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-rw-r--r--src/mesa/swrast/s_blend.c667
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diff --git a/src/mesa/swrast/s_blend.c b/src/mesa/swrast/s_blend.c
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+++ b/src/mesa/swrast/s_blend.c
@@ -0,0 +1,667 @@
+/* $Id: s_blend.c,v 1.1 2000/10/31 18:00:04 keithw Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version: 3.5
+ *
+ * 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.
+ */
+
+
+
+#include "glheader.h"
+#include "context.h"
+#include "macros.h"
+
+#include "s_alphabuf.h"
+#include "s_blend.h"
+#include "s_pb.h"
+#include "s_span.h"
+
+
+#ifdef USE_MMX_ASM
+#define _BLENDAPI _ASMAPI
+#else
+#define _BLENDAPI
+#endif
+
+/*
+ * Common transparency blending mode.
+ */
+static void _BLENDAPI
+blend_transparency( GLcontext *ctx, GLuint n, const GLubyte mask[],
+ GLchan rgba[][4], CONST GLchan dest[][4] )
+{
+ GLuint i;
+ ASSERT(ctx->Color.BlendEquation==GL_FUNC_ADD_EXT);
+ ASSERT(ctx->Color.BlendSrcRGB==GL_SRC_ALPHA);
+ ASSERT(ctx->Color.BlendDstRGB==GL_ONE_MINUS_SRC_ALPHA);
+ (void) ctx;
+
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ const GLint t = rgba[i][ACOMP]; /* t in [0, CHAN_MAX] */
+ if (t == 0) {
+ /* 0% alpha */
+ rgba[i][RCOMP] = dest[i][RCOMP];
+ rgba[i][GCOMP] = dest[i][GCOMP];
+ rgba[i][BCOMP] = dest[i][BCOMP];
+ rgba[i][ACOMP] = dest[i][ACOMP];
+ }
+ else if (t == CHAN_MAX) {
+ /* 100% alpha, no-op */
+ }
+ else {
+#if 0
+ /* This is pretty close, but Glean complains */
+ const GLint s = CHAN_MAX - t;
+ const GLint r = (rgba[i][RCOMP] * t + dest[i][RCOMP] * s + 1) >> 8;
+ const GLint g = (rgba[i][GCOMP] * t + dest[i][GCOMP] * s + 1) >> 8;
+ const GLint b = (rgba[i][BCOMP] * t + dest[i][BCOMP] * s + 1) >> 8;
+ const GLint a = (rgba[i][ACOMP] * t + dest[i][ACOMP] * s + 1) >> 8;
+#elif 0
+ /* This is slower but satisfies Glean */
+ const GLint s = CHAN_MAX - t;
+ const GLint r = (rgba[i][RCOMP] * t + dest[i][RCOMP] * s) / 255;
+ const GLint g = (rgba[i][GCOMP] * t + dest[i][GCOMP] * s) / 255;
+ const GLint b = (rgba[i][BCOMP] * t + dest[i][BCOMP] * s) / 255;
+ const GLint a = (rgba[i][ACOMP] * t + dest[i][ACOMP] * s) / 255;
+#else
+#if CHAN_BITS == 8
+ /* This satisfies Glean and should be reasonably fast */
+ /* Contributed by Nathan Hand */
+#define DIV255(X) (((X) << 8) + (X) + 256) >> 16
+ const GLint s = CHAN_MAX - t;
+ const GLint r = DIV255(rgba[i][RCOMP] * t + dest[i][RCOMP] * s);
+ const GLint g = DIV255(rgba[i][GCOMP] * t + dest[i][GCOMP] * s);
+ const GLint b = DIV255(rgba[i][BCOMP] * t + dest[i][BCOMP] * s);
+ const GLint a = DIV255(rgba[i][ACOMP] * t + dest[i][ACOMP] * s);
+#undef DIV255
+#else
+ const GLint s = CHAN_MAX - t;
+ const GLint r = (rgba[i][RCOMP] * t + dest[i][RCOMP] * s) / CHAN_MAX;
+ const GLint g = (rgba[i][GCOMP] * t + dest[i][GCOMP] * s) / CHAN_MAX;
+ const GLint b = (rgba[i][BCOMP] * t + dest[i][BCOMP] * s) / CHAN_MAX;
+ const GLint a = (rgba[i][ACOMP] * t + dest[i][ACOMP] * s) / CHAN_MAX;
+#endif
+#endif
+ ASSERT(r <= CHAN_MAX);
+ ASSERT(g <= CHAN_MAX);
+ ASSERT(b <= CHAN_MAX);
+ ASSERT(a <= CHAN_MAX);
+ rgba[i][RCOMP] = (GLchan) r;
+ rgba[i][GCOMP] = (GLchan) g;
+ rgba[i][BCOMP] = (GLchan) b;
+ rgba[i][ACOMP] = (GLchan) a;
+ }
+ }
+ }
+}
+
+
+
+/*
+ * Add src and dest.
+ */
+static void _BLENDAPI
+blend_add( GLcontext *ctx, GLuint n, const GLubyte mask[],
+ GLchan rgba[][4], CONST GLchan dest[][4] )
+{
+ GLuint i;
+ ASSERT(ctx->Color.BlendEquation==GL_FUNC_ADD_EXT);
+ ASSERT(ctx->Color.BlendSrcRGB==GL_ONE);
+ ASSERT(ctx->Color.BlendDstRGB==GL_ONE);
+ (void) ctx;
+
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ GLint r = rgba[i][RCOMP] + dest[i][RCOMP];
+ GLint g = rgba[i][GCOMP] + dest[i][GCOMP];
+ GLint b = rgba[i][BCOMP] + dest[i][BCOMP];
+ GLint a = rgba[i][ACOMP] + dest[i][ACOMP];
+ rgba[i][RCOMP] = (GLchan) MIN2( r, CHAN_MAX );
+ rgba[i][GCOMP] = (GLchan) MIN2( g, CHAN_MAX );
+ rgba[i][BCOMP] = (GLchan) MIN2( b, CHAN_MAX );
+ rgba[i][ACOMP] = (GLchan) MIN2( a, CHAN_MAX );
+ }
+ }
+}
+
+
+
+/*
+ * Blend min function (for GL_EXT_blend_minmax)
+ */
+static void _BLENDAPI
+blend_min( GLcontext *ctx, GLuint n, const GLubyte mask[],
+ GLchan rgba[][4], CONST GLchan dest[][4] )
+{
+ GLuint i;
+ ASSERT(ctx->Color.BlendEquation==GL_MIN_EXT);
+ (void) ctx;
+
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ rgba[i][RCOMP] = (GLchan) MIN2( rgba[i][RCOMP], dest[i][RCOMP] );
+ rgba[i][GCOMP] = (GLchan) MIN2( rgba[i][GCOMP], dest[i][GCOMP] );
+ rgba[i][BCOMP] = (GLchan) MIN2( rgba[i][BCOMP], dest[i][BCOMP] );
+ rgba[i][ACOMP] = (GLchan) MIN2( rgba[i][ACOMP], dest[i][ACOMP] );
+ }
+ }
+}
+
+
+
+/*
+ * Blend max function (for GL_EXT_blend_minmax)
+ */
+static void _BLENDAPI
+blend_max( GLcontext *ctx, GLuint n, const GLubyte mask[],
+ GLchan rgba[][4], CONST GLchan dest[][4] )
+{
+ GLuint i;
+ ASSERT(ctx->Color.BlendEquation==GL_MAX_EXT);
+ (void) ctx;
+
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ rgba[i][RCOMP] = (GLchan) MAX2( rgba[i][RCOMP], dest[i][RCOMP] );
+ rgba[i][GCOMP] = (GLchan) MAX2( rgba[i][GCOMP], dest[i][GCOMP] );
+ rgba[i][BCOMP] = (GLchan) MAX2( rgba[i][BCOMP], dest[i][BCOMP] );
+ rgba[i][ACOMP] = (GLchan) MAX2( rgba[i][ACOMP], dest[i][ACOMP] );
+ }
+ }
+}
+
+
+
+/*
+ * Modulate: result = src * dest
+ */
+static void _BLENDAPI
+blend_modulate( GLcontext *ctx, GLuint n, const GLubyte mask[],
+ GLchan rgba[][4], CONST GLchan dest[][4] )
+{
+ GLuint i;
+ (void) ctx;
+
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ GLint r = (rgba[i][RCOMP] * dest[i][RCOMP]) >> 8;
+ GLint g = (rgba[i][GCOMP] * dest[i][GCOMP]) >> 8;
+ GLint b = (rgba[i][BCOMP] * dest[i][BCOMP]) >> 8;
+ GLint a = (rgba[i][ACOMP] * dest[i][ACOMP]) >> 8;
+ rgba[i][RCOMP] = (GLchan) r;
+ rgba[i][GCOMP] = (GLchan) g;
+ rgba[i][BCOMP] = (GLchan) b;
+ rgba[i][ACOMP] = (GLchan) a;
+ }
+ }
+}
+
+
+
+/*
+ * General case blend pixels.
