From: Brian <brian.paul@tungstengraphics.com>
Date: Wed, 11 Jul 2007 19:02:03 +0000 (-0600)
Subject: Fix broken depth offset.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=aac212966314852936352b024bfd897485aa5e83;p=mesa.git

Fix broken depth offset.

The edge vectors were totally wrong.
Need to multiply bias units by the min resolvable depth delta.
---

diff --git a/src/mesa/pipe/draw/draw_offset.c b/src/mesa/pipe/draw/draw_offset.c
index 62ab2e46430..1a412656179 100644
--- a/src/mesa/pipe/draw/draw_offset.c
+++ b/src/mesa/pipe/draw/draw_offset.c
@@ -54,8 +54,9 @@ static INLINE struct offset_stage *offset_stage( struct prim_stage *stage )
 static void offset_begin( struct prim_stage *stage )
 {
    struct offset_stage *offset = offset_stage(stage);
+   GLfloat mrd = 1.0 / 65535.0; /* XXX this depends on depthbuffer bits! */
 
-   offset->units = stage->draw->setup.offset_units;
+   offset->units = stage->draw->setup.offset_units * mrd;
    offset->scale = stage->draw->setup.offset_scale;
 
    stage->next->begin( stage->next );
@@ -79,11 +80,11 @@ static void do_offset_tri( struct prim_stage *stage,
    GLfloat *v2 = header->v[2]->data[0];
 
    /* edge vectors e = v0 - v2, f = v1 - v2 */
-   GLfloat ex = v0[0] - v2[2];
-   GLfloat ey = v0[1] - v2[2];
+   GLfloat ex = v0[0] - v2[0];
+   GLfloat ey = v0[1] - v2[1];
    GLfloat ez = v0[2] - v2[2];
-   GLfloat fx = v1[0] - v2[2];
-   GLfloat fy = v1[1] - v2[2];
+   GLfloat fx = v1[0] - v2[0];
+   GLfloat fy = v1[1] - v2[1];
    GLfloat fz = v1[2] - v2[2];
 
    /* (a,b) = cross(e,f).xy */