2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
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:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
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.
26 #include "main/glheader.h"
27 #include "main/context.h"
28 #include "main/macros.h"
29 #include "main/imports.h"
30 #include "main/fbobject.h"
33 #include "s_context.h"
34 #include "s_masking.h"
38 /* XXX this would have to change for accum buffers with more or less
39 * than 16 bits per color channel.
41 #define ACCUM_SCALE16 32767.0
45 * Accumulation buffer notes
47 * Normally, accumulation buffer values are GLshorts with values in
48 * [-32767, 32767] which represent floating point colors in [-1, 1],
49 * as defined by the OpenGL specification.
51 * We optimize for the common case used for full-scene antialiasing:
52 * // start with accum buffer cleared to zero
53 * glAccum(GL_LOAD, w); // or GL_ACCUM the first image
54 * glAccum(GL_ACCUM, w);
56 * glAccum(GL_ACCUM, w);
57 * glAccum(GL_RETURN, 1.0);
58 * That is, we start with an empty accumulation buffer and accumulate
59 * n images, each with weight w = 1/n.
60 * In this scenario, we can simply store unscaled integer values in
61 * the accum buffer instead of scaled integers. We'll also keep track
62 * of the w value so when we do GL_RETURN we simply divide the accumulated
63 * values by n (n=1/w).
64 * This lets us avoid _many_ int->float->int conversions.
69 /* enable the optimization */
70 #define USE_OPTIMIZED_ACCUM 1
72 #define USE_OPTIMIZED_ACCUM 0
77 * This is called when we fall out of optimized/unscaled accum buffer mode.
78 * That is, we convert each unscaled accum buffer value into a scaled value
79 * representing the range[-1, 1].
82 rescale_accum( GLcontext *ctx )
84 SWcontext *swrast = SWRAST_CONTEXT(ctx);
85 struct gl_renderbuffer *rb
86 = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
87 const GLfloat s = swrast->_IntegerAccumScaler * (32767.0F / CHAN_MAXF);
90 assert(rb->_BaseFormat == GL_RGBA);
91 /* add other types in future? */
92 assert(rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT);
93 assert(swrast->_IntegerAccumMode);
95 if (rb->GetPointer(ctx, rb, 0, 0)) {
96 /* directly-addressable memory */
98 for (y = 0; y < rb->Height; y++) {
100 GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, 0, y);
101 for (i = 0; i < 4 * rb->Width; i++) {
102 acc[i] = (GLshort) (acc[i] * s);
107 /* use get/put row funcs */
109 for (y = 0; y < rb->Height; y++) {
110 GLshort accRow[MAX_WIDTH * 4];
112 rb->GetRow(ctx, rb, rb->Width, 0, y, accRow);
113 for (i = 0; i < 4 * rb->Width; i++) {
114 accRow[i] = (GLshort) (accRow[i] * s);
116 rb->PutRow(ctx, rb, rb->Width, 0, y, accRow, NULL);
120 swrast->_IntegerAccumMode = GL_FALSE;
126 * Clear the accumulation Buffer.
129 _swrast_clear_accum_buffer( GLcontext *ctx, struct gl_renderbuffer *rb )
131 SWcontext *swrast = SWRAST_CONTEXT(ctx);
132 GLuint x, y, width, height;
134 if (ctx->Visual.accumRedBits == 0) {
135 /* No accumulation buffer! Not an error. */
139 if (!rb || !rb->Data)
142 assert(rb->_BaseFormat == GL_RGBA);
143 /* add other types in future? */
144 assert(rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT);
146 /* bounds, with scissor */
147 x = ctx->DrawBuffer->_Xmin;
148 y = ctx->DrawBuffer->_Ymin;
149 width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
150 height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
152 if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
153 const GLfloat accScale = 32767.0;
157 clearVal[0] = (GLshort) (ctx->Accum.ClearColor[0] * accScale);
158 clearVal[1] = (GLshort) (ctx->Accum.ClearColor[1] * accScale);
159 clearVal[2] = (GLshort) (ctx->Accum.ClearColor[2] * accScale);
160 clearVal[3] = (GLshort) (ctx->Accum.ClearColor[3] * accScale);
162 for (i = 0; i < height; i++) {
163 rb->PutMonoRow(ctx, rb, width, x, y + i, clearVal, NULL);
167 /* someday support other sizes */
170 /* update optimized accum state vars */
171 if (ctx->Accum.ClearColor[0] == 0.0 && ctx->Accum.ClearColor[1] == 0.0 &&
172 ctx->Accum.ClearColor[2] == 0.0 && ctx->Accum.ClearColor[3] == 0.0) {
173 #if USE_OPTIMIZED_ACCUM
174 swrast->_IntegerAccumMode = GL_TRUE;
176 swrast->_IntegerAccumMode = GL_FALSE;
178 swrast->_IntegerAccumScaler = 0.0; /* denotes empty accum buffer */
181 swrast->_IntegerAccumMode = GL_FALSE;
187 accum_add(GLcontext *ctx, GLfloat value,
188 GLint xpos, GLint ypos, GLint width, GLint height )
190 SWcontext *swrast = SWRAST_CONTEXT(ctx);
191 struct gl_renderbuffer *rb
192 = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
196 /* Leave optimized accum buffer mode */
197 if (swrast->_IntegerAccumMode)
200 if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
201 const GLshort incr = (GLshort) (value * ACCUM_SCALE16);
202 if (rb->GetPointer(ctx, rb, 0, 0)) {
204 for (i = 0; i < height; i++) {
205 GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
206 for (j = 0; j < 4 * width; j++) {
213 for (i = 0; i < height; i++) {
214 GLshort accRow[4 * MAX_WIDTH];
215 rb->GetRow(ctx, rb, width, xpos, ypos + i, accRow);
216 for (j = 0; j < 4 * width; j++) {
219 rb->PutRow(ctx, rb, width, xpos, ypos + i, accRow, NULL);
224 /* other types someday */
230 accum_mult(GLcontext *ctx, GLfloat mult,
231 GLint xpos, GLint ypos, GLint width, GLint height )
233 SWcontext *swrast = SWRAST_CONTEXT(ctx);
234 struct gl_renderbuffer *rb
235 = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
239 /* Leave optimized accum buffer mode */
240 if (swrast->_IntegerAccumMode)
243 if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
244 if (rb->GetPointer(ctx, rb, 0, 0)) {
246 for (i = 0; i < height; i++) {
247 GLshort *acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
248 for (j = 0; j < 4 * width; j++) {
249 acc[j] = (GLshort) (acc[j] * mult);
255 for (i = 0; i < height; i++) {
256 GLshort accRow[4 * MAX_WIDTH];
257 rb->GetRow(ctx, rb, width, xpos, ypos + i, accRow);
258 for (j = 0; j < 4 * width; j++) {
259 accRow[j] = (GLshort) (accRow[j] * mult);
261 rb->PutRow(ctx, rb, width, xpos, ypos + i, accRow, NULL);
266 /* other types someday */
273 accum_accum(GLcontext *ctx, GLfloat value,
274 GLint xpos, GLint ypos, GLint width, GLint height )
276 SWcontext *swrast = SWRAST_CONTEXT(ctx);
277 struct gl_renderbuffer *rb
278 = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
279 const GLboolean directAccess = (rb->GetPointer(ctx, rb, 0, 0) != NULL);
283 if (!ctx->ReadBuffer->_ColorReadBuffer) {
284 /* no read buffer - OK */
288 /* May have to leave optimized accum buffer mode */
289 if (swrast->_IntegerAccumScaler == 0.0 && value > 0.0 && value <= 1.0)
290 swrast->_IntegerAccumScaler = value;
291 if (swrast->_IntegerAccumMode && value != swrast->_IntegerAccumScaler)
294 if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
295 const GLfloat scale = value * ACCUM_SCALE16 / CHAN_MAXF;
296 GLshort accumRow[4 * MAX_WIDTH];
297 GLchan rgba[MAX_WIDTH][4];
300 for (i = 0; i < height; i++) {
303 acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
306 rb->GetRow(ctx, rb, width, xpos, ypos + i, accumRow);
