }
        else
        {
            // No text nor image, skip this element
            continue;
        }
 
        skip_element:
        t = elements.front()["tooltip"].t_str().c_str();
        if (!t.empty()) {
            if (tooltip_test && !used_ellipsis) {
                tooltips::add_tooltip(area, t, elements.front()["help"].t_str().c_str());
            } else {
                // Collect all tooltips for the ellipsis.
                // TODO: need a better separator
                // TODO: assign an action
                ellipsis_tooltip << t;
                config::const_child_iterator ee = elements.begin();
                if (++ee != elements.end())
                    ellipsis_tooltip << "\n  _________\n\n";
            }
        }
    }
 
    if (tooltip_test && used_ellipsis) {
        tooltips::add_tooltip(ellipsis_area, ellipsis_tooltip.str());
    }
}
 
bool display::draw_reports(const rect& region)
{
    bool drew = false;
    for(const auto& it : reports_) {
        const std::string& name = it.first;
        const rect& loc = reportLocations_[name];
        if(loc.overlaps(region)) {
            draw_report(name);
            drew = true;
        }
    }
    return drew;
}
 
void display::invalidate_all()
{
    DBG_DP << "invalidate_all()";
    invalidateAll_ = true;
    invalidated_.clear();
}
 
bool display::invalidate(const map_location& loc)
{
    if(invalidateAll_ && !map_screenshot_)
        return false;
 
    bool tmp;
    tmp = invalidated_.insert(loc).second;
    return tmp;
}
 
bool display::invalidate(const std::set<map_location>& locs)
{
    if(invalidateAll_ && !map_screenshot_)
        return false;
    bool ret = false;
    for (const map_location& loc : locs) {
        ret = invalidated_.insert(loc).second || ret;
    }
    return ret;
}
 
bool display::propagate_invalidation(const std::set<map_location>& locs)
{
    if(invalidateAll_)
        return false;
 
    if(locs.size()<=1)
        return false; // propagation never needed
 
    bool result = false;
    {
        // search the first hex invalidated (if any)
        std::set<map_location>::const_iterator i = locs.begin();
        for(; i != locs.end() && invalidated_.count(*i) == 0 ; ++i) {}
 
        if (i != locs.end()) {
 
            // propagate invalidation
            // 'i' is already in, but I suspect that splitting the range is bad
            // especially because locs are often adjacents
            std::size_t previous_size = invalidated_.size();
            invalidated_.insert(locs.begin(), locs.end());
            result = previous_size < invalidated_.size();
        }
    }
    return result;
}
 
bool display::invalidate_visible_locations_in_rect(const rect& rect)
{
    return invalidate_locations_in_rect(map_area().intersect(rect));
}
 
bool display::invalidate_locations_in_rect(const rect& rect)
{
    if(invalidateAll_ && !map_screenshot_)
        return false;
 
    DBG_DP << "invalidating locations in " << rect;
 
    bool result = false;
    for(const map_location& loc : hexes_under_rect(rect)) {
        //DBG_DP << "invalidating " << loc.x << ',' << loc.y;
        result |= invalidate(loc);
    }
    return result;
}
 
void display::invalidate_animations_location(const map_location& loc)
{
    if(context().map().is_village(loc)) {
        const int owner = context().village_owner(loc) - 1;
        if(owner >= 0 && flags_[owner].need_update()
            && (!fogged(loc) || !viewing_team().is_enemy(owner + 1))) {
            invalidate(loc);
        }
    }
}
 
void display::invalidate_animations()
{
    // There are timing issues with this, but i'm not touching it.
    new_animation_frame();
    animate_map_ = prefs::get().animate_map();
    if(animate_map_) {
        for(const map_location& loc : get_visible_hexes()) {
            if(shrouded(loc))
                continue;
            if(builder_->update_animation(loc)) {
                invalidate(loc);
            } else {
                invalidate_animations_location(loc);
            }
        }
    }
 
    for(const unit& u : context().units()) {
        u.anim_comp().refresh();
    }
    for(const unit* u : *fake_unit_man_) {
        u->anim_comp().refresh();
    }
 