+ * Input: n - number of pixels
+ * mask - the usual write mask
+ * In/Out: rgba - the incoming and modified pixels
+ * Input: dest - the pixels from the dest color buffer
+ */
+static void _BLENDAPI
+blend_general( GLcontext *ctx, GLuint n, const GLubyte mask[],
+ GLchan rgba[][4], CONST GLchan dest[][4] )
+{
+ GLfloat rscale = 1.0F / CHAN_MAXF;
+ GLfloat gscale = 1.0F / CHAN_MAXF;
+ GLfloat bscale = 1.0F / CHAN_MAXF;
+ GLfloat ascale = 1.0F / CHAN_MAXF;
+ GLuint i;
+
+ for (i=0;i<n;i++) {
+ if (mask[i]) {
+ GLint Rs, Gs, Bs, As; /* Source colors */
+ GLint Rd, Gd, Bd, Ad; /* Dest colors */
+ GLfloat sR, sG, sB, sA; /* Source scaling */
+ GLfloat dR, dG, dB, dA; /* Dest scaling */
+ GLfloat r, g, b, a;
+
+ /* Source Color */
+ Rs = rgba[i][RCOMP];
+ Gs = rgba[i][GCOMP];
+ Bs = rgba[i][BCOMP];
+ As = rgba[i][ACOMP];
+
+ /* Frame buffer color */
+ Rd = dest[i][RCOMP];
+ Gd = dest[i][GCOMP];
+ Bd = dest[i][BCOMP];
+ Ad = dest[i][ACOMP];
+
+ /* Source RGB factor */
+ switch (ctx->Color.BlendSrcRGB) {
+ case GL_ZERO:
+ sR = sG = sB = 0.0F;
+ break;
+ case GL_ONE:
+ sR = sG = sB = 1.0F;
+ break;
+ case GL_DST_COLOR:
+ sR = (GLfloat) Rd * rscale;
+ sG = (GLfloat) Gd * gscale;
+ sB = (GLfloat) Bd * bscale;
+ break;
+ case GL_ONE_MINUS_DST_COLOR:
+ sR = 1.0F - (GLfloat) Rd * rscale;
+ sG = 1.0F - (GLfloat) Gd * gscale;
+ sB = 1.0F - (GLfloat) Bd * bscale;
+ break;
+ case GL_SRC_ALPHA:
+ sR = sG = sB = (GLfloat) As * ascale;
+ break;
+ case GL_ONE_MINUS_SRC_ALPHA:
+ sR = sG = sB = (GLfloat) 1.0F - (GLfloat) As * ascale;
+ break;
+ case GL_DST_ALPHA:
+ sR = sG = sB = (GLfloat) Ad * ascale;
+ break;
+ case GL_ONE_MINUS_DST_ALPHA:
+ sR = sG = sB = 1.0F - (GLfloat) Ad * ascale;
+ break;
+ case GL_SRC_ALPHA_SATURATE:
+ if (As < CHAN_MAX - Ad) {
+ sR = sG = sB = (GLfloat) As * ascale;
+ }
+ else {
+ sR = sG = sB = 1.0F - (GLfloat) Ad * ascale;
+ }
+ break;
+ case GL_CONSTANT_COLOR:
+ sR = ctx->Color.BlendColor[0];
+ sG = ctx->Color.BlendColor[1];
+ sB = ctx->Color.BlendColor[2];
+ break;
+ case GL_ONE_MINUS_CONSTANT_COLOR:
+ sR = 1.0F - ctx->Color.BlendColor[0];
+ sG = 1.0F - ctx->Color.BlendColor[1];
+ sB = 1.0F - ctx->Color.BlendColor[2];
+ break;
+ case GL_CONSTANT_ALPHA:
+ sR = sG = sB = ctx->Color.BlendColor[3];
+ break;
+ case GL_ONE_MINUS_CONSTANT_ALPHA:
