sdl_2.c

#include <stdio.h>
#include <stdlib.h>

#include <SDL2/SDL.h>

int main() {
    int windowHeight = 240;
    int windowWidth = 320;

    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
				printf("Initialization failed\n");
        return 1;
    }

    SDL_Window *window = SDL_CreateWindow("Practice making sdl Window",
            SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, windowWidth,
            windowHeight, SDL_WINDOW_SHOWN);

    if (window == NULL) {
        SDL_Quit();
        return 2;
    }

    // We create a renderer with hardware acceleration, we also present according with the vertical sync refresh.
    SDL_Renderer *s = SDL_CreateRenderer(window, 0, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC) ;
	
		 SDL_Texture * texture = SDL_CreateTexture(s,
        SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, windowWidth, windowHeight);

    int  quit = 0;
    SDL_Event event;
		int x=0;
		int y=0;
		int color = 0;
		int frames = 0;
		int fps = 0;
		int prev_time = SDL_GetTicks();
		int current_time = SDL_GetTicks();
		int *pixels = (int*)malloc(windowWidth*windowHeight*sizeof(int));
		int addr= 0;
	  memset(pixels, 255, windowWidth * windowHeight * sizeof(int));
			
    while (!quit) {
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_QUIT) {
                quit = 1;
            }
						if(event.type == SDL_KEYDOWN) {
							
							if ( event.key.keysym.sym == SDLK_q) {
								printf("Quiting...\n");
								quit=1;
								break;
							}
						}
        }
				
				for(y=0;y<windowHeight;y++) {
					for(x=0;x<windowWidth;x++) {
						addr = x +y*windowWidth;
						pixels[addr] = rand()%255;
					}
				}
				SDL_UpdateTexture(texture, NULL, pixels, windowWidth * sizeof(int));
				/*
        SDL_RenderClear(s);
				for (x=0;x<windowWidth;x++) {
					for(y=0;y<windowHeight;y++) {
						color = rand()%0xff;			
		        SDL_SetRenderDrawColor(s, color,color,color, 0xFF);		
		        SDL_RenderDrawPoint(s,x,y);
					}
				}

        SDL_SetRenderDrawColor(s, 0x00, 0x00, 0x00, 0xFF);
				*/
				
			  SDL_RenderClear(s);
				SDL_RenderCopy(s, texture, NULL, NULL);
        SDL_RenderPresent(s);

				frames++;
				current_time = SDL_GetTicks();
				if( (current_time - prev_time) > 10000) {
					fps = frames/10;
					printf("fps is %d\n",fps);
					frames = 0;
					prev_time = current_time;
				}
    }

    SDL_DestroyWindow(window);
    SDL_DestroyRenderer(s);
    SDL_Quit();
		free(pixels);

}