This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
testintersections.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
/* Simple program: draw as many random objects on the screen as possible */
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include "common.h"
#define SWAP(typ,a,b) do{typ t=a;a=b;b=t;}while(0)
#define NUM_OBJECTS 100
static CommonState *state;
static int num_objects;
static SDL_bool cycle_color;
static SDL_bool cycle_alpha;
static int cycle_direction = 1;
static int current_alpha = 255;
static int current_color = 255;
static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;
void
23
DrawPoints(SDL_Renderer * renderer)
24
25
26
{
int i;
int x, y;
27
SDL_Rect viewport;
28
29
/* Query the sizes */
30
SDL_RenderGetViewport(renderer, &viewport);
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
for (i = 0; i < num_objects * 4; ++i) {
/* Cycle the color and alpha, if desired */
if (cycle_color) {
current_color += cycle_direction;
if (current_color < 0) {
current_color = 0;
cycle_direction = -cycle_direction;
}
if (current_color > 255) {
current_color = 255;
cycle_direction = -cycle_direction;
}
}
if (cycle_alpha) {
current_alpha += cycle_direction;
if (current_alpha < 0) {
current_alpha = 0;
cycle_direction = -cycle_direction;
}
if (current_alpha > 255) {
current_alpha = 255;
cycle_direction = -cycle_direction;
}
}
56
SDL_SetRenderDrawColor(renderer, 255, (Uint8) current_color,
57
58
(Uint8) current_color, (Uint8) current_alpha);
59
60
x = rand() % viewport.w;
y = rand() % viewport.h;
61
SDL_RenderDrawPoint(renderer, x, y);
62
63
64
65
66
67
}
}
#define MAX_LINES 16
int num_lines = 0;
SDL_Rect lines[MAX_LINES];
68
69
70
71
72
73
74
static int
add_line(int x1, int y1, int x2, int y2)
{
if (num_lines >= MAX_LINES)
return 0;
if ((x1 == x2) && (y1 == y2))
return 0;
75
76
77
78
79
80
81
82
83
84
85
86
printf("adding line (%d, %d), (%d, %d)\n", x1, y1, x2, y2);
lines[num_lines].x = x1;
lines[num_lines].y = y1;
lines[num_lines].w = x2;
lines[num_lines].h = y2;
return ++num_lines;
}
void
87
DrawLines(SDL_Renderer * renderer)
88
89
90
{
int i;
int x1, y1, x2, y2;
91
SDL_Rect viewport;
92
93
/* Query the sizes */
94
SDL_RenderGetViewport(renderer, &viewport);
96
SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
98
for (i = 0; i < num_lines; ++i) {
99
if (i == -1) {
100
101
102
103
SDL_RenderDrawLine(renderer, 0, 0, viewport.w - 1, viewport.h - 1);
SDL_RenderDrawLine(renderer, 0, viewport.h - 1, viewport.w - 1, 0);
SDL_RenderDrawLine(renderer, 0, viewport.h / 2, viewport.w - 1, viewport.h / 2);
SDL_RenderDrawLine(renderer, viewport.w / 2, 0, viewport.w / 2, viewport.h - 1);
104
} else {
105
SDL_RenderDrawLine(renderer, lines[i].x, lines[i].y, lines[i].w, lines[i].h);
106
107
108
109
110
111
112
}
}
}
#define MAX_RECTS 16
int num_rects = 0;
SDL_Rect rects[MAX_RECTS];
113
114
115
116
117
118
119
static int
add_rect(int x1, int y1, int x2, int y2)
{
if (num_rects >= MAX_RECTS)
return 0;
if ((x1 == x2) || (y1 == y2))
return 0;
121
122
123
124
if (x1 > x2)
SWAP(int, x1, x2);
if (y1 > y2)
SWAP(int, y1, y2);
126
127
printf("adding rect (%d, %d), (%d, %d) [%dx%d]\n", x1, y1, x2, y2,
x2 - x1, y2 - y1);
128
129
130
131
132
133
134
135
136
137
rects[num_rects].x = x1;
rects[num_rects].y = y1;
rects[num_rects].w = x2 - x1;
rects[num_rects].h = y2 - y1;
return ++num_rects;
}
static void
138
DrawRects(SDL_Renderer * renderer)
140
141
SDL_SetRenderDrawColor(renderer, 255, 127, 0, 255);
SDL_RenderFillRects(renderer, rects, num_rects);
142
143
144
}
static void
145
DrawRectLineIntersections(SDL_Renderer * renderer)
149
SDL_SetRenderDrawColor(renderer, 0, 255, 55, 255);
150
151
for (i = 0; i < num_rects; i++)
152
153
154
155
156
157
158
159
160
161
162
for (j = 0; j < num_lines; j++) {
int x1, y1, x2, y2;
SDL_Rect r;
r = rects[i];
x1 = lines[j].x;
y1 = lines[j].y;
x2 = lines[j].w;
y2 = lines[j].h;
if (SDL_IntersectRectAndLine(&r, &x1, &y1, &x2, &y2)) {
163
SDL_RenderDrawLine(renderer, x1, y1, x2, y2);
164
}
165
