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Don't unpremultiply Cairo data

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Instead of unpremultiplying the Cairo data, pass it directly to Cogl
in premultiplied form; we now *prefer* premultiplied data.

http://bugzilla.openedhand.com/show_bug.cgi?id=1406

Signed-off-by: Robert Bragg <robert@linux.intel.com>
This commit is contained in:
Owen W. Taylor 2009-06-04 13:45:43 -04:00 committed by Robert Bragg
parent c3448314d5
commit 1e5b5d10c5
1 changed files with 9 additions and 49 deletions
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58
clutter/clutter-cairo-texture.c
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@ -292,14 +292,13 @@ clutter_cairo_texture_surface_resize_internal (ClutterCairoTexture *cairo)
cairo,
clutter_cairo_texture_surface_destroy);
/* The texture data will be all zeroes so we can use it to create a
* blank Cogl texture even though its in a different format
/* Create a blank Cogl texture
*/
clutter_texture_set_from_rgb_data (CLUTTER_TEXTURE (cairo),
priv->cr_surface_data,
TRUE, priv->width, priv->height,
priv->rowstride,
4, 0, NULL);
4, CLUTTER_TEXTURE_RGB_FLAG_PREMULT, NULL);
}
static void
@ -451,9 +450,7 @@ clutter_cairo_texture_context_destroy (void *data)
gint cairo_width, cairo_height, cairo_rowstride;
gint surface_width, surface_height;
guchar *pixbuf_data, *dst, *cairo_data;
guint *src, pixbuf_rowstride;
gint x, y;
guchar *cairo_data;
priv = CLUTTER_CAIRO_TEXTURE_GET_PRIVATE (cairo);
@ -473,56 +470,19 @@ clutter_cairo_texture_context_destroy (void *data)
}
cairo_rowstride = priv->rowstride;
cairo_data = priv->cr_surface_data;
pixbuf_data = g_malloc (cairo_width * cairo_height * 4);
pixbuf_rowstride = cairo_width * 4;
/* BAH BAH BAH ! un-pre-multiply alpha...
*
* FIXME: Need to figure out if GL has a premult texture
* format, or we need to change the order of the
* paint sequence in Clutter. or go back to battling
* glitz (ugh).
*
* in theory, this could be moved to a shader, but apparently
* the performance gain is not really worth it.
*/
for (y = 0; y < cairo_height; y++)
{
src = (unsigned int *) (cairo_data
+ ((y + ctxt->rect.y) * cairo_rowstride)
+ (ctxt->rect.x * 4));
dst = pixbuf_data + y * pixbuf_rowstride;
for (x = 0; x < cairo_width; x++)
{
guchar alpha = (*src >> 24) & 0xff;
if (alpha == 0)
dst[0] = dst[1] = dst[2] = dst[3] = alpha;
else
{
dst[0] = (((*src >> 16) & 0xff) * 255 ) / alpha;
dst[1] = (((*src >> 8) & 0xff) * 255 ) / alpha;
dst[2] = (((*src >> 0) & 0xff) * 255 ) / alpha;
dst[3] = alpha;
}
dst += 4;
src++;
}
}
cairo_data = (priv->cr_surface_data
+ ctxt->rect.y * cairo_rowstride
+ ctxt->rect.x * 4);
clutter_texture_set_area_from_rgb_data (CLUTTER_TEXTURE (cairo),
pixbuf_data,
cairo_data,
TRUE,
ctxt->rect.x,
ctxt->rect.y,
cairo_width, cairo_height,
pixbuf_rowstride,
4, 0, NULL);
cairo_rowstride,
4, CLUTTER_TEXTURE_RGB_FLAG_PREMULT, NULL);
g_free (pixbuf_data);
g_free (ctxt);
if (CLUTTER_ACTOR_IS_VISIBLE (cairo))