[Mesa-dev] [PATCH 1/2] st/egl: Add support for EGL_NOK_swap_region

[Fredrik Höglund]

Backends indicate that they support this extension by returning
EGL_TRUE when native_display::get_param() is called with
NATIVE_PARAM_PRESENT_REGION and NATIVE_PARAM_PRESERVE_BUFFER.

native_present_control is extended to include the region that should
be presented. When native_present_control::num_rects is zero,
the whole surface is to be presented.

Signed-off-by: Fredrik Höglund <fredrik at kde.org>
---
 src/gallium/state_trackers/egl/common/egl_g3d.c    |    6 ++++
 .../state_trackers/egl/common/egl_g3d_api.c        |   30 ++++++++++++++++++-
 src/gallium/state_trackers/egl/common/native.h     |   13 ++++++++-
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/src/gallium/state_trackers/egl/common/egl_g3d.c b/src/gallium/state_trackers/egl/common/egl_g3d.c
index 182ce68..53811b8 100644
--- a/src/gallium/state_trackers/egl/common/egl_g3d.c
+++ b/src/gallium/state_trackers/egl/common/egl_g3d.c
@@ -606,6 +606,12 @@ egl_g3d_initialize(_EGLDriver *drv, _EGLDisplay *dpy)
       dpy->Extensions.WL_bind_wayland_display = EGL_TRUE;
 #endif
 
+#ifdef EGL_NOK_swap_region
+   if (gdpy->native->get_param(gdpy->native, NATIVE_PARAM_PRESENT_REGION) &&
+       gdpy->native->get_param(gdpy->native, NATIVE_PARAM_PRESERVE_BUFFER))
+      dpy->Extensions.NOK_swap_region = EGL_TRUE;
+#endif
+
    if (egl_g3d_add_configs(drv, dpy, 1) == 1) {
       _eglError(EGL_NOT_INITIALIZED, "eglInitialize(unable to add configs)");
       goto fail;
diff --git a/src/gallium/state_trackers/egl/common/egl_g3d_api.c b/src/gallium/state_trackers/egl/common/egl_g3d_api.c
index 911540e..2e3ead6 100644
--- a/src/gallium/state_trackers/egl/common/egl_g3d_api.c
+++ b/src/gallium/state_trackers/egl/common/egl_g3d_api.c
@@ -546,7 +546,8 @@ egl_g3d_make_current(_EGLDriver *drv, _EGLDisplay *dpy,
 }
 
 static EGLBoolean
-egl_g3d_swap_buffers(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf)
+swap_buffers(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf,
+             EGLint num_rects, const EGLint *rects, EGLBoolean preserve)
 {
    struct egl_g3d_surface *gsurf = egl_g3d_surface(surf);
    _EGLContext *ctx = _eglGetCurrentContext();
@@ -572,14 +573,35 @@ egl_g3d_swap_buffers(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf)
 
    memset(&ctrl, 0, sizeof(ctrl));
    ctrl.natt = NATIVE_ATTACHMENT_BACK_LEFT;
-   ctrl.preserve = (gsurf->base.SwapBehavior == EGL_BUFFER_PRESERVED);
+   ctrl.preserve = preserve;
    ctrl.swap_interval = gsurf->base.SwapInterval;
    ctrl.premultiplied_alpha = (gsurf->base.VGAlphaFormat == EGL_VG_ALPHA_FORMAT_PRE);
+   ctrl.num_rects = num_rects;
+   ctrl.rects = rects;
 
    return gsurf->native->present(gsurf->native, &ctrl);
 }
 
 static EGLBoolean
+egl_g3d_swap_buffers(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf)
+{
+   struct egl_g3d_surface *gsurf = egl_g3d_surface(surf);
+
+   return swap_buffers(drv, dpy, surf, 0, NULL,
+                       (gsurf->base.SwapBehavior == EGL_BUFFER_PRESERVED));
+}
+
+#ifdef EGL_NOK_swap_region
+static EGLBoolean
+egl_g3d_swap_buffers_region(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf,
+                            EGLint num_rects, const EGLint *rects)
+{
+   /* Note: y=0=top */
+   return swap_buffers(drv, dpy, surf, num_rects, rects, EGL_TRUE);
+}
+#endif /* EGL_NOK_swap_region */
+
+static EGLBoolean
 egl_g3d_copy_buffers(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf,
                      EGLNativePixmapType target)
 {
@@ -867,4 +889,8 @@ egl_g3d_init_driver_api(_EGLDriver *drv)
    drv->API.CreateScreenSurfaceMESA = egl_g3d_create_screen_surface;
    drv->API.ShowScreenSurfaceMESA = egl_g3d_show_screen_surface;
 #endif
+
+#ifdef EGL_NOK_swap_region
+   drv->API.SwapBuffersRegionNOK = egl_g3d_swap_buffers_region;
+#endif
 }
diff --git a/src/gallium/state_trackers/egl/common/native.h b/src/gallium/state_trackers/egl/common/native.h
index ee24c22..312b079 100644
--- a/src/gallium/state_trackers/egl/common/native.h
+++ b/src/gallium/state_trackers/egl/common/native.h
@@ -81,7 +81,13 @@ enum native_param_type {
     * EGL_ALPHA_SIZE.  EGL_VG_ALPHA_FORMAT attribute of a surface will affect
     * how the surface is presented.
     */
-   NATIVE_PARAM_PREMULTIPLIED_ALPHA
+   NATIVE_PARAM_PREMULTIPLIED_ALPHA,
+
+   /**
+    * Return TRUE if native_surface::present supports presenting a partial
+    * surface.
+    */
+   NATIVE_PARAM_PRESENT_REGION
 };
 
 /**
@@ -99,6 +105,11 @@ struct native_present_control {
 
    /**< pixels use premultiplied alpha */
    boolean premultiplied_alpha;
+
+   /**< The region to present. y=0=top.
+        If num_rects is 0, the whole surface is to be presented */
+   int num_rects;
+   const int *rects; /* x, y, width, height */
 };
 
 struct native_surface {
-- 
1.7.7.3