+ sR = sG = sB = 1.0F - ctx->Color.BlendColor[3];
+ break;
+ case GL_SRC_COLOR: /* GL_NV_blend_square */
+ sR = (GLfloat) Rs * rscale;
+ sG = (GLfloat) Gs * gscale;
+ sB = (GLfloat) Bs * bscale;
+ break;
+ case GL_ONE_MINUS_SRC_COLOR: /* GL_NV_blend_square */
+ sR = 1.0F - (GLfloat) Rs * rscale;
+ sG = 1.0F - (GLfloat) Gs * gscale;
+ sB = 1.0F - (GLfloat) Bs * bscale;
+ break;
+ default:
+ /* this should never happen */
+ gl_problem(ctx, "Bad blend source RGB factor in do_blend");
+ return;
+ }
+
+ /* Source Alpha factor */
+ switch (ctx->Color.BlendSrcA) {
+ case GL_ZERO:
+ sA = 0.0F;
+ break;
+ case GL_ONE:
+ sA = 1.0F;
+ break;
+ case GL_DST_COLOR:
+ sA = (GLfloat) Ad * ascale;
+ break;
+ case GL_ONE_MINUS_DST_COLOR:
+ sA = 1.0F - (GLfloat) Ad * ascale;
+ break;
+ case GL_SRC_ALPHA:
+ sA = (GLfloat) As * ascale;
+ break;
+ case GL_ONE_MINUS_SRC_ALPHA:
+ sA = (GLfloat) 1.0F - (GLfloat) As * ascale;
+ break;
+ case GL_DST_ALPHA:
+ sA =(GLfloat) Ad * ascale;
+ break;
+ case GL_ONE_MINUS_DST_ALPHA:
+ sA = 1.0F - (GLfloat) Ad * ascale;
+ break;
+ case GL_SRC_ALPHA_SATURATE:
+ sA = 1.0;
+ break;
+ case GL_CONSTANT_COLOR:
+ sA = ctx->Color.BlendColor[3];
+ break;
+ case GL_ONE_MINUS_CONSTANT_COLOR:
+ sA = 1.0F - ctx->Color.BlendColor[3];
+ break;
+ case GL_CONSTANT_ALPHA:
+ sA = ctx->Color.BlendColor[3];
+ break;
+ case GL_ONE_MINUS_CONSTANT_ALPHA:
+ sA = 1.0F - ctx->Color.BlendColor[3];
+ break;
+ case GL_SRC_COLOR: /* GL_NV_blend_square */
+ sA = (GLfloat) As * ascale;
+ break;
+ case GL_ONE_MINUS_SRC_COLOR: /* GL_NV_blend_square */
+ sA = 1.0F - (GLfloat) As * ascale;
+ break;
+ default:
+ /* this should never happen */
+ sA = 0.0F;
+ gl_problem(ctx, "Bad blend source A factor in do_blend");
+ }
+
+ /* Dest RGB factor */
+ switch (ctx->Color.BlendDstRGB) {
+ case GL_ZERO:
+ dR = dG = dB = 0.0F;
+ break;
+ case GL_ONE:
+ dR = dG = dB = 1.0F;
+ break;
+ case GL_SRC_COLOR:
+ dR = (GLfloat) Rs * rscale;
+ dG = (GLfloat) Gs * gscale;
+ dB = (GLfloat) Bs * bscale;
+ break;
+ case GL_ONE_MINUS_SRC_COLOR:
+ dR = 1.0F - (GLfloat) Rs * rscale;
+ dG = 1.0F - (GLfloat) Gs * gscale;
+ dB = 1.0F - (GLfloat) Bs * bscale;
+ break;
+ case GL_SRC_ALPHA:
+ dR = dG = dB = (GLfloat) As * ascale;
+ break;
+ case GL_ONE_MINUS_SRC_ALPHA:
