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-rw-r--r--src/mesa/main/accum.c495
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diff --git a/src/mesa/main/accum.c b/src/mesa/main/accum.c
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+/* $Id: accum.c,v 1.1 1999/08/19 00:55:41 jtg Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version: 3.1
+ *
+ * Copyright (C) 1999 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 <assert.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include "accum.h"
+#include "context.h"
+#include "macros.h"
+#include "masking.h"
+#include "span.h"
+#include "types.h"
+#ifdef XFree86Server
+#include "GL/xf86glx.h"
+#endif
+#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.
+ */
+
+
+
+void gl_alloc_accum_buffer( GLcontext *ctx )
+{
+ GLint n;
+
+ if (ctx->Buffer->Accum) {
+ free( ctx->Buffer->Accum );
+ ctx->Buffer->Accum = NULL;
+ }
+
+ /* allocate accumulation buffer if not already present */
+ n = ctx->Buffer->Width * ctx->Buffer->Height * 4 * sizeof(GLaccum);
+ ctx->Buffer->Accum = (GLaccum *) malloc( n );
+ if (!ctx->Buffer->Accum) {
+ /* unable to setup accumulation buffer */
+ gl_error( ctx, GL_OUT_OF_MEMORY, "glAccum" );
+ }
+ ctx->IntegerAccumMode = GL_TRUE;
+ ctx->IntegerAccumScaler = 0.0;
+}
+
+
+
+void gl_ClearAccum( GLcontext *ctx,
+ GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha )
+{
+ 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->Buffer->Width * ctx->Buffer->Height * 4;
+ const GLfloat s = ctx->IntegerAccumScaler * (32767.0 / 255.0);
+ GLaccum *accum = ctx->Buffer->Accum;
+ GLuint i;
+
+ assert(ctx->IntegerAccumMode);
+ assert(sizeof(GLchan) == 1); /* if not true, 255.0 above must be fixed */
+ assert(accum);
+
+ for (i = 0; i < n; i++) {
+ accum[i] = (GLaccum) (accum[i] * s);
+ }
+
+ ctx->IntegerAccumMode = GL_FALSE;
+}
+
+
+
+void gl_Accum( GLcontext *ctx, GLenum op, GLfloat value )
+{
+ GLuint xpos, ypos, width, height, width4;
+ GLfloat acc_scale;
+ GLubyte rgba[MAX_WIDTH][4];
+
+ ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glAccum");
+
+ if (ctx->Visual->AccumBits==0 || !ctx->Buffer->Accum) {
+ /* No accumulation buffer! */
+ gl_warning(ctx, "Calling glAccum() without an 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;
+ }
+
+ 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->Buffer->Width;
+ height = ctx->Buffer->Height;
+ }
+
+ width4 = 4 * width;
+
+ switch (op) {
+ case GL_ADD:
+ {
+ const GLaccum intVal = (GLaccum) (value * acc_scale);
+ GLuint j;
+ /* May have to leave optimized accum buffer mode */
+ if (ctx->IntegerAccumMode)
+ rescale_accum(ctx);
+ for (j = 0; j < height; j++) {
+ GLaccum * acc = ctx->Buffer->Accum + ypos * width4 + 4 * xpos;
+ GLuint i;
+ for (i = 0; i < width4; i++) {
+ acc[i] += intVal;
+ }
+ ypos++;
+ }
+ }
+ break;
+
+ case GL_MULT:
+ {
+ GLuint j;
+ /* May have to leave optimized accum buffer mode */
+ if (ctx->IntegerAccumMode)
+ rescale_accum(ctx);
+ for (j = 0; j < height; j++) {
+ GLaccum *acc = ctx->Buffer->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:
+ (void) (*ctx->Driver.SetBuffer)( ctx, 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->Buffer->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, 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 / 255.0;
+ const GLfloat gscale = value * acc_scale / 255.0;
+ const GLfloat bscale = value * acc_scale / 255.0;
+ const GLfloat ascale = value * acc_scale / 255.0;
+ GLuint j;
+ for (j=0;j<height;j++) {
+ GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+ GLuint i;
+ gl_read_rgba_span(ctx, 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++;
+ }
+ }
+ (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Color.DriverDrawBuffer );
+ break;
+
+ case GL_LOAD:
+ (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Pixel.DriverReadBuffer );
