histogram.c revision 7117f1b4
1/*
2 * Mesa 3-D graphics library
3 * Version:  6.3
4 *
5 * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26#include "glheader.h"
27#include "bufferobj.h"
28#include "colormac.h"
29#include "context.h"
30#include "image.h"
31#include "histogram.h"
32
33
34/**********************************************************************
35 * Internal functions
36 */
37
38
39/*
40 * Update the min/max values from an array of fragment colors.
41 */
42void
43_mesa_update_minmax(GLcontext *ctx, GLuint n, const GLfloat rgba[][4])
44{
45   GLuint i;
46   for (i = 0; i < n; i++) {
47      /* update mins */
48      if (rgba[i][RCOMP] < ctx->MinMax.Min[RCOMP])
49         ctx->MinMax.Min[RCOMP] = rgba[i][RCOMP];
50      if (rgba[i][GCOMP] < ctx->MinMax.Min[GCOMP])
51         ctx->MinMax.Min[GCOMP] = rgba[i][GCOMP];
52      if (rgba[i][BCOMP] < ctx->MinMax.Min[BCOMP])
53         ctx->MinMax.Min[BCOMP] = rgba[i][BCOMP];
54      if (rgba[i][ACOMP] < ctx->MinMax.Min[ACOMP])
55         ctx->MinMax.Min[ACOMP] = rgba[i][ACOMP];
56
57      /* update maxs */
58      if (rgba[i][RCOMP] > ctx->MinMax.Max[RCOMP])
59         ctx->MinMax.Max[RCOMP] = rgba[i][RCOMP];
60      if (rgba[i][GCOMP] > ctx->MinMax.Max[GCOMP])
61         ctx->MinMax.Max[GCOMP] = rgba[i][GCOMP];
62      if (rgba[i][BCOMP] > ctx->MinMax.Max[BCOMP])
63         ctx->MinMax.Max[BCOMP] = rgba[i][BCOMP];
64      if (rgba[i][ACOMP] > ctx->MinMax.Max[ACOMP])
65         ctx->MinMax.Max[ACOMP] = rgba[i][ACOMP];
66   }
67}
68
69
70/*
71 * Update the histogram values from an array of fragment colors.
72 */
73void
74_mesa_update_histogram(GLcontext *ctx, GLuint n, const GLfloat rgba[][4])
75{
76   const GLint max = ctx->Histogram.Width - 1;
77   GLfloat w = (GLfloat) max;
78   GLuint i;
79
80   if (ctx->Histogram.Width == 0)
81      return;
82
83   for (i = 0; i < n; i++) {
84      GLint ri = IROUND(rgba[i][RCOMP] * w);
85      GLint gi = IROUND(rgba[i][GCOMP] * w);
86      GLint bi = IROUND(rgba[i][BCOMP] * w);
87      GLint ai = IROUND(rgba[i][ACOMP] * w);
88      ri = CLAMP(ri, 0, max);
89      gi = CLAMP(gi, 0, max);
90      bi = CLAMP(bi, 0, max);
91      ai = CLAMP(ai, 0, max);
92      ctx->Histogram.Count[ri][RCOMP]++;
93      ctx->Histogram.Count[gi][GCOMP]++;
94      ctx->Histogram.Count[bi][BCOMP]++;
95      ctx->Histogram.Count[ai][ACOMP]++;
96   }
97}
98
99
100/*
101 * XXX the packed pixel formats haven't been tested.
102 */
103static void
104pack_histogram( GLcontext *ctx,
105                GLuint n, CONST GLuint rgba[][4],
106                GLenum format, GLenum type, GLvoid *destination,
107                const struct gl_pixelstore_attrib *packing )
108{
109   const GLint comps = _mesa_components_in_format(format);
110   GLuint luminance[MAX_WIDTH];
111
112   if (format == GL_LUMINANCE || format == GL_LUMINANCE_ALPHA) {
113      GLuint i;
114      for (i = 0; i < n; i++) {
115         luminance[i] = rgba[i][RCOMP] + rgba[i][GCOMP] + rgba[i][BCOMP];
116      }
117   }
118
119#define PACK_MACRO(TYPE)					\
120   {								\
121      GLuint i;							\
122      switch (format) {						\
123         case GL_RED:						\
124            for (i=0;i<n;i++)					\
125               dst[i] = (TYPE) rgba[i][RCOMP];			\
126            break;						\
127         case GL_GREEN:						\
128            for (i=0;i<n;i++)					\
129               dst[i] = (TYPE) rgba[i][GCOMP];			\
130            break;						\
131         case GL_BLUE:						\
132            for (i=0;i<n;i++)					\
133               dst[i] = (TYPE) rgba[i][BCOMP];			\
134            break;						\
135         case GL_ALPHA:						\
136            for (i=0;i<n;i++)					\
137               dst[i] = (TYPE) rgba[i][ACOMP];			\
138            break;						\
139         case GL_LUMINANCE:					\
140            for (i=0;i<n;i++)					\
141               dst[i] = (TYPE) luminance[i];			\
142            break;						\
143         case GL_LUMINANCE_ALPHA:				\
144            for (i=0;i<n;i++) {					\
145               dst[i*2+0] = (TYPE) luminance[i];		\
146               dst[i*2+1] = (TYPE) rgba[i][ACOMP];		\
147            }							\
148            break;						\
149         case GL_RGB:						\
150            for (i=0;i<n;i++) {					\
151               dst[i*3+0] = (TYPE) rgba[i][RCOMP];		\
152               dst[i*3+1] = (TYPE) rgba[i][GCOMP];		\
153               dst[i*3+2] = (TYPE) rgba[i][BCOMP];		\
154            }							\
155            break;						\
156         case GL_RGBA:						\
157            for (i=0;i<n;i++) {					\
158               dst[i*4+0] = (TYPE) rgba[i][RCOMP];		\
159               dst[i*4+1] = (TYPE) rgba[i][GCOMP];		\
160               dst[i*4+2] = (TYPE) rgba[i][BCOMP];		\
161               dst[i*4+3] = (TYPE) rgba[i][ACOMP];		\
162            }							\
163            break;						\
164         case GL_BGR:						\
165            for (i=0;i<n;i++) {					\
166               dst[i*3+0] = (TYPE) rgba[i][BCOMP];		\
167               dst[i*3+1] = (TYPE) rgba[i][GCOMP];		\
168               dst[i*3+2] = (TYPE) rgba[i][RCOMP];		\
169            }							\
170            break;						\
171         case GL_BGRA:						\
