1 /*
2   Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
3 
4   This software is provided 'as-is', without any express or implied
5   warranty.  In no event will the authors be held liable for any damages
6   arising from the use of this software.
7 
8   Permission is granted to anyone to use this software for any purpose,
9   including commercial applications, and to alter it and redistribute it
10   freely.
11 */
12 /* Simple program:  Move N sprites around on the screen as fast as possible */
13 
14 #include <stdlib.h>
15 #include <stdio.h>
16 #include <time.h>
17 
18 #ifdef __EMSCRIPTEN__
19 #include <emscripten/emscripten.h>
20 #endif
21 
22 #include "SDL_test_common.h"
23 
24 
25 static SDLTest_CommonState *state;
26 
27 typedef struct {
28     SDL_Window *window;
29     SDL_Renderer *renderer;
30     SDL_Texture *background;
31     SDL_Texture *sprite;
32     SDL_Rect sprite_rect;
33     int scale_direction;
34 } DrawState;
35 
36 DrawState *drawstates;
37 int done;
38 SDL_bool test_composite = SDL_FALSE;
39 
40 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
41 static void
quit(int rc)42 quit(int rc)
43 {
44     SDLTest_CommonQuit(state);
45     exit(rc);
46 }
47 
48 SDL_Texture *
LoadTexture(SDL_Renderer * renderer,const char * file,SDL_bool transparent)49 LoadTexture(SDL_Renderer *renderer, const char *file, SDL_bool transparent)
50 {
51     SDL_Surface *temp;
52     SDL_Texture *texture;
53 
54     /* Load the sprite image */
55     temp = SDL_LoadBMP(file);
56     if (temp == NULL) {
57         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s", file, SDL_GetError());
58         return NULL;
59     }
60 
61     /* Set transparent pixel as the pixel at (0,0) */
62     if (transparent) {
63         if (temp->format->palette) {
64             SDL_SetColorKey(temp, SDL_TRUE, *(Uint8 *) temp->pixels);
65         } else {
66             switch (temp->format->BitsPerPixel) {
67             case 15:
68                 SDL_SetColorKey(temp, SDL_TRUE,
69                                 (*(Uint16 *) temp->pixels) & 0x00007FFF);
70                 break;
71             case 16:
72                 SDL_SetColorKey(temp, SDL_TRUE, *(Uint16 *) temp->pixels);
73                 break;
74             case 24:
75                 SDL_SetColorKey(temp, SDL_TRUE,
76                                 (*(Uint32 *) temp->pixels) & 0x00FFFFFF);
77                 break;
78             case 32:
79                 SDL_SetColorKey(temp, SDL_TRUE, *(Uint32 *) temp->pixels);
80                 break;
81             }
82         }
83     }
84 
85     /* Create textures from the image */
86     texture = SDL_CreateTextureFromSurface(renderer, temp);
87     if (!texture) {
88         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create texture: %s\n", SDL_GetError());
89         SDL_FreeSurface(temp);
90         return NULL;
91     }
92     SDL_FreeSurface(temp);
93 
94     /* We're ready to roll. :) */
95     return texture;
96 }
97 
98 SDL_bool
DrawComposite(DrawState * s)99 DrawComposite(DrawState *s)
100 {
101     SDL_Rect viewport, R;
102     SDL_Texture *target;
103 
104     static SDL_bool blend_tested = SDL_FALSE;
105     if (!blend_tested) {
106         SDL_Texture *A, *B;
107         Uint32 P;
108 
109         A = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, 1, 1);
110         SDL_SetTextureBlendMode(A, SDL_BLENDMODE_BLEND);
111 
112         B = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, 1, 1);
113         SDL_SetTextureBlendMode(B, SDL_BLENDMODE_BLEND);
114 
115         SDL_SetRenderTarget(s->renderer, A);
116         SDL_SetRenderDrawColor(s->renderer, 0x00, 0x00, 0x00, 0x80);
117         SDL_RenderFillRect(s->renderer, NULL);
118 
119         SDL_SetRenderTarget(s->renderer, B);
120         SDL_SetRenderDrawColor(s->renderer, 0x00, 0x00, 0x00, 0x00);
121         SDL_RenderFillRect(s->renderer, NULL);
122         SDL_RenderCopy(s->renderer, A, NULL, NULL);
123         SDL_RenderReadPixels(s->renderer, NULL, SDL_PIXELFORMAT_ARGB8888, &P, sizeof(P));
124 
125         SDL_Log("Blended pixel: 0x%8.8X\n", P);
126 
127         SDL_DestroyTexture(A);
128         SDL_DestroyTexture(B);
129         blend_tested = SDL_TRUE;
130     }
131 
132     SDL_RenderGetViewport(s->renderer, &viewport);
133 
134     target = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, viewport.w, viewport.h);
135     SDL_SetTextureBlendMode(target, SDL_BLENDMODE_BLEND);
136     SDL_SetRenderTarget(s->renderer, target);
137 
138     /* Draw the background.
