-/* $Id: s_fog.c,v 1.14 2001/09/19 20:30:44 kschultz Exp $ */
+/* $Id: s_fog.c,v 1.23 2002/08/07 00:45:07 brianp Exp $ */
/*
* Mesa 3-D graphics library
- * Version: 3.5
+ * Version: 4.1
*
- * Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
+ * Copyright (C) 1999-2002 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"),
#include "s_context.h"
#include "s_fog.h"
-#include "s_pb.h"
+#include "s_span.h"
-/*
+/**
* Used to convert current raster distance to a fog factor in [0,1].
*/
GLfloat
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 an array of RGBA pixels.
- * Input: n - number of pixels
- * 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( const GLcontext *ctx,
- GLuint n,
- const GLfloat fog[],
- GLchan rgba[][4] )
-{
- GLuint i;
- GLchan rFog, gFog, bFog;
-
- 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 < n; 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 an array of color index pixels.
- * Input: n - number of pixels
- * fog - array of fog factors in [0,1]
- * index - pixel color indexes
- * Output: index - fogged pixel color indexes
- */
-void
-_mesa_fog_ci_pixels( const GLcontext *ctx,
- GLuint n, const GLfloat fog[], GLuint index[] )
-{
- GLuint idx = (GLuint) ctx->Fog.Index;
- GLuint i;
-
- for (i = 0; i < n; 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
* z - array of integer depth values
const GLdepth z[],
GLfloat fogFact[] )
{
- const GLboolean ortho = (ctx->ProjectionMatrix.m[15] != 0.0F);
- const GLfloat p10 = ctx->ProjectionMatrix.m[10];
- const GLfloat p14 = ctx->ProjectionMatrix.m[14];
+ const GLfloat *proj = ctx->ProjectionMatrixStack.Top->m;
+ const GLboolean ortho = (proj[15] != 0.0F);
+ const GLfloat p10 = proj[10];
+ const GLfloat p14 = proj[14];
const GLfloat tz = ctx->Viewport._WindowMap.m[MAT_TZ];
GLfloat szInv;
GLuint i;
for (i=0;i<n;i++) {
GLfloat ndcz = ((GLfloat) z[i] - tz) * szInv;
GLfloat eyez = (ndcz - p14) / p10;
+ GLfloat f;
if (eyez < 0.0)
eyez = -eyez;
- fogFact[i] = (fogEnd - eyez) * fogScale;
+ f = (fogEnd - eyez) * fogScale;
+ fogFact[i] = CLAMP(f, 0.0F, 1.0F);
}
}
else {
for (i=0;i<n;i++) {
GLfloat ndcz = ((GLfloat) z[i] - tz) * szInv;
GLfloat eyez = p14 / (ndcz + p10);
+ GLfloat f;
if (eyez < 0.0)
eyez = -eyez;
- fogFact[i] = (fogEnd - eyez) * fogScale;
+ f = (fogEnd - eyez) * fogScale;
+ fogFact[i] = CLAMP(f, 0.0F, 1.0F);
}
}
}
}
-/*
- * Apply fog to an array of RGBA pixels.
- * Input: n - number of pixels
- * z - array of integer depth values
- * red, green, blue, alpha - pixel colors
- * Output: red, green, blue, alpha - fogged pixel colors
+
+/**
+ * Apply fog to a span of RGBA pixels.
+ * The fog factors are either in the span->array->fog 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,
- GLuint n, const GLdepth z[], GLchan rgba[][4] )
+_mesa_fog_rgba_span( const GLcontext *ctx, struct sw_span *span )
{
- GLfloat fogFact[PB_SIZE];
- ASSERT(n <= PB_SIZE);
- compute_fog_factors_from_z( ctx, n, z, fogFact );
- _mesa_fog_rgba_pixels( ctx, n, fogFact, rgba );
+ const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+ const GLuint n = span->end;
+ GLchan (*rgba)[4] = (GLchan (*)[4]) span->array->rgba;
+ GLchan rFog, gFog, bFog;
+
+ ASSERT(ctx->Fog.Enabled);
+ ASSERT((span->interpMask | span->arrayMask) & 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]);
+
+ 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->array->z, span->array->fog);
+ span->arrayMask |= SPAN_FOG;
+ }
+
+ if (span->arrayMask & SPAN_FOG) {
+ /* use fog array in span */
+ GLuint i;
+ for (i = 0; i < n; i++) {
+ const GLfloat fog = span->array->fog[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 {
+ /* interpolate fog factors */
+ 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 an array of color index pixels.
- * Input: n - number of pixels
- * z - array of integer depth values
- * 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,
- GLuint n, const GLdepth z[], GLuint index[] )
+_mesa_fog_ci_span( const GLcontext *ctx, struct sw_span *span )
{
- GLfloat fogFact[PB_SIZE];
- ASSERT(n <= PB_SIZE);
- compute_fog_factors_from_z( ctx, n, z, fogFact );
- _mesa_fog_ci_pixels( ctx, n, fogFact, index );
+ const SWcontext *swrast = SWRAST_CONTEXT(ctx);
+ const GLuint n = span->end;
+ GLuint *index = span->array->index;
+
+ ASSERT(ctx->Fog.Enabled);
+ 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->array->z, span->array->fog);
+ span->arrayMask |= SPAN_FOG;
+ }
+
+ 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->array->fog[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;
+ }
+ }
}
projects / mesa.git / blobdiff