172            for (i=0;i<n;i++) {					\
173               dst[i*4+0] = (TYPE) rgba[i][BCOMP];		\
174               dst[i*4+1] = (TYPE) rgba[i][GCOMP];		\
175               dst[i*4+2] = (TYPE) rgba[i][RCOMP];		\
176               dst[i*4+3] = (TYPE) rgba[i][ACOMP];		\
177            }							\
178            break;						\
179         case GL_ABGR_EXT:					\
180            for (i=0;i<n;i++) {					\
181               dst[i*4+0] = (TYPE) rgba[i][ACOMP];		\
182               dst[i*4+1] = (TYPE) rgba[i][BCOMP];		\
183               dst[i*4+2] = (TYPE) rgba[i][GCOMP];		\
184               dst[i*4+3] = (TYPE) rgba[i][RCOMP];		\
185            }							\
186            break;						\
187         default:						\
188            _mesa_problem(ctx, "bad format in pack_histogram");	\
189      }								\
190   }
191
192   switch (type) {
193      case GL_UNSIGNED_BYTE:
194         {
195            GLubyte *dst = (GLubyte *) destination;
196            PACK_MACRO(GLubyte);
197         }
198         break;
199      case GL_BYTE:
200         {
201            GLbyte *dst = (GLbyte *) destination;
202            PACK_MACRO(GLbyte);
203         }
204         break;
205      case GL_UNSIGNED_SHORT:
206         {
207            GLushort *dst = (GLushort *) destination;
208            PACK_MACRO(GLushort);
209            if (packing->SwapBytes) {
210               _mesa_swap2(dst, n * comps);
211            }
212         }
213         break;
214      case GL_SHORT:
215         {
216            GLshort *dst = (GLshort *) destination;
217            PACK_MACRO(GLshort);
218            if (packing->SwapBytes) {
219               _mesa_swap2((GLushort *) dst, n * comps);
220            }
221         }
222         break;
223      case GL_UNSIGNED_INT:
224         {
225            GLuint *dst = (GLuint *) destination;
226            PACK_MACRO(GLuint);
227            if (packing->SwapBytes) {
228               _mesa_swap4(dst, n * comps);
229            }
230         }
231         break;
232      case GL_INT:
233         {
234            GLint *dst = (GLint *) destination;
235            PACK_MACRO(GLint);
236            if (packing->SwapBytes) {
237               _mesa_swap4((GLuint *) dst, n * comps);
238            }
239         }
240         break;
241      case GL_FLOAT:
242         {
243            GLfloat *dst = (GLfloat *) destination;
244            PACK_MACRO(GLfloat);
245            if (packing->SwapBytes) {
246               _mesa_swap4((GLuint *) dst, n * comps);
247            }
248         }
249         break;
250      case GL_HALF_FLOAT_ARB:
251         {
252            /* temporarily store as GLuints */
253            GLuint temp[4*HISTOGRAM_TABLE_SIZE];
254            GLhalfARB *dst = (GLhalfARB *) destination;
255            GLuint i;
256            /* get GLuint values */
257            PACK_MACRO(GLuint);
258            /* convert to GLhalf */
259            for (i = 0; i < n * comps; i++) {
260               dst[i] = _mesa_float_to_half((GLfloat) temp[i]);
261            }
262            if (packing->SwapBytes) {
263               _mesa_swap2((GLushort *) dst, n * comps);
264            }
265         }
266         break;
267      case GL_UNSIGNED_BYTE_3_3_2:
268         if (format == GL_RGB) {
269            GLubyte *dst = (GLubyte *) destination;
270            GLuint i;
271            for (i = 0; i < n; i++) {
272               dst[i] = ((rgba[i][RCOMP] & 0x7) << 5)
273                      | ((rgba[i][GCOMP] & 0x7) << 2)
274                      | ((rgba[i][BCOMP] & 0x3)     );
275            }
276         }
277         else {
278            GLubyte *dst = (GLubyte *) destination;
279            GLuint i;
280            ASSERT(format == GL_BGR);
281            for (i = 0; i < n; i++) {
282               dst[i] = ((rgba[i][BCOMP] & 0x7) << 5)
283                      | ((rgba[i][GCOMP] & 0x7) << 2)
284                      | ((rgba[i][RCOMP] & 0x3)     );
285            }
286         }
287         break;
288      case GL_UNSIGNED_BYTE_2_3_3_REV:
289         if (format == GL_RGB) {
290            GLubyte *dst = (GLubyte *) destination;
291            GLuint i;
292            for (i = 0; i < n; i++) {
293               dst[i] = ((rgba[i][RCOMP] & 0x3) << 6)
294                      | ((rgba[i][GCOMP] & 0x7) << 3)
295                      | ((rgba[i][BCOMP] & 0x7)     );
296            }
297         }
298         else {
299            GLubyte *dst = (GLubyte *) destination;
300            GLuint i;
301            ASSERT(format == GL_BGR);
302            for (i = 0; i < n; i++) {
303               dst[i] = ((rgba[i][BCOMP] & 0x3) << 6)
304                      | ((rgba[i][GCOMP] & 0x7) << 3)
305                      | ((rgba[i][RCOMP] & 0x7)     );
306            }
307         }
308         break;
309      case GL_UNSIGNED_SHORT_5_6_5:
310         if (format == GL_RGB) {
311            GLushort *dst = (GLushort *) destination;
312            GLuint i;
313            for (i = 0; i < n; i++) {
314               dst[i] = ((rgba[i][RCOMP] & 0x1f) << 11)
315                      | ((rgba[i][GCOMP] & 0x3f) <<  5)
