gallium: Reusable pipe buffer library.

This is an optional library that winsys drivers can use to simplify memory
management, and help meet the winsys interface requirements.

1 files changed, 175 insertions, 0 deletions

diff --git a/src/mesa/pipe/pipebuffer/pb_buffer.h b/src/mesa/pipe/pipebuffer/pb_buffer.h
new file mode 100644
index 0000000000..0523531395
--- /dev/null
+++ b/src/mesa/pipe/pipebuffer/pb_buffer.h
@@ -0,0 +1,175 @@
+/**************************************************************************
+ *
+ * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/**
+ * \file
+ * Generic code for buffers.
+ * 
+ * Behind a pipe buffle handle there can be DMA buffers, client (or user) 
+ * buffers, regular malloced buffers, etc. This file provides an abstract base 
+ * buffer handle that allows the driver to cope with all those kinds of buffers 
+ * in a more flexible way.
+ * 
+ * There is no obligation of a winsys driver to use this library. And a pipe
+ * driver should be completly agnostic about it.
+ * 
+ * \author José Fonseca <jrfonseca@tungstengraphics.com>
+ */
+
+#ifndef PB_BUFFER_H_
+#define PB_BUFFER_H_
+
+
+#include <assert.h>
+#include <stdlib.h>
+
+
+struct pipe_buffer_vtbl;
+
+
+/**
+ * Base class for all pipe buffers.
+ */
+struct pipe_buffer 
+{
+   /**
+    * Pointer to the virtual function table.
+    *
+    * Avoid accessing this table directly. Use the inline functions below 
+    * instead to avoid mistakes. 
+    */
+   const struct pipe_buffer_vtbl *vtbl;
+};
+
+
+/**
+ * Virtual function table for the buffer storage operations.
+ * 
+ * Note that creation is not done through this table.
+ */
+struct pipe_buffer_vtbl
+{
+   /**
+    * Add a reference to the buffer.
+    *
+    * This method can be a no-op for buffers that don't need reference
+    * counting.
+    */
+   void (*reference)( struct pipe_buffer *buf );
+
+   /**
+    * Release a reference to this buffer and destroy it.
+    */
+   void (*release)( struct pipe_buffer *buf );
+
+   /** 
+    * Map the entire data store of a buffer object into the client's address.
+    * flags is bitmask of PIPE_BUFFER_FLAG_READ/WRITE. 
+    */
+   void *(*map)( struct pipe_buffer *buf, 
+                 unsigned flags );
+   
+   void (*unmap)( struct pipe_buffer *buf );
+
+   /**
+    * Get the base buffer and the offset.
+    * 
+    * A buffer can be subdivided in smaller buffers. This method should return
+    * the underlaying buffer, and the relative offset.
+    * 
+    * Buffers without an underlaying base buffer should return themselves, with 
+    * a zero offset.
+    * 
+    * Note that this will increase the reference count of the base buffer.
+    */
+   void (*get_base_buffer)( struct pipe_buffer *buf,
+                            struct pipe_buffer **base_buf,
+                            unsigned *offset );
+};
+
+
+/** *dst = src with reference counting */
+void
+buffer_reference(struct pipe_buffer **dst,
+                 struct pipe_buffer *src);
+
+
+static inline void
+buffer_release(struct pipe_buffer *buf)
+{
+   assert(buf);
+   buf->vtbl->release(buf);
+}
+
+
+static inline void *
+buffer_map(struct pipe_buffer *buf, 
+           unsigned flags)
+{
+   assert(buf);
+   return buf->vtbl->map(buf, flags);
+}
+
+
+static inline void 
+buffer_unmap(struct pipe_buffer *buf)
+{
+   assert(buf);
+   buf->vtbl->unmap(buf);
+}
+
+
+static inline void
+buffer_get_base_buffer( struct pipe_buffer *buf,
+                        struct pipe_buffer **base_buf,
+                        unsigned *offset )
+{
+   buf->vtbl->get_base_buffer(buf, base_buf, offset);
+}
+
+
+/** Placeholder for empty buffers. */
+extern struct pipe_buffer null_buffer;
+
+
+/**
+ * Client buffers (also designated as user buffers) are just for convenience 
+ * of the state tracker, so that it can masquerade its own data as a buffer.
+ */
+struct pipe_buffer *
+client_buffer_create(void *data);
+
+
+/**
+ * Malloc-based buffer to store data that can't be used by the graphics 
+ * hardware.
+ */
+struct pipe_buffer *
+malloc_buffer_create(unsigned size);
+
+
+#endif /*PB_BUFFER_H_*/