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
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
|
/* $Id: accum.c,v 1.24 2000/09/07 15:45:26 brianp Exp $ */
/*
* Mesa 3-D graphics library
* Version: 3.3
*
* Copyright (C) 1999-2000 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifdef PC_HEADER
#include "all.h"
#else
#include "glheader.h"
#include "accum.h"
#include "context.h"
#include "mem.h"
#include "masking.h"
#include "span.h"
#include "state.h"
#include "types.h"
#endif
/*
* Accumulation buffer notes
*
* Normally, accumulation buffer values are GLshorts with values in
* [-32767, 32767] which represent floating point colors in [-1, 1],
* as suggested by the OpenGL specification.
*
* We optimize for the common case used for full-scene antialiasing:
* // start with accum buffer cleared to zero
* glAccum(GL_LOAD, w); // or GL_ACCUM the first image
* glAccum(GL_ACCUM, w);
* ...
* glAccum(GL_ACCUM, w);
* glAccum(GL_RETURN, 1.0);
* That is, we start with an empty accumulation buffer and accumulate
* n images, each with weight w = 1/n.
* In this scenario, we can simply store unscaled integer values in
* the accum buffer instead of scaled integers. We'll also keep track
* of the w value so when we do GL_RETURN we simply divide the accumulated
* values by n (=1/w).
* This lets us avoid _many_ int->float->int conversions.
*/
#define USE_OPTIMIZED_ACCUM /* enable the optimization */
void
_mesa_alloc_accum_buffer( GLcontext *ctx )
{
GLint n;
if (ctx->DrawBuffer->Accum) {
FREE( ctx->DrawBuffer->Accum );
ctx->DrawBuffer->Accum = NULL;
}
/* allocate accumulation buffer if not already present */
n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height * 4 * sizeof(GLaccum);
ctx->DrawBuffer->Accum = (GLaccum *) MALLOC( n );
if (!ctx->DrawBuffer->Accum) {
/* unable to setup accumulation buffer */
gl_error( ctx, GL_OUT_OF_MEMORY, "glAccum" );
}
#ifdef USE_OPTIMIZED_ACCUM
ctx->IntegerAccumMode = GL_TRUE;
#else
ctx->IntegerAccumMode = GL_FALSE;
#endif
ctx->IntegerAccumScaler = 0.0;
}
void
_mesa_ClearAccum( GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
{
GET_CURRENT_CONTEXT(ctx);
ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
ctx->Accum.ClearColor[0] = CLAMP( red, -1.0, 1.0 );
ctx->Accum.ClearColor[1] = CLAMP( green, -1.0, 1.0 );
ctx->Accum.ClearColor[2] = CLAMP( blue, -1.0, 1.0 );
ctx->Accum.ClearColor[3] = CLAMP( alpha, -1.0, 1.0 );
}
/*
* This is called when we fall out of optimized/unscaled accum buffer mode.
* That is, we convert each unscaled accum buffer value into a scaled value
* representing the range[-1, 1].
*/
static void rescale_accum( GLcontext *ctx )
{
const GLuint n = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height * 4;
const GLfloat fChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
const GLfloat s = ctx->IntegerAccumScaler * (32767.0 / fChanMax);
GLaccum *accum = ctx->DrawBuffer->Accum;
GLuint i;
assert(ctx->IntegerAccumMode);
assert(accum);
for (i = 0; i < n; i++) {
accum[i] = (GLaccum) (accum[i] * s);
}
ctx->IntegerAccumMode = GL_FALSE;
}
void
_mesa_Accum( GLenum op, GLfloat value )
{
GET_CURRENT_CONTEXT(ctx);
GLuint xpos, ypos, width, height, width4;
GLfloat acc_scale;
GLubyte rgba[MAX_WIDTH][4];
const GLuint colorMask = *((GLuint *) &ctx->Color.ColorMask);
const GLint iChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
const GLfloat fChanMax = (1 << (sizeof(GLchan) * 8)) - 1;
ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
if (ctx->Visual->AccumRedBits == 0 || ctx->DrawBuffer != ctx->ReadBuffer) {
gl_error(ctx, GL_INVALID_OPERATION, "glAccum");
