Question

我正在寻找最快的方法来在SDL中将单个像素绘制到屏幕上。当前，我正在使用一个数组到SDL_Texture中，然后使用SDL_RenderCopy复制它。我怀疑这是最有效的方法，因为绘制960x540屏幕需要6毫秒。.我想尽可能地坚持使用软件，并且不想使用OpenGL或Vulkan。

这是我的代码：

#include <SDL2/SDL.h>
#include <stdbool.h>


#define RESX 960
#define RESY 540
#define CRESX RESY*0xFF
#define CRESY RESY*0xFF
#define N 10

void main() {

  SDL_Window* window =  NULL;
  SDL_Renderer* renderer = NULL;



  bool running = true;
  if( SDL_Init( SDL_INIT_VIDEO ) < 0 )  {
    printf( "SDL could not initialize! SDL_Error: %s\n", SDL_GetError() );
    running = false;
  }

  window = SDL_CreateWindow("SDL Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, RESX, RESY, SDL_WINDOW_SHOWN );

  if( window==NULL) {
    printf( "SDL_Error: %s\n", SDL_GetError() );
    running = false;
  }

  renderer = SDL_CreateRenderer( window, -1, SDL_RENDERER_ACCELERATED);

  if(renderer==NULL) {
    printf("Renderer error: %s\n", SDL_GetError() );
    running = false;
  }

  SDL_Texture * texture = SDL_CreateTexture(renderer,
       SDL_PIXELFORMAT_RGB888, SDL_TEXTUREACCESS_STREAMING, RESX,RESY);

  Uint32 pixels[RESX*RESY];



  while( running ) {

    clock_t t1, t2;
    t1 = SDL_GetTicks();

    SDL_Event e;
    running  = !(SDL_PollEvent( &e ) && e.type == SDL_QUIT);

    for( int n = 0; n < N; n++) {

      for( int x = 0; x < RESX; x++) { 
        for( int y = 0 ; y < RESY; y++) {
          pixels[y*RESX+x] = 0xFFFFFF;

        }
      }
      SDL_UpdateTexture(texture, NULL, pixels, RESX * sizeof(Uint32));
      SDL_RenderCopy(renderer, texture, NULL, NULL);
      SDL_RenderPresent( renderer );
    }


    t2 = SDL_GetTicks();
    printf("%ldms to draw %dx%d screen %d times.\n", t2-t1, RESX, RESY, N );
  }
  SDL_DestroyWindow( window );
  SDL_DestroyRenderer( renderer );
  SDL_DestroyTexture( texture );
  SDL_Quit();
}

在SDL2中绘制像素的最快方法是什么？

0 个答案: