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-rw-r--r--mesalib/src/mesa/swrast/s_fog.c330
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diff --git a/mesalib/src/mesa/swrast/s_fog.c b/mesalib/src/mesa/swrast/s_fog.c
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+/*
+ * Mesa 3-D graphics library
+ * Version: 6.5.2
+ *
+ * Copyright (C) 1999-2006 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 "main/glheader.h"
+#include "main/colormac.h"
+#include "main/context.h"
+#include "main/macros.h"
+
+#include "s_context.h"
+#include "s_fog.h"
+
+
+/**
+ * Used to convert current raster distance to a fog factor in [0,1].
+ */
+GLfloat
+_swrast_z_to_fogfactor(GLcontext *ctx, GLfloat z)
+{
+ GLfloat d, f;
+
+ switch (ctx->Fog.Mode) {
+ case GL_LINEAR:
+ if (ctx->Fog.Start == ctx->Fog.End)
+ d = 1.0F;
+ else
+ d = 1.0F / (ctx->Fog.End - ctx->Fog.Start);
+ f = (ctx->Fog.End - z) * d;
+ return CLAMP(f, 0.0F, 1.0F);
+ case GL_EXP:
+ d = ctx->Fog.Density;
+ f = EXPF(-d * z);
+ f = CLAMP(f, 0.0F, 1.0F);
+ return f;
+ case GL_EXP2:
+ d = ctx->Fog.Density;
+ f = EXPF(-(d * d * z * z));
+ f = CLAMP(f, 0.0F, 1.0F);
+ return f;
+ default:
+ _mesa_problem(ctx, "Bad fog mode in _swrast_z_to_fogfactor");
+ return 0.0;
+ }
+}
+
+
+#define LINEAR_FOG(f, coord) f = (fogEnd - coord) * fogScale
+
+#define EXP_FOG(f, coord) f = EXPF(density * coord)
+
+#define EXP2_FOG(f, coord) \
+do { \
+ GLfloat tmp = negDensitySquared * coord * coord; \
+ if (tmp < FLT_MIN_10_EXP) \
+ tmp = FLT_MIN_10_EXP; \
+ f = EXPF(tmp); \
+ } while(0)
+
+
+#define BLEND_FOG(f, coord) f = coord
+
+
+
+/**
+ * Template code for computing fog blend factor and applying it to colors.
+ * \param TYPE either GLubyte, GLushort or GLfloat.
+ * \param COMPUTE_F code to compute the fog blend factor, f.
+ */
+#define FOG_LOOP(TYPE, FOG_FUNC) \
+if (span->arrayAttribs & FRAG_BIT_FOGC) { \
+ GLuint i; \
+ for (i = 0; i < span->end; i++) { \
+ const GLfloat fogCoord = span->array->attribs[FRAG_ATTRIB_FOGC][i][0]; \
+ const GLfloat c = FABSF(fogCoord); \
+ GLfloat f, oneMinusF; \
+ FOG_FUNC(f, c); \
+ f = CLAMP(f, 0.0F, 1.0F); \
+ oneMinusF = 1.0F - f; \
+ rgba[i][RCOMP] = (TYPE) (f * rgba[i][RCOMP] + oneMinusF * rFog); \
+ rgba[i][GCOMP] = (TYPE) (f * rgba[i][GCOMP] + oneMinusF * gFog); \
+ rgba[i][BCOMP] = (TYPE) (f * rgba[i][BCOMP] + oneMinusF * bFog); \
+ } \
+} \
+else { \
+ const GLfloat fogStep = span->attrStepX[FRAG_ATTRIB_FOGC][0]; \
+ GLfloat fogCoord = span->attrStart[FRAG_ATTRIB_FOGC][0]; \
+ const GLfloat wStep = span->attrStepX[FRAG_ATTRIB_WPOS][3]; \
+ GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3]; \
+ GLuint i; \
