materials: Get the right blend function for alpha

The correct blend function for the alpha channel is:

  GL_ONE, GL_ONE_MINUS_SRC_ALPHA

As per bug 1406. This fix was dropped when the switch to premultiplied
alpha was merged.

diff --git a/clutter/cogl/cogl/cogl-material.c b/clutter/cogl/cogl/cogl-material.c
index 1a641a7..6c292ac 100644 (file)
--- a/clutter/cogl/cogl/cogl-material.c
+++ b/clutter/cogl/cogl/cogl-material.c
@@ -106,7 +106,7 @@ _cogl_material_init_default_material (void)
 #ifndef HAVE_COGL_GLES
   material->blend_equation_rgb = GL_FUNC_ADD;
   material->blend_equation_alpha = GL_FUNC_ADD;
-  material->blend_src_factor_alpha = GL_SRC_ALPHA;
+  material->blend_src_factor_alpha = GL_ONE;
   material->blend_dst_factor_alpha = GL_ONE_MINUS_SRC_ALPHA;
   material->blend_constant[0] = 0;
   material->blend_constant[1] = 0;