gallium: beginnings of draw module vertex rework

Trying to put a structure in place that we can actually optimize.
Initially just implementing a passthrough mode, this will fairly soon
replace all the vertex_cache/prim_queue/shader_queue stuff that's so
hard to understand...

Split the vertex processing into a couple of distinct stages:
- Frontend
    - Prepares two lists of elements (fetch and draw) to be processed
      by the next stage.  This stage doesn't fetch or draw vertices, but
      makes the decision which to draw.  Multiple implementations of this
      will implement different strategies, currently just a vcache
      implementation.
- MiddleEnd
    - Takes the list of fetch elements, fetches them, runs the vertex
      shader, cliptest, viewport transform on them to produce a
      linear array of vertex_header vertices.
    - Passes that list of vertices, plus the draw_elements (which index
      into that list) onto the backend
- Backend
    - Either the existing primitive/clipping pipeline, or the vbuf_render
      hardware backend provided by the driver.

Currently, the middle-end is the old passthrough code, and it build hardware
vertices, not vertex_header vertices as above.  It may be that passthrough
is a special case in this respect.

1 files changed, 116 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/draw/draw_pt.h b/src/gallium/auxiliary/draw/draw_pt.h
new file mode 100644
index 0000000000..1b81d196f6
--- /dev/null
+++ b/src/gallium/auxiliary/draw/draw_pt.h
@@ -0,0 +1,116 @@
+/**************************************************************************

+ * 

+ * 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.

+ * 

+ **************************************************************************/

+

+ /*

+  * Authors:

+  *   Keith Whitwell <keith@tungstengraphics.com>

+  */

+

+#ifndef DRAW_PT_H

+#define DRAW_PT_H

+

+#include "pipe/p_compiler.h"

+

+typedef ushort (*pt_elt_func)( const void *elts, ushort idx );

+

+

+/* The "front end" - prepare sets of fetch, draw elements for the

+ * middle end.

+ *

+ * Currenly one version of this:

+ *    - vcache - catchall implementation, decomposes to TRI/LINE/POINT prims

+ * Later:

+ *    - varray, varray_split

+ *    - velement, velement_split

+ *

+ * Currenly only using the vcache version.

+ */

+struct draw_pt_front_end {

+   void (*prepare)( struct draw_pt_front_end *,

+                    struct draw_pt_middle_end * );

+

+   void (*run)( struct draw_pt_front_end *,

+                unsigned prim,

+                pt_elt_func elt_func,

+                const void *elt_ptr,

+                unsigned count );

+

+   void (*finish)( struct draw_pt_front_end * );

+   void (*destroy)( struct draw_pt_front_end * );

+};

+

+

+/* The "middle end" - prepares actual hardware vertices for the

+ * hardware backend.

+ *

+ * Currently two versions of this:

+ *     - fetch, vertex shade, cliptest, prim-pipeline

+ *     - fetch, emit (ie passthrough)

+ * Later:

+ *     - fetch, vertex shade, cliptest, maybe-pipeline, maybe-emit

+ *     - fetch, vertex shade, emit

+ *

+ * Currenly only using the passthrough version.

+ */

+struct draw_pt_middle_end {

+   void (*prepare)( struct draw_pt_middle_end * );

+

+   void (*run)( struct draw_pt_middle_end *,

+                unsigned prim,

+                const unsigned *fetch_elts,

+                unsigned fetch_count,

+                const ushort *draw_elts,

+                unsigned draw_count );

+

+   void (*finish)( struct draw_pt_middle_end * );

+   void (*destroy)( struct draw_pt_middle_end * );

+};

+

+

+/* The "back end" - supplied by the driver, defined in draw_vbuf.h.

+ *

+ * Not sure whether to wrap the prim pipeline up as an alternate

+ * backend.  Would be a win for everything except pure passthrough

+ * mode...  

+ */

+struct vbuf_render;

+

+

+/* Helper functions.

+ */

+pt_elt_func draw_pt_elt_func( struct draw_context *draw );

+const void *draw_pt_elt_ptr( struct draw_context *draw,

+                             unsigned start );

+

+/* Implementations:

+ */

+struct draw_pt_front_end *draw_pt_vcache( void );

+struct draw_pt_middle_end *draw_pt_fetch_emit( struct draw_context *draw );

+

+

+

+#endif