+ for (i = 0; i < span->end; i++) { \
+ const GLfloat c = FABSF(fogCoord) / w; \
+ GLfloat f, oneMinusF; \
+ FOG_FUNC(f, c); \
+ f = CLAMP(f, 0.0F, 1.0F); \
+ oneMinusF = 1.0F - f; \
+ rgba[i][RCOMP] = (TYPE) (f * rgba[i][RCOMP] + oneMinusF * rFog); \
+ rgba[i][GCOMP] = (TYPE) (f * rgba[i][GCOMP] + oneMinusF * gFog); \
+ rgba[i][BCOMP] = (TYPE) (f * rgba[i][BCOMP] + oneMinusF * bFog); \
+ fogCoord += fogStep; \
+ w += wStep; \
+ } \
+}
+
+/* As above, but CI mode (XXX try to merge someday) */
+#define FOG_LOOP_CI(FOG_FUNC) \
+if (span->arrayAttribs & FRAG_BIT_FOGC) { \
+ GLuint i; \
+ for (i = 0; i < span->end; i++) { \
+ const GLfloat fogCoord = span->array->attribs[FRAG_ATTRIB_FOGC][i][0]; \
+ const GLfloat c = FABSF(fogCoord); \
+ GLfloat f; \
+ FOG_FUNC(f, c); \
+ f = CLAMP(f, 0.0F, 1.0F); \
+ index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * fogIndex); \
+ } \
+} \
+else { \
+ const GLfloat fogStep = span->attrStepX[FRAG_ATTRIB_FOGC][0]; \
+ GLfloat fogCoord = span->attrStart[FRAG_ATTRIB_FOGC][0]; \
+ const GLfloat wStep = span->attrStepX[FRAG_ATTRIB_WPOS][3]; \
+ GLfloat w = span->attrStart[FRAG_ATTRIB_WPOS][3]; \
+ GLuint i; \
+ for (i = 0; i < span->end; i++) { \
+ const GLfloat c = FABSF(fogCoord) / w; \
+ GLfloat f; \
+ FOG_FUNC(f, c); \
+ f = CLAMP(f, 0.0F, 1.0F); \
+ index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * fogIndex); \
+ fogCoord += fogStep; \
+ w += wStep; \
+ } \
+}
+
+
+
+/**
+ * Apply fog to a span of RGBA pixels.
+ * The fog value are either in the span->array->fog array or interpolated from
+ * the fog/fogStep values.
+ * They fog values are either fog coordinates (Z) or fog blend factors.
+ * _PreferPixelFog should be in sync with that state!
+ */
+void
+_swrast_fog_rgba_span( const GLcontext *ctx, SWspan *span )
+{
+ const SWcontext *swrast = CONST_SWRAST_CONTEXT(ctx);
+ GLfloat rFog, gFog, bFog;
+
+ ASSERT(swrast->_FogEnabled);
+ ASSERT(span->arrayMask & SPAN_RGBA);
+
+ /* compute (scaled) fog color */
+ if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+ rFog = ctx->Fog.Color[RCOMP] * 255.0;
+ gFog = ctx->Fog.Color[GCOMP] * 255.0;
+ bFog = ctx->Fog.Color[BCOMP] * 255.0;
+ }
+ else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
+ rFog = ctx->Fog.Color[RCOMP] * 65535.0;
+ gFog = ctx->Fog.Color[GCOMP] * 65535.0;
+ bFog = ctx->Fog.Color[BCOMP] * 65535.0;
+ }
+ else {
+ rFog = ctx->Fog.Color[RCOMP];
+ gFog = ctx->Fog.Color[GCOMP];
+ bFog = ctx->Fog.Color[BCOMP];
+ }
+
+ if (swrast->_PreferPixelFog) {
+ /* The span's fog values are fog coordinates, now compute blend factors
+ * and blend the fragment colors with the fog color.
