[Mesa-dev] [PATCH] intel: Don't advertise GLX_SWAP_COPY_OML

[Ian Romanick]

The tail should not wag the dog. If the application requests such a config, we should not page flip.  There are cases where the copy is preferable because it leaves the backbuffer intact.

On Aug 9, 2012, at 9:11 AM, Chad Versace <chad.versace at linux.intel.com> wrote:

> This patch removes all gl_config's with swapMethod=GLX_SWAP_COPY_OML. When
> page flipping, we are unable to comply with swap-copy semantics.
> 
> CC: Eric Anholt <eric at anholt.net>
> Signed-off-by: Chad Versace <chad.versace at linux.intel.com>
> ---
> src/mesa/drivers/dri/intel/intel_screen.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/intel/intel_screen.c b/src/mesa/drivers/dri/intel/intel_screen.c
> index 3c595bc..1010615 100644
> --- a/src/mesa/drivers/dri/intel/intel_screen.c
> +++ b/src/mesa/drivers/dri/intel/intel_screen.c
> @@ -822,8 +822,9 @@ intel_detect_swizzling(struct intel_screen *screen)
> static __DRIconfig**
> intel_screen_make_configs(__DRIscreen *dri_screen)
> {
> +   /* GLX_SWAP_COPY_OML is not supported due to page flipping. */
>    static const GLenum back_buffer_modes[] = {
> -       GLX_NONE, GLX_SWAP_UNDEFINED_OML, GLX_SWAP_COPY_OML
> +       GLX_SWAP_UNDEFINED_OML, GLX_NONE,
>    };
> 
>    static const uint8_t singlesample_samples[1] = {0};
> @@ -868,8 +869,7 @@ intel_screen_make_configs(__DRIscreen *dri_screen)
>                                      depth_bits,
>                                      stencil_bits,
>                                      num_depth_stencil_bits,
> -                                     back_buffer_modes,
> -                                     ARRAY_SIZE(back_buffer_modes),
> +                                     back_buffer_modes, 2,
>                                      singlesample_samples, 1,
>                                      false);
>       configs = driConcatConfigs(configs, new_configs);
> @@ -891,7 +891,7 @@ intel_screen_make_configs(__DRIscreen *dri_screen)
> 
>       new_configs = driCreateConfigs(fb_format[i], fb_type[i],
>                                      depth_bits, stencil_bits, 1,
> -                                     back_buffer_modes + 1, 1,
> +                                     back_buffer_modes, 1,
>                                      singlesample_samples, 1,
>                                      true);
>       configs = driConcatConfigs(configs, new_configs);
> @@ -908,7 +908,7 @@ intel_screen_make_configs(__DRIscreen *dri_screen)
>     *
>     * Only doublebuffer configs with GLX_SWAP_UNDEFINED_OML behavior are
>     * supported.  Singlebuffer configs are not supported because no one wants
> -    * them. GLX_SWAP_COPY_OML is not supported due to page flipping.
> +    * them.
>     */
>    for (int i = 0; i < ARRAY_SIZE(fb_format); i++) {
>       if (screen->gen < 6)
> @@ -938,7 +938,7 @@ intel_screen_make_configs(__DRIscreen *dri_screen)
>                                      depth_bits,
>                                      stencil_bits,
>                                      num_depth_stencil_bits,
> -                                     back_buffer_modes + 1, 1,
> +                                     back_buffer_modes, 1,
>                                      multisample_samples,
>                                      num_msaa_modes,
>                                      false);
> -- 
> 1.7.11.4
> 
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