Commit 66a5edd3 authored by Robert Bragg's avatar Robert Bragg

[mutter-shaped-texture] workaround multi-tex combine mode for RGB tfp textures

It seems that with the latest intel drivers when multi-texturing using an RGB
TFP texture, the texture is being setup internally as an RGBA texture, where
the alpha channel is mostly 0.0 so you only see a shimmer of the window. This
workaround forcibly defines the alpha channel as 1.0. Maybe there is some
clutter/cogl state that is interacting with this that is being overlooked,
but for now this seems to work. (Tested on i945 + DRI2)
parent 9ebb135c
......@@ -365,6 +365,15 @@ mutter_shaped_texture_paint (ClutterActor *actor)
GLfloat vertex_coords[8], paint_tex_coords[8];
ClutterActorBox alloc;
static const ClutterColor white = { 0xff, 0xff, 0xff, 0xff };
#if 1 /* please see comment below about workaround */
guint depth;
GLint orig_gl_tex_env_mode;
GLint orig_gl_combine_alpha;
GLint orig_gl_src0_alpha;
GLfloat orig_gl_tex_env_color[4];
gboolean need_to_restore_tex_env = FALSE;
const GLfloat const_alpha[4] = { 0.0, 0.0, 0.0, 1.0 };
#endif
if (!CLUTTER_ACTOR_IS_REALIZED (CLUTTER_ACTOR (stex)))
clutter_actor_realize (CLUTTER_ACTOR (stex));
......@@ -430,6 +439,36 @@ mutter_shaped_texture_paint (ClutterActor *actor)
&paint_gl_width,
&paint_gl_height);
#if 1
/* This was added as a workaround. It seems that with the intel drivers when
* multi-texturing using an RGB TFP texture, the texture is actually
* setup internally as an RGBA texture, where the alpha channel is mostly
* 0.0 so you only see a shimmer of the window. This workaround forcibly
* defines the alpha channel as 1.0. Maybe there is some clutter/cogl state
* that is interacting with this that is being overlooked, but for now this
* seems to work. */
g_object_get (G_OBJECT (stex), "pixmap-depth", &depth, NULL);
if (depth == 24)
{
glGetTexEnviv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,
&orig_gl_tex_env_mode);
glGetTexEnviv (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, &orig_gl_combine_alpha);
glGetTexEnviv (GL_TEXTURE_ENV, GL_SRC0_ALPHA, &orig_gl_src0_alpha);
glGetTexEnvfv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR,
orig_gl_tex_env_color);
need_to_restore_tex_env = TRUE;
glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_REPLACE);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_CONSTANT);
glTexEnvfv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, const_alpha);
/* Replace the RGB in the second texture with that of the first
texture */
glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_REPLACE);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_RGB, GL_PREVIOUS);
}
#endif
/* Put the mask texture in the second texture unit */
tst_active_texture (GL_TEXTURE1);
tst_client_active_texture (GL_TEXTURE1);
......@@ -442,11 +481,33 @@ mutter_shaped_texture_paint (ClutterActor *actor)
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
#if 1 /* see workaround notes above */
if (depth == 24)
{
/* NOTE: This should be redundant, since we already explicitly forced an
* an alhpa value of 1.0 for texture unit 0, but this workaround only
* seems to help if we explicitly force the alpha values for both texture
* units. */
/* XXX - we should also save/restore the values for this texture unit too
*/
glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_TEXTURE);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC1_ALPHA, GL_CONSTANT);
glTexEnvfv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, const_alpha);
}
else
{
#endif
/* Multiply the alpha by the alpha in the second texture */
glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_MODULATE);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, GL_TEXTURE);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC1_ALPHA, GL_PREVIOUS);
#if 1 /* see workaround notes above */
}
#endif
/* Replace the RGB in the second texture with that of the first
texture */
glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_REPLACE);
......@@ -497,6 +558,15 @@ mutter_shaped_texture_paint (ClutterActor *actor)
glDisableClientState (GL_TEXTURE_COORD_ARRAY);
if (color_array_was_enabled)
glEnableClientState (GL_COLOR_ARRAY);
#if 1 /* see note about workaround above */
if (need_to_restore_tex_env)
{
glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, orig_gl_tex_env_mode);
glTexEnvi (GL_TEXTURE_ENV, GL_COMBINE_ALPHA, orig_gl_combine_alpha);
glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA, orig_gl_src0_alpha);
glTexEnvfv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR, orig_gl_tex_env_color);
}
#endif
}
static void
......
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