Mesa (master): mesa: Update image unit state when glBindImageTexture is called with texture=0.

[Francisco Jerez]

Module: Mesa
Branch: master
Commit: b5854ee72b25078616f04b49004011036fef5a87
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=b5854ee72b25078616f04b49004011036fef5a87

Author: Francisco Jerez <currojerez at riseup.net>
Date:   Wed Jan 21 16:47:02 2015 +0200

mesa: Update image unit state when glBindImageTexture is called with texture=0.

There's no indication in the spec that the image unit state other than the
bound texture object shouldn't be updated when glBindImageTexture() is called
passing the zero texture as argument.  It's very unlikely that any application
would ever have relied on this, but it's easy to get right, and it fixes the
"state" ARB_shader_image_load_store piglit test.

Reviewed-by: Matt Turner <mattst88 at gmail.com>

---

 src/mesa/main/shaderimage.c |   31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
index efe439c..80b7727 100644
--- a/src/mesa/main/shaderimage.c
+++ b/src/mesa/main/shaderimage.c
@@ -456,7 +456,6 @@ _mesa_BindImageTexture(GLuint unit, GLuint texture, GLint level,
                        GLenum format)
 {
    GET_CURRENT_CONTEXT(ctx);
-   struct gl_texture_object *t = NULL;
    struct gl_image_unit *u;
 
    if (!validate_bind_image_texture(ctx, unit, texture, level,
@@ -469,34 +468,34 @@ _mesa_BindImageTexture(GLuint unit, GLuint texture, GLint level,
    ctx->NewDriverState |= ctx->DriverFlags.NewImageUnits;
 
    if (texture) {
-      t = _mesa_lookup_texture(ctx, texture);
+      struct gl_texture_object *t = _mesa_lookup_texture(ctx, texture);
+
       if (!t) {
          _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(texture)");
          return;
       }
 
       _mesa_reference_texobj(&u->TexObj, t);
-      u->Level = level;
-      u->Access = access;
-      u->Format = format;
-      u->_ActualFormat = _mesa_get_shader_image_format(format);
-
-      if (_mesa_tex_target_is_layered(t->Target)) {
-         u->Layered = layered;
-         u->Layer = (layered ? 0 : layer);
-      } else {
-         u->Layered = GL_FALSE;
-         u->Layer = 0;
-      }
-
    } else {
       _mesa_reference_texobj(&u->TexObj, NULL);
    }
 
+   u->Level = level;
+   u->Access = access;
+   u->Format = format;
+   u->_ActualFormat = _mesa_get_shader_image_format(format);
    u->_Valid = validate_image_unit(ctx, u);
 
+   if (u->TexObj && _mesa_tex_target_is_layered(u->TexObj->Target)) {
+      u->Layered = layered;
+      u->Layer = (layered ? 0 : layer);
+   } else {
+      u->Layered = GL_FALSE;
+      u->Layer = 0;
+   }
+
    if (ctx->Driver.BindImageTexture)
-      ctx->Driver.BindImageTexture(ctx, u, t, level, layered,
+      ctx->Driver.BindImageTexture(ctx, u, u->TexObj, level, layered,
                                    layer, access, format);
 }