1 /*
2   Copyright (C) 1997-2020 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 
13 /* Simple program:  draw as many random objects on the screen as possible */
14 
15 #include <stdlib.h>
16 #include <stdio.h>
17 #include <time.h>
18 
19 #ifdef __EMSCRIPTEN__
20 #include <emscripten/emscripten.h>
21 #endif
22 
23 #include "SDL_test_common.h"
24 
25 #define SWAP(typ,a,b) do{typ t=a;a=b;b=t;}while(0)
26 #define NUM_OBJECTS 100
27 
28 static SDLTest_CommonState *state;
29 static int num_objects;
30 static SDL_bool cycle_color;
31 static SDL_bool cycle_alpha;
32 static int cycle_direction = 1;
33 static int current_alpha = 255;
34 static int current_color = 255;
35 static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;
36 
37 int mouse_begin_x = -1, mouse_begin_y = -1;
38 int done;
39 
40 void
DrawPoints(SDL_Renderer * renderer)41 DrawPoints(SDL_Renderer * renderer)
42 {
43     int i;
44     int x, y;
45     SDL_Rect viewport;
46 
47     /* Query the sizes */
48     SDL_RenderGetViewport(renderer, &viewport);
49 
50     for (i = 0; i < num_objects * 4; ++i) {
51         /* Cycle the color and alpha, if desired */
52         if (cycle_color) {
53             current_color += cycle_direction;
54             if (current_color < 0) {
55                 current_color = 0;
56                 cycle_direction = -cycle_direction;
57             }
58             if (current_color > 255) {
59                 current_color = 255;
60                 cycle_direction = -cycle_direction;
61             }
62         }
63         if (cycle_alpha) {
64             current_alpha += cycle_direction;
65             if (current_alpha < 0) {
66                 current_alpha = 0;
67                 cycle_direction = -cycle_direction;
68             }
69             if (current_alpha > 255) {
70                 current_alpha = 255;
71                 cycle_direction = -cycle_direction;
72             }
73         }
74         SDL_SetRenderDrawColor(renderer, 255, (Uint8) current_color,
75                                (Uint8) current_color, (Uint8) current_alpha);
76 
77         x = rand() % viewport.w;
78         y = rand() % viewport.h;
79         SDL_RenderDrawPoint(renderer, x, y);
80     }
81 }
82 
83 #define MAX_LINES 16
84 int num_lines = 0;
85 SDL_Rect lines[MAX_LINES];
86 static int
add_line(int x1,int y1,int x2,int y2)87 add_line(int x1, int y1, int x2, int y2)
88 {
89     if (num_lines >= MAX_LINES)
90         return 0;
91     if ((x1 == x2) && (y1 == y2))
92         return 0;
93 
94     SDL_Log("adding line (%d, %d), (%d, %d)\n", x1, y1, x2, y2);
95     lines[num_lines].x = x1;
96     lines[num_lines].y = y1;
97     lines[num_lines].w = x2;
98     lines[num_lines].h = y2;
99 
100     return ++num_lines;
101 }
102 
103 
104 void
DrawLines(SDL_Renderer * renderer)105 DrawLines(SDL_Renderer * renderer)
106 {
107     int i;
108     SDL_Rect viewport;
109 
110     /* Query the sizes */
111     SDL_RenderGetViewport(renderer, &viewport);
112 
113     SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
114 
115     for (i = 0; i < num_lines; ++i) {
116         if (i == -1) {
117             SDL_RenderDrawLine(renderer, 0, 0, viewport.w - 1, viewport.h - 1);
118             SDL_RenderDrawLine(renderer, 0, viewport.h - 1, viewport.w - 1, 0);
119             SDL_RenderDrawLine(renderer, 0, viewport.h / 2, viewport.w - 1, viewport.h / 2);
120             SDL_RenderDrawLine(renderer, viewport.w / 2, 0, viewport.w / 2, viewport.h - 1);
121         } else {
122             SDL_RenderDrawLine(renderer, lines[i].x, lines[i].y, lines[i].w, lines[i].h);
123         }
124     }
125 }
126 
127 #define MAX_RECTS 16
128 int num_rects = 0;
129 SDL_Rect rects[MAX_RECTS];
130 static int
add_rect(int x1,int y1,int x2,int y2)131 add_rect(int x1, int y1, int x2, int y2)