+ dR = dG = dB = (GLfloat) 1.0F - (GLfloat) As * ascale;
+ break;
+ case GL_DST_ALPHA:
+ dR = dG = dB = (GLfloat) Ad * ascale;
+ break;
+ case GL_ONE_MINUS_DST_ALPHA:
+ dR = dG = dB = 1.0F - (GLfloat) Ad * ascale;
+ break;
+ case GL_CONSTANT_COLOR:
+ dR = ctx->Color.BlendColor[0];
+ dG = ctx->Color.BlendColor[1];
+ dB = ctx->Color.BlendColor[2];
+ break;
+ case GL_ONE_MINUS_CONSTANT_COLOR:
+ dR = 1.0F - ctx->Color.BlendColor[0];
+ dG = 1.0F - ctx->Color.BlendColor[1];
+ dB = 1.0F - ctx->Color.BlendColor[2];
+ break;
+ case GL_CONSTANT_ALPHA:
+ dR = dG = dB = ctx->Color.BlendColor[3];
+ break;
+ case GL_ONE_MINUS_CONSTANT_ALPHA:
+ dR = dG = dB = 1.0F - ctx->Color.BlendColor[3];
+ break;
+ case GL_DST_COLOR: /* GL_NV_blend_square */
+ dR = (GLfloat) Rd * rscale;
+ dG = (GLfloat) Gd * gscale;
+ dB = (GLfloat) Bd * bscale;
+ break;
+ case GL_ONE_MINUS_DST_COLOR: /* GL_NV_blend_square */
+ dR = 1.0F - (GLfloat) Rd * rscale;
+ dG = 1.0F - (GLfloat) Gd * gscale;
+ dB = 1.0F - (GLfloat) Bd * bscale;
+ break;
+ default:
+ /* this should never happen */
+ dR = dG = dB = 0.0F;
+ gl_problem(ctx, "Bad blend dest RGB factor in do_blend");
+ }
+
+ /* Dest Alpha factor */
+ switch (ctx->Color.BlendDstA) {
+ case GL_ZERO:
+ dA = 0.0F;
+ break;
+ case GL_ONE:
+ dA = 1.0F;
+ break;
+ case GL_SRC_COLOR:
+ dA = (GLfloat) As * ascale;
+ break;
+ case GL_ONE_MINUS_SRC_COLOR:
+ dA = 1.0F - (GLfloat) As * ascale;
+ break;
+ case GL_SRC_ALPHA:
+ dA = (GLfloat) As * ascale;
+ break;
+ case GL_ONE_MINUS_SRC_ALPHA:
+ dA = (GLfloat) 1.0F - (GLfloat) As * ascale;
+ break;
+ case GL_DST_ALPHA:
+ dA = (GLfloat) Ad * ascale;
+ break;
+ case GL_ONE_MINUS_DST_ALPHA:
+ dA = 1.0F - (GLfloat) Ad * ascale;
+ break;
+ case GL_CONSTANT_COLOR:
+ dA = ctx->Color.BlendColor[3];
+ break;
+ case GL_ONE_MINUS_CONSTANT_COLOR:
+ dA = 1.0F - ctx->Color.BlendColor[3];
+ break;
+ case GL_CONSTANT_ALPHA:
+ dA = ctx->Color.BlendColor[3];
+ break;
+ case GL_ONE_MINUS_CONSTANT_ALPHA:
+ dA = 1.0F - ctx->Color.BlendColor[3];
+ break;
+ case GL_DST_COLOR: /* GL_NV_blend_square */
+ dA = (GLfloat) Ad * ascale;
+ break;
+ case GL_ONE_MINUS_DST_COLOR: /* GL_NV_blend_square */
+ dA = 1.0F - (GLfloat) Ad * ascale;
+ break;
+ default:
+ /* this should never happen */
+ dA = 0.0F;
+ gl_problem(ctx, "Bad blend dest A factor in do_blend");