316                      | ((rgba[i][BCOMP] & 0x1f)      );
317            }
318         }
319         else {
320            GLushort *dst = (GLushort *) destination;
321            GLuint i;
322            ASSERT(format == GL_BGR);
323            for (i = 0; i < n; i++) {
324               dst[i] = ((rgba[i][BCOMP] & 0x1f) << 11)
325                      | ((rgba[i][GCOMP] & 0x3f) <<  5)
326                      | ((rgba[i][RCOMP] & 0x1f)      );
327            }
328         }
329         break;
330      case GL_UNSIGNED_SHORT_5_6_5_REV:
331         if (format == GL_RGB) {
332            GLushort *dst = (GLushort *) destination;
333            GLuint i;
334            for (i = 0; i < n; i++) {
335               dst[i] = ((rgba[i][BCOMP] & 0x1f) << 11)
336                      | ((rgba[i][GCOMP] & 0x3f) <<  5)
337                      | ((rgba[i][RCOMP] & 0x1f)      );
338            }
339         }
340         else {
341            GLushort *dst = (GLushort *) destination;
342            GLuint i;
343            ASSERT(format == GL_BGR);
344            for (i = 0; i < n; i++) {
345               dst[i] = ((rgba[i][RCOMP] & 0x1f) << 11)
346                      | ((rgba[i][GCOMP] & 0x3f) <<  5)
347                      | ((rgba[i][BCOMP] & 0x1f)      );
348            }
349         }
350         break;
351      case GL_UNSIGNED_SHORT_4_4_4_4:
352         if (format == GL_RGBA) {
353            GLushort *dst = (GLushort *) destination;
354            GLuint i;
355            for (i = 0; i < n; i++) {
356               dst[i] = ((rgba[i][RCOMP] & 0xf) << 12)
357                      | ((rgba[i][GCOMP] & 0xf) <<  8)
358                      | ((rgba[i][BCOMP] & 0xf) <<  4)
359                      | ((rgba[i][ACOMP] & 0xf)      );
360            }
361         }
362         else if (format == GL_BGRA) {
363            GLushort *dst = (GLushort *) destination;
364            GLuint i;
365            for (i = 0; i < n; i++) {
366               dst[i] = ((rgba[i][BCOMP] & 0xf) << 12)
367                      | ((rgba[i][GCOMP] & 0xf) <<  8)
368                      | ((rgba[i][RCOMP] & 0xf) <<  4)
369                      | ((rgba[i][ACOMP] & 0xf)      );
370            }
371         }
372         else {
373            GLushort *dst = (GLushort *) destination;
374            GLuint i;
375            ASSERT(format == GL_ABGR_EXT);
376            for (i = 0; i < n; i++) {
377               dst[i] = ((rgba[i][ACOMP] & 0xf) << 12)
378                      | ((rgba[i][BCOMP] & 0xf) <<  8)
379                      | ((rgba[i][GCOMP] & 0xf) <<  4)
380                      | ((rgba[i][RCOMP] & 0xf)      );
381            }
382         }
383         break;
384      case GL_UNSIGNED_SHORT_4_4_4_4_REV:
385         if (format == GL_RGBA) {
386            GLushort *dst = (GLushort *) destination;
387            GLuint i;
388            for (i = 0; i < n; i++) {
389               dst[i] = ((rgba[i][ACOMP] & 0xf) << 12)
390                      | ((rgba[i][BCOMP] & 0xf) <<  8)
391                      | ((rgba[i][GCOMP] & 0xf) <<  4)
392                      | ((rgba[i][RCOMP] & 0xf)      );
393            }
394         }
395         else if (format == GL_BGRA) {
396            GLushort *dst = (GLushort *) destination;
397            GLuint i;
398            for (i = 0; i < n; i++) {
399               dst[i] = ((rgba[i][ACOMP] & 0xf) << 12)
400                      | ((rgba[i][RCOMP] & 0xf) <<  8)
401                      | ((rgba[i][GCOMP] & 0xf) <<  4)
402                      | ((rgba[i][BCOMP] & 0xf)      );
403            }
404         }
405         else {
406            GLushort *dst = (GLushort *) destination;
407            GLuint i;
408            ASSERT(format == GL_ABGR_EXT);
409            for (i = 0; i < n; i++) {
410               dst[i] = ((rgba[i][RCOMP] & 0xf) << 12)
411                      | ((rgba[i][GCOMP] & 0xf) <<  8)
412                      | ((rgba[i][BCOMP] & 0xf) <<  4)
413                      | ((rgba[i][ACOMP] & 0xf)      );
414            }
415         }
416         break;
417      case GL_UNSIGNED_SHORT_5_5_5_1:
418         if (format == GL_RGBA) {
419            GLushort *dst = (GLushort *) destination;
420            GLuint i;
421            for (i = 0; i < n; i++) {
422               dst[i] = ((rgba[i][RCOMP] & 0x1f) << 11)
423                      | ((rgba[i][GCOMP] & 0x1f) <<  6)
424                      | ((rgba[i][BCOMP] & 0x1f) <<  1)
425                      | ((rgba[i][ACOMP] & 0x1)       );
426            }
427         }
428         else if (format == GL_BGRA) {
429            GLushort *dst = (GLushort *) destination;
430            GLuint i;
431            for (i = 0; i < n; i++) {
432               dst[i] = ((rgba[i][BCOMP] & 0x1f) << 11)
433                      | ((rgba[i][GCOMP] & 0x1f) <<  6)
434                      | ((rgba[i][RCOMP] & 0x1f) <<  1)
435                      | ((rgba[i][ACOMP] & 0x1)       );
436            }
437         }
438         else {
439            GLushort *dst = (GLushort *) destination;
440            GLuint i;
441            ASSERT(format == GL_ABGR_EXT);
442            for (i = 0; i < n; i++) {