return;
}
if (!ctx->DrawBuffer->Accum) {
gl_warning(ctx, "Calling glAccum() without an accumulation buffer (low memory?)");
return;
}
if (sizeof(GLaccum)==1) {
acc_scale = 127.0;
}
else if (sizeof(GLaccum)==2) {
acc_scale = 32767.0;
}
else {
/* sizeof(GLaccum) > 2 (Cray) */
acc_scale = (float) SHRT_MAX;
}
if (ctx->NewState)
gl_update_state( ctx );
/* Determine region to operate upon. */
if (ctx->Scissor.Enabled) {
xpos = ctx->Scissor.X;
ypos = ctx->Scissor.Y;
width = ctx->Scissor.Width;
height = ctx->Scissor.Height;
}
else {
/* whole window */
xpos = 0;
ypos = 0;
width = ctx->DrawBuffer->Width;
height = ctx->DrawBuffer->Height;
}
width4 = 4 * width;
switch (op) {
case GL_ADD:
if (value != 0.0F) {
const GLaccum intVal = (GLaccum) (value * acc_scale);
GLuint j;
/* Leave optimized accum buffer mode */
if (ctx->IntegerAccumMode)
rescale_accum(ctx);
for (j = 0; j < height; j++) {
GLaccum * acc = ctx->DrawBuffer->Accum + ypos * width4 + 4 * xpos;
GLuint i;
for (i = 0; i < width4; i++) {
acc[i] += intVal;
}
ypos++;
}
}
break;
case GL_MULT:
if (value != 1.0F) {
GLuint j;
/* Leave optimized accum buffer mode */
if (ctx->IntegerAccumMode)
rescale_accum(ctx);
for (j = 0; j < height; j++) {
GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + 4 * xpos;
GLuint i;
for (i = 0; i < width4; i++) {
acc[i] = (GLaccum) ( (GLfloat) acc[i] * value );
}
ypos++;
}
}
break;
case GL_ACCUM:
if (value == 0.0F)
return;
(*ctx->Driver.SetReadBuffer)( ctx, ctx->ReadBuffer,
ctx->Pixel.DriverReadBuffer );
/* May have to leave optimized accum buffer mode */
if (ctx->IntegerAccumScaler == 0.0 && value > 0.0 && value <= 1.0)
ctx->IntegerAccumScaler = value;
if (ctx->IntegerAccumMode && value != ctx->IntegerAccumScaler)
rescale_accum(ctx);
if (ctx->IntegerAccumMode) {
/* simply add integer color values into accum buffer */
GLuint j;
GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
assert(ctx->IntegerAccumScaler > 0.0);
assert(ctx->IntegerAccumScaler <= 1.0);
for (j = 0; j < height; j++) {
GLuint i, i4;
gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
for (i = i4 = 0; i < width; i++, i4+=4) {
acc[i4+0] += rgba[i][RCOMP];
acc[i4+1] += rgba[i][GCOMP];
acc[i4+2] += rgba[i][BCOMP];
acc[i4+3] += rgba[i][ACOMP];
}
acc += width4;
ypos++;
}
}
else {
/* scaled integer accum buffer */
const GLfloat rscale = value * acc_scale / fChanMax;
const GLfloat gscale = value * acc_scale / fChanMax;
const GLfloat bscale = value * acc_scale / fChanMax;
const GLfloat ascale = value * acc_scale / fChanMax;
GLuint j;
for (j=0;j<height;j++) {
GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
GLuint i;
gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
for (i=0;i<width;i++) {
*acc += (GLaccum) ( (GLfloat) rgba[i][RCOMP] * rscale ); acc++;
*acc += (GLaccum) ( (GLfloat) rgba[i][GCOMP] * gscale ); acc++;
*acc += (GLaccum) ( (GLfloat) rgba[i][BCOMP] * bscale ); acc++;
*acc += (GLaccum) ( (GLfloat) rgba[i][ACOMP] * ascale ); acc++;
}
ypos++;
}
}
/* restore read buffer = draw buffer (the default) */
(*ctx->Driver.SetReadBuffer)( ctx, ctx->DrawBuffer,
ctx->Color.DriverDrawBuffer );
break;
case GL_LOAD:
(*ctx->Driver.SetReadBuffer)( ctx, ctx->ReadBuffer,
ctx->Pixel.DriverReadBuffer );
/* This is a change to go into optimized accum buffer mode */
if (value > 0.0 && value <= 1.0) {
#ifdef USE_OPTIMIZED_ACCUM
ctx->IntegerAccumMode = GL_TRUE;
#else
ctx->IntegerAccumMode = GL_FALSE;
#endif
ctx->IntegerAccumScaler = value;
}
else {
ctx->IntegerAccumMode = GL_FALSE;
ctx->IntegerAccumScaler = 0.0;
}
if (ctx->IntegerAccumMode) {
/* just copy values into accum buffer */
