[cairo] [PATCH 1/3] gl: Convert images to rgba or a8 formats when uploading with GLESv2

[Uli Schlachter]

On 08.12.2016 00:46, Bryce Harrington wrote:
> From: Bryce Harrington <bryce at bryceharrington.org>
> 
> The GLESv2 backend supports only GL_RGBA and GL_ALPHA as supported
> texture formats.  So, make _cairo_gl_get_image_format_and_type_gles2
> force conversion of other image formats to either of these two as
> appropriate when uploading images.
> 
> Patch originally from Henry Song <henry.song at samsung.com>
> 
> Bryce Harrington <bryce at osg.samsung.com>
> 
> Signed-off-by: Bryce Harrington <bryce at osg.samsung.com>
> ---
>  src/cairo-gl-surface.c          | 45 +++++++++++++++++++++++++++++++++++++++++
>  src/cairo-gl-traps-compositor.c | 30 ---------------------------
>  2 files changed, 45 insertions(+), 30 deletions(-)
> 
> diff --git a/src/cairo-gl-surface.c b/src/cairo-gl-surface.c
> index e5e8205..8ecc3a9 100644
> --- a/src/cairo-gl-surface.c
> +++ b/src/cairo-gl-surface.c
> @@ -868,12 +868,54 @@ _cairo_gl_surface_draw_image (cairo_gl_surface_t *dst,
>      cairo_image_surface_t *clone = NULL;
>      cairo_gl_context_t *ctx;
>      int cpp;
> +    cairo_image_surface_t *rgba_clone = NULL;
>      cairo_int_status_t status = CAIRO_INT_STATUS_SUCCESS;
>  
>      status = _cairo_gl_context_acquire (dst->base.device, &ctx);
>      if (unlikely (status))
>  	return status;
>  
> +    if (_cairo_gl_get_flavor () == CAIRO_GL_FLAVOR_ES2) {
> +	pixman_format_code_t pixman_format;
> +	cairo_surface_pattern_t pattern;
> +	cairo_bool_t require_conversion = FALSE;
> +	pixman_format = _cairo_is_little_endian () ? PIXMAN_a8b8g8r8 : PIXMAN_r8g8b8a8;
> +
> +	if (src->base.content != CAIRO_CONTENT_ALPHA) {
> +	    if (src->pixman_format != pixman_format)
> +		require_conversion = TRUE;
> +	}
> +	else if (dst->base.content != CAIRO_CONTENT_ALPHA)
> +	    require_conversion = TRUE;
> +	else {
> +	    if (src->pixman_format == PIXMAN_a1) {

Should this perhaps better be src->pixman_format != PIXMAN_a8?
Seems safer / more general to me.

> +		pixman_format = PIXMAN_a8;
> +		require_conversion = TRUE;
> +	    }
> +	}
[...]

Besides that, I don't have enough clue about the requirements of GLES to
say anything.

Uli
-- 
Happiness can't be found -- it finds you.
 - Majic