310 /* read colors from color buffer */
311 _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer, width,
312 xpos, ypos + i, CHAN_TYPE, rgba);
314 /* do accumulation */
315 if (swrast->_IntegerAccumMode) {
316 /* simply add integer color values into accum buffer */
318 for (j = 0; j < width; j++) {
319 acc[j * 4 + 0] += rgba[j][RCOMP];
320 acc[j * 4 + 1] += rgba[j][GCOMP];
321 acc[j * 4 + 2] += rgba[j][BCOMP];
322 acc[j * 4 + 3] += rgba[j][ACOMP];
326 /* scaled integer (or float) accum buffer */
328 for (j = 0; j < width; j++) {
329 acc[j * 4 + 0] += (GLshort) ((GLfloat) rgba[j][RCOMP] * scale);
330 acc[j * 4 + 1] += (GLshort) ((GLfloat) rgba[j][GCOMP] * scale);
331 acc[j * 4 + 2] += (GLshort) ((GLfloat) rgba[j][BCOMP] * scale);
332 acc[j * 4 + 3] += (GLshort) ((GLfloat) rgba[j][ACOMP] * scale);
337 rb->PutRow(ctx, rb, width, xpos, ypos + i, accumRow, NULL);
342 /* other types someday */
349 accum_load(GLcontext *ctx, GLfloat value,
350 GLint xpos, GLint ypos, GLint width, GLint height )
352 SWcontext *swrast = SWRAST_CONTEXT(ctx);
353 struct gl_renderbuffer *rb
354 = ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer;
355 const GLboolean directAccess = (rb->GetPointer(ctx, rb, 0, 0) != NULL);
359 if (!ctx->ReadBuffer->_ColorReadBuffer) {
360 /* no read buffer - OK */
364 /* This is a change to go into optimized accum buffer mode */
365 if (value > 0.0 && value <= 1.0) {
366 #if USE_OPTIMIZED_ACCUM
367 swrast->_IntegerAccumMode = GL_TRUE;
369 swrast->_IntegerAccumMode = GL_FALSE;
371 swrast->_IntegerAccumScaler = value;
374 swrast->_IntegerAccumMode = GL_FALSE;
375 swrast->_IntegerAccumScaler = 0.0;
378 if (rb->DataType == GL_SHORT || rb->DataType == GL_UNSIGNED_SHORT) {
379 const GLfloat scale = value * ACCUM_SCALE16 / CHAN_MAXF;
380 GLshort accumRow[4 * MAX_WIDTH];
381 GLchan rgba[MAX_WIDTH][4];
384 for (i = 0; i < height; i++) {
387 acc = (GLshort *) rb->GetPointer(ctx, rb, xpos, ypos + i);
390 rb->GetRow(ctx, rb, width, xpos, ypos + i, accumRow);
394 /* read colors from color buffer */
395 _swrast_read_rgba_span(ctx, ctx->ReadBuffer->_ColorReadBuffer, width,
396 xpos, ypos + i, CHAN_TYPE, rgba);
399 if (swrast->_IntegerAccumMode) {
400 /* just copy values in */
402 assert(swrast->_IntegerAccumScaler > 0.0);
403 assert(swrast->_IntegerAccumScaler <= 1.0);
404 for (j = 0; j < width; j++) {
405 acc[j * 4 + 0] = rgba[j][RCOMP];
406 acc[j * 4 + 1] = rgba[j][GCOMP];
407 acc[j * 4 + 2] = rgba[j][BCOMP];
408 acc[j * 4 + 3] = rgba[j][ACOMP];
412 /* scaled integer (or float) accum buffer */
414 for (j = 0; j < width; j++) {
415 acc[j * 4 + 0] = (GLshort) ((GLfloat) rgba[j][RCOMP] * scale);
416 acc[j * 4 + 1] = (GLshort) ((GLfloat) rgba[j][GCOMP] * scale);
417 acc[j * 4 + 2] = (GLshort) ((GLfloat) rgba[j][BCOMP] * scale);
418 acc[j * 4 + 3] = (GLshort) ((GLfloat) rgba[j][ACOMP] * scale);
423 rb->PutRow(ctx, rb, width, xpos, ypos + i, accumRow, NULL);
431 accum_return(GLcontext *ctx, GLfloat value,
432 GLint xpos, GLint ypos, GLint width, GLint height )
434 SWcontext *swrast = SWRAST_CONTEXT(ctx);
435 struct gl_framebuffer *fb = ctx->DrawBuffer;
436 struct gl_renderbuffer *accumRb = fb->Attachment[BUFFER_ACCUM].Renderbuffer;
437 const GLboolean directAccess
438 = (accumRb->GetPointer(ctx, accumRb, 0, 0) != NULL);
439 const GLboolean masking = (!ctx->Color.ColorMask[RCOMP] ||
440 !ctx->Color.ColorMask[GCOMP] ||
441 !ctx->Color.ColorMask[BCOMP] ||
442 !ctx->Color.ColorMask[ACOMP]);
444 static GLchan multTable[32768];
445 static GLfloat prevMult = 0.0;
446 const GLfloat mult = swrast->_IntegerAccumScaler;