+ */
+ switch (swrast->_FogMode) {
+ case GL_LINEAR:
+ {
+ const GLfloat fogEnd = ctx->Fog.End;
+ const GLfloat fogScale = (ctx->Fog.Start == ctx->Fog.End)
+ ? 1.0F : 1.0F / (ctx->Fog.End - ctx->Fog.Start);
+ if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+ GLubyte (*rgba)[4] = span->array->rgba8;
+ FOG_LOOP(GLubyte, LINEAR_FOG);
+ }
+ else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
+ GLushort (*rgba)[4] = span->array->rgba16;
+ FOG_LOOP(GLushort, LINEAR_FOG);
+ }
+ else {
+ GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+ ASSERT(span->array->ChanType == GL_FLOAT);
+ FOG_LOOP(GLfloat, LINEAR_FOG);
+ }
+ }
+ break;
+
+ case GL_EXP:
+ {
+ const GLfloat density = -ctx->Fog.Density;
+ if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+ GLubyte (*rgba)[4] = span->array->rgba8;
+ FOG_LOOP(GLubyte, EXP_FOG);
+ }
+ else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
+ GLushort (*rgba)[4] = span->array->rgba16;
+ FOG_LOOP(GLushort, EXP_FOG);
+ }
+ else {
+ GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+ ASSERT(span->array->ChanType == GL_FLOAT);
+ FOG_LOOP(GLfloat, EXP_FOG);
+ }
+ }
+ break;
+
+ case GL_EXP2:
+ {
+ const GLfloat negDensitySquared = -ctx->Fog.Density * ctx->Fog.Density;
+ if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+ GLubyte (*rgba)[4] = span->array->rgba8;
+ FOG_LOOP(GLubyte, EXP2_FOG);
+ }
+ else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
+ GLushort (*rgba)[4] = span->array->rgba16;
+ FOG_LOOP(GLushort, EXP2_FOG);
+ }
+ else {
+ GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+ ASSERT(span->array->ChanType == GL_FLOAT);
+ FOG_LOOP(GLfloat, EXP2_FOG);
+ }
+ }
+ break;
+
+ default:
+ _mesa_problem(ctx, "Bad fog mode in _swrast_fog_rgba_span");
+ return;
+ }
+ }
+ else {
+ /* The span's fog start/step/array values are blend factors in [0,1].
+ * They were previously computed per-vertex.
+ */
+ if (span->array->ChanType == GL_UNSIGNED_BYTE) {
+ GLubyte (*rgba)[4] = span->array->rgba8;
+ FOG_LOOP(GLubyte, BLEND_FOG);
+ }
+ else if (span->array->ChanType == GL_UNSIGNED_SHORT) {
+ GLushort (*rgba)[4] = span->array->rgba16;
+ FOG_LOOP(GLushort, BLEND_FOG);
+ }
+ else {
+ GLfloat (*rgba)[4] = span->array->attribs[FRAG_ATTRIB_COL0];
+ ASSERT(span->array->ChanType == GL_FLOAT);
+ FOG_LOOP(GLfloat, BLEND_FOG);
+ }
+ }
+}
+
+
+/**
+ * As above, but color index mode.
+ */
+void
+_swrast_fog_ci_span( const GLcontext *ctx, SWspan *span )
+{
+ const SWcontext *swrast = CONST_SWRAST_CONTEXT(ctx);
+ const GLuint fogIndex = (GLuint) ctx->Fog.Index;
+ GLuint *index = span->array->index;
+
+ ASSERT(swrast->_FogEnabled);
+ ASSERT(span->arrayMask & SPAN_INDEX);
+
+ /* we need to compute fog blend factors */
+ if (swrast->_PreferPixelFog) {
+ /* The span's fog values are fog coordinates, now compute blend factors
+ * and blend the fragment colors with the fog color.
+ */
+ switch (ctx->Fog.Mode) {
+ case GL_LINEAR:
+ {
+ const GLfloat fogEnd = ctx->Fog.End;
+ const GLfloat fogScale = (ctx->Fog.Start == ctx->Fog.End)
+ ? 1.0F : 1.0F / (ctx->Fog.End - ctx->Fog.Start);
+ FOG_LOOP_CI(LINEAR_FOG);
+ }
+ break;
+ case GL_EXP:
+ {
+ const GLfloat density = -ctx->Fog.Density;
+ FOG_LOOP_CI(EXP_FOG);
+ }
+ break;
+ case GL_EXP2:
+ {
+ const GLfloat negDensitySquared = -ctx->Fog.Density * ctx->Fog.Density;
+ FOG_LOOP_CI(EXP2_FOG);
+ }
+ break;
+ default:
+ _mesa_problem(ctx, "Bad fog mode in _swrast_fog_ci_span");
+ return;
+ }
+ }
+ else {
+ /* The span's fog start/step/array values are blend factors in [0,1].
+ * They were previously computed per-vertex.
+ */
+ FOG_LOOP_CI(BLEND_FOG);
+ }
+}
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