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54459def69
Now we render directly to the window, scaling as appropriate. This fixes some concerns the render target introduced, like the quality of the final scaled output, how to step outside of the logical size temporarily to draw some things sharply at the native resolution, and loss of sub-pixel precision. Fixes #8736.
95 lines
3.2 KiB
C
95 lines
3.2 KiB
C
/*
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* This example creates an SDL window and renderer, and then draws some lines,
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* rectangles and points to it every frame.
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*
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* This code is public domain. Feel free to use it for any purpose!
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*/
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#define SDL_MAIN_USE_CALLBACKS 1 /* use the callbacks instead of main() */
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#include <SDL3/SDL.h>
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#include <SDL3/SDL_main.h>
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/* We will use this renderer to draw into this window every frame. */
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static SDL_Window *window = NULL;
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static SDL_Renderer *renderer = NULL;
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static SDL_FPoint points[500];
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/* This function runs once at startup. */
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SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
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{
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int i;
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if (!SDL_Init(SDL_INIT_VIDEO)) {
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SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't initialize SDL!", SDL_GetError(), NULL);
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return SDL_APP_FAILURE;
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}
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if (!SDL_CreateWindowAndRenderer("examples/renderer/primitives", 640, 480, 0, &window, &renderer)) {
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SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't create window/renderer!", SDL_GetError(), NULL);
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return SDL_APP_FAILURE;
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}
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SDL_srand(0); /* seed the random number generator */
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/* set up some random points */
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for (i = 0; i < SDL_arraysize(points); i++) {
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points[i].x = (SDL_randf() * 440.0f) + 100.0f;
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points[i].y = (SDL_randf() * 280.0f) + 100.0f;
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}
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return SDL_APP_CONTINUE; /* carry on with the program! */
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}
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/* This function runs when a new event (mouse input, keypresses, etc) occurs. */
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SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
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{
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if (event->type == SDL_EVENT_QUIT) {
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return SDL_APP_SUCCESS; /* end the program, reporting success to the OS. */
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}
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return SDL_APP_CONTINUE; /* carry on with the program! */
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}
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/* This function runs once per frame, and is the heart of the program. */
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SDL_AppResult SDL_AppIterate(void *appstate)
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{
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SDL_FRect rect;
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/* as you can see from this, rendering draws over whatever was drawn before it. */
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SDL_SetRenderDrawColor(renderer, 33, 33, 33, 255); /* dark gray, full alpha */
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SDL_RenderClear(renderer); /* start with a blank canvas. */
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/* draw a filled rectangle in the middle of the canvas. */
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SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255); /* blue, full alpha */
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rect.x = rect.y = 100;
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rect.w = 440;
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rect.h = 280;
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SDL_RenderFillRect(renderer, &rect);
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/* draw some points across the canvas. */
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SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255); /* red, full alpha */
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SDL_RenderPoints(renderer, points, SDL_arraysize(points));
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/* draw a unfilled rectangle in-set a little bit. */
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SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255); /* green, full alpha */
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rect.x += 30;
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rect.y += 30;
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rect.w -= 60;
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rect.h -= 60;
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SDL_RenderRect(renderer, &rect);
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/* draw two lines in an X across the whole canvas. */
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SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255); /* yellow, full alpha */
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SDL_RenderLine(renderer, 0, 0, 640, 480);
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SDL_RenderLine(renderer, 0, 480, 640, 0);
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SDL_RenderPresent(renderer); /* put it all on the screen! */
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return SDL_APP_CONTINUE; /* carry on with the program! */
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}
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/* This function runs once at shutdown. */
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void SDL_AppQuit(void *appstate)
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{
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/* SDL will clean up the window/renderer for us. */
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}
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