EXA: Handle separate alpha maps properly in Composite fallback.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=18710 .

As this can't work without new EXA_PREPARE_AUX* indices, this requires a major
version bump, so we can also drop the UploadToScratch driver hook and
ExaOffscreenSwap*(). So this also fixes
http://bugs.freedesktop.org/show_bug.cgi?id=20213 .

Moreover, introduce EXA_DRIVER_KNOWN_MAJOR to break compilation of drivers
which may not be able to handle EXA_PREPARE_AUX*, giving instructions how to
make them build again in the #error message.

Signed-off-by: Michel Dänzer <daenzer@vmware.com>

1 files changed, 18 insertions, 28 deletions

diff --git a/exa/exa.h b/exa/exa.h
index 21a0f1abf..b80d0d4a2 100644
--- a/exa/exa.h
+++ b/exa/exa.h
@@ -38,8 +38,17 @@
 #include "picturestr.h"
 #include "fb.h"
 
-#define EXA_VERSION_MAJOR   2
-#define EXA_VERSION_MINOR   4
+/* If the driver can't seem to handle this major version, abort compilation with
+ * instructions how to fix it.
+ */
+#if !defined(EXA_DRIVER_KNOWN_MAJOR) || EXA_DRIVER_KNOWN_MAJOR < 3
+#error Make sure this EXA driver either does not have Prepare/FinishAccess \
+    hooks or that they can handle EXA_PREPARE_AUX*, and	\
+    #define EXA_DRIVER_KNOWN_MAJOR 3 before including exa.h
+#endif
+
+#define EXA_VERSION_MAJOR   3
+#define EXA_VERSION_MINOR   0
 #define EXA_VERSION_RELEASE 0
 
 typedef struct _ExaOffscreenArea ExaOffscreenArea;
@@ -499,32 +508,6 @@ typedef struct _ExaDriver {
                                    int                  src_pitch);
 
     /**
-     * UploadToScratch() is used to upload a pixmap to a scratch area for
-     * acceleration.
-     *
-     * @param pSrc source pixmap in host memory
-     * @param pDst fake, scratch pixmap to be set up in offscreen memory.
-     *
-     * The UploadToScratch() call was added to support Xati before Xati had
-     * support for hostdata uploads and before exaGlyphs() was written.  It
-     * behaves incorrectly (uses an invalid pixmap as pDst),
-     * and UploadToScreen() should be implemented instead.
-     *
-     * Drivers implementing UploadToScratch() had to set up space (likely in a
-     * statically allocated area) in offscreen memory, copy pSrc to that
-     * scratch area, and adust pDst->devKind for the pitch and
-     * pDst->devPrivate.ptr for the pointer to that scratch area.  The driver
-     * was responsible for syncing (as it was implemented using memcpy() in
-     * Xati), and only the data from the last UploadToScratch() was guaranteed
-     * to be valid at any given time.
-     *
-     * UploadToScratch() should not be implemented by drivers, and will likely
-     * be removed in a future version of EXA.
-     */
-    Bool        (*UploadToScratch) (PixmapPtr           pSrc,
-                                    PixmapPtr           pDst);
-
-    /**
      * DownloadFromScreen() loads a rectangle of data from pSrc into dst
      *
      * @param pSrc source pixmap
@@ -672,6 +655,13 @@ typedef struct _ExaDriver {
 	 * from.
 	 */
 	#define EXA_PREPARE_MASK	2
+	/**
+	 * EXA_PREPARE_AUX* are additional indices for other purposes, e.g.
+	 * separate alpha maps with Composite operations.
+	 */
+	#define EXA_PREPARE_AUX0	3
+	#define EXA_PREPARE_AUX1	4
+	#define EXA_PREPARE_AUX2	5
 	/** @} */
 
     /**