139        This is solid black so when the sprite is copied to it, any per-pixel alpha will be blended through.
140      */
141     SDL_SetRenderDrawColor(s->renderer, 0x00, 0x00, 0x00, 0x00);
142     SDL_RenderFillRect(s->renderer, NULL);
143 
144     /* Scale and draw the sprite */
145     s->sprite_rect.w += s->scale_direction;
146     s->sprite_rect.h += s->scale_direction;
147     if (s->scale_direction > 0) {
148         if (s->sprite_rect.w >= viewport.w || s->sprite_rect.h >= viewport.h) {
149             s->scale_direction = -1;
150         }
151     } else {
152         if (s->sprite_rect.w <= 1 || s->sprite_rect.h <= 1) {
153             s->scale_direction = 1;
154         }
155     }
156     s->sprite_rect.x = (viewport.w - s->sprite_rect.w) / 2;
157     s->sprite_rect.y = (viewport.h - s->sprite_rect.h) / 2;
158 
159     SDL_RenderCopy(s->renderer, s->sprite, NULL, &s->sprite_rect);
160 
161     SDL_SetRenderTarget(s->renderer, NULL);
162     SDL_RenderCopy(s->renderer, s->background, NULL, NULL);
163 
164     SDL_SetRenderDrawBlendMode(s->renderer, SDL_BLENDMODE_BLEND);
165     SDL_SetRenderDrawColor(s->renderer, 0xff, 0x00, 0x00, 0x80);
166     R.x = 0;
167     R.y = 0;
168     R.w = 100;
169     R.h = 100;
170     SDL_RenderFillRect(s->renderer, &R);
171     SDL_SetRenderDrawBlendMode(s->renderer, SDL_BLENDMODE_NONE);
172 
173     SDL_RenderCopy(s->renderer, target, NULL, NULL);
174     SDL_DestroyTexture(target);
175 
176     /* Update the screen! */
177     SDL_RenderPresent(s->renderer);
178     return SDL_TRUE;
179 }
180 
181 SDL_bool
Draw(DrawState * s)182 Draw(DrawState *s)
183 {
184     SDL_Rect viewport;
185     SDL_Texture *target;
186 
187     SDL_RenderGetViewport(s->renderer, &viewport);
188 
189     target = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, viewport.w, viewport.h);
190     if (!target) {
191         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create render target texture: %s\n", SDL_GetError());
192         return SDL_FALSE;
193     }
194     SDL_SetRenderTarget(s->renderer, target);
195 
196     /* Draw the background */
197     SDL_RenderCopy(s->renderer, s->background, NULL, NULL);
198 
199     /* Scale and draw the sprite */
200     s->sprite_rect.w += s->scale_direction;
201     s->sprite_rect.h += s->scale_direction;
202     if (s->scale_direction > 0) {
203         if (s->sprite_rect.w >= viewport.w || s->sprite_rect.h >= viewport.h) {
204             s->scale_direction = -1;
205         }
206     } else {
207         if (s->sprite_rect.w <= 1 || s->sprite_rect.h <= 1) {
208             s->scale_direction = 1;
209         }
210     }
211     s->sprite_rect.x = (viewport.w - s->sprite_rect.w) / 2;
212     s->sprite_rect.y = (viewport.h - s->sprite_rect.h) / 2;
213 
214     SDL_RenderCopy(s->renderer, s->sprite, NULL, &s->sprite_rect);
215 
216     SDL_SetRenderTarget(s->renderer, NULL);
217     SDL_RenderCopy(s->renderer, target, NULL, NULL);
218     SDL_DestroyTexture(target);
219 
220     /* Update the screen! */
221     SDL_RenderPresent(s->renderer);
222     return SDL_TRUE;
223 }
224 
225 void
loop()226 loop()
227 {
228     int i;
229     SDL_Event event;
230 
231     /* Check for events */