443               dst[i] = ((rgba[i][ACOMP] & 0x1f) << 11)
444                      | ((rgba[i][BCOMP] & 0x1f) <<  6)
445                      | ((rgba[i][GCOMP] & 0x1f) <<  1)
446                      | ((rgba[i][RCOMP] & 0x1)       );
447            }
448         }
449         break;
450      case GL_UNSIGNED_SHORT_1_5_5_5_REV:
451         if (format == GL_RGBA) {
452            GLushort *dst = (GLushort *) destination;
453            GLuint i;
454            for (i = 0; i < n; i++) {
455               dst[i] = ((rgba[i][ACOMP] & 0x1f) << 11)
456                      | ((rgba[i][BCOMP] & 0x1f) <<  6)
457                      | ((rgba[i][GCOMP] & 0x1f) <<  1)
458                      | ((rgba[i][RCOMP] & 0x1)       );
459            }
460         }
461         else if (format == GL_BGRA) {
462            GLushort *dst = (GLushort *) destination;
463            GLuint i;
464            for (i = 0; i < n; i++) {
465               dst[i] = ((rgba[i][ACOMP] & 0x1f) << 11)
466                      | ((rgba[i][RCOMP] & 0x1f) <<  6)
467                      | ((rgba[i][GCOMP] & 0x1f) <<  1)
468                      | ((rgba[i][BCOMP] & 0x1)       );
469            }
470         }
471         else {
472            GLushort *dst = (GLushort *) destination;
473            GLuint i;
474            ASSERT(format == GL_ABGR_EXT);
475            for (i = 0; i < n; i++) {
476               dst[i] = ((rgba[i][RCOMP] & 0x1f) << 11)
477                      | ((rgba[i][GCOMP] & 0x1f) <<  6)
478                      | ((rgba[i][BCOMP] & 0x1f) <<  1)
479                      | ((rgba[i][ACOMP] & 0x1)       );
480            }
481         }
482         break;
483      case GL_UNSIGNED_INT_8_8_8_8:
484         if (format == GL_RGBA) {
485            GLuint *dst = (GLuint *) destination;
486            GLuint i;
487            for (i = 0; i < n; i++) {
488               dst[i] = ((rgba[i][RCOMP] & 0xff) << 24)
489                      | ((rgba[i][GCOMP] & 0xff) << 16)
490                      | ((rgba[i][BCOMP] & 0xff) <<  8)
491                      | ((rgba[i][ACOMP] & 0xff)      );
492            }
493         }
494         else if (format == GL_BGRA) {
495            GLuint *dst = (GLuint *) destination;
496            GLuint i;
497            for (i = 0; i < n; i++) {
498               dst[i] = ((rgba[i][BCOMP] & 0xff) << 24)
499                      | ((rgba[i][GCOMP] & 0xff) << 16)
500                      | ((rgba[i][RCOMP] & 0xff) <<  8)
501                      | ((rgba[i][ACOMP] & 0xff)      );
502            }
503         }
504         else {
505            GLuint *dst = (GLuint *) destination;
506            GLuint i;
507            ASSERT(format == GL_ABGR_EXT);
508            for (i = 0; i < n; i++) {
509               dst[i] = ((rgba[i][ACOMP] & 0xff) << 24)
510                      | ((rgba[i][BCOMP] & 0xff) << 16)
511                      | ((rgba[i][GCOMP] & 0xff) <<  8)
512                      | ((rgba[i][RCOMP] & 0xff)      );
513            }
514         }
515         break;
516      case GL_UNSIGNED_INT_8_8_8_8_REV:
517         if (format == GL_RGBA) {
518            GLuint *dst = (GLuint *) destination;
519            GLuint i;
520            for (i = 0; i < n; i++) {
521               dst[i] = ((rgba[i][ACOMP] & 0xff) << 24)
522                      | ((rgba[i][BCOMP] & 0xff) << 16)
523                      | ((rgba[i][GCOMP] & 0xff) <<  8)
524                      | ((rgba[i][RCOMP] & 0xff)      );
525            }
526         }
527         else if (format == GL_BGRA) {
528            GLuint *dst = (GLuint *) destination;
529            GLuint i;
530            for (i = 0; i < n; i++) {
531               dst[i] = ((rgba[i][ACOMP] & 0xff) << 24)
532                      | ((rgba[i][RCOMP] & 0xff) << 16)
533                      | ((rgba[i][GCOMP] & 0xff) <<  8)
534                      | ((rgba[i][BCOMP] & 0xff)      );
535            }
536         }
537         else {
538            GLuint *dst = (GLuint *) destination;
539            GLuint i;
540            ASSERT(format == GL_ABGR_EXT);
541            for (i = 0; i < n; i++) {
542               dst[i] = ((rgba[i][RCOMP] & 0xff) << 24)
543                      | ((rgba[i][GCOMP] & 0xff) << 16)
544                      | ((rgba[i][BCOMP] & 0xff) <<  8)
545                      | ((rgba[i][ACOMP] & 0xff)      );
546            }
547         }
548         break;
549      case GL_UNSIGNED_INT_10_10_10_2:
550         if (format == GL_RGBA) {
551            GLuint *dst = (GLuint *) destination;
552            GLuint i;
553            for (i = 0; i < n; i++) {
554               dst[i] = ((rgba[i][RCOMP] & 0x3ff) << 22)
555                      | ((rgba[i][GCOMP] & 0x3ff) << 12)
556                      | ((rgba[i][BCOMP] & 0x3ff) <<  2)
557                      | ((rgba[i][ACOMP] & 0x3)        );
558            }
559         }
560         else if (format == GL_BGRA) {
561            GLuint *dst = (GLuint *) destination;
562            GLuint i;
563            for (i = 0; i < n; i++) {
564               dst[i] = ((rgba[i][BCOMP] & 0x3ff) << 22)
565                      | ((rgba[i][GCOMP] & 0x3ff) << 12)
