svn merge ^/branches/released . --username marha

1 files changed, 330 insertions, 0 deletions

diff --git a/mesalib/src/mesa/swrast/s_fog.c b/mesalib/src/mesa/swrast/s_fog.c
new file mode 100644
index 000000000..77ed0cfef
--- /dev/null
+++ b/mesalib/src/mesa/swrast/s_fog.c
@@ -0,0 +1,330 @@
+/*
+ * 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);
+   }
+}