[PATCH 4/8] glamor: Use GL_RED instead of GL_ALPHA if we have texture_swizzle

[Eric Anholt]

Dave Airlie <airlied at gmail.com> writes:

> From: Keith Packard <keithp at keithp.com>
>
> GL_RED is supported by core profiles while GL_ALPHA is not; use GL_RED
> for one channel objects (depth 1 to 8), and then swizzle them into the
> alpha channel when used as a mask.
>
> [airlied: updated to master, add swizzle to composited glyphs and xv paths]
>
> Signed-off-by: Keith Packard <keithp at keithp.com>
> Signed-off-by: Dave Airlie <airlied at redhat.com>
> ---
>  glamor/glamor.c                  |  4 ++++
>  glamor/glamor_composite_glyphs.c |  5 +++++
>  glamor/glamor_fbo.c              |  2 ++
>  glamor/glamor_picture.c          | 22 ++++++++++++++--------
>  glamor/glamor_priv.h             |  2 ++
>  glamor/glamor_render.c           |  9 +++++++++
>  glamor/glamor_transfer.c         |  2 +-
>  glamor/glamor_utils.h            |  4 +++-
>  glamor/glamor_xv.c               | 12 ++++++++++++
>  9 files changed, 52 insertions(+), 10 deletions(-)
>
> diff --git a/glamor/glamor.c b/glamor/glamor.c
> index 8828ad3..7fa3a46 100644
> --- a/glamor/glamor.c
> +++ b/glamor/glamor.c
> @@ -596,6 +596,10 @@ glamor_init(ScreenPtr screen, unsigned int flags)
>      glamor_priv->max_fbo_size = MAX_FBO_SIZE;
>  #endif
>  
> +    glamor_priv->one_channel_format = GL_ALPHA;
> +    if (epoxy_has_gl_extension("GL_ARB_texture_rg") && epoxy_has_gl_extension("GL_ARB_texture_swizzle"))
> +        glamor_priv->one_channel_format = GL_RED;
> +
>      glamor_set_debug_level(&glamor_debug_level);
>  
>      glamor_priv->saved_procs.create_screen_resources =
> diff --git a/glamor/glamor_composite_glyphs.c b/glamor/glamor_composite_glyphs.c
> index fb31340..5f0fda5 100644
> --- a/glamor/glamor_composite_glyphs.c
> +++ b/glamor/glamor_composite_glyphs.c
> @@ -247,6 +247,11 @@ glamor_glyphs_flush(CARD8 op, PicturePtr src, PicturePtr dst,
>      glActiveTexture(GL_TEXTURE1);
>      glBindTexture(GL_TEXTURE_2D, atlas_fbo->tex);
>  
> +    if (glamor_priv->one_channel_format == GL_RED &&
> +        atlas->atlas->drawable.depth <= 8)
> +    {
> +        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_A, GL_RED);
> +    }
>      for (;;) {
>          if (!glamor_use_program_render(prog, op, src, dst))
>              break;

Since these TexParameters are stored in the texture object, I think what
we really want is when we make an 8-bit FBO, at that point set SWIZZLE_A
to RED and SWIZZLE_RED to 0.  (If we don't do RED to 0, I expect this
will cause Render regressions).  Then we don't have to do these
expensive TexParameters at draw time.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.x.org/archives/xorg-devel/attachments/20160119/7b5fab15/attachment.sig>