From dfe7aedf845ce9117065c6cee2146df7eee1c0fa Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 7 Oct 2005 03:56:29 +0000
Subject: Fix a number of point size attenuation problems. Move size clamping
 into the rasterization function.

---
 src/mesa/tnl/t_vb_points.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

(limited to 'src/mesa/tnl/t_vb_points.c')

diff --git a/src/mesa/tnl/t_vb_points.c b/src/mesa/tnl/t_vb_points.c
index ccceba3262d..47c37930d57 100644
--- a/src/mesa/tnl/t_vb_points.c
+++ b/src/mesa/tnl/t_vb_points.c
@@ -1,8 +1,8 @@
 /*
  * Mesa 3-D graphics library
- * Version:  6.1
+ * Version:  6.5
  *
- * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2005  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"),
@@ -38,11 +38,14 @@ struct point_stage_data {
 #define POINT_STAGE_DATA(stage) ((struct point_stage_data *)stage->privatePtr)
 
 
-/*
- * Compute attenuated point sizes
+/**
+ * Compute point size for each vertex from the vertex eye-space Z
+ * coordinate and the point size attenuation factors.
+ * Only done when point size attenuation is enabled and vertex program is
+ * disabled.
  */
-static GLboolean run_point_stage( GLcontext *ctx,
-				  struct tnl_pipeline_stage *stage )
+static GLboolean
+run_point_stage(GLcontext *ctx, struct tnl_pipeline_stage *stage)
 {
    if (ctx->Point._Attenuated && !ctx->VertexProgram._Enabled) {
       struct point_stage_data *store = POINT_STAGE_DATA(stage);
@@ -51,14 +54,15 @@ static GLboolean run_point_stage( GLcontext *ctx,
       const GLfloat p0 = ctx->Point.Params[0];
       const GLfloat p1 = ctx->Point.Params[1];
       const GLfloat p2 = ctx->Point.Params[2];
-      const GLfloat pointSize = ctx->Point._Size;
+      const GLfloat pointSize = ctx->Point.Size;
       GLfloat (*size)[4] = store->PointSize.data;
       GLuint i;
 
       for (i = 0; i < VB->Count; i++) {
-	 const GLfloat dist = -eye[i][2];
-	 /* GLfloat dist = SQRTF(pos[0]*pos[0]+pos[1]*pos[1]+pos[2]*pos[2]);*/
-	 size[i][0] = pointSize / (p0 + dist * (p1 + dist * p2));
+         const GLfloat dist = FABSF(eye[i][2]);
+         const GLfloat q = p0 + dist * (p1 + dist * p2);
+         const GLfloat atten = (q != 0.0) ? SQRTF(1.0 / q) : 1.0;
+         size[i][0] = pointSize * atten; /* clamping done in rasterization */
       }
 
       VB->PointSizePtr = &store->PointSize;
@@ -69,13 +73,12 @@ static GLboolean run_point_stage( GLcontext *ctx,
 }
 
 
-
-static GLboolean alloc_point_data( GLcontext *ctx,
-				   struct tnl_pipeline_stage *stage )
+static GLboolean
+alloc_point_data(GLcontext *ctx, struct tnl_pipeline_stage *stage)
 {
    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
    struct point_stage_data *store;
-   stage->privatePtr = MALLOC(sizeof(*store));
+   stage->privatePtr = _mesa_malloc(sizeof(*store));
    store = POINT_STAGE_DATA(stage);
    if (!store)
       return GL_FALSE;
@@ -85,16 +88,18 @@ static GLboolean alloc_point_data( GLcontext *ctx,
 }
 
 
-static void free_point_data( struct tnl_pipeline_stage *stage )
+static void
+free_point_data(struct tnl_pipeline_stage *stage)
 {
    struct point_stage_data *store = POINT_STAGE_DATA(stage);
    if (store) {
       _mesa_vector4f_free( &store->PointSize );
-      FREE( store );
+      _mesa_free( store );
       stage->privatePtr = NULL;
    }
 }
 
+
 const struct tnl_pipeline_stage _tnl_point_attenuation_stage =
 {
    "point size attenuation",	/* name */
-- 
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