egl: deduplicate allocations of local buffer over each platform backend (v2)

platform_drm, platform_wayland and platform_android have similiar local buffer
allocation routines. For deduplicating, it unifies dri2_egl_surface's
local buffer allocation routines. And it polishes inconsistent indentations.

Note that as dri2_wl_get_buffers_with_format() have not make a __DRI_BUFFER_BACK_LEFT
attachment buffer for local_buffers, new helper function, dri2_egl_surface_free_local_buffers(),
will drop the __DRI_BUFFER_BACK_LEFT check.
So if other platforms use new helper functions, we have to ensure not to make
__DRI_BUFFER_BACK_LEFT attachment buffer for local_buffers.

v2: Fixes from Emil's review:
   a) Make local_buffers variable, dri2_egl_surface_alloc_local_buffer() and
      dri2_egl_surface_free_local_buffers() unconditionally.
   b) Preserve the original codeflow for error_path and normal_path.
   c) Add note on commit messages for dropping of __DRI_BUFFER_BACK_LEFT check.
   c) Rollback the unrelated whitespace changes.
   d) Add a missing blank line.

Signed-off-by: Mun Gwan-gyeong <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>
Reviewed-by: Eric Engestrom <[email protected]>
Reviewed-by: Tomasz Figa <[email protected]>

1 files changed, 34 insertions, 0 deletions

diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index 125943333be..aa6f02a34b5 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -1011,6 +1011,40 @@ dri2_display_destroy(_EGLDisplay *disp)
    disp->DriverData = NULL;
 }
 
+__DRIbuffer *
+dri2_egl_surface_alloc_local_buffer(struct dri2_egl_surface *dri2_surf,
+                                    unsigned int att, unsigned int format)
+{
+   struct dri2_egl_display *dri2_dpy =
+      dri2_egl_display(dri2_surf->base.Resource.Display);
+
+   if (att >= ARRAY_SIZE(dri2_surf->local_buffers))
+      return NULL;
+
+   if (!dri2_surf->local_buffers[att]) {
+      dri2_surf->local_buffers[att] =
+         dri2_dpy->dri2->allocateBuffer(dri2_dpy->dri_screen, att, format,
+                                        dri2_surf->base.Width, dri2_surf->base.Height);
+   }
+
+   return dri2_surf->local_buffers[att];
+}
+
+void
+dri2_egl_surface_free_local_buffers(struct dri2_egl_surface *dri2_surf)
+{
+   struct dri2_egl_display *dri2_dpy =
+      dri2_egl_display(dri2_surf->base.Resource.Display);
+
+   for (int i = 0; i < ARRAY_SIZE(dri2_surf->local_buffers); i++) {
+      if (dri2_surf->local_buffers[i]) {
+         dri2_dpy->dri2->releaseBuffer(dri2_dpy->dri_screen,
+                                       dri2_surf->local_buffers[i]);
+         dri2_surf->local_buffers[i] = NULL;
+      }
+   }
+}
+
 /**
  * Called via eglTerminate(), drv->API.Terminate().
  *