166
167
168
}
}
static void
169
DrawRectRectIntersections(SDL_Renderer * renderer)
170
171
172
{
int i, j;
173
174
SDL_SetRenderDrawColor(renderer, 255, 200, 0, 255);
175
for (i = 0; i < num_rects; i++)
176
177
178
for (j = i + 1; j < num_rects; j++) {
SDL_Rect r;
if (SDL_IntersectRect(&rects[i], &rects[j], &r)) {
179
SDL_RenderFillRect(renderer, &r);
180
}
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
}
}
int
main(int argc, char *argv[])
{
int mouse_begin_x = -1, mouse_begin_y = -1;
int i, done;
SDL_Event event;
Uint32 then, now, frames;
/* Initialize parameters */
num_objects = NUM_OBJECTS;
/* Initialize test framework */
state = CommonCreateState(argv, SDL_INIT_VIDEO);
if (!state) {
return 1;
}
for (i = 1; i < argc;) {
int consumed;
consumed = CommonArg(state, i);
if (consumed == 0) {
consumed = -1;
if (SDL_strcasecmp(argv[i], "--blend") == 0) {
if (argv[i + 1]) {
if (SDL_strcasecmp(argv[i + 1], "none") == 0) {
blendMode = SDL_BLENDMODE_NONE;
consumed = 2;
} else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {
blendMode = SDL_BLENDMODE_BLEND;
consumed = 2;
} else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {
blendMode = SDL_BLENDMODE_ADD;
consumed = 2;
217
218
219
} else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {
blendMode = SDL_BLENDMODE_MOD;
consumed = 2;
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
}
}
} else if (SDL_strcasecmp(argv[i], "--cyclecolor") == 0) {
cycle_color = SDL_TRUE;
consumed = 1;
} else if (SDL_strcasecmp(argv[i], "--cyclealpha") == 0) {
cycle_alpha = SDL_TRUE;
consumed = 1;
} else if (SDL_isdigit(*argv[i])) {
num_objects = SDL_atoi(argv[i]);
consumed = 1;
}
}
if (consumed < 0) {
fprintf(stderr,
235
"Usage: %s %s [--blend none|blend|add|mod] [--cyclecolor] [--cyclealpha]\n",
236
237
238
239
240
241
242
243
244
245
246
argv[0], CommonUsage(state));
return 1;
}
i += consumed;
}
if (!CommonInit(state)) {
return 2;
}
/* Create the windows and initialize the renderers */
for (i = 0; i < state->num_windows; ++i) {
247
248
249
250
SDL_Renderer *renderer = state->renderers[i];
SDL_SetRenderDrawBlendMode(renderer, blendMode);
SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);
SDL_RenderClear(renderer);
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
}
srand(time(NULL));
/* Main render loop */
frames = 0;
then = SDL_GetTicks();
done = 0;
while (!done) {
/* Check for events */
++frames;
while (SDL_PollEvent(&event)) {
CommonEvent(state, &event, &done);
switch (event.type) {
case SDL_MOUSEBUTTONDOWN:
266
267
mouse_begin_x = event.button.x;
mouse_begin_y = event.button.y;
268
269
break;
case SDL_MOUSEBUTTONUP:
270
271
272
273
274
275
if (event.button.button == 3)
add_line(mouse_begin_x, mouse_begin_y, event.button.x,
event.button.y);
if (event.button.button == 1)
add_rect(mouse_begin_x, mouse_begin_y, event.button.x,
event.button.y);
276
277
278
break;
case SDL_KEYDOWN:
switch (event.key.keysym.sym) {
279
280
281
282
283
284
285
286
287
288
289
290
291
292
case 'l':
if (event.key.keysym.mod & KMOD_SHIFT)
num_lines = 0;
else
add_line(rand() % 640, rand() % 480, rand() % 640,
rand() % 480);
break;
case 'r':
if (event.key.keysym.mod & KMOD_SHIFT)
num_rects = 0;
else
add_rect(rand() % 640, rand() % 480, rand() % 640,
rand() % 480);
break;
293
294
295
296
297
298
299
}
break;
default:
break;
}
}
for (i = 0; i < state->num_windows; ++i) {
300
301
302
SDL_Renderer *renderer = state->renderers[i];
SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);
SDL_RenderClear(renderer);
304
305
306
307
308
DrawRects(renderer);
DrawPoints(renderer);
DrawRectRectIntersections(renderer);
DrawLines(renderer);
DrawRectLineIntersections(renderer);
310
SDL_RenderPresent(renderer);
311
312
313
}
}
314
315
CommonQuit(state);
316
317
318
319
320
321
322
323
324
325
/* Print out some timing information */
now = SDL_GetTicks();
if (now > then) {
double fps = ((double) frames * 1000) / (now - then);
printf("%2.2f frames per second\n", fps);
}
return 0;
}
/* vi: set ts=4 sw=4 expandtab: */