1 files changed, 96 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/r200/r200_tcl.c b/src/mesa/drivers/dri/r200/r200_tcl.c
index 78d16ed0f3..d2dfc5fda1 100644
--- a/src/mesa/drivers/dri/r200/r200_tcl.c
+++ b/src/mesa/drivers/dri/r200/r200_tcl.c
@@ -269,6 +269,90 @@ void r200TclPrimitive( GLcontext *ctx,
 
 
 /**********************************************************************/
+/*             Fog blend factor computation for hw tcl                */
+/*             same calculation used as in t_vb_fog.c                 */
+/**********************************************************************/
+
+#define FOG_EXP_TABLE_SIZE 256
+#define FOG_MAX (10.0)
+#define EXP_FOG_MAX .0006595
+#define FOG_INCR (FOG_MAX/FOG_EXP_TABLE_SIZE)
+static GLfloat exp_table[FOG_EXP_TABLE_SIZE];
+
+#if 1
+#define NEG_EXP( result, narg )						\
+do {									\
+   GLfloat f = (GLfloat) (narg * (1.0/FOG_INCR));			\
+   GLint k = (GLint) f;							\
+   if (k > FOG_EXP_TABLE_SIZE-2) 					\
+      result = (GLfloat) EXP_FOG_MAX;					\
+   else									\
+      result = exp_table[k] + (f-k)*(exp_table[k+1]-exp_table[k]);	\
+} while (0)
+#else
+#define NEG_EXP( result, narg )					\
+do {								\
+   result = exp(-narg);						\
+} while (0)
+#endif
+
+
+/**
+ * Initialize the exp_table[] lookup table for approximating exp().
+ */
+void
+r200InitStaticFogData( void )
+{
+   GLfloat f = 0.0F;
+   GLint i = 0;
+   for ( ; i < FOG_EXP_TABLE_SIZE ; i++, f += FOG_INCR) {
+      exp_table[i] = (GLfloat) exp(-f);
+   }
+}
+
+
+/**
+ * Compute per-vertex fog blend factors from fog coordinates by
+ * evaluating the GL_LINEAR, GL_EXP or GL_EXP2 fog function.
+ * Fog coordinates are distances from the eye (typically between the
+ * near and far clip plane distances).
+ * Note the fog (eye Z) coords may be negative so we use ABS(z) below.
+ * Fog blend factors are in the range [0,1].
+ */
+float
+r200ComputeFogBlendFactor( GLcontext *ctx, GLfloat fogcoord )
+{
+   GLfloat end  = ctx->Fog.End;
+   GLfloat d, temp;
+   const GLfloat z = FABSF(fogcoord);
+
+   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);
+      temp = (end - z) * d;
+      return CLAMP(temp, 0.0F, 1.0F);
+      break;
+   case GL_EXP:
+      d = ctx->Fog.Density;
+      NEG_EXP( temp, d * z );
+      return temp;
+      break;
+   case GL_EXP2:
+      d = ctx->Fog.Density*ctx->Fog.Density;
+      NEG_EXP( temp, d * z * z );
+      return temp;
+      break;
+   default:
+      _mesa_problem(ctx, "Bad fog mode in make_fog_coord");
+      return 0;
+   }
+}
+
+
+/**********************************************************************/
 /*                          Render pipeline stage                     */
 /**********************************************************************/
 
@@ -349,6 +433,10 @@ static void r200_check_tcl_render( GLcontext *ctx,
 	 }
       }
 
+      if ( ctx->Fog.FogCoordinateSource == GL_FOG_COORD ) {
+	 inputs |= VERT_BIT_FOG;
+      }
+
       for (unit = 0 ; unit < ctx->Const.MaxTextureUnits; unit++) {
 	 if (ctx->Texture.Unit[unit]._ReallyEnabled) {
 	    if (rmesa->TexGenNeedNormals[unit]) {
@@ -457,6 +545,14 @@ static void transition_to_hwtnl( GLcontext *ctx )
    rmesa->hw.vap.cmd[VAP_SE_VAP_CNTL] |= R200_VAP_TCL_ENABLE;
    rmesa->hw.vap.cmd[VAP_SE_VAP_CNTL] &= ~R200_VAP_FORCE_W_TO_ONE;
 
+   if ( ((rmesa->hw.ctx.cmd[CTX_PP_FOG_COLOR] & R200_FOG_USE_MASK)
+      == R200_FOG_USE_SPEC_ALPHA) &&
+      (ctx->Fog.FogCoordinateSource == GL_FOG_COORD )) {
+      R200_STATECHANGE( rmesa, ctx );
+      rmesa->hw.ctx.cmd[CTX_PP_FOG_COLOR] &= ~R200_FOG_USE_MASK;
+      rmesa->hw.ctx.cmd[CTX_PP_FOG_COLOR] |= R200_FOG_USE_VTX_FOG;
+   }
+   
    R200_STATECHANGE( rmesa, vte );
    rmesa->hw.vte.cmd[VTE_SE_VTE_CNTL] &= ~(R200_VTX_XY_FMT|R200_VTX_Z_FMT);