egl: support EGL_LARGEST_PBUFFER in eglCreatePbufferSurface(...)

Patch provides a default for a set pbuffer surface size when
EGL_LARGEST_PBUFFER is used by the client. MIN2 macro is moved
to egldefines so that it can be shared.

Fixes following Piglit test:
   egl-create-largest-pbuffer-surface

From EGL 1.5 spec:
   "Use EGL_LARGEST_PBUFFER to get the largest available pbuffer
   when the allocation of the pbuffer would otherwise fail."

Currently there exists no API to query largest available pixmap size
using xlib or xcb so right now this seems most straightforward way to
ensure that we fulfill above API and also we don't attempt to allocate
'too big' pixmap which might succeed on server side but not work in
practice when driver starts to use it as a texture.

v2: add more explanation about the change (Emil)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Cc: "11.0 11.1" <mesa-stable@lists.freedesktop.org
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

diff --git a/src/egl/main/eglconfig.c b/src/egl/main/eglconfig.c
index c445d9b0c926ce5d6000f26861976c5ca7b118ef..d79c0e15422e044852c860a9409316be7c4d68ab 100644 (file)
--- a/src/egl/main/eglconfig.c
+++ b/src/egl/main/eglconfig.c
@@ -44,7 +44,6 @@
 #include "egllog.h"
 
 
-#define MIN2(A, B)  (((A) < (B)) ? (A) : (B))
 
 
 /**

diff --git a/src/egl/main/egldefines.h b/src/egl/main/egldefines.h
index a32cab2640802fa9eb3d36c5e2c22824b361a84b..13a7563ce046733d5c50866d6103fc537ca111e2 100644 (file)
--- a/src/egl/main/egldefines.h
+++ b/src/egl/main/egldefines.h
@@ -40,9 +40,16 @@ extern "C" {
 
 #define _EGL_MAX_EXTENSIONS_LEN 1000
 
+/* Hardcoded, conservative default for EGL_LARGEST_PBUFFER,
+ * this is used to implement EGL_LARGEST_PBUFFER.
+ */
+#define _EGL_MAX_PBUFFER_WIDTH 4096
+#define _EGL_MAX_PBUFFER_HEIGHT 4096
+
 #define _EGL_VENDOR_STRING "Mesa Project"
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+#define MIN2(A, B)  (((A) < (B)) ? (A) : (B))
 
 #ifdef __cplusplus
 }

diff --git a/src/egl/main/eglsurface.c b/src/egl/main/eglsurface.c
index 4fa43f3e2b11193db9a3f610e6e78f1fd1cfd2d4..2971bb0983af07e42f02933006a9a8e49c0ddbf6 100644 (file)
--- a/src/egl/main/eglsurface.c
+++ b/src/egl/main/eglsurface.c
@@ -307,6 +307,12 @@ _eglInitSurface(_EGLSurface *surf, _EGLDisplay *dpy, EGLint type,
    if (err != EGL_SUCCESS)
       return _eglError(err, func);
 
+   /* if EGL_LARGEST_PBUFFER in use, clamp width and height */
+   if (surf->LargestPbuffer) {
+      surf->Width = MIN2(surf->Width, _EGL_MAX_PBUFFER_WIDTH);
+      surf->Height = MIN2(surf->Height, _EGL_MAX_PBUFFER_HEIGHT);
+   }
+
    return EGL_TRUE;
 }