+ return;
+ }
+
+ /* Due to round-off problems we have to clamp against zero. */
+ /* Optimization: we don't have to do this for all src & dst factors */
+ if (dA < 0.0F) dA = 0.0F;
+ if (dR < 0.0F) dR = 0.0F;
+ if (dG < 0.0F) dG = 0.0F;
+ if (dB < 0.0F) dB = 0.0F;
+ if (sA < 0.0F) sA = 0.0F;
+ if (sR < 0.0F) sR = 0.0F;
+ if (sG < 0.0F) sG = 0.0F;
+ if (sB < 0.0F) sB = 0.0F;
+
+ ASSERT( sR <= 1.0 );
+ ASSERT( sG <= 1.0 );
+ ASSERT( sB <= 1.0 );
+ ASSERT( sA <= 1.0 );
+ ASSERT( dR <= 1.0 );
+ ASSERT( dG <= 1.0 );
+ ASSERT( dB <= 1.0 );
+ ASSERT( dA <= 1.0 );
+
+ /* compute blended color */
+ if (ctx->Color.BlendEquation==GL_FUNC_ADD_EXT) {
+ r = Rs * sR + Rd * dR + 0.5F;
+ g = Gs * sG + Gd * dG + 0.5F;
+ b = Bs * sB + Bd * dB + 0.5F;
+ a = As * sA + Ad * dA + 0.5F;
+ }
+ else if (ctx->Color.BlendEquation==GL_FUNC_SUBTRACT_EXT) {
+ r = Rs * sR - Rd * dR + 0.5F;
+ g = Gs * sG - Gd * dG + 0.5F;
+ b = Bs * sB - Bd * dB + 0.5F;
+ a = As * sA - Ad * dA + 0.5F;
+ }
+ else if (ctx->Color.BlendEquation==GL_FUNC_REVERSE_SUBTRACT_EXT) {
+ r = Rd * dR - Rs * sR + 0.5F;
+ g = Gd * dG - Gs * sG + 0.5F;
+ b = Bd * dB - Bs * sB + 0.5F;
+ a = Ad * dA - As * sA + 0.5F;
+ }
+ else {
+ /* should never get here */
+ r = g = b = a = 0.0F; /* silence uninitialized var warning */
+ gl_problem(ctx, "unexpected BlendEquation in blend_general()");
+ }
+
+ /* final clamping */
+ rgba[i][RCOMP] = (GLchan) (GLint) CLAMP( r, 0.0F, CHAN_MAXF );
+ rgba[i][GCOMP] = (GLchan) (GLint) CLAMP( g, 0.0F, CHAN_MAXF );
+ rgba[i][BCOMP] = (GLchan) (GLint) CLAMP( b, 0.0F, CHAN_MAXF );
+ rgba[i][ACOMP] = (GLchan) (GLint) CLAMP( a, 0.0F, CHAN_MAXF );
+ }
+ }
+}
+
+
+
+#if defined(USE_MMX_ASM)
+#include "X86/mmx.h"
+#include "X86/common_x86_asm.h"
+#endif
+
+
+/*
+ * Analyze current blending parameters to pick fastest blending function.
+ * Result: the ctx->Color.BlendFunc pointer is updated.
+ */
+static void set_blend_function( GLcontext *ctx )
+{
+ const GLenum eq = ctx->Color.BlendEquation;
+ const GLenum srcRGB = ctx->Color.BlendSrcRGB;
+ const GLenum dstRGB = ctx->Color.BlendDstRGB;
+ const GLenum srcA = ctx->Color.BlendSrcA;
+ const GLenum dstA = ctx->Color.BlendDstA;
+
+#if defined(USE_MMX_ASM)
+ /* Hmm. A table here would have 12^4 == way too many entries.