447 const GLint max = MIN2((GLint) (256 / mult), 32767);
449 /* May have to leave optimized accum buffer mode */
450 if (swrast->_IntegerAccumMode && value != 1.0)
453 if (swrast->_IntegerAccumMode && swrast->_IntegerAccumScaler > 0) {
454 /* build lookup table to avoid many floating point multiplies */
456 assert(swrast->_IntegerAccumScaler <= 1.0);
457 if (mult != prevMult) {
458 for (j = 0; j < max; j++)
459 multTable[j] = IROUND((GLfloat) j * mult);
464 if (accumRb->DataType == GL_SHORT ||
465 accumRb->DataType == GL_UNSIGNED_SHORT) {
466 const GLfloat scale = value * CHAN_MAXF / ACCUM_SCALE16;
470 /* XXX maybe transpose the 'i' and 'buffer' loops??? */
471 for (i = 0; i < height; i++) {
472 GLshort accumRow[4 * MAX_WIDTH];
476 /* init color span */
477 INIT_SPAN(span, GL_BITMAP);
479 span.arrayMask = SPAN_RGBA;
484 acc = (GLshort *) accumRb->GetPointer(ctx, accumRb, xpos, ypos +i);
487 accumRb->GetRow(ctx, accumRb, width, xpos, ypos + i, accumRow);
491 /* get the colors to return */
492 if (swrast->_IntegerAccumMode) {
494 for (j = 0; j < width; j++) {
495 ASSERT(acc[j * 4 + 0] < max);
496 ASSERT(acc[j * 4 + 1] < max);
497 ASSERT(acc[j * 4 + 2] < max);
498 ASSERT(acc[j * 4 + 3] < max);
499 span.array->rgba[j][RCOMP] = multTable[acc[j * 4 + 0]];
500 span.array->rgba[j][GCOMP] = multTable[acc[j * 4 + 1]];
501 span.array->rgba[j][BCOMP] = multTable[acc[j * 4 + 2]];
502 span.array->rgba[j][ACOMP] = multTable[acc[j * 4 + 3]];
506 /* scaled integer (or float) accum buffer */
508 for (j = 0; j < width; j++) {
510 GLchan r = acc[j * 4 + 0] * scale;
511 GLchan g = acc[j * 4 + 1] * scale;
512 GLchan b = acc[j * 4 + 2] * scale;
513 GLchan a = acc[j * 4 + 3] * scale;
515 GLint r = IROUND( (GLfloat) (acc[j * 4 + 0]) * scale );
516 GLint g = IROUND( (GLfloat) (acc[j * 4 + 1]) * scale );
517 GLint b = IROUND( (GLfloat) (acc[j * 4 + 2]) * scale );
518 GLint a = IROUND( (GLfloat) (acc[j * 4 + 3]) * scale );
520 span.array->rgba[j][RCOMP] = CLAMP( r, 0, CHAN_MAX );
521 span.array->rgba[j][GCOMP] = CLAMP( g, 0, CHAN_MAX );
522 span.array->rgba[j][BCOMP] = CLAMP( b, 0, CHAN_MAX );
523 span.array->rgba[j][ACOMP] = CLAMP( a, 0, CHAN_MAX );
528 for (buffer = 0; buffer < fb->_NumColorDrawBuffers; buffer++) {
529 struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buffer];
531 _swrast_mask_rgba_span(ctx, rb, &span);
533 rb->PutRow(ctx, rb, width, xpos, ypos + i, span.array->rgba, NULL);
538 /* other types someday */
545 * Software fallback for glAccum.
548 _swrast_Accum(GLcontext *ctx, GLenum op, GLfloat value)
550 SWcontext *swrast = SWRAST_CONTEXT(ctx);
551 GLint xpos, ypos, width, height;
553 if (SWRAST_CONTEXT(ctx)->NewState)
554 _swrast_validate_derived( ctx );
556 if (!ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer) {
557 _mesa_warning(ctx, "Calling glAccum() without an accumulation buffer");
561 RENDER_START(swrast, ctx);
563 /* Compute region after calling RENDER_START so that we know the
564 * drawbuffer's size/bounds are up to date.
566 xpos = ctx->DrawBuffer->_Xmin;
567 ypos = ctx->DrawBuffer->_Ymin;
568 width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
569 height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
574 accum_add(ctx, value, xpos, ypos, width, height);
579 accum_mult(ctx, value, xpos, ypos, width, height);
584 accum_accum(ctx, value, xpos, ypos, width, height);
588 accum_load(ctx, value, xpos, ypos, width, height);
591 accum_return(ctx, value, xpos, ypos, width, height);
594 _mesa_problem(ctx, "invalid mode in _swrast_Accum()");
598 RENDER_FINISH(swrast, ctx);