GLuint j;
GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
assert(ctx->IntegerAccumScaler > 0.0);
assert(ctx->IntegerAccumScaler <= 1.0);
for (j = 0; j < height; j++) {
GLuint i, i4;
gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
for (i = i4 = 0; i < width; i++, i4 += 4) {
acc[i4+0] = rgba[i][RCOMP];
acc[i4+1] = rgba[i][GCOMP];
acc[i4+2] = rgba[i][BCOMP];
acc[i4+3] = rgba[i][ACOMP];
}
acc += width4;
ypos++;
}
}
else {
/* scaled integer accum buffer */
const GLfloat rscale = value * acc_scale / fChanMax;
const GLfloat gscale = value * acc_scale / fChanMax;
const GLfloat bscale = value * acc_scale / fChanMax;
const GLfloat ascale = value * acc_scale / fChanMax;
const GLfloat d = 3.0 / acc_scale;
GLuint i, j;
for (j = 0; j < height; j++) {
GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos * 4;
gl_read_rgba_span(ctx, ctx->DrawBuffer, width, xpos, ypos, rgba);
for (i=0;i<width;i++) {
*acc++ = (GLaccum) ((GLfloat) rgba[i][RCOMP] * rscale + d);
*acc++ = (GLaccum) ((GLfloat) rgba[i][GCOMP] * gscale + d);
*acc++ = (GLaccum) ((GLfloat) rgba[i][BCOMP] * bscale + d);
*acc++ = (GLaccum) ((GLfloat) rgba[i][ACOMP] * ascale + d);
}
ypos++;
}
}
/* restore read buffer = draw buffer (the default) */
(*ctx->Driver.SetReadBuffer)( ctx, ctx->DrawBuffer,
ctx->Color.DriverDrawBuffer );
break;
case GL_RETURN:
/* May have to leave optimized accum buffer mode */
if (ctx->IntegerAccumMode && value != 1.0)
rescale_accum(ctx);
if (ctx->IntegerAccumMode && ctx->IntegerAccumScaler > 0) {
/* build lookup table to avoid many floating point multiplies */
static GLchan multTable[32768];
static GLfloat prevMult = 0.0;
const GLfloat mult = ctx->IntegerAccumScaler;
const GLint max = MIN2((GLint) (256 / mult), 32767);
GLuint j;
if (mult != prevMult) {
for (j = 0; j < max; j++)
multTable[j] = (GLint) ((GLfloat) j * mult + 0.5F);
prevMult = mult;
}
assert(ctx->IntegerAccumScaler > 0.0);
assert(ctx->IntegerAccumScaler <= 1.0);
for (j = 0; j < height; j++) {
const GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos*4;
GLuint i, i4;
for (i = i4 = 0; i < width; i++, i4 += 4) {
ASSERT(acc[i4+0] < max);
ASSERT(acc[i4+1] < max);
ASSERT(acc[i4+2] < max);
ASSERT(acc[i4+3] < max);
rgba[i][RCOMP] = multTable[acc[i4+0]];
rgba[i][GCOMP] = multTable[acc[i4+1]];
rgba[i][BCOMP] = multTable[acc[i4+2]];
rgba[i][ACOMP] = multTable[acc[i4+3]];
}
if (colorMask != 0xffffffff) {
_mesa_mask_rgba_span( ctx, width, xpos, ypos, rgba );
}
(*ctx->Driver.WriteRGBASpan)( ctx, width, xpos, ypos,
(const GLubyte (*)[4])rgba, NULL );
ypos++;
}
}
else {
const GLfloat rscale = value / acc_scale * fChanMax;
const GLfloat gscale = value / acc_scale * fChanMax;
const GLfloat bscale = value / acc_scale * fChanMax;
const GLfloat ascale = value / acc_scale * fChanMax;
GLuint i, j;
for (j=0;j<height;j++) {
const GLaccum *acc = ctx->DrawBuffer->Accum + ypos * width4 + xpos*4;
for (i=0;i<width;i++) {
GLint r, g, b, a;
r = (GLint) ( (GLfloat) (*acc++) * rscale + 0.5F );
g = (GLint) ( (GLfloat) (*acc++) * gscale + 0.5F );
b = (GLint) ( (GLfloat) (*acc++) * bscale + 0.5F );
a = (GLint) ( (GLfloat) (*acc++) * ascale + 0.5F );
rgba[i][RCOMP] = CLAMP( r, 0, iChanMax );
rgba[i][GCOMP] = CLAMP( g, 0, iChanMax );
rgba[i][BCOMP] = CLAMP( b, 0, iChanMax );
rgba[i][ACOMP] = CLAMP( a, 0, iChanMax );
}
if (colorMask != 0xffffffff) {
_mesa_mask_rgba_span( ctx, width, xpos, ypos, rgba );
}
(*ctx->Driver.WriteRGBASpan)( ctx, width, xpos, ypos,
(const GLubyte (*)[4])rgba, NULL );
ypos++;
}
}
break;
default:
gl_error( ctx, GL_INVALID_ENUM, "glAccum" );
}
}
/*
* Clear the accumulation Buffer.