132 {
133     if (num_rects >= MAX_RECTS)
134         return 0;
135     if ((x1 == x2) || (y1 == y2))
136         return 0;
137 
138     if (x1 > x2)
139         SWAP(int, x1, x2);
140     if (y1 > y2)
141         SWAP(int, y1, y2);
142 
143     SDL_Log("adding rect (%d, %d), (%d, %d) [%dx%d]\n", x1, y1, x2, y2,
144            x2 - x1, y2 - y1);
145 
146     rects[num_rects].x = x1;
147     rects[num_rects].y = y1;
148     rects[num_rects].w = x2 - x1;
149     rects[num_rects].h = y2 - y1;
150 
151     return ++num_rects;
152 }
153 
154 static void
DrawRects(SDL_Renderer * renderer)155 DrawRects(SDL_Renderer * renderer)
156 {
157     SDL_SetRenderDrawColor(renderer, 255, 127, 0, 255);
158     SDL_RenderFillRects(renderer, rects, num_rects);
159 }
160 
161 static void
DrawRectLineIntersections(SDL_Renderer * renderer)162 DrawRectLineIntersections(SDL_Renderer * renderer)
163 {
164     int i, j;
165 
166     SDL_SetRenderDrawColor(renderer, 0, 255, 55, 255);
167 
168     for (i = 0; i < num_rects; i++)
169         for (j = 0; j < num_lines; j++) {
170             int x1, y1, x2, y2;
171             SDL_Rect r;
172 
173             r = rects[i];
174             x1 = lines[j].x;
175             y1 = lines[j].y;
176             x2 = lines[j].w;
177             y2 = lines[j].h;
178 
179             if (SDL_IntersectRectAndLine(&r, &x1, &y1, &x2, &y2)) {
180                 SDL_RenderDrawLine(renderer, x1, y1, x2, y2);
181             }
182         }
183 }
184 
185 static void
DrawRectRectIntersections(SDL_Renderer * renderer)186 DrawRectRectIntersections(SDL_Renderer * renderer)
187 {
188     int i, j;
189 
190     SDL_SetRenderDrawColor(renderer, 255, 200, 0, 255);
191 
192     for (i = 0; i < num_rects; i++)
193         for (j = i + 1; j < num_rects; j++) {
194             SDL_Rect r;
195             if (SDL_IntersectRect(&rects[i], &rects[j], &r)) {
196                 SDL_RenderFillRect(renderer, &r);
197             }
198         }
199 }
200 
201 void
loop()202 loop()
203 {
204     int i;
205     SDL_Event event;
206 
207     /* Check for events */
208     while (SDL_PollEvent(&event)) {
209         SDLTest_CommonEvent(state, &event, &done);
210         switch (event.type) {
211         case SDL_MOUSEBUTTONDOWN:
212             mouse_begin_x = event.button.x;
213             mouse_begin_y = event.button.y;
214             break;
215         case SDL_MOUSEBUTTONUP:
216             if (event.button.button == 3)
217                 add_line(mouse_begin_x, mouse_begin_y, event.button.x,
218                          event.button.y);
219             if (event.button.button == 1)
220                 add_rect(mouse_begin_x, mouse_begin_y, event.button.x,
221                          event.button.y);
222             break;
223         case SDL_KEYDOWN:
224             switch (event.key.keysym.sym) {
225             case 'l':
226                 if (event.key.keysym.mod & KMOD_SHIFT)
227                     num_lines = 0;
228                 else
229                     add_line(rand() % 640, rand() % 480, rand() % 640,
230                              rand() % 480);
231                 break;
232             case 'r':
233                 if (event.key.keysym.mod & KMOD_SHIFT)
234                     num_rects = 0;
235                 else
236                     add_rect(rand() % 640, rand() % 480, rand() % 640,
237                              rand() % 480);
238                 break;
239             }
240             break;
241         default:
242             break;
243         }
244     }
245     for (i = 0; i < state->num_windows; ++i) {
246         SDL_Renderer *renderer = state->renderers[i];
247         if (state->windows[i] == NULL)
248             continue;
249         SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);
250         SDL_RenderClear(renderer);
