API: map-to-image and create-similar-image

A common requirement is the fast upload of pixel data. In order to
allocate the most appropriate image buffer, we need knowledge of the
destination. The most obvious example is that we could use a
shared-memory region for the image to avoid the transfer cost of
uploading the pixels to the X server. Similarly, gl, win32, quartz...

The other side of the equation is that for manual modification of a
remote surface, it would be more efficient if we can create a similar
image to reduce the transfer costs. This strategy is already followed
for the destination fallbacks and this merely exposes the same
capability for the application fallbacks.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/cairo-error-private.h b/src/cairo-error-private.h
index 953e8afaf..5f517d40c 100644
--- a/src/cairo-error-private.h
+++ b/src/cairo-error-private.h
@@ -41,6 +41,8 @@
 #include "cairo.h"
 #include "cairo-compiler-private.h"
 
+#include <assert.h>
+
 CAIRO_BEGIN_DECLS
 
 enum _cairo_int_status {
@@ -100,6 +102,13 @@ enum _cairo_int_status {
 #define _cairo_int_status_is_error(status) \
     (status != CAIRO_INT_STATUS_SUCCESS && status <= CAIRO_INT_STATUS_LAST_STATUS)
 
+static inline cairo_status_t
+_cairo_public_status (cairo_int_status_t status)
+{
+    assert (status <= CAIRO_INT_STATUS_LAST_STATUS);
+    return status;
+}
+
 cairo_private cairo_status_t
 _cairo_error (cairo_status_t status);