sdl2_default_v.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#include "../stdafx.h"
#include "../openttd.h"
#include "../error_func.h"
#include "../gfx_func.h"
#include "../rev.h"
#include "../blitter/factory.hpp"
#include "../network/network.h"
#include "../thread.h"
#include "../progress.h"
#include "../core/geometry_func.hpp"
#include "../fileio_func.h"
#include "../framerate_type.h"
#include "../window_func.h"
#include "sdl2_default_v.h"
#include <SDL.h>
#include <mutex>
#include <condition_variable>
#ifdef __EMSCRIPTEN__
# include <emscripten.h>
# include <emscripten/html5.h>
#endif
 
#include "../safeguards.h"
 
static FVideoDriver_SDL_Default iFVideoDriver_SDL_Default; 
 
static SDL_Surface *_sdl_surface; 
static SDL_Surface *_sdl_rgb_surface; 
static SDL_Surface *_sdl_real_surface; 
static SDL_Palette *_sdl_palette; 

void VideoDriver_SDL_Default::UpdatePalette()
{
  SDL_Color pal[256];
 
  for (int i = 0; i != this->local_palette.count_dirty; i++) {
    pal[i].r = this->local_palette.palette[this->local_palette.first_dirty + i].r;
    pal[i].g = this->local_palette.palette[this->local_palette.first_dirty + i].g;
    pal[i].b = this->local_palette.palette[this->local_palette.first_dirty + i].b;
    pal[i].a = 0;
  }
 
  SDL_SetPaletteColors(_sdl_palette, pal, this->local_palette.first_dirty, this->local_palette.count_dirty);
  SDL_SetSurfacePalette(_sdl_surface, _sdl_palette);
}

void VideoDriver_SDL_Default::MakePalette()
{
  if (_sdl_palette == nullptr) {
    _sdl_palette = SDL_AllocPalette(256);
    if (_sdl_palette == nullptr) UserError("SDL2: Couldn't allocate palette: {}", SDL_GetError());
  }
 
  CopyPalette(this->local_palette, true);
  this->UpdatePalette();
 
  if (_sdl_surface != _sdl_real_surface) {
    /* When using a shadow surface, also set our palette on the real screen. This lets SDL
     * allocate as many colours (or approximations) as
     * possible, instead of using only the default SDL
     * palette. This allows us to get more colours exactly
     * right and might allow using better approximations for
     * other colours.
     *
     * Note that colours allocations are tried in-order, so
     * this favors colours further up into the palette. Also
     * note that if two colours from the same animation
     * sequence are approximated using the same colour, that
     * animation will stop working.
     *
     * Since changing the system palette causes the colours
     * to change right away, and allocations might
     * drastically change, we can't use this for animation,
     * since that could cause weird colouring between the
     * palette change and the blitting below, so we only set
     * the real palette during initialisation.
     */
    SDL_SetSurfacePalette(_sdl_real_surface, _sdl_palette);
  }
}
 
void VideoDriver_SDL_Default::Paint()
{
  PerformanceMeasurer framerate(PerformanceElement::Video);
 
  if (IsEmptyRect(this->dirty_rect) && this->local_palette.count_dirty == 0) return;
 
  if (this->local_palette.count_dirty != 0) {
    Blitter *blitter = BlitterFactory::GetCurrentBlitter();
 
    switch (blitter->UsePaletteAnimation()) {
      case Blitter::PaletteAnimation::VideoBackend:
        this->UpdatePalette();
        break;
 
      case Blitter::PaletteAnimation::Blitter: {
        blitter->PaletteAnimate(this->local_palette);
        break;
      }
 
      case Blitter::PaletteAnimation::None:
        break;
 
      default:
        NOT_REACHED();
    }
    this->local_palette.count_dirty = 0;
  }
 
  SDL_Rect r = { this->dirty_rect.left, this->dirty_rect.top, this->dirty_rect.right - this->dirty_rect.left, this->dirty_rect.bottom - this->dirty_rect.top };
 
  if (_sdl_surface != _sdl_real_surface) {
    SDL_BlitSurface(_sdl_surface, &r, _sdl_real_surface, &r);
  }
  SDL_UpdateWindowSurfaceRects(this->sdl_window, &r, 1);
 
  this->dirty_rect = {};
}
 
bool VideoDriver_SDL_Default::AllocateBackingStore(int w, int h, bool force)
{
  int bpp = BlitterFactory::GetCurrentBlitter()->GetScreenDepth();
 
  _sdl_real_surface = SDL_GetWindowSurface(this->sdl_window);
  if (_sdl_real_surface == nullptr) UserError("SDL2: Couldn't get window surface: {}", SDL_GetError());
 
  if (!force && w == _sdl_real_surface->w && h == _sdl_real_surface->h) return false;
 
  /* Free any previously allocated rgb surface. */
  if (_sdl_rgb_surface != nullptr) {
    SDL_FreeSurface(_sdl_rgb_surface);
    _sdl_rgb_surface = nullptr;
  }
 
  if (bpp == 8) {
    _sdl_rgb_surface = SDL_CreateRGBSurface(0, w, h, 8, 0, 0, 0, 0);
    if (_sdl_rgb_surface == nullptr) UserError("SDL2: Couldn't allocate shadow surface: {}", SDL_GetError());
 
    _sdl_surface = _sdl_rgb_surface;
  } else {
    _sdl_surface = _sdl_real_surface;
  }
 
  /* X11 doesn't appreciate it if we invalidate areas outside the window
   * if shared memory is enabled (read: it crashes). So, as we might have
   * gotten smaller, reset our dirty rects. GameSizeChanged() a bit lower
   * will mark the whole screen dirty again anyway, but this time with the
   * new dimensions. */
  this->dirty_rect = {};
 
  _screen.width = _sdl_surface->w;
  _screen.height = _sdl_surface->h;
  _screen.pitch = _sdl_surface->pitch / (bpp / 8);
  _screen.dst_ptr = this->GetVideoPointer();
 
  this->MakePalette();
 
  return true;
}
 
void *VideoDriver_SDL_Default::GetVideoPointer()
{
  return _sdl_surface->pixels;
}