232     while (SDL_PollEvent(&event)) {
233         SDLTest_CommonEvent(state, &event, &done);
234     }
235     for (i = 0; i < state->num_windows; ++i) {
236         if (state->windows[i] == NULL)
237             continue;
238         if (test_composite) {
239             if (!DrawComposite(&drawstates[i])) done = 1;
240         } else {
241             if (!Draw(&drawstates[i])) done = 1;
242         }
243     }
244 #ifdef __EMSCRIPTEN__
245     if (done) {
246         emscripten_cancel_main_loop();
247     }
248 #endif
249 }
250 
251 int
main(int argc,char * argv[])252 main(int argc, char *argv[])
253 {
254     int i;
255     int frames;
256     Uint32 then, now;
257 
258     /* Enable standard application logging */
259     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
260 
261     /* Initialize test framework */
262     state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);
263     if (!state) {
264         return 1;
265     }
266     for (i = 1; i < argc;) {
267         int consumed;
268 
269         consumed = SDLTest_CommonArg(state, i);
270         if (consumed == 0) {
271             consumed = -1;
272             if (SDL_strcasecmp(argv[i], "--composite") == 0) {
273                 test_composite = SDL_TRUE;
274                 consumed = 1;
275             }
276         }
277         if (consumed < 0) {
278             static const char *options[] = { "[--composite]", NULL };
279             SDLTest_CommonLogUsage(state, argv[0], options);
280             quit(1);
281         }
282         i += consumed;
283     }
284     if (!SDLTest_CommonInit(state)) {
285         quit(2);
286     }
287 
288     drawstates = SDL_stack_alloc(DrawState, state->num_windows);
289     for (i = 0; i < state->num_windows; ++i) {
290         DrawState *drawstate = &drawstates[i];
291 
292         drawstate->window = state->windows[i];
293         drawstate->renderer = state->renderers[i];
294         if (test_composite) {
295             drawstate->sprite = LoadTexture(drawstate->renderer, "icon-alpha.bmp", SDL_TRUE);
296         } else {
297             drawstate->sprite = LoadTexture(drawstate->renderer, "icon.bmp", SDL_TRUE);
298         }
299         drawstate->background = LoadTexture(drawstate->renderer, "sample.bmp", SDL_FALSE);
300         if (!drawstate->sprite || !drawstate->background) {
301             quit(2);
302         }
303         SDL_QueryTexture(drawstate->sprite, NULL, NULL,
304                          &drawstate->sprite_rect.w, &drawstate->sprite_rect.h);
305         drawstate->scale_direction = 1;
306     }
307 
308     /* Main render loop */
309     frames = 0;
310     then = SDL_GetTicks();
311     done = 0;
312 
313 #ifdef __EMSCRIPTEN__
314     emscripten_set_main_loop(loop, 0, 1);
315 #else
316     while (!done) {
317         ++frames;
318         loop();
319     }
320 #endif
321 
322     /* Print out some timing information */
323     now = SDL_GetTicks();
324     if (now > then) {
325         double fps = ((double) frames * 1000) / (now - then);
326         SDL_Log("%2.2f frames per second\n", fps);
327     }
328 
329     SDL_stack_free(drawstates);
330 
331     quit(0);
332     return 0;
333 }
334 
335 /* vi: set ts=4 sw=4 expandtab: */
336