Repository navigation
Expand file tree
/
Copy pathSDL_rect_impl.h
More file actions
441 lines (402 loc) · 12.2 KB
/
Copy pathSDL_rect_impl.h
File metadata and controls
441 lines (402 loc) · 12.2 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
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
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
/*
Simple DirectMedia Layer
Copyright (C) 1997-2023 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, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
/* This file is #included twice to support int and float versions with the same code. */
SDL_bool SDL_HASINTERSECTION(const RECTTYPE *A, const RECTTYPE *B)
{
SCALARTYPE Amin, Amax, Bmin, Bmax;
if (!A) {
SDL_InvalidParamError("A");
return SDL_FALSE;
} else if (!B) {
SDL_InvalidParamError("B");
return SDL_FALSE;
} else if (SDL_RECTEMPTY(A) || SDL_RECTEMPTY(B)) {
return SDL_FALSE; /* Special cases for empty rects */
}
/* Horizontal intersection */
Amin = A->x;
Amax = Amin + A->w;
Bmin = B->x;
Bmax = Bmin + B->w;
if (Bmin > Amin) {
Amin = Bmin;
}
if (Bmax < Amax) {
Amax = Bmax;
}
if (Amax <= Amin) {
return SDL_FALSE;
}
/* Vertical intersection */
Amin = A->y;
Amax = Amin + A->h;
Bmin = B->y;
Bmax = Bmin + B->h;
if (Bmin > Amin) {
Amin = Bmin;
}
if (Bmax < Amax) {
Amax = Bmax;
}
if (Amax <= Amin) {
return SDL_FALSE;
}
return SDL_TRUE;
}
SDL_bool SDL_INTERSECTRECT(const RECTTYPE *A, const RECTTYPE *B, RECTTYPE *result)
{
SCALARTYPE Amin, Amax, Bmin, Bmax;
if (!A) {
SDL_InvalidParamError("A");
return SDL_FALSE;
} else if (!B) {
SDL_InvalidParamError("B");
return SDL_FALSE;
} else if (!result) {
SDL_InvalidParamError("result");
return SDL_FALSE;
} else if (SDL_RECTEMPTY(A) || SDL_RECTEMPTY(B)) { /* Special cases for empty rects */
result->w = 0;
result->h = 0;
return SDL_FALSE;
}
/* Horizontal intersection */
Amin = A->x;
Amax = Amin + A->w;
Bmin = B->x;
Bmax = Bmin + B->w;
if (Bmin > Amin) {
Amin = Bmin;
}
result->x = Amin;
if (Bmax < Amax) {
Amax = Bmax;
}
result->w = Amax - Amin;
/* Vertical intersection */
Amin = A->y;
Amax = Amin + A->h;
Bmin = B->y;
Bmax = Bmin + B->h;
if (Bmin > Amin) {
Amin = Bmin;
}
result->y = Amin;
if (Bmax < Amax) {
Amax = Bmax;
}
result->h = Amax - Amin;
return !SDL_RECTEMPTY(result);
}
void SDL_UNIONRECT(const RECTTYPE *A, const RECTTYPE *B, RECTTYPE *result)
{
SCALARTYPE Amin, Amax, Bmin, Bmax;
if (!A) {
SDL_InvalidParamError("A");
return;
} else if (!B) {
SDL_InvalidParamError("B");
return;
} else if (!result) {
SDL_InvalidParamError("result");
return;
} else if (SDL_RECTEMPTY(A)) { /* Special cases for empty Rects */
if (SDL_RECTEMPTY(B)) { /* A and B empty */
SDL_zerop(result);
} else { /* A empty, B not empty */
*result = *B;
}
return;
} else if (SDL_RECTEMPTY(B)) { /* A not empty, B empty */
*result = *A;
return;
}
/* Horizontal union */
Amin = A->x;
Amax = Amin + A->w;
Bmin = B->x;
Bmax = Bmin + B->w;
if (Bmin < Amin) {
Amin = Bmin;
}
result->x = Amin;
if (Bmax > Amax) {
Amax = Bmax;
}
result->w = Amax - Amin;
/* Vertical union */
Amin = A->y;
Amax = Amin + A->h;
Bmin = B->y;
Bmax = Bmin + B->h;
