From a0c4815433ccd57322f4f7703ca35e9ccfa59250 Mon Sep 17 00:00:00 2001 From: marha Date: Thu, 8 Oct 2009 13:15:52 +0000 Subject: Added MesaLib-7.6 --- mesalib/src/mesa/swrast/s_fog.c | 330 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 330 insertions(+) create mode 100644 mesalib/src/mesa/swrast/s_fog.c (limited to 'mesalib/src/mesa/swrast/s_fog.c') 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); + } +} -- cgit v1.2.3