566                      | ((rgba[i][RCOMP] & 0x3ff) <<  2)
567                      | ((rgba[i][ACOMP] & 0x3)        );
568            }
569         }
570         else {
571            GLuint *dst = (GLuint *) destination;
572            GLuint i;
573            ASSERT(format == GL_ABGR_EXT);
574            for (i = 0; i < n; i++) {
575               dst[i] = ((rgba[i][ACOMP] & 0x3ff) << 22)
576                      | ((rgba[i][BCOMP] & 0x3ff) << 12)
577                      | ((rgba[i][GCOMP] & 0x3ff) <<  2)
578                      | ((rgba[i][RCOMP] & 0x3)        );
579            }
580         }
581         break;
582      case GL_UNSIGNED_INT_2_10_10_10_REV:
583         if (format == GL_RGBA) {
584            GLuint *dst = (GLuint *) destination;
585            GLuint i;
586            for (i = 0; i < n; i++) {
587               dst[i] = ((rgba[i][ACOMP] & 0x3ff) << 22)
588                      | ((rgba[i][BCOMP] & 0x3ff) << 12)
589                      | ((rgba[i][GCOMP] & 0x3ff) <<  2)
590                      | ((rgba[i][RCOMP] & 0x3)        );
591            }
592         }
593         else if (format == GL_BGRA) {
594            GLuint *dst = (GLuint *) destination;
595            GLuint i;
596            for (i = 0; i < n; i++) {
597               dst[i] = ((rgba[i][ACOMP] & 0x3ff) << 22)
598                      | ((rgba[i][RCOMP] & 0x3ff) << 12)
599                      | ((rgba[i][GCOMP] & 0x3ff) <<  2)
600                      | ((rgba[i][BCOMP] & 0x3)        );
601            }
602         }
603         else {
604            GLuint *dst = (GLuint *) destination;
605            GLuint i;
606            ASSERT(format == GL_ABGR_EXT);
607            for (i = 0; i < n; i++) {
608               dst[i] = ((rgba[i][RCOMP] & 0x3ff) << 22)
609                      | ((rgba[i][GCOMP] & 0x3ff) << 12)
610                      | ((rgba[i][BCOMP] & 0x3ff) <<  2)
611                      | ((rgba[i][ACOMP] & 0x3)        );
612            }
613         }
614         break;
615      default:
616         _mesa_problem(ctx, "Bad type in pack_histogram");
617   }
618
619#undef PACK_MACRO
620}
621
622
623/*
624 * Given an internalFormat token passed to glHistogram or glMinMax,
625 * return the corresponding base format.
626 * Return -1 if invalid token.
627 */
628static GLint
629base_histogram_format( GLenum format )
630{
631   switch (format) {
632      case GL_ALPHA:
633      case GL_ALPHA4:
634      case GL_ALPHA8:
635      case GL_ALPHA12:
636      case GL_ALPHA16:
637         return GL_ALPHA;
638      case GL_LUMINANCE:
639      case GL_LUMINANCE4:
640      case GL_LUMINANCE8:
641      case GL_LUMINANCE12:
642      case GL_LUMINANCE16:
643         return GL_LUMINANCE;
644      case GL_LUMINANCE_ALPHA:
645      case GL_LUMINANCE4_ALPHA4:
646      case GL_LUMINANCE6_ALPHA2:
647      case GL_LUMINANCE8_ALPHA8:
648      case GL_LUMINANCE12_ALPHA4:
649      case GL_LUMINANCE12_ALPHA12:
650      case GL_LUMINANCE16_ALPHA16:
651         return GL_LUMINANCE_ALPHA;
652      case GL_RGB:
653      case GL_R3_G3_B2:
654      case GL_RGB4:
655      case GL_RGB5:
656      case GL_RGB8:
657      case GL_RGB10:
658      case GL_RGB12:
659      case GL_RGB16:
660         return GL_RGB;
661      case GL_RGBA:
662      case GL_RGBA2:
663      case GL_RGBA4:
664      case GL_RGB5_A1:
665      case GL_RGBA8:
666      case GL_RGB10_A2:
667      case GL_RGBA12:
668      case GL_RGBA16:
669         return GL_RGBA;
670      default:
671         return -1;  /* error */
672   }
673}
674
675
676
677/**********************************************************************
678 * API functions
679 */
680
681
682void GLAPIENTRY
683_mesa_GetMinmax(GLenum target, GLboolean reset, GLenum format, GLenum type, GLvoid *values)
684{
685   GET_CURRENT_CONTEXT(ctx);
686   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
687
688   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
689      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetMinmax");
690      return;
691   }
692
693   if (target != GL_MINMAX) {
694      _mesa_error(ctx, GL_INVALID_ENUM, "glGetMinmax(target)");
695      return;
696   }
697
698   if (format != GL_RED &&
699       format != GL_GREEN &&
700       format != GL_BLUE &&
701       format != GL_ALPHA &&
702       format != GL_RGB &&
703       format != GL_BGR &&
704       format != GL_RGBA &&
705       format != GL_BGRA &&
706       format != GL_ABGR_EXT &&
707       format != GL_LUMINANCE &&
708       format != GL_LUMINANCE_ALPHA) {
709      _mesa_error(ctx, GL_INVALID_ENUM, "glGetMinMax(format)");
710   }
711
712   if (!_mesa_is_legal_format_and_type(ctx, format, type)) {
713      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetMinmax(format or type)");
714      return;
715   }
716
717   if (ctx->Pack.BufferObj->Name) {
718      /* pack min/max values into a PBO */
719      GLubyte *buf;
720      if (!_mesa_validate_pbo_access(1, &ctx->Pack, 2, 1, 1,
721                                     format, type, values)) {
722         _mesa_error(ctx, GL_INVALID_OPERATION,
723                     "glGetMinMax(invalid PBO access)");
