renderSDL2.cpp

#include <string.h>

#include "SDL.h"

#include <stdio.h>
#define LOG(format, ...) fprintf(stderr, format, ##__VA_ARGS__);

static void
quit(int rc)
{
  SDL_Quit();
  exit(rc);
}

namespace render {

struct State {
  SDL_Window *window;
  SDL_Renderer *renderer;
  SDL_Texture *texture;
  int width;
  int height;
  State() : window(0), renderer(0), texture(0), width(0), height(0) {}
};

static State* sState = nullptr;

void
Initialize()
{
  if (sState) {
    return;
  }

  sState = new State;
}

void
Shutdown()
{
  SDL_DestroyRenderer(sState->renderer);
  delete sState;
  sState = 0;
}

void
Draw(const unsigned char* aImage, int size, int aWidth, int aHeight)
{
  if (!sState) {
    return;
  }

  if (!sState->window) {
    SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);

    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
      SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't initialize SDL: %s\n", SDL_GetError());
      return;
    }

    sState->window = SDL_CreateWindow("WebRTC Player",
                                      SDL_WINDOWPOS_UNDEFINED,
                                      SDL_WINDOWPOS_UNDEFINED,
                                      aWidth, aHeight,
                                      0);
                                    // SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL);
    if (!sState->window) {
      SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't set create window: %s\n", SDL_GetError());
      quit(3);
    }

    sState->renderer = SDL_CreateRenderer(sState->window, -1, 0);
    if (!sState->renderer) {
      SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't set create renderer: %s\n", SDL_GetError());
      quit(4);
    }

    sState->width = aWidth;
    sState->height = aHeight;
  }

  if (!sState->texture) {
    sState->texture = SDL_CreateTexture(sState->renderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, aWidth, aHeight);
    if (!sState->texture) {
      SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't set create texture: %s\n", SDL_GetError());
      quit(5);
    }
  }

  if ((sState->width != aWidth) || (sState->height != aHeight)) {
    if (sState->texture) {
      SDL_DestroyTexture(sState->texture); sState->texture = 0;
    }

    sState->texture = SDL_CreateTexture(sState->renderer,
                                        SDL_PIXELFORMAT_IYUV,
                                        SDL_TEXTUREACCESS_STREAMING,
                                        aWidth, aHeight);
    SDL_SetWindowSize(sState->window, aWidth, aHeight);
    sState->width = aWidth;
    sState->height = aHeight;
  }

  Uint8* dst = nullptr;
  void* pixels = nullptr;
  int pitch = 0;

  if (SDL_LockTexture(sState->texture, NULL, &pixels, &pitch) < 0) {
    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't lock texture: %s\n", SDL_GetError());
    quit(5);
  }

  dst = (Uint8*)pixels;
  memcpy(dst, aImage, size);
  SDL_UnlockTexture(sState->texture);

  SDL_RenderClear(sState->renderer);
  SDL_RenderCopy(sState->renderer, sState->texture, NULL, NULL);
  SDL_RenderPresent(sState->renderer);
}

bool
KeepRunning()
{
  bool result = true;
  if (sState->window) {
    SDL_Event event;
    while (SDL_PollEvent(&event)) {
      switch (event.type) {
        case SDL_KEYDOWN:
          if (event.key.keysym.sym == SDLK_ESCAPE) {
            result = false;
          }
        break;
        case SDL_QUIT:
          result = false;
        break;
      }
    }
  }
  return result;
}

} // namespace standalone