sdl

testscale.c (5672B)

---

 /*
   Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
   arising from the use of this software.
 
   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely.
 */
 /* Simple program:  Move N sprites around on the screen as fast as possible */
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>
 
 #ifdef __EMSCRIPTEN__
 #include <emscripten/emscripten.h>
 #endif
 
 #include "SDL_test_common.h"
 
 #define WINDOW_WIDTH    640
 #define WINDOW_HEIGHT   480
 
 static SDLTest_CommonState *state;
 
 typedef struct {
     SDL_Window *window;
     SDL_Renderer *renderer;
     SDL_Texture *background;
     SDL_Texture *sprite;
     SDL_Rect sprite_rect;
     int scale_direction;
 } DrawState;
 
 DrawState *drawstates;
 int done;
 
 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
 static void
 quit(int rc)
 {
     SDLTest_CommonQuit(state);
     exit(rc);
 }
 
 SDL_Texture *
 LoadTexture(SDL_Renderer *renderer, char *file, SDL_bool transparent)
 {
     SDL_Surface *temp;
     SDL_Texture *texture;
 
     /* Load the sprite image */
     temp = SDL_LoadBMP(file);
     if (temp == NULL) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s", file, SDL_GetError());
         return NULL;
     }
 
     /* Set transparent pixel as the pixel at (0,0) */
     if (transparent) {
         if (temp->format->palette) {
             SDL_SetColorKey(temp, SDL_TRUE, *(Uint8 *) temp->pixels);
         } else {
             switch (temp->format->BitsPerPixel) {
             case 15:
                 SDL_SetColorKey(temp, SDL_TRUE,
                                 (*(Uint16 *) temp->pixels) & 0x00007FFF);
                 break;
             case 16:
                 SDL_SetColorKey(temp, SDL_TRUE, *(Uint16 *) temp->pixels);
                 break;
             case 24:
                 SDL_SetColorKey(temp, SDL_TRUE,
                                 (*(Uint32 *) temp->pixels) & 0x00FFFFFF);
                 break;
             case 32:
                 SDL_SetColorKey(temp, SDL_TRUE, *(Uint32 *) temp->pixels);
                 break;
             }
         }
     }
 
     /* Create textures from the image */
     texture = SDL_CreateTextureFromSurface(renderer, temp);
     if (!texture) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create texture: %s\n", SDL_GetError());
         SDL_FreeSurface(temp);
         return NULL;
     }
     SDL_FreeSurface(temp);
 
     /* We're ready to roll. :) */
     return texture;
 }
 
 void
 Draw(DrawState *s)
 {
     SDL_Rect viewport;
 
     SDL_RenderGetViewport(s->renderer, &viewport);
 
     /* Draw the background */
     SDL_RenderCopy(s->renderer, s->background, NULL, NULL);
 
     /* Scale and draw the sprite */
     s->sprite_rect.w += s->scale_direction;
     s->sprite_rect.h += s->scale_direction;
     if (s->scale_direction > 0) {
         if (s->sprite_rect.w >= viewport.w || s->sprite_rect.h >= viewport.h) {
             s->scale_direction = -1;
         }
     } else {
         if (s->sprite_rect.w <= 1 || s->sprite_rect.h <= 1) {
             s->scale_direction = 1;
         }
     }
     s->sprite_rect.x = (viewport.w - s->sprite_rect.w) / 2;
     s->sprite_rect.y = (viewport.h - s->sprite_rect.h) / 2;
 
     SDL_RenderCopy(s->renderer, s->sprite, NULL, &s->sprite_rect);
 
     /* Update the screen! */
     SDL_RenderPresent(s->renderer);
 }
 
 void
 loop()
 {
     int i;
     SDL_Event event;
 
     /* Check for events */
     while (SDL_PollEvent(&event)) {
         SDLTest_CommonEvent(state, &event, &done);
     }
     for (i = 0; i < state->num_windows; ++i) {
         if (state->windows[i] == NULL)
             continue;
         Draw(&drawstates[i]);
     }
 #ifdef __EMSCRIPTEN__
     if (done) {
         emscripten_cancel_main_loop();
     }
 #endif
 }
 
 int
 main(int argc, char *argv[])
 {
     int i;
     int frames;
     Uint32 then, now;
 
     /* Enable standard application logging */
     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
 
     /* Initialize test framework */
     state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);
     if (!state) {
         return 1;
     }
 
     if (!SDLTest_CommonDefaultArgs(state, argc, argv) || !SDLTest_CommonInit(state)) {
         SDLTest_CommonQuit(state);
         return 1;
     }
 
     drawstates = SDL_stack_alloc(DrawState, state->num_windows);
     for (i = 0; i < state->num_windows; ++i) {
         DrawState *drawstate = &drawstates[i];
 
         drawstate->window = state->windows[i];
         drawstate->renderer = state->renderers[i];
         drawstate->sprite = LoadTexture(drawstate->renderer, "icon.bmp", SDL_TRUE);
         drawstate->background = LoadTexture(drawstate->renderer, "sample.bmp", SDL_FALSE);
         if (!drawstate->sprite || !drawstate->background) {
             quit(2);
         }
         SDL_QueryTexture(drawstate->sprite, NULL, NULL,
                          &drawstate->sprite_rect.w, &drawstate->sprite_rect.h);
         drawstate->scale_direction = 1;
     }
 
     /* Main render loop */
     frames = 0;
     then = SDL_GetTicks();
     done = 0;
 
 #ifdef __EMSCRIPTEN__
     emscripten_set_main_loop(loop, 0, 1);
 #else
     while (!done) {
         ++frames;
         loop();
     }
 #endif
 
     /* Print out some timing information */
     now = SDL_GetTicks();
     if (now > then) {
         double fps = ((double) frames * 1000) / (now - then);
         SDL_Log("%2.2f frames per second\n", fps);
     }
 
     SDL_stack_free(drawstates);
 
     quit(0);
     return 0;
 }
 
 /* vi: set ts=4 sw=4 expandtab: */