diff options
| -rw-r--r-- | src/mesa/swrast/s_fog.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/src/mesa/swrast/s_fog.c b/src/mesa/swrast/s_fog.c index 6e6c207aa4..f103bdb02d 100644 --- a/src/mesa/swrast/s_fog.c +++ b/src/mesa/swrast/s_fog.c @@ -1,4 +1,4 @@ -/* $Id: s_fog.c,v 1.7 2001/01/03 15:59:30 brianp Exp $ */ +/* $Id: s_fog.c,v 1.8 2001/01/03 22:55:26 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -119,9 +119,14 @@ _mesa_win_fog_coords_from_z( const GLcontext *ctx, const GLfloat p10 = ctx->ProjectionMatrix.m[10]; const GLfloat p14 = ctx->ProjectionMatrix.m[14]; const GLfloat tz = ctx->Viewport._WindowMap.m[MAT_TZ]; - const GLfloat szInv = 1.0F / ctx->Viewport._WindowMap.m[MAT_SZ]; + GLfloat szInv; GLuint i; + if (ctx->Viewport._WindowMap.m[MAT_SZ] == 0.0) + szInv = 1.0F; + else + szInv = 1.0F / ctx->Viewport._WindowMap.m[MAT_SZ]; + /* * Note: to compute eyeZ from the ndcZ we have to solve the following: * @@ -149,7 +154,11 @@ _mesa_win_fog_coords_from_z( const GLcontext *ctx, case GL_LINEAR: { GLfloat fogEnd = ctx->Fog.End; - GLfloat fogScale = 1.0F / (ctx->Fog.End - ctx->Fog.Start); + GLfloat fogScale; + if (ctx->Fog.Start == ctx->Fog.End) + fogScale = 1.0; + else + fogScale = 1.0F / (ctx->Fog.End - ctx->Fog.Start); if (ortho) { for (i=0;i<n;i++) { GLfloat ndcz = ((GLfloat) z[i] - tz) * szInv; |