From 711e27fda27e4235b20a4cf73c2767c984ab2b81 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Sun, 17 Feb 2002 17:30:57 +0000 Subject: Simplified fog code. --- src/mesa/swrast/s_fog.c | 226 +++++++++++++++++------------------------------- 1 file changed, 80 insertions(+), 146 deletions(-) (limited to 'src/mesa/swrast/s_fog.c') diff --git a/src/mesa/swrast/s_fog.c b/src/mesa/swrast/s_fog.c index caaefcb688..0988ebb1a7 100644 --- a/src/mesa/swrast/s_fog.c +++ b/src/mesa/swrast/s_fog.c @@ -1,4 +1,4 @@ -/* $Id: s_fog.c,v 1.21 2002/02/02 21:40:33 brianp Exp $ */ +/* $Id: s_fog.c,v 1.22 2002/02/17 17:30:58 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -33,6 +33,7 @@ #include "s_context.h" #include "s_fog.h" +#include "s_span.h" @@ -62,134 +63,13 @@ _mesa_z_to_fogfactor(GLcontext *ctx, GLfloat z) f = (GLfloat) exp(-(d * d * z * z)); return f; default: - _mesa_problem(ctx, "Bad fog mode in make_fog_coord"); + _mesa_problem(ctx, "Bad fog mode in _mesa_z_to_fogfactor"); return 0.0; } } -/** - * Apply fog to a span of RGBA pixels. - * Input: ctx - - * span - where span->fog and span->fogStep have to be set. - * red, green, blue, alpha - pixel colors - * Output: red, green, blue, alpha - fogged pixel colors - */ -void -_mesa_fog_rgba_pixels( const GLcontext *ctx, struct sw_span *span, - GLchan rgba[][4] ) -{ - GLuint i; - GLfloat fog = span->fog, Dfog = span->fogStep; - GLchan rFog, gFog, bFog; - - ASSERT(ctx->Fog.Enabled); - ASSERT(span->interpMask & SPAN_FOG); - ASSERT(span->arrayMask & SPAN_RGBA); - - UNCLAMPED_FLOAT_TO_CHAN(rFog, ctx->Fog.Color[RCOMP]); - UNCLAMPED_FLOAT_TO_CHAN(gFog, ctx->Fog.Color[GCOMP]); - UNCLAMPED_FLOAT_TO_CHAN(bFog, ctx->Fog.Color[BCOMP]); - - for (i = 0; i < span->end; i++) { - const GLfloat one_min_fog = 1.0F - fog; - rgba[i][RCOMP] = (GLchan) (fog * rgba[i][RCOMP] + one_min_fog * rFog); - rgba[i][GCOMP] = (GLchan) (fog * rgba[i][GCOMP] + one_min_fog * gFog); - rgba[i][BCOMP] = (GLchan) (fog * rgba[i][BCOMP] + one_min_fog * bFog); - fog += Dfog; - } -} - - -/** - * Apply fog given in an array to RGBA pixels. - * Input: ctx - - * span - - * fog - array of fog factors in [0,1] - * red, green, blue, alpha - pixel colors - * Output: red, green, blue, alpha - fogged pixel colors - */ -void -_mesa_fog_rgba_pixels_with_array( const GLcontext *ctx, struct sw_span *span, - const GLfloat fog[], GLchan rgba[][4] ) -{ - GLuint i; - GLchan rFog, gFog, bFog; - - ASSERT(fog != NULL); - ASSERT(ctx->Fog.Enabled); - ASSERT(span->arrayMask & SPAN_RGBA); - - UNCLAMPED_FLOAT_TO_CHAN(rFog, ctx->Fog.Color[RCOMP]); - UNCLAMPED_FLOAT_TO_CHAN(gFog, ctx->Fog.Color[GCOMP]); - UNCLAMPED_FLOAT_TO_CHAN(bFog, ctx->Fog.Color[BCOMP]); - - for (i = span->start; i < span->end; i++) { - const GLfloat f = fog[i]; - const GLfloat g = 1.0F - f; - rgba[i][RCOMP] = (GLchan) (f * rgba[i][RCOMP] + g * rFog); - rgba[i][GCOMP] = (GLchan) (f * rgba[i][GCOMP] + g * gFog); - rgba[i][BCOMP] = (GLchan) (f * rgba[i][BCOMP] + g * bFog); - } -} - - - -/** - * Apply fog to a span of color index pixels. - * Input: ctx - - * span - where span->fog and span->fogStep have to be set. - * index - pixel color indexes - * Output: index - fogged pixel color indexes - */ -void -_mesa_fog_ci_pixels( const GLcontext *ctx, struct sw_span *span, - GLuint index[] ) -{ - GLuint idx = (GLuint) ctx->Fog.Index; - GLuint i; - GLfloat fog = span->fog, Dfog = span->fogStep; - - ASSERT(ctx->Fog.Enabled); - ASSERT(span->interpMask & SPAN_FOG); - ASSERT(span->arrayMask & SPAN_INDEX); - - for (i = 0; i < span->end; i++) { - const GLfloat f = CLAMP(fog, 0.0F, 1.0F); - index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * idx); - fog += Dfog; - } -} - - -/** - * Apply fog given in an array to a span of color index pixels. - * Input: ctx - - * span - - * fog - array of fog factors in [0,1] - * index - pixel color indexes - * Output: index - fogged pixel color indexes - */ -void -_mesa_fog_ci_pixels_with_array( const GLcontext *ctx, struct sw_span *span, - const GLfloat fog[], GLuint index[] ) -{ - GLuint idx = (GLuint) ctx->Fog.Index; - GLuint i; - - ASSERT(fog != NULL); - ASSERT(ctx->Fog.Enabled); - ASSERT(span->arrayMask & SPAN_INDEX); - - for (i = span->start; i < span->end; i++) { - const GLfloat f = CLAMP(fog[i], 0.0F, 1.0F); - index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * idx); - } -} - - - /** * Calculate fog factors (in [0,1]) from window z values * Input: n - number of pixels @@ -331,45 +211,99 @@ compute_fog_factors_from_z( const GLcontext *ctx, } + /** * Apply fog to a span of RGBA pixels. - * Input: ctx - - * span - where span->zArray has to be filled. - * red, green, blue, alpha - pixel colors - * Output: red, green, blue, alpha - fogged pixel colors + * The fog factors are either in the span->fogArray or stored as base/step. + * These are fog _factors_, not fog coords. Fog coords were converted to + * fog factors per vertex. */ void -_mesa_depth_fog_rgba_pixels(const GLcontext *ctx, struct sw_span *span, - GLchan rgba[][4]) +_mesa_fog_rgba_span( const GLcontext *ctx, struct sw_span *span ) { - GLfloat fogFact[MAX_WIDTH]; + const SWcontext *swrast = SWRAST_CONTEXT(ctx); + const GLuint n = span->end; + GLchan (*rgba)[4] = (GLchan (*)[4]) span->color.rgba; + GLchan rFog, gFog, bFog; ASSERT(ctx->Fog.Enabled); - ASSERT(span->arrayMask & SPAN_Z); - ASSERT(span->end <= MAX_WIDTH); + ASSERT((span->interpMask | span->arrayMask) & SPAN_FOG); + ASSERT(span->arrayMask & SPAN_RGBA); - compute_fog_factors_from_z(ctx, span->end, span->zArray, fogFact ); - _mesa_fog_rgba_pixels_with_array( ctx, span, fogFact, rgba ); + UNCLAMPED_FLOAT_TO_CHAN(rFog, ctx->Fog.Color[RCOMP]); + UNCLAMPED_FLOAT_TO_CHAN(gFog, ctx->Fog.Color[GCOMP]); + UNCLAMPED_FLOAT_TO_CHAN(bFog, ctx->Fog.Color[BCOMP]); + + if (swrast->_PreferPixelFog) { + /* compute fog factor from each fragment's Z value */ + if ((span->interpMask & SPAN_Z) && (span->arrayMask & SPAN_Z) == 0) + _mesa_span_interpolate_z(ctx, span); + compute_fog_factors_from_z(ctx, n, span->zArray, span->fogArray); + span->arrayMask |= SPAN_FOG; + } + + if (span->arrayMask & SPAN_FOG) { + GLuint i; + for (i = 0; i < n; i++) { + const GLfloat fog = span->fogArray[i]; + const GLfloat oneMinusFog = 1.0F - fog; + rgba[i][RCOMP] = (GLchan) (fog * rgba[i][RCOMP] + oneMinusFog * rFog); + rgba[i][GCOMP] = (GLchan) (fog * rgba[i][GCOMP] + oneMinusFog * gFog); + rgba[i][BCOMP] = (GLchan) (fog * rgba[i][BCOMP] + oneMinusFog * bFog); + } + } + else { + GLfloat fog = span->fog, dFog = span->fogStep; + GLuint i; + for (i = 0; i < n; i++) { + const GLfloat oneMinusFog = 1.0F - fog; + rgba[i][RCOMP] = (GLchan) (fog * rgba[i][RCOMP] + oneMinusFog * rFog); + rgba[i][GCOMP] = (GLchan) (fog * rgba[i][GCOMP] + oneMinusFog * gFog); + rgba[i][BCOMP] = (GLchan) (fog * rgba[i][BCOMP] + oneMinusFog * bFog); + fog += dFog; + } + } } /** - * Apply fog to a span of color index pixels. - * Input: ctx - - * span - where span->zArray has to be filled. - * index - pixel color indexes - * Output: index - fogged pixel color indexes + * As above, but color index mode. */ void -_mesa_depth_fog_ci_pixels( const GLcontext *ctx, struct sw_span *span, - GLuint index[] ) +_mesa_fog_ci_span( const GLcontext *ctx, struct sw_span *span ) { - GLfloat fogFact[MAX_WIDTH]; + const SWcontext *swrast = SWRAST_CONTEXT(ctx); + const GLuint n = span->end; + GLuint *index = span->color.index; ASSERT(ctx->Fog.Enabled); - ASSERT(span->arrayMask & SPAN_Z); - ASSERT(span->end <= MAX_WIDTH); + ASSERT(span->arrayMask & SPAN_INDEX); + ASSERT((span->interpMask | span->arrayMask) & SPAN_FOG); + + if (swrast->_PreferPixelFog) { + /* compute fog factor from each fragment's Z value */ + if ((span->interpMask & SPAN_Z) && (span->arrayMask & SPAN_Z) == 0) + _mesa_span_interpolate_z(ctx, span); + compute_fog_factors_from_z(ctx, n, span->zArray, span->fogArray); + span->arrayMask |= SPAN_FOG; + } - compute_fog_factors_from_z(ctx, span->end, span->zArray, fogFact ); - _mesa_fog_ci_pixels_with_array( ctx, span, fogFact, index ); + if (span->arrayMask & SPAN_FOG) { + const GLuint idx = (GLuint) ctx->Fog.Index; + GLuint i; + for (i = 0; i < n; i++) { + const GLfloat f = CLAMP(span->fogArray[i], 0.0F, 1.0F); + index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * idx); + } + } + else { + GLfloat fog = span->fog, dFog = span->fogStep; + const GLuint idx = (GLuint) ctx->Fog.Index; + GLuint i; + for (i = 0; i < n; i++) { + const GLfloat f = CLAMP(fog, 0.0F, 1.0F); + index[i] = (GLuint) ((GLfloat) index[i] + (1.0F - f) * idx); + fog += dFog; + } + } } -- cgit v1.2.3