724         return;
725      }
726      buf = (GLubyte *) ctx->Driver.MapBuffer(ctx, GL_PIXEL_PACK_BUFFER_EXT,
727                                              GL_WRITE_ONLY_ARB,
728                                              ctx->Pack.BufferObj);
729      if (!buf) {
730         /* buffer is already mapped - that's an error */
731         _mesa_error(ctx, GL_INVALID_OPERATION,"glGetMinMax(PBO is mapped)");
732         return;
733      }
734      values = ADD_POINTERS(buf, values);
735   }
736   else if (!values) {
737      /* not an error */
738      return;
739   }
740
741   {
742      GLfloat minmax[2][4];
743      minmax[0][RCOMP] = CLAMP(ctx->MinMax.Min[RCOMP], 0.0F, 1.0F);
744      minmax[0][GCOMP] = CLAMP(ctx->MinMax.Min[GCOMP], 0.0F, 1.0F);
745      minmax[0][BCOMP] = CLAMP(ctx->MinMax.Min[BCOMP], 0.0F, 1.0F);
746      minmax[0][ACOMP] = CLAMP(ctx->MinMax.Min[ACOMP], 0.0F, 1.0F);
747      minmax[1][RCOMP] = CLAMP(ctx->MinMax.Max[RCOMP], 0.0F, 1.0F);
748      minmax[1][GCOMP] = CLAMP(ctx->MinMax.Max[GCOMP], 0.0F, 1.0F);
749      minmax[1][BCOMP] = CLAMP(ctx->MinMax.Max[BCOMP], 0.0F, 1.0F);
750      minmax[1][ACOMP] = CLAMP(ctx->MinMax.Max[ACOMP], 0.0F, 1.0F);
751      _mesa_pack_rgba_span_float(ctx, 2, minmax,
752                                 format, type, values, &ctx->Pack, 0x0);
753   }
754
755   if (ctx->Pack.BufferObj->Name) {
756      ctx->Driver.UnmapBuffer(ctx, GL_PIXEL_PACK_BUFFER_EXT,
757                              ctx->Pack.BufferObj);
758   }
759
760   if (reset) {
761      _mesa_ResetMinmax(GL_MINMAX);
762   }
763}
764
765
766void GLAPIENTRY
767_mesa_GetHistogram(GLenum target, GLboolean reset, GLenum format, GLenum type, GLvoid *values)
768{
769   GET_CURRENT_CONTEXT(ctx);
770   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
771
772   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
773      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetHistogram");
774      return;
775   }
776
777   if (target != GL_HISTOGRAM) {
778      _mesa_error(ctx, GL_INVALID_ENUM, "glGetHistogram(target)");
779      return;
780   }
781
782   if (format != GL_RED &&
783       format != GL_GREEN &&
784       format != GL_BLUE &&
785       format != GL_ALPHA &&
786       format != GL_RGB &&
787       format != GL_BGR &&
788       format != GL_RGBA &&
789       format != GL_BGRA &&
790       format != GL_ABGR_EXT &&
791       format != GL_LUMINANCE &&
792       format != GL_LUMINANCE_ALPHA) {
793      _mesa_error(ctx, GL_INVALID_ENUM, "glGetHistogram(format)");
794   }
795
796   if (!_mesa_is_legal_format_and_type(ctx, format, type)) {
797      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetHistogram(format or type)");
798      return;
799   }
800
801   if (ctx->Pack.BufferObj->Name) {
802      /* pack min/max values into a PBO */
803      GLubyte *buf;
804      if (!_mesa_validate_pbo_access(1, &ctx->Pack, ctx->Histogram.Width, 1, 1,
805                                     format, type, values)) {
806         _mesa_error(ctx, GL_INVALID_OPERATION,
807                     "glGetHistogram(invalid PBO access)");
808         return;
809      }
810      buf = (GLubyte *) ctx->Driver.MapBuffer(ctx, GL_PIXEL_PACK_BUFFER_EXT,
811                                              GL_WRITE_ONLY_ARB,
812                                              ctx->Pack.BufferObj);
813      if (!buf) {
814         /* buffer is already mapped - that's an error */
815         _mesa_error(ctx,GL_INVALID_OPERATION,"glGetHistogram(PBO is mapped)");
816         return;
817      }
818      values = ADD_POINTERS(buf, values);
819   }
820   else if (!values) {
821      /* not an error */
822      return;
823   }
824
825   pack_histogram(ctx, ctx->Histogram.Width,
826                  (CONST GLuint (*)[4]) ctx->Histogram.Count,
827                  format, type, values, &ctx->Pack);
828
829   if (ctx->Pack.BufferObj->Name) {
830      ctx->Driver.UnmapBuffer(ctx, GL_PIXEL_PACK_BUFFER_EXT,
831                              ctx->Pack.BufferObj);
832   }
833
834   if (reset) {
835      GLuint i;
836      for (i = 0; i < HISTOGRAM_TABLE_SIZE; i++) {
837         ctx->Histogram.Count[i][0] = 0;
838         ctx->Histogram.Count[i][1] = 0;
839         ctx->Histogram.Count[i][2] = 0;
840         ctx->Histogram.Count[i][3] = 0;
841      }
842   }
843}
844
845
846void GLAPIENTRY
847_mesa_GetHistogramParameterfv(GLenum target, GLenum pname, GLfloat *params)
848{
849   GET_CURRENT_CONTEXT(ctx);
850   ASSERT_OUTSIDE_BEGIN_END(ctx);
851
852   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
853      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetHistogramParameterfv");
854      return;
855   }
856
857   if (target != GL_HISTOGRAM && target != GL_PROXY_HISTOGRAM) {
858      _mesa_error(ctx, GL_INVALID_ENUM, "glGetHistogramParameterfv(target)");
859      return;
860   }
861
862   switch (pname) {
863      case GL_HISTOGRAM_WIDTH:
864         *params = (GLfloat) ctx->Histogram.Width;
865         break;
866      case GL_HISTOGRAM_FORMAT:
867         *params = (GLfloat) ctx->Histogram.Format;
868         break;