if (Bmin < Amin) {
Amin = Bmin;
}
result->y = Amin;
if (Bmax > Amax) {
Amax = Bmax;
}
result->h = Amax - Amin;
}
SDL_bool SDL_ENCLOSEPOINTS(const POINTTYPE *points, int count, const RECTTYPE *clip,
RECTTYPE *result)
{
SCALARTYPE minx = 0;
SCALARTYPE miny = 0;
SCALARTYPE maxx = 0;
SCALARTYPE maxy = 0;
SCALARTYPE x, y;
int i;
if (!points) {
SDL_InvalidParamError("points");
return SDL_FALSE;
} else if (count < 1) {
SDL_InvalidParamError("count");
return SDL_FALSE;
}
if (clip) {
SDL_bool added = SDL_FALSE;
const SCALARTYPE clip_minx = clip->x;
const SCALARTYPE clip_miny = clip->y;
const SCALARTYPE clip_maxx = clip->x + clip->w - 1;
const SCALARTYPE clip_maxy = clip->y + clip->h - 1;
/* Special case for empty rectangle */
if (SDL_RECTEMPTY(clip)) {
return SDL_FALSE;
}
for (i = 0; i < count; ++i) {
x = points[i].x;
y = points[i].y;
if (x < clip_minx || x > clip_maxx ||
y < clip_miny || y > clip_maxy) {
continue;
}
if (!added) {
/* Special case: if no result was requested, we are done */
if (!result) {
return SDL_TRUE;
}
/* First point added */
minx = maxx = x;
miny = maxy = y;
added = SDL_TRUE;
continue;
}
if (x < minx) {
minx = x;
} else if (x > maxx) {
maxx = x;
}
if (y < miny) {
miny = y;
} else if (y > maxy) {
maxy = y;
}
}
if (!added) {
return SDL_FALSE;
}
} else {
/* Special case: if no result was requested, we are done */
if (!result) {
return SDL_TRUE;
}
/* No clipping, always add the first point */
minx = maxx = points[0].x;
miny = maxy = points[0].y;
for (i = 1; i < count; ++i) {
x = points[i].x;
y = points[i].y;
if (x < minx) {
minx = x;
} else if (x > maxx) {
maxx = x;
}
if (y < miny) {
miny = y;
} else if (y > maxy) {
maxy = y;
}
}
}
if (result) {
result->x = minx;
result->y = miny;
result->w = (maxx - minx) + 1;
result->h = (maxy - miny) + 1;
}
return SDL_TRUE;
}
/* Use the Cohen-Sutherland algorithm for line clipping */
static int COMPUTEOUTCODE(const RECTTYPE *rect, SCALARTYPE x, SCALARTYPE y)
{
int code = 0;
if (y < rect->y) {
code |= CODE_TOP;
} else if (y >= rect->y + rect->h) {
code |= CODE_BOTTOM;
}
if (x < rect->x) {
code |= CODE_LEFT;
} else if (x >= rect->x + rect->w) {
code |= CODE_RIGHT;
}
return code;
}
SDL_bool SDL_INTERSECTRECTANDLINE(const RECTTYPE *rect, SCALARTYPE *X1, SCALARTYPE *Y1, SCALARTYPE *X2, SCALARTYPE *Y2)
{
SCALARTYPE x = 0;
SCALARTYPE y = 0;
SCALARTYPE x1, y1;
SCALARTYPE x2, y2;
SCALARTYPE rectx1;
SCALARTYPE recty1;
SCALARTYPE rectx2;
SCALARTYPE recty2;
int outcode1, outcode2;
if (!rect) {
SDL_InvalidParamError("rect");
return SDL_FALSE;
} else if (!X1) {
SDL_InvalidParamError("X1");
return SDL_FALSE;
} else if (!Y1) {
SDL_InvalidParamError("Y1");
return SDL_FALSE;
} else if (!X2) {
SDL_InvalidParamError("X2");
return SDL_FALSE;
} else if (!Y2) {
SDL_InvalidParamError("Y2");
return SDL_FALSE;
} else if (SDL_RECTEMPTY(rect)) {
return SDL_FALSE; /* Special case for empty rect */
}
x1 = *X1;
y1 = *Y1;
x2 = *X2;
y2 = *Y2;
rectx1 = rect->x;
recty1 = rect->y;
rectx2 = rect->x + rect->w - 1;
recty2 = rect->y + rect->h - 1;
/* Check to see if entire line is inside rect */
