[Mesa-dev] [PATCH v6 4/5] st/dri2: Implement DRI2bufferDamageExtension

[Qiang Yu]

On Mon, Jul 15, 2019 at 8:50 PM Boris Brezillon
<boris.brezillon at collabora.com> wrote:
>
> From: Daniel Stone <daniels at collabora.com>
>
> Add a pipe_screen->set_damage_region() hook to propagate
> set-damage-region requests to the driver, it's then up to the driver to
> decide what to do with this piece of information.
>
> If the hook is left unassigned, the buffer-damage extension is
> considered unsupported.
>
> Signed-off-by: Daniel Stone <daniels at collabora.com>
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
> ---
> Hello Qiang,
>
> I intentionally dropped your R-b/T-b on this patch since the
> ->set_damage_region() prototype has changed. Feel free to add it back.
>
> Regards,
>
> Boris
>
> Changes in v6:
> * Pass pipe_box objects instead ints
> * Document the set_damage_region() hook
>
> Changes in v5:
> * Add Alyssa's R-b
> ---
>  src/gallium/include/pipe/p_screen.h   | 17 ++++++++++++++
>  src/gallium/state_trackers/dri/dri2.c | 34 +++++++++++++++++++++++++++
>  2 files changed, 51 insertions(+)
>
> diff --git a/src/gallium/include/pipe/p_screen.h b/src/gallium/include/pipe/p_screen.h
> index 3f9bad470950..11a6aa939124 100644
> --- a/src/gallium/include/pipe/p_screen.h
> +++ b/src/gallium/include/pipe/p_screen.h
> @@ -464,6 +464,23 @@ struct pipe_screen {
>     bool (*is_parallel_shader_compilation_finished)(struct pipe_screen *screen,
>                                                     void *shader,
>                                                     unsigned shader_type);
> +
> +   /**
> +    * Set the damage region (called when KHR_partial_update() is invoked).
> +    * This function is passed an array of rectangles encoding the damage area.
> +    * rects are using the bottom-left origin convention.
> +    * nrects = 0 means 'reset the damage region'. What 'reset' implies is HW
> +    * specific. For tile-based renderers, the damage extent is typically set
> +    * to cover the whole resource with no damage rect (or a 0-size damage
> +    * rect). This way, the existing resource content is reloaded into the
> +    * local tile buffer for every tile thus making partial tile update
> +    * possible. For HW operating in immediate mode, this reset operation is
> +    * likely to be a NOOP.
> +    */
> +   void (*set_damage_region)(struct pipe_screen *screen,
> +                             struct pipe_resource *resource,
> +                             unsigned int nrects,
> +                             const struct pipe_box *rects);
>  };
>
>
> diff --git a/src/gallium/state_trackers/dri/dri2.c b/src/gallium/state_trackers/dri/dri2.c
> index 5a7ec878bab0..5273b95cd5fb 100644
> --- a/src/gallium/state_trackers/dri/dri2.c
> +++ b/src/gallium/state_trackers/dri/dri2.c
> @@ -1807,6 +1807,35 @@ static const __DRI2interopExtension dri2InteropExtension = {
>     .export_object = dri2_interop_export_object
>  };
>
> +/**
> + * \brief the DRI2bufferDamageExtension set_damage_region method
> + */
> +static void
> +dri2_set_damage_region(__DRIdrawable *dPriv, unsigned int nrects, int *rects)
> +{
> +   struct dri_drawable *drawable = dri_drawable(dPriv);
> +   struct pipe_resource *resource = drawable->textures[ST_ATTACHMENT_BACK_LEFT];
> +   struct pipe_screen *screen = resource->screen;
> +   struct pipe_box *boxes = NULL;
> +
> +   if (nrects) {
> +      boxes = CALLOC(nrects, sizeof(*boxes));
> +      assert(boxes);

Where does this boxes array get freed? I can't find in your patch 6 either.
In fact I prefer the v5 way which just uses `int *rects` to avoid unnecessary
conversion.

Regards,
Qiang

> +
> +      for (unsigned int i = 0; i < nrects; i++) {
> +         int *rect = &rects[i * 4];
> +
> +         u_box_2d(rect[0], rect[1], rect[2], rect[3], &boxes[i]);
> +      }
> +   }
> +
> +   screen->set_damage_region(screen, resource, nrects, boxes);
> +}
> +
> +static __DRI2bufferDamageExtension dri2BufferDamageExtension = {
> +   .base = { __DRI2_BUFFER_DAMAGE, 1 },
> +};
> +
>  /**
>   * \brief the DRI2ConfigQueryExtension configQueryb method
>   */
> @@ -1908,6 +1937,7 @@ static const __DRIextension *dri_screen_extensions[] = {
>     &dri2GalliumConfigQueryExtension.base,
>     &dri2ThrottleExtension.base,
>     &dri2FenceExtension.base,
> +   &dri2BufferDamageExtension.base,
>     &dri2InteropExtension.base,
>     &dri2NoErrorExtension.base,
>     &driBlobExtension.base,
> @@ -1923,6 +1953,7 @@ static const __DRIextension *dri_robust_screen_extensions[] = {
>     &dri2ThrottleExtension.base,
>     &dri2FenceExtension.base,
>     &dri2InteropExtension.base,
> +   &dri2BufferDamageExtension.base,
>     &dri2Robustness.base,
>     &dri2NoErrorExtension.base,
>     &driBlobExtension.base,
> @@ -1983,6 +2014,9 @@ dri2_init_screen(__DRIscreen * sPriv)
>        }
>     }
>
> +   if (pscreen->set_damage_region)
> +      dri2BufferDamageExtension.set_damage_region = dri2_set_damage_region;
> +
>     if (pscreen->get_param(pscreen, PIPE_CAP_DEVICE_RESET_STATUS_QUERY)) {
>        sPriv->extensions = dri_robust_screen_extensions;
>        screen->has_reset_status_query = true;
> --
> 2.21.0
>