+
+ /* This is a change to go into optimized accum buffer mode */
+ if (value > 0.0 && value <= 1.0) {
+ ctx->IntegerAccumMode = GL_TRUE;
+ 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->Buffer->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, 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 / 255.0;
+ const GLfloat gscale = value * acc_scale / 255.0;
+ const GLfloat bscale = value * acc_scale / 255.0;
+ const GLfloat ascale = value * acc_scale / 255.0;
+ GLuint i, j;
+ for (j = 0; j < height; j++) {
+ GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos * 4;
+ gl_read_rgba_span(ctx, width, xpos, ypos, rgba);
+ for (i=0;i<width;i++) {
+ *acc++ = (GLaccum) ( (GLfloat) rgba[i][RCOMP] * rscale );
+ *acc++ = (GLaccum) ( (GLfloat) rgba[i][GCOMP] * gscale );
+ *acc++ = (GLaccum) ( (GLfloat) rgba[i][BCOMP] * bscale );
+ *acc++ = (GLaccum) ( (GLfloat) rgba[i][ACOMP] * ascale );
+ }
+ ypos++;
+ }
+ }
+ (void) (*ctx->Driver.SetBuffer)( ctx, 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) {
+ /* build lookup table to avoid integer divides */
+ GLint divisor = (GLint) ((1.0F / ctx->IntegerAccumScaler) + 0.5F);
+ static GLubyte divTable[32768];
+ static GLint prevDivisor = 0.0;
+ GLuint j;
+ if (divisor != prevDivisor) {
+ assert(divisor * 256 <= 32768);
+ for (j = 0; j < divisor * 256; j++)
+ divTable[j] = j / divisor;
+ prevDivisor = divisor;
+ }
+
+ assert(ctx->IntegerAccumScaler > 0.0);
+ assert(ctx->IntegerAccumScaler <= 1.0);
+ for (j = 0; j < height; j++) {
+ const GLaccum *acc = ctx->Buffer->Accum + ypos * width4 + xpos*4;
+ GLuint i, i4;
+ for (i = i4 = 0; i < width; i++, i4 += 4) {
+ ASSERT(acc[i4+0] < divisor * 256);
+ ASSERT(acc[i4+1] < divisor * 256);
+ ASSERT(acc[i4+2] < divisor * 256);
+ ASSERT(acc[i4+3] < divisor * 256);
+ rgba[i][RCOMP] = divTable[acc[i4+0]];
+ rgba[i][GCOMP] = divTable[acc[i4+1]];
+ rgba[i][BCOMP] = divTable[acc[i4+2]];
+ rgba[i][ACOMP] = divTable[acc[i4+3]];
+ }
+ if (ctx->Color.SWmasking) {
+ gl_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 * 255.0F;
+ const GLfloat gscale = value / acc_scale * 255.0F;
+ const GLfloat bscale = value / acc_scale * 255.0F;
+ const GLfloat ascale = value / acc_scale * 255.0F;
+ GLuint i, j;
+ for (j=0;j<height;j++) {
+ const GLaccum *acc = ctx->Buffer->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, 255 );
+ rgba[i][GCOMP] = CLAMP( g, 0, 255 );
+ rgba[i][BCOMP] = CLAMP( b, 0, 255 );
+ rgba[i][ACOMP] = CLAMP( a, 0, 255 );
+ }
+ if (ctx->Color.SWmasking) {
+ gl_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 gl_clear_accum_buffer( GLcontext *ctx )
+{
+ GLuint buffersize;
+ GLfloat acc_scale;
+
+ if (ctx->Visual->AccumBits==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->Buffer->Width * ctx->Buffer->Height;
+
+ if (!ctx->Buffer->Accum) {
+ /* try to alloc accumulation buffer */
+ ctx->Buffer->Accum = (GLaccum *)
+ malloc( buffersize * 4 * sizeof(GLaccum) );
+ }
+
+ if (ctx->Buffer->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->Buffer->Xmax - ctx->Buffer->Xmin + 1);
+ height = ctx->Buffer->Ymax - ctx->Buffer->Ymin + 1;
+ /* ptr to first element to clear */
+ row = ctx->Buffer->Accum
+ + 4 * (ctx->Buffer->Ymin * ctx->Buffer->Width
+ + ctx->Buffer->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->Buffer->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 */
+ MEMSET( ctx->Buffer->Accum, 0, buffersize * 4 * sizeof(GLaccum) );
+ }
+ else {
+ /* Not black */
+ GLaccum *acc, r, g, b, a;
+ GLuint i;
+
+ acc = ctx->Buffer->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) {
+ ctx->IntegerAccumMode = GL_TRUE;
+ ctx->IntegerAccumScaler = 0.0; /* denotes empty accum buffer */
+ }
+ else {
+ ctx->IntegerAccumMode = GL_FALSE;
+ }
+ }
+}
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