gallium: unify transfer functions

"get_transfer + transfer_map" becomes "transfer_map".
"transfer_unmap + transfer_destroy" becomes "transfer_unmap".

transfer_map must create and return the transfer object and transfer_unmap
must destroy it.

transfer_map is successful if the returned buffer pointer is not NULL.
If transfer_map fails, the pointer to the transfer object remains unchanged
(i.e. doesn't have to be NULL).

Acked-by: Brian Paul <[email protected]>

2 files changed, 18 insertions, 19 deletions

diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
index 09760ddbe0f..761761da773 100644
--- a/src/gallium/include/pipe/p_context.h
+++ b/src/gallium/include/pipe/p_context.h
@@ -60,6 +60,7 @@ struct pipe_shader_state;
 struct pipe_stencil_ref;
 struct pipe_stream_output_target;
 struct pipe_surface;
+struct pipe_transfer;
 struct pipe_vertex_buffer;
 struct pipe_vertex_element;
 struct pipe_video_buffer;
@@ -374,22 +375,21 @@ struct pipe_context {
                            struct pipe_surface *);
 
    /**
-    * Get a transfer object for transferring data to/from a texture.
+    * Map a resource.
     *
     * Transfers are (by default) context-private and allow uploads to be
-    * interleaved with
+    * interleaved with rendering.
+    *
+    * out_transfer will contain the transfer object that must be passed
+    * to all the other transfer functions. It also contains useful
+    * information (like texture strides).
     */
-   struct pipe_transfer *(*get_transfer)(struct pipe_context *,
-                                         struct pipe_resource *resource,
-                                         unsigned level,
-                                         unsigned usage,  /* a combination of PIPE_TRANSFER_x */
-                                         const struct pipe_box *);
-
-   void (*transfer_destroy)(struct pipe_context *,
-                            struct pipe_transfer *);
-
-   void *(*transfer_map)( struct pipe_context *,
-                          struct pipe_transfer *transfer );
+   void *(*transfer_map)(struct pipe_context *,
+                         struct pipe_resource *resource,
+                         unsigned level,
+                         unsigned usage,  /* a combination of PIPE_TRANSFER_x */
+                         const struct pipe_box *,
+                         struct pipe_transfer **out_transfer);
 
    /* If transfer was created with WRITE|FLUSH_EXPLICIT, only the
     * regions specified with this call are guaranteed to be written to
@@ -399,9 +399,8 @@ struct pipe_context {
 				  struct pipe_transfer *transfer,
 				  const struct pipe_box *);
 
-   void (*transfer_unmap)( struct pipe_context *,
-                           struct pipe_transfer *transfer );
-
+   void (*transfer_unmap)(struct pipe_context *,
+                          struct pipe_transfer *transfer);
 
    /* One-shot transfer operation with data supplied in a user
     * pointer.  XXX: strides??
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index aed1ea60207..b145bc0e8ee 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -205,7 +205,7 @@ enum pipe_transfer_usage {
    PIPE_TRANSFER_READ = (1 << 0),
    
    /**
-    * Resource contents will be written back at transfer_destroy
+    * Resource contents will be written back at transfer_unmap
     * time (or modified as a result of being accessed directly).
     */
    PIPE_TRANSFER_WRITE = (1 << 1),
@@ -300,8 +300,8 @@ enum pipe_transfer_usage {
 #define PIPE_BIND_INDEX_BUFFER         (1 << 5) /* draw_elements */
 #define PIPE_BIND_CONSTANT_BUFFER      (1 << 6) /* set_constant_buffer */
 #define PIPE_BIND_DISPLAY_TARGET       (1 << 8) /* flush_front_buffer */
-#define PIPE_BIND_TRANSFER_WRITE       (1 << 9) /* get_transfer */
-#define PIPE_BIND_TRANSFER_READ        (1 << 10) /* get_transfer */
+#define PIPE_BIND_TRANSFER_WRITE       (1 << 9) /* transfer_map */
+#define PIPE_BIND_TRANSFER_READ        (1 << 10) /* transfer_map */
 #define PIPE_BIND_STREAM_OUTPUT        (1 << 11) /* set_stream_output_buffers */
 #define PIPE_BIND_CURSOR               (1 << 16) /* mouse cursor */
 #define PIPE_BIND_CUSTOM               (1 << 17) /* state-tracker/winsys usages */