+ * Provide a hook for MMX instead.
+ */
+ if ( cpu_has_mmx ) {
+ gl_mmx_set_blend_function( ctx );
+ }
+ else
+#endif
+ if (srcRGB != srcA || dstRGB != dstA) {
+ ctx->Color.BlendFunc = blend_general;
+ }
+ else if (eq==GL_FUNC_ADD_EXT && srcRGB==GL_SRC_ALPHA
+ && dstRGB==GL_ONE_MINUS_SRC_ALPHA) {
+ ctx->Color.BlendFunc = blend_transparency;
+ }
+ else if (eq==GL_FUNC_ADD_EXT && srcRGB==GL_ONE && dstRGB==GL_ONE) {
+ ctx->Color.BlendFunc = blend_add;
+ }
+ else if (((eq==GL_FUNC_ADD_EXT || eq==GL_FUNC_REVERSE_SUBTRACT_EXT)
+ && (srcRGB==GL_ZERO && dstRGB==GL_SRC_COLOR))
+ ||
+ ((eq==GL_FUNC_ADD_EXT || eq==GL_FUNC_SUBTRACT_EXT)
+ && (srcRGB==GL_DST_COLOR && dstRGB==GL_ZERO))) {
+ ctx->Color.BlendFunc = blend_modulate;
+ }
+ else if (eq==GL_MIN_EXT) {
+ ctx->Color.BlendFunc = blend_min;
+ }
+ else if (eq==GL_MAX_EXT) {
+ ctx->Color.BlendFunc = blend_max;
+ }
+ else {
+ ctx->Color.BlendFunc = blend_general;
+ }
+}
+
+
+
+/*
+ * Apply the blending operator to a span of pixels.
+ * Input: n - number of pixels in span
+ * x, y - location of leftmost pixel in span in window coords.
+ * mask - boolean mask indicating which pixels to blend.
+ * In/Out: rgba - pixel values
+ */
+void
+_mesa_blend_span( GLcontext *ctx, GLuint n, GLint x, GLint y,
+ GLchan rgba[][4], const GLubyte mask[] )
+{
+ GLchan dest[MAX_WIDTH][4];
+
+ /* Check if device driver can do the work */
+ if (ctx->Color.BlendEquation==GL_LOGIC_OP &&
+ !ctx->Color.ColorLogicOpEnabled) {
+ return;
+ }
+
+ /* Read span of current frame buffer pixels */
+ gl_read_rgba_span( ctx, ctx->DrawBuffer, n, x, y, dest );
+
+ if (!ctx->Color.BlendFunc)
+ set_blend_function(ctx);
+
+ (*ctx->Color.BlendFunc)( ctx, n, mask, rgba, (const GLchan (*)[4])dest );
+}
+
+
+
+/*
+ * Apply the blending operator to an array of pixels.
+ * Input: n - number of pixels in span
+ * x, y - array of pixel locations
+ * mask - boolean mask indicating which pixels to blend.
+ * In/Out: rgba - pixel values
+ */
+void
+_mesa_blend_pixels( GLcontext *ctx,
+ GLuint n, const GLint x[], const GLint y[],
+ GLchan rgba[][4], const GLubyte mask[] )
+{
+ GLchan dest[PB_SIZE][4];
+
+ /* Check if device driver can do the work */
+ if (ctx->Color.BlendEquation==GL_LOGIC_OP &&
+ !ctx->Color.ColorLogicOpEnabled) {
+ return;
+ }
+
+ /* Read pixels from current color buffer */
+ (*ctx->Driver.ReadRGBAPixels)( ctx, n, x, y, dest, mask );
+ if (ctx->RasterMask & ALPHABUF_BIT) {
+ _mesa_read_alpha_pixels( ctx, n, x, y, dest, mask );
+ }
+
+ if (!ctx->Color.BlendFunc)
+ set_blend_function(ctx);
+
+ (*ctx->Color.BlendFunc)( ctx, n, mask, rgba, (const GLchan (*)[4])dest );
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 22:16:30 +0000