869      case GL_HISTOGRAM_RED_SIZE:
870         *params = (GLfloat) ctx->Histogram.RedSize;
871         break;
872      case GL_HISTOGRAM_GREEN_SIZE:
873         *params = (GLfloat) ctx->Histogram.GreenSize;
874         break;
875      case GL_HISTOGRAM_BLUE_SIZE:
876         *params = (GLfloat) ctx->Histogram.BlueSize;
877         break;
878      case GL_HISTOGRAM_ALPHA_SIZE:
879         *params = (GLfloat) ctx->Histogram.AlphaSize;
880         break;
881      case GL_HISTOGRAM_LUMINANCE_SIZE:
882         *params = (GLfloat) ctx->Histogram.LuminanceSize;
883         break;
884      case GL_HISTOGRAM_SINK:
885         *params = (GLfloat) ctx->Histogram.Sink;
886         break;
887      default:
888         _mesa_error(ctx, GL_INVALID_ENUM, "glGetHistogramParameterfv(pname)");
889   }
890}
891
892
893void GLAPIENTRY
894_mesa_GetHistogramParameteriv(GLenum target, GLenum pname, GLint *params)
895{
896   GET_CURRENT_CONTEXT(ctx);
897   ASSERT_OUTSIDE_BEGIN_END(ctx);
898
899   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
900      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetHistogramParameteriv");
901      return;
902   }
903
904   if (target != GL_HISTOGRAM && target != GL_PROXY_HISTOGRAM) {
905      _mesa_error(ctx, GL_INVALID_ENUM, "glGetHistogramParameteriv(target)");
906      return;
907   }
908
909   switch (pname) {
910      case GL_HISTOGRAM_WIDTH:
911         *params = (GLint) ctx->Histogram.Width;
912         break;
913      case GL_HISTOGRAM_FORMAT:
914         *params = (GLint) ctx->Histogram.Format;
915         break;
916      case GL_HISTOGRAM_RED_SIZE:
917         *params = (GLint) ctx->Histogram.RedSize;
918         break;
919      case GL_HISTOGRAM_GREEN_SIZE:
920         *params = (GLint) ctx->Histogram.GreenSize;
921         break;
922      case GL_HISTOGRAM_BLUE_SIZE:
923         *params = (GLint) ctx->Histogram.BlueSize;
924         break;
925      case GL_HISTOGRAM_ALPHA_SIZE:
926         *params = (GLint) ctx->Histogram.AlphaSize;
927         break;
928      case GL_HISTOGRAM_LUMINANCE_SIZE:
929         *params = (GLint) ctx->Histogram.LuminanceSize;
930         break;
931      case GL_HISTOGRAM_SINK:
932         *params = (GLint) ctx->Histogram.Sink;
933         break;
934      default:
935         _mesa_error(ctx, GL_INVALID_ENUM, "glGetHistogramParameteriv(pname)");
936   }
937}
938
939
940void GLAPIENTRY
941_mesa_GetMinmaxParameterfv(GLenum target, GLenum pname, GLfloat *params)
942{
943   GET_CURRENT_CONTEXT(ctx);
944   ASSERT_OUTSIDE_BEGIN_END(ctx);
945
946   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
947      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetMinmaxParameterfv");
948      return;
949   }
950   if (target != GL_MINMAX) {
951      _mesa_error(ctx, GL_INVALID_ENUM, "glGetMinmaxParameterfv(target)");
952      return;
953   }
954   if (pname == GL_MINMAX_FORMAT) {
955      *params = (GLfloat) ctx->MinMax.Format;
956   }
957   else if (pname == GL_MINMAX_SINK) {
958      *params = (GLfloat) ctx->MinMax.Sink;
959   }
960   else {
961      _mesa_error(ctx, GL_INVALID_ENUM, "glGetMinMaxParameterfv(pname)");
962   }
963}
964
965
966void GLAPIENTRY
967_mesa_GetMinmaxParameteriv(GLenum target, GLenum pname, GLint *params)
968{
969   GET_CURRENT_CONTEXT(ctx);
970   ASSERT_OUTSIDE_BEGIN_END(ctx);
971
972   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
973      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetMinmaxParameteriv");
974      return;
975   }
976   if (target != GL_MINMAX) {
977      _mesa_error(ctx, GL_INVALID_ENUM, "glGetMinmaxParameteriv(target)");
978      return;
979   }
980   if (pname == GL_MINMAX_FORMAT) {
981      *params = (GLint) ctx->MinMax.Format;
982   }
983   else if (pname == GL_MINMAX_SINK) {
984      *params = (GLint) ctx->MinMax.Sink;
985   }
986   else {
987      _mesa_error(ctx, GL_INVALID_ENUM, "glGetMinMaxParameteriv(pname)");
988   }
989}
990
991
992void GLAPIENTRY
993_mesa_Histogram(GLenum target, GLsizei width, GLenum internalFormat, GLboolean sink)
994{
995   GLuint i;
996   GLboolean error = GL_FALSE;
997   GET_CURRENT_CONTEXT(ctx);
998   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* sideeffects */
999
1000   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
1001      _mesa_error(ctx, GL_INVALID_OPERATION, "glHistogram");
1002      return;
1003   }
1004
1005   if (target != GL_HISTOGRAM && target != GL_PROXY_HISTOGRAM) {
1006      _mesa_error(ctx, GL_INVALID_ENUM, "glHistogram(target)");
1007      return;
1008   }
1009
1010   if (width < 0 || width > HISTOGRAM_TABLE_SIZE) {
1011      if (target == GL_PROXY_HISTOGRAM) {
1012         error = GL_TRUE;
1013      }
1014      else {
1015         if (width < 0)
1016            _mesa_error(ctx, GL_INVALID_VALUE, "glHistogram(width)");
1017         else
1018            _mesa_error(ctx, GL_TABLE_TOO_LARGE, "glHistogram(width)");
1019         return;
1020      }
1021   }
1022
1023   if (width != 0 && _mesa_bitcount(width) != 1) {
1024      if (target == GL_PROXY_HISTOGRAM) {
1025         error = GL_TRUE;
1026      }
1027      else {
1028         _mesa_error(ctx, GL_INVALID_VALUE, "glHistogram(width)");
