-
-
-/**
- * As above, but color index mode.
- */
-void
-_swrast_fog_ci_span( const GLcontext *ctx, SWspan *span )
-{
- const SWcontext *swrast = 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);
- }
-}