if (x1 >= rectx1 && x1 <= rectx2 && x2 >= rectx1 && x2 <= rectx2 &&
y1 >= recty1 && y1 <= recty2 && y2 >= recty1 && y2 <= recty2) {
return SDL_TRUE;
}
/* Check to see if entire line is to one side of rect */
if ((x1 < rectx1 && x2 < rectx1) || (x1 > rectx2 && x2 > rectx2) ||
(y1 < recty1 && y2 < recty1) || (y1 > recty2 && y2 > recty2)) {
return SDL_FALSE;
}
if (y1 == y2) { /* Horizontal line, easy to clip */
if (x1 < rectx1) {
*X1 = rectx1;
} else if (x1 > rectx2) {
*X1 = rectx2;
}
if (x2 < rectx1) {
*X2 = rectx1;
} else if (x2 > rectx2) {
*X2 = rectx2;
}
return SDL_TRUE;
}
if (x1 == x2) { /* Vertical line, easy to clip */
if (y1 < recty1) {
*Y1 = recty1;
} else if (y1 > recty2) {
*Y1 = recty2;
}
if (y2 < recty1) {
*Y2 = recty1;
} else if (y2 > recty2) {
*Y2 = recty2;
}
return SDL_TRUE;
}
/* More complicated Cohen-Sutherland algorithm */
outcode1 = COMPUTEOUTCODE(rect, x1, y1);
outcode2 = COMPUTEOUTCODE(rect, x2, y2);
while (outcode1 || outcode2) {
if (outcode1 & outcode2) {
return SDL_FALSE;
}
if (outcode1) {
if (outcode1 & CODE_TOP) {
y = recty1;
x = (SCALARTYPE) (x1 + ((BIGSCALARTYPE)(x2 - x1) * (y - y1)) / (y2 - y1));
} else if (outcode1 & CODE_BOTTOM) {
y = recty2;
x = (SCALARTYPE) (x1 + ((BIGSCALARTYPE)(x2 - x1) * (y - y1)) / (y2 - y1));
} else if (outcode1 & CODE_LEFT) {
x = rectx1;
y = (SCALARTYPE) (y1 + ((BIGSCALARTYPE)(y2 - y1) * (x - x1)) / (x2 - x1));
} else if (outcode1 & CODE_RIGHT) {
x = rectx2;
y = (SCALARTYPE) (y1 + ((BIGSCALARTYPE)(y2 - y1) * (x - x1)) / (x2 - x1));
}
x1 = x;
y1 = y;
outcode1 = COMPUTEOUTCODE(rect, x, y);
} else {
if (outcode2 & CODE_TOP) {
SDL_assert(y2 != y1); /* if equal: division by zero. */
y = recty1;
x = (SCALARTYPE) (x1 + ((BIGSCALARTYPE)(x2 - x1) * (y - y1)) / (y2 - y1));
} else if (outcode2 & CODE_BOTTOM) {
SDL_assert(y2 != y1); /* if equal: division by zero. */
y = recty2;
x = (SCALARTYPE) (x1 + ((BIGSCALARTYPE)(x2 - x1) * (y - y1)) / (y2 - y1));
} else if (outcode2 & CODE_LEFT) {
/* If this assertion ever fires, here's the static analysis that warned about it:
http://buildbot.libsdl.org/sdl-static-analysis/sdl-macosx-static-analysis/sdl-macosx-static-analysis-1101/report-b0d01a.html#EndPath */
SDL_assert(x2 != x1); /* if equal: division by zero. */
x = rectx1;
y = (SCALARTYPE) (y1 + ((BIGSCALARTYPE)(y2 - y1) * (x - x1)) / (x2 - x1));
} else if (outcode2 & CODE_RIGHT) {
/* If this assertion ever fires, here's the static analysis that warned about it:
http://buildbot.libsdl.org/sdl-static-analysis/sdl-macosx-static-analysis/sdl-macosx-static-analysis-1101/report-39b114.html#EndPath */
SDL_assert(x2 != x1); /* if equal: division by zero. */
x = rectx2;
y = (SCALARTYPE) (y1 + ((BIGSCALARTYPE)(y2 - y1) * (x - x1)) / (x2 - x1));
}
x2 = x;
y2 = y;
outcode2 = COMPUTEOUTCODE(rect, x, y);
}
}
*X1 = x1;
*Y1 = y1;
*X2 = x2;
*Y2 = y2;
return SDL_TRUE;
}
#undef RECTTYPE
#undef POINTTYPE
#undef SCALARTYPE
#undef BIGSCALARTYPE
#undef COMPUTEOUTCODE
#undef SDL_HASINTERSECTION
#undef SDL_INTERSECTRECT
#undef SDL_RECTEMPTY
#undef SDL_UNIONRECT
#undef SDL_ENCLOSEPOINTS
#undef SDL_INTERSECTRECTANDLINE
/* vi: set ts=4 sw=4 expandtab: */