cogl: Don't use GL_ALPHA

It was deprecated in OpenGL and it isn't even a valid value anymore for
functions like `glTextImage2D()` in OpenGL 4.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/612
This commit is contained in:
Niels De Graef 2019-06-12 09:09:31 +02:00
parent d3e789e677
commit e04cbddf92
3 changed files with 6 additions and 21 deletions

View File

@ -111,20 +111,8 @@ _cogl_driver_pixel_format_to_gl (CoglContext *context,
switch (format) switch (format)
{ {
case COGL_PIXEL_FORMAT_A_8: case COGL_PIXEL_FORMAT_A_8:
/* If the driver doesn't natively support alpha textures then we
* will use a red component texture with a swizzle to implement
* the texture */
if (_cogl_has_private_feature
(context, COGL_PRIVATE_FEATURE_ALPHA_TEXTURES) == 0)
{
glintformat = GL_RED; glintformat = GL_RED;
glformat = GL_RED; glformat = GL_RED;
}
else
{
glintformat = GL_ALPHA;
glformat = GL_ALPHA;
}
gltype = GL_UNSIGNED_BYTE; gltype = GL_UNSIGNED_BYTE;
break; break;
case COGL_PIXEL_FORMAT_G_8: case COGL_PIXEL_FORMAT_G_8:

View File

@ -98,11 +98,8 @@ _cogl_texture_driver_gen (CoglContext *ctx,
g_assert_not_reached(); g_assert_not_reached();
} }
/* If the driver doesn't support alpha textures directly then we'll /* GL_ALPHA is deprecated; instead, use GL_RED with a swizzle mask */
* fake them by setting the swizzle parameters */ if (internal_format == COGL_PIXEL_FORMAT_A_8)
if (internal_format == COGL_PIXEL_FORMAT_A_8 &&
!_cogl_has_private_feature (ctx, COGL_PRIVATE_FEATURE_ALPHA_TEXTURES) &&
_cogl_has_private_feature (ctx, COGL_PRIVATE_FEATURE_TEXTURE_SWIZZLE))
{ {
static const GLint red_swizzle[] = { GL_ZERO, GL_ZERO, GL_ZERO, GL_RED }; static const GLint red_swizzle[] = { GL_ZERO, GL_ZERO, GL_ZERO, GL_RED };

View File

@ -83,8 +83,8 @@ _cogl_driver_pixel_format_to_gl (CoglContext *context,
switch (format) switch (format)
{ {
case COGL_PIXEL_FORMAT_A_8: case COGL_PIXEL_FORMAT_A_8:
glintformat = GL_ALPHA; glintformat = GL_RED;
glformat = GL_ALPHA; glformat = GL_RED;
gltype = GL_UNSIGNED_BYTE; gltype = GL_UNSIGNED_BYTE;
break; break;
case COGL_PIXEL_FORMAT_G_8: case COGL_PIXEL_FORMAT_G_8: