egl: Rework eglSwapInterval.

This adds error checking to eglSwapInterval and clamps the swap
interval.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>

1 files changed, 22 insertions, 5 deletions

diff --git a/src/egl/main/eglsurface.c b/src/egl/main/eglsurface.c
index e7a1a8329e..940a1b760c 100644
--- a/src/egl/main/eglsurface.c
+++ b/src/egl/main/eglsurface.c
@@ -15,6 +15,22 @@
 #include "eglsurface.h"
 
 
+static void
+_eglClampSwapInterval(_EGLSurface *surf, EGLint interval)
+{
+   EGLint bound = GET_CONFIG_ATTRIB(surf->Config, EGL_MAX_SWAP_INTERVAL);
+   if (interval >= bound) {
+      interval = bound;
+   }
+   else {
+      bound = GET_CONFIG_ATTRIB(surf->Config, EGL_MIN_SWAP_INTERVAL);
+      if (interval < bound)
+         interval = bound;
+   }
+   surf->SwapInterval = interval;
+}
+
+
 /**
  * Do error check on parameters and initialize the given _EGLSurface object.
  * \return EGL_TRUE if no errors, EGL_FALSE otherwise.
@@ -194,7 +210,9 @@ _eglInitSurface(_EGLDriver *drv, _EGLSurface *surf, EGLint type,
    surf->TextureTarget = texTarget;
    surf->MipmapTexture = mipmapTex;
    surf->MipmapLevel = 0;
-   surf->SwapInterval = 0;
+   /* the default swap interval is 1 */
+   _eglClampSwapInterval(surf, 1);
+
 #ifdef EGL_VERSION_1_2
    surf->SwapBehavior = EGL_BUFFER_DESTROYED; /* XXX ok? */
    surf->HorizontalResolution = EGL_UNKNOWN; /* set by caller */
@@ -466,11 +484,10 @@ _eglReleaseTexImage(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surface,
 
 
 EGLBoolean
-_eglSwapInterval(_EGLDriver *drv, _EGLDisplay *dpy, EGLint interval)
+_eglSwapInterval(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf,
+                 EGLint interval)
 {
-   _EGLSurface *surf = _eglGetCurrentSurface(EGL_DRAW);
-   if (surf)
-      surf->SwapInterval = interval;
+   _eglClampSwapInterval(surf, interval);
    return EGL_TRUE;
 }