[mutter/wip/chergert/KHR_swap_buffers_with_damage] winsys: Check for KHR_swap_buffers_with_damage

[Christian Hergert <chergert src gnome org>]

commit f7fccb2644f5825a9e1d6cc7284309e176a9bc69
Author: Christian Hergert <chergert redhat com>
Date:   Thu Mar 3 00:30:56 2022 -0800

    winsys: Check for KHR_swap_buffers_with_damage
    
    Previously, we would only check for EXT_swap_buffers_with_damage which
    generally will find an implementation. However, some EGL implementations
    do not appear to support that naming of the extension, preferring to
    only advertise KHR_swap_buffers_with_damage.

 cogl/cogl/winsys/cogl-onscreen-egl.c                 | 18 +++++++++++++-----
 cogl/cogl/winsys/cogl-winsys-egl-feature-functions.h | 15 +++++++++++++--
 2 files changed, 26 insertions(+), 7 deletions(-)
---
diff --git a/cogl/cogl/winsys/cogl-onscreen-egl.c b/cogl/cogl/winsys/cogl-onscreen-egl.c
index f078968668..a2fc73d96f 100644
--- a/cogl/cogl/winsys/cogl-onscreen-egl.c
+++ b/cogl/cogl/winsys/cogl-onscreen-egl.c
@@ -36,6 +36,9 @@
 typedef struct _CoglOnscreenEglPrivate
 {
   EGLSurface egl_surface;
+
+  /* eglSwapBuffersWithDamage() implementation, KHR or EXT */
+  EGLBoolean (*pf_eglSwapBuffersWithDamage) (EGLDisplay, EGLSurface, const EGLint *, EGLint);
 } CoglOnscreenEglPrivate;
 
 G_DEFINE_TYPE_WITH_PRIVATE (CoglOnscreenEgl, cogl_onscreen_egl,
@@ -143,6 +146,11 @@ bind_onscreen_with_context (CoglOnscreen *onscreen,
       CoglRenderer *renderer = context->display->renderer;
       CoglRendererEGL *egl_renderer = renderer->winsys;
 
+      if (egl_renderer->pf_eglSwapBuffersWithDamageKHR)
+        priv->pf_eglSwapBuffersWithDamage = egl_renderer->pf_eglSwapBuffersWithDamageKHR;
+      else
+        priv->pf_eglSwapBuffersWithDamage = egl_renderer->pf_eglSwapBuffersWithDamageEXT;
+
       eglSwapInterval (egl_renderer->edpy, 1);
     }
 }
@@ -310,7 +318,7 @@ cogl_onscreen_egl_swap_buffers_with_damage (CoglOnscreen  *onscreen,
         cogl_framebuffer_create_timestamp_query (COGL_FRAMEBUFFER (onscreen));
     }
 
-  if (n_rectangles && egl_renderer->pf_eglSwapBuffersWithDamage)
+  if (n_rectangles && priv->pf_eglSwapBuffersWithDamage)
     {
       CoglFramebuffer *framebuffer = COGL_FRAMEBUFFER (onscreen);
       size_t size = n_rectangles * sizeof (int) * 4;
@@ -327,10 +335,10 @@ cogl_onscreen_egl_swap_buffers_with_damage (CoglOnscreen  *onscreen,
             cogl_framebuffer_get_height (framebuffer) - rect[1] - rect[3];
         }
 
-      if (egl_renderer->pf_eglSwapBuffersWithDamage (egl_renderer->edpy,
-                                                     priv->egl_surface,
-                                                     flipped,
-                                                     n_rectangles) == EGL_FALSE)
+      if (priv->pf_eglSwapBuffersWithDamage (egl_renderer->edpy,
+                                             priv->egl_surface,
+                                             flipped,
+                                             n_rectangles) == EGL_FALSE)
         g_warning ("Error reported by eglSwapBuffersWithDamage");
     }
   else
diff --git a/cogl/cogl/winsys/cogl-winsys-egl-feature-functions.h 
b/cogl/cogl/winsys/cogl-winsys-egl-feature-functions.h
index 53d9bd27b1..494d5ea39f 100644
--- a/cogl/cogl/winsys/cogl-winsys-egl-feature-functions.h
+++ b/cogl/cogl/winsys/cogl-winsys-egl-feature-functions.h
@@ -105,11 +105,22 @@ COGL_WINSYS_FEATURE_BEGIN (buffer_age,
                            COGL_EGL_WINSYS_FEATURE_BUFFER_AGE)
 COGL_WINSYS_FEATURE_END ()
 
-COGL_WINSYS_FEATURE_BEGIN (swap_buffers_with_damage,
+COGL_WINSYS_FEATURE_BEGIN (KHR_swap_buffers_with_damage,
+                           "KHR\0",
+                           "swap_buffers_with_damage\0",
+                           0)
+COGL_WINSYS_FEATURE_FUNCTION (EGLBoolean, eglSwapBuffersWithDamageKHR,
+                              (EGLDisplay dpy,
+                               EGLSurface surface,
+                               const EGLint *rects,
+                               EGLint n_rects))
+COGL_WINSYS_FEATURE_END ()
+
+COGL_WINSYS_FEATURE_BEGIN (EXT_swap_buffers_with_damage,
                            "EXT\0",
                            "swap_buffers_with_damage\0",
                            0)
-COGL_WINSYS_FEATURE_FUNCTION (EGLBoolean, eglSwapBuffersWithDamage,
+COGL_WINSYS_FEATURE_FUNCTION (EGLBoolean, eglSwapBuffersWithDamageEXT,
                               (EGLDisplay dpy,
                                EGLSurface surface,
                                const EGLint *rects,