*/
void
_mesa_clear_accum_buffer( GLcontext *ctx )
{
GLuint buffersize;
GLfloat acc_scale;
if (ctx->Visual->AccumRedBits==0) {
/* No accumulation buffer! */
return;
}
if (sizeof(GLaccum)==1) {
acc_scale = 127.0;
}
else if (sizeof(GLaccum)==2) {
acc_scale = 32767.0;
}
else {
/* sizeof(GLaccum) > 2 (Cray) */
acc_scale = (float) SHRT_MAX;
}
/* number of pixels */
buffersize = ctx->DrawBuffer->Width * ctx->DrawBuffer->Height;
if (!ctx->DrawBuffer->Accum) {
/* try to alloc accumulation buffer */
ctx->DrawBuffer->Accum = (GLaccum *)
MALLOC( buffersize * 4 * sizeof(GLaccum) );
}
if (ctx->DrawBuffer->Accum) {
if (ctx->Scissor.Enabled) {
/* Limit clear to scissor box */
GLaccum r, g, b, a;
GLint i, j;
GLint width, height;
GLaccum *row;
r = (GLaccum) (ctx->Accum.ClearColor[0] * acc_scale);
g = (GLaccum) (ctx->Accum.ClearColor[1] * acc_scale);
b = (GLaccum) (ctx->Accum.ClearColor[2] * acc_scale);
a = (GLaccum) (ctx->Accum.ClearColor[3] * acc_scale);
/* size of region to clear */
width = 4 * (ctx->DrawBuffer->Xmax - ctx->DrawBuffer->Xmin + 1);
height = ctx->DrawBuffer->Ymax - ctx->DrawBuffer->Ymin + 1;
/* ptr to first element to clear */
row = ctx->DrawBuffer->Accum
+ 4 * (ctx->DrawBuffer->Ymin * ctx->DrawBuffer->Width
+ ctx->DrawBuffer->Xmin);
for (j=0;j<height;j++) {
for (i=0;i<width;i+=4) {
row[i+0] = r;
row[i+1] = g;
row[i+2] = b;
row[i+3] = a;
}
row += 4 * ctx->DrawBuffer->Width;
}
}
else {
/* clear whole buffer */
if (ctx->Accum.ClearColor[0]==0.0 &&
ctx->Accum.ClearColor[1]==0.0 &&
ctx->Accum.ClearColor[2]==0.0 &&
ctx->Accum.ClearColor[3]==0.0) {
/* Black */
BZERO( ctx->DrawBuffer->Accum, buffersize * 4 * sizeof(GLaccum) );
}
else {
/* Not black */
GLaccum *acc, r, g, b, a;
GLuint i;
acc = ctx->DrawBuffer->Accum;
r = (GLaccum) (ctx->Accum.ClearColor[0] * acc_scale);
g = (GLaccum) (ctx->Accum.ClearColor[1] * acc_scale);
b = (GLaccum) (ctx->Accum.ClearColor[2] * acc_scale);
a = (GLaccum) (ctx->Accum.ClearColor[3] * acc_scale);
for (i=0;i<buffersize;i++) {
*acc++ = r;
*acc++ = g;
*acc++ = b;
*acc++ = a;
}
}
}
/* update optimized accum state vars */
if (ctx->Accum.ClearColor[0] == 0.0 && ctx->Accum.ClearColor[1] == 0.0 &&
ctx->Accum.ClearColor[2] == 0.0 && ctx->Accum.ClearColor[3] == 0.0) {
#ifdef USE_OPTIMIZED_ACCUM
ctx->IntegerAccumMode = GL_TRUE;
#else
ctx->IntegerAccumMode = GL_FALSE;
#endif
ctx->IntegerAccumScaler = 0.0; /* denotes empty accum buffer */
}
else {
ctx->IntegerAccumMode = GL_FALSE;
}
}
}
|