Create a 2D software rendering context for a surface.
SDL_Renderer* SDL_CreateSoftwareRenderer(SDL_Surface *surface);| surface | the SDL_Surface structure representing the surface where rendering is done |
Returns a valid rendering context or NULL if there was an error; call SDL_GetError() for more information.
Two other API which can be used to create SDL_Renderer: SDL_CreateRenderer() and SDL_CreateWindowAndRenderer(). These can also create a software renderer, but they are intended to be used with an SDL_Window as the final destination and not an SDL_Surface.
This function is available since SDL 3.0.0.
#include "SDL.h"
SDL_Window *window;
SDL_Renderer *renderer;
int done;
void
DrawChessBoard(SDL_Renderer * renderer)
{
int row = 0,column = 0,x = 0;
SDL_Rect rect, darea;
/* Get the Size of drawing surface */
SDL_GetRenderViewport(renderer, &darea);
for ( ; row < 8; row++) {
column = row%2;
x = column;
for ( ; column < 4+(row%2); column++) {
SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0xFF);
rect.w = darea.w/8;
rect.h = darea.h/8;
rect.x = x * rect.w;
rect.y = row * rect.h;
x = x + 2;
SDL_RenderFillRect(renderer, &rect);
}
}
}
void
loop()
{
SDL_Event e;
while (SDL_PollEvent(&e)) {
if (e.type == SDL_EVENT_QUIT) {
done = 1;
return;
}
if ((e.type == SDL_EVENT_KEY_DOWN) && (e.key.keysym.sym == SDLK_ESCAPE)) {
done = 1;
return;
}
}
DrawChessBoard(renderer);
/* Got everything on rendering surface,
now Update the drawing image on window screen */
SDL_UpdateWindowSurface(window);
}
int
main(int argc, char *argv[])
{
SDL_Surface *surface;
/* Enable standard application logging */
SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
/* Initialize SDL */
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_Init fail : %s\n", SDL_GetError());
return 1;
}
/* Create window and renderer for given surface */
window = SDL_CreateWindow("Chess Board", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);
if (!window) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Window creation fail : %s\n",SDL_GetError());
return 1;
}
surface = SDL_GetWindowSurface(window);
renderer = SDL_CreateSoftwareRenderer(surface);
if (!renderer) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Render creation for surface fail : %s\n",SDL_GetError());
return 1;
}
/* Clear the rendering surface with the specified color */
SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
SDL_RenderClear(renderer);
/* Draw the Image on rendering surface */
done = 0;
while (!done) {
loop();
}
SDL_Quit();
return 0;
}