251 
252         DrawRects(renderer);
253         DrawPoints(renderer);
254         DrawRectRectIntersections(renderer);
255         DrawLines(renderer);
256         DrawRectLineIntersections(renderer);
257 
258         SDL_RenderPresent(renderer);
259     }
260 #ifdef __EMSCRIPTEN__
261     if (done) {
262         emscripten_cancel_main_loop();
263     }
264 #endif
265 }
266 
267 int
main(int argc,char * argv[])268 main(int argc, char *argv[])
269 {
270     int i;
271     Uint32 then, now, frames;
272 
273     /* Enable standard application logging */
274     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
275 
276     /* Initialize parameters */
277     num_objects = NUM_OBJECTS;
278 
279     /* Initialize test framework */
280     state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);
281     if (!state) {
282         return 1;
283     }
284     for (i = 1; i < argc;) {
285         int consumed;
286 
287         consumed = SDLTest_CommonArg(state, i);
288         if (consumed == 0) {
289             consumed = -1;
290             if (SDL_strcasecmp(argv[i], "--blend") == 0) {
291                 if (argv[i + 1]) {
292                     if (SDL_strcasecmp(argv[i + 1], "none") == 0) {
293                         blendMode = SDL_BLENDMODE_NONE;
294                         consumed = 2;
295                     } else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {
296                         blendMode = SDL_BLENDMODE_BLEND;
297                         consumed = 2;
298                     } else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {
299                         blendMode = SDL_BLENDMODE_ADD;
300                         consumed = 2;
301                     } else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {
302                         blendMode = SDL_BLENDMODE_MOD;
303                         consumed = 2;
304                     }
305                 }
306             } else if (SDL_strcasecmp(argv[i], "--cyclecolor") == 0) {
307                 cycle_color = SDL_TRUE;
308                 consumed = 1;
309             } else if (SDL_strcasecmp(argv[i], "--cyclealpha") == 0) {
310                 cycle_alpha = SDL_TRUE;
311                 consumed = 1;
312             } else if (SDL_isdigit(*argv[i])) {
313                 num_objects = SDL_atoi(argv[i]);
314                 consumed = 1;
315             }
316         }
317         if (consumed < 0) {
318             static const char *options[] = { "[--blend none|blend|add|mod]", "[--cyclecolor]", "[--cyclealpha]", NULL };
319             SDLTest_CommonLogUsage(state, argv[0], options);
320             return 1;
321         }
322         i += consumed;
323     }
324     if (!SDLTest_CommonInit(state)) {
325         return 2;
326     }
327 
328     /* Create the windows and initialize the renderers */
329     for (i = 0; i < state->num_windows; ++i) {
330         SDL_Renderer *renderer = state->renderers[i];
331         SDL_SetRenderDrawBlendMode(renderer, blendMode);
332         SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);
333         SDL_RenderClear(renderer);
334     }
335 
336     srand(time(NULL));
337 
338     /* Main render loop */
339     frames = 0;
340     then = SDL_GetTicks();
341     done = 0;
342 
343 #ifdef __EMSCRIPTEN__
344     emscripten_set_main_loop(loop, 0, 1);
345 #else
346     while (!done) {
347         ++frames;
348         loop();
349     }
350 #endif
351 
352     SDLTest_CommonQuit(state);
353 
354     /* Print out some timing information */
355     now = SDL_GetTicks();
356     if (now > then) {
357         double fps = ((double) frames * 1000) / (now - then);
358         SDL_Log("%2.2f frames per second\n", fps);
359     }
360     return 0;
361 }
362 
363 /* vi: set ts=4 sw=4 expandtab: */
364