1029         return;
1030      }
1031   }
1032
1033   if (base_histogram_format(internalFormat) < 0) {
1034      if (target == GL_PROXY_HISTOGRAM) {
1035         error = GL_TRUE;
1036      }
1037      else {
1038         _mesa_error(ctx, GL_INVALID_ENUM, "glHistogram(internalFormat)");
1039         return;
1040      }
1041   }
1042
1043   /* reset histograms */
1044   for (i = 0; i < HISTOGRAM_TABLE_SIZE; i++) {
1045      ctx->Histogram.Count[i][0] = 0;
1046      ctx->Histogram.Count[i][1] = 0;
1047      ctx->Histogram.Count[i][2] = 0;
1048      ctx->Histogram.Count[i][3] = 0;
1049   }
1050
1051   if (error) {
1052      ctx->Histogram.Width = 0;
1053      ctx->Histogram.Format = 0;
1054      ctx->Histogram.RedSize       = 0;
1055      ctx->Histogram.GreenSize     = 0;
1056      ctx->Histogram.BlueSize      = 0;
1057      ctx->Histogram.AlphaSize     = 0;
1058      ctx->Histogram.LuminanceSize = 0;
1059   }
1060   else {
1061      ctx->Histogram.Width = width;
1062      ctx->Histogram.Format = internalFormat;
1063      ctx->Histogram.Sink = sink;
1064      ctx->Histogram.RedSize       = 8 * sizeof(GLuint);
1065      ctx->Histogram.GreenSize     = 8 * sizeof(GLuint);
1066      ctx->Histogram.BlueSize      = 8 * sizeof(GLuint);
1067      ctx->Histogram.AlphaSize     = 8 * sizeof(GLuint);
1068      ctx->Histogram.LuminanceSize = 8 * sizeof(GLuint);
1069   }
1070
1071   ctx->NewState |= _NEW_PIXEL;
1072}
1073
1074
1075void GLAPIENTRY
1076_mesa_Minmax(GLenum target, GLenum internalFormat, GLboolean sink)
1077{
1078   GET_CURRENT_CONTEXT(ctx);
1079   ASSERT_OUTSIDE_BEGIN_END(ctx);
1080
1081   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
1082      _mesa_error(ctx, GL_INVALID_OPERATION, "glMinmax");
1083      return;
1084   }
1085
1086   if (target != GL_MINMAX) {
1087      _mesa_error(ctx, GL_INVALID_ENUM, "glMinMax(target)");
1088      return;
1089   }
1090
1091   if (base_histogram_format(internalFormat) < 0) {
1092      _mesa_error(ctx, GL_INVALID_ENUM, "glMinMax(internalFormat)");
1093      return;
1094   }
1095
1096   if (ctx->MinMax.Sink == sink)
1097      return;
1098   FLUSH_VERTICES(ctx, _NEW_PIXEL);
1099   ctx->MinMax.Sink = sink;
1100}
1101
1102
1103void GLAPIENTRY
1104_mesa_ResetHistogram(GLenum target)
1105{
1106   GLuint i;
1107   GET_CURRENT_CONTEXT(ctx);
1108   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* sideeffects */
1109
1110   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
1111      _mesa_error(ctx, GL_INVALID_OPERATION, "glResetHistogram");
1112      return;
1113   }
1114
1115   if (target != GL_HISTOGRAM) {
1116      _mesa_error(ctx, GL_INVALID_ENUM, "glResetHistogram(target)");
1117      return;
1118   }
1119
1120   for (i = 0; i < HISTOGRAM_TABLE_SIZE; i++) {
1121      ctx->Histogram.Count[i][0] = 0;
1122      ctx->Histogram.Count[i][1] = 0;
1123      ctx->Histogram.Count[i][2] = 0;
1124      ctx->Histogram.Count[i][3] = 0;
1125   }
1126
1127   ctx->NewState |= _NEW_PIXEL;
1128}
1129
1130
1131void GLAPIENTRY
1132_mesa_ResetMinmax(GLenum target)
1133{
1134   GET_CURRENT_CONTEXT(ctx);
1135   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
1136
1137   if (!ctx->Extensions.EXT_histogram && !ctx->Extensions.ARB_imaging) {
1138      _mesa_error(ctx, GL_INVALID_OPERATION, "glResetMinmax");
1139      return;
1140   }
1141
1142   if (target != GL_MINMAX) {
1143      _mesa_error(ctx, GL_INVALID_ENUM, "glResetMinMax(target)");
1144      return;
1145   }
1146
1147   ctx->MinMax.Min[RCOMP] = 1000;    ctx->MinMax.Max[RCOMP] = -1000;
1148   ctx->MinMax.Min[GCOMP] = 1000;    ctx->MinMax.Max[GCOMP] = -1000;
1149   ctx->MinMax.Min[BCOMP] = 1000;    ctx->MinMax.Max[BCOMP] = -1000;
1150   ctx->MinMax.Min[ACOMP] = 1000;    ctx->MinMax.Max[ACOMP] = -1000;
1151   ctx->NewState |= _NEW_PIXEL;
1152}
1153
1154
1155
1156/**********************************************************************/
1157/*****                      Initialization                        *****/
1158/**********************************************************************/
1159
1160void _mesa_init_histogram( GLcontext * ctx )
1161{
1162   int i;
1163
1164   /* Histogram group */
1165   ctx->Histogram.Width = 0;
1166   ctx->Histogram.Format = GL_RGBA;
1167   ctx->Histogram.Sink = GL_FALSE;
1168   ctx->Histogram.RedSize       = 0;
1169   ctx->Histogram.GreenSize     = 0;
1170   ctx->Histogram.BlueSize      = 0;
1171   ctx->Histogram.AlphaSize     = 0;
1172   ctx->Histogram.LuminanceSize = 0;
1173   for (i = 0; i < HISTOGRAM_TABLE_SIZE; i++) {
1174      ctx->Histogram.Count[i][0] = 0;
1175      ctx->Histogram.Count[i][1] = 0;
1176      ctx->Histogram.Count[i][2] = 0;
1177      ctx->Histogram.Count[i][3] = 0;
1178   }
1179
1180   /* Min/Max group */
1181   ctx->MinMax.Format = GL_RGBA;
1182   ctx->MinMax.Sink = GL_FALSE;
1183   ctx->MinMax.Min[RCOMP] = 1000;    ctx->MinMax.Max[RCOMP] = -1000;
1184   ctx->MinMax.Min[GCOMP] = 1000;    ctx->MinMax.Max[GCOMP] = -1000;
1185   ctx->MinMax.Min[BCOMP] = 1000;    ctx->MinMax.Max[BCOMP] = -1000;
1186   ctx->MinMax.Min[ACOMP] = 1000;    ctx->MinMax.Max[ACOMP] = -1000;
1187}
1188