r300: Fix new incarnation of bug 3195.

tests/bug_3195 doesn't render right, but at least it doesn't segfault this way.

3 files changed, 16 insertions, 6 deletions

diff --git a/progs/demos/lodbias.c b/progs/demos/lodbias.c
index c5a2a1b4573..28215d46c07 100644
--- a/progs/demos/lodbias.c
+++ b/progs/demos/lodbias.c
@@ -40,7 +40,7 @@
 
 static GLfloat Xrot = 0, Yrot = -30, Zrot = 0;
 static GLboolean Anim = GL_TRUE;
-static GLint Bias = 0, BiasStepSign = +1; /* ints avoid fp precision problem */
+static GLint Bias = 4, BiasStepSign = +1; /* ints avoid fp precision problem */
 static GLint BiasMin = -400, BiasMax = 400;
 
 
diff --git a/src/mesa/drivers/dri/r300/r300_context.h b/src/mesa/drivers/dri/r300/r300_context.h
index 1a90f5cabb2..6279a67ab16 100644
--- a/src/mesa/drivers/dri/r300/r300_context.h
+++ b/src/mesa/drivers/dri/r300/r300_context.h
@@ -925,6 +925,7 @@ struct r300_context {
 	driTextureObject swapped;
 	int texture_depth;
 	float initialMaxAnisotropy;
+	float LODBias;
 
 	/* Clientdata textures;
 	 */
diff --git a/src/mesa/drivers/dri/r300/r300_tex.c b/src/mesa/drivers/dri/r300/r300_tex.c
index b672baca1b6..a3d6f90ef6a 100644
--- a/src/mesa/drivers/dri/r300/r300_tex.c
+++ b/src/mesa/drivers/dri/r300/r300_tex.c
@@ -1005,6 +1005,7 @@ static GLenum r300TexUnitTarget(struct gl_texture_unit *unit) {
 	} else if (unit->Enabled & (TEXTURE_CUBE_BIT)) {
 		return GL_TEXTURE_CUBE_MAP;
 	}
+	return 0;
 }
 
 static void r300TexEnv(GLcontext * ctx, GLenum target,
@@ -1037,13 +1038,17 @@ static void r300TexEnv(GLcontext * ctx, GLenum target,
 
 		/* This next part feels quite hackish;
 		 * is there a cleaner way? */
-		struct gl_texture_object *texObj;
 		GLenum target = r300TexUnitTarget(&ctx->Texture.Unit[ctx->Texture.CurrentUnit]);
-		texObj = _mesa_select_tex_object(ctx, &ctx->Texture.Unit[ctx->Texture.CurrentUnit], target);
-		r300TexObjPtr t = (r300TexObjPtr) texObj->DriverData;
-		texObj->LodBias = bias;
+		if (target) {
+			struct gl_texture_object *texObj =
+				_mesa_select_tex_object(ctx, &ctx->Texture.Unit[ctx->Texture.CurrentUnit], target);
+			r300TexObjPtr t = (r300TexObjPtr) texObj->DriverData;
+			texObj->LodBias = bias;
 
-		r300SetTexLodBias(t, texObj->LodBias);
+			r300SetTexLodBias(t, texObj->LodBias);
+		}
+
+		rmesa->LODBias = bias;
 
 		break;
 	}
@@ -1175,6 +1180,10 @@ static struct gl_texture_object *r300NewTextureObject(GLcontext * ctx,
 		return NULL;
 	obj->MaxAnisotropy = rmesa->initialMaxAnisotropy;
 
+	/* Attempt to fill LOD bias, if previously set.
+	 * Should start at 0.0, which won't affect the HW. */
+	obj->LodBias = rmesa->LODBias;
+
 	r300AllocTexObj(obj);
 	return obj;
 }