    bool new_inval;
    do {
        new_inval = false;
        for(const unit& u : context().units()) {
            new_inval |= u.anim_comp().invalidate(*this);
        }
        for(const unit* u : *fake_unit_man_) {
            new_inval |= u->anim_comp().invalidate(*this);
        }
    } while(new_inval);
 
    halo_man_.update();
}
 
void display::reset_standing_animations()
{
    for(const unit & u : context().units()) {
        u.anim_comp().set_standing();
    }
}
 
void display::add_arrow(arrow& arrow)
{
    for(const map_location& loc : arrow.get_path()) {
        arrows_map_[loc].push_back(&arrow);
    }
}
 
void display::remove_arrow(arrow& arrow)
{
    for(const map_location& loc : arrow.get_path()) {
        arrows_map_[loc].remove(&arrow);
    }
}
 
void display::update_arrow(arrow & arrow)
{
    for(const map_location& loc : arrow.get_previous_path()) {
        arrows_map_[loc].remove(&arrow);
    }
 
    for(const map_location& loc : arrow.get_path()) {
        arrows_map_[loc].push_back(&arrow);
    }
}
 
map_location display::get_middle_location() const
{
    auto [center_x, center_y] = viewport_origin_ + map_area().center();
    return pixel_position_to_hex(center_x, center_y);
}
 
void display::write(config& cfg) const
{
    cfg["view_locked"] = view_locked_;
    cfg["color_adjust_red"] = color_adjust_.r;
    cfg["color_adjust_green"] = color_adjust_.g;
    cfg["color_adjust_blue"] = color_adjust_.b;
    get_middle_location().write(cfg.add_child("location"));
}
 
void display::read(const config& cfg)
{
    view_locked_ = cfg["view_locked"].to_bool(false);
    color_adjust_.r = cfg["color_adjust_red"].to_int(0);
    color_adjust_.g = cfg["color_adjust_green"].to_int(0);
    color_adjust_.b = cfg["color_adjust_blue"].to_int(0);
}
 
void display::process_reachmap_changes()
{
    if (!reach_map_changed_) return;
    if (reach_map_.empty() != reach_map_old_.empty()) {
        // Invalidate everything except the non-darkened tiles
        reach_map &full = reach_map_.empty() ? reach_map_old_ : reach_map_;
 
        for (const auto& hex : get_visible_hexes()) {
            reach_map::iterator reach = full.find(hex);
            if (reach != full.end()) {
                // Location needs to be darkened or brightened
                invalidate(hex);
            }
        }
    } else if (!reach_map_.empty()) {
        // Invalidate new and old reach
        reach_map::iterator reach, reach_old;
        for (reach = reach_map_.begin(); reach != reach_map_.end(); ++reach) {
            invalidate(reach->first);
        }
        for (reach_old = reach_map_old_.begin(); reach_old != reach_map_old_.end(); ++reach_old) {
            invalidate(reach_old->first);
        }
    }
    reach_map_old_ = reach_map_;
    reach_map_changed_ = false;
 
    // Make sure there are teams before trying to access units.
    if(!context().teams().empty()){
        // Update the reachmap-context team, the selected unit's team shall override the displayed unit's.
        if(context().units().count(selectedHex_)) {
            reach_map_team_index_ = context().get_visible_unit(selectedHex_, viewing_team())->side();
        } else if(context().get_visible_unit(mouseoverHex_, viewing_team()) != nullptr){
            reach_map_team_index_ = context().get_visible_unit(mouseoverHex_, viewing_team())->side();
        } else {
            /**
             * If no unit is selected or displayed, the reachmap-context team should failsafe to
             * the viewing team index, this makes sure the team is invalid when getting the reachmap
             * images in game_display::get_reachmap_images().
             */
            reach_map_team_index_ = viewing_team_index_;
        }
        DBG_DP << "Updated reachmap context team index to " << std::to_string(reach_map_team_index_);
    }
}
 
display *display::singleton_ = nullptr;