Skip to content

Instantly share code, notes, and snippets.

@CoryBloyd
Last active October 10, 2024 20:24
Show Gist options
  • Save CoryBloyd/6725bb78323bb1157ff8d4175d42d789 to your computer and use it in GitHub Desktop.
Save CoryBloyd/6725bb78323bb1157ff8d4175d42d789 to your computer and use it in GitHub Desktop.
Minimal code to set up a window in SDL and blit from CPU RAM to the window
// This work (SDLblit.cpp, by Cory Bloyd) is free of known copyright restrictions.
// https://creativecommons.org/publicdomain/zero/1.0/
#include <SDL.h>
inline uint32_t argb(uint8_t a, uint8_t r, uint8_t g, uint8_t b) { return (a<<24) | (r << 16) | (g << 8) | (b << 0); }
int main(int argc, char *argv[]) {
SDL_Init(SDL_INIT_VIDEO);
SDL_Rect screenRect = { 0,0,1024,1024 };
SDL_Window *window = SDL_CreateWindow("SDL", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, screenRect.w, screenRect.h, SDL_WINDOW_SHOWN);
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
SDL_Texture *texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, screenRect.w, screenRect.h);
for (int frame = 0; ; ++frame) {
SDL_Event event;
while (SDL_PollEvent(&event) != 0)
if (event.type == SDL_QUIT)
return 0;
int pitch;
uint32_t *pixels;
SDL_LockTexture(texture, &screenRect, (void**)&pixels, &pitch);
uint32_t startTicks = SDL_GetTicks();
for (int y = 0; y < screenRect.h; y++) {
for (int x = 0; x < screenRect.w; x++) {
pixels[y*screenRect.w + x] = argb(255, frame>>3, y+frame, x+frame);
}
}
uint32_t endTicks = SDL_GetTicks();
SDL_UnlockTexture(texture);
SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
SDL_RenderClear(renderer);
SDL_RenderCopy(renderer, texture, &screenRect, &screenRect);
SDL_RenderPresent(renderer);
char title[32];
SDL_SetWindowTitle(window, SDL_itoa(endTicks - startTicks, title, 10));
}
}
@w3ntao
Copy link

w3ntao commented Sep 5, 2024

Do I have to release pointer window, renderer, texture after usage?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment