Consolidate vertex-related code in new draw_vertex.c

A few functions which were basically duplicated between softpipe and the
i915 driver are now re-used:
  draw_emit_vertex_attr()
  draw_compute_vertex_size()

1 files changed, 167 insertions, 0 deletions

diff --git a/src/mesa/pipe/draw/draw_vertex.c b/src/mesa/pipe/draw/draw_vertex.c
new file mode 100644
index 0000000000..64bc323207
--- /dev/null
+++ b/src/mesa/pipe/draw/draw_vertex.c
@@ -0,0 +1,167 @@
+/**************************************************************************
+ * 
+ * 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.
+ * 
+ **************************************************************************/
+
+/*
+ * Functions for specifying the post-transformation vertex layout.
+ *
+ * Author:
+ *    Brian Paul
+ *    Keith Whitwell
+ */
+
+
+#include "pipe/p_defines.h"
+#include "pipe/p_context.h"
+#include "pipe/p_winsys.h"
+#include "pipe/p_util.h"
+
+#include "pipe/draw/draw_private.h"
+#include "pipe/draw/draw_context.h"
+#include "pipe/draw/draw_vertex.h"
+
+
+static INLINE void
+emit_vertex_attr(struct vertex_info *vinfo, uint vfAttr, uint format,
+                 uint interp)
+{
+   const uint n = vinfo->num_attribs;
+   vinfo->attr_mask |= (1 << vfAttr);
+   vinfo->slot_to_attrib[n] = vfAttr;
+   if (n >= 2) {
+      /* the first two slots are the vertex header & clippos */
+      assert(vfAttr < Elements(vinfo->attrib_to_slot));
+      vinfo->attrib_to_slot[vfAttr] = n - 2;
+   }
+   vinfo->interp_mode[n] = interp;
+   vinfo->format[n] = format;
+   vinfo->num_attribs++;
+
+}
+
+
+/**
+ * Compute the size of a vertex, in dwords/floats, to update the
+ * vinfo->size field.
+ */
+void
+draw_compute_vertex_size(struct vertex_info *vinfo)
+{
+   uint i;
+
+   vinfo->size = 0;
+   for (i = 0; i < vinfo->num_attribs; i++) {
+      switch (vinfo->format[i]) {
+      case FORMAT_OMIT:
+         break;
+      case FORMAT_4UB:
+         /* fall-through */
+      case FORMAT_1F:
+         vinfo->size += 1;
+         break;
+      case FORMAT_2F:
+         vinfo->size += 2;
+         break;
+      case FORMAT_3F:
+         vinfo->size += 3;
+         break;
+      case FORMAT_4F:
+         vinfo->size += 4;
+         break;
+      default:
+         assert(0);
+      }
+   }
+}
+
+
+/**
+ * Tell the drawing module about the layout of post-transformation vertices
+ */
+void
+draw_set_vertex_attributes( struct draw_context *draw,
+                            const uint *slot_to_vf_attr,
+                            const uint *interp_mode,
+                            unsigned nr_attrs )
+{
+   struct vertex_info *vinfo = &draw->vertex_info;
+   unsigned i;
+
+   assert(slot_to_vf_attr[0] == TGSI_ATTRIB_POS);
+
+   memset(vinfo, 0, sizeof(*vinfo));
+
+   /*
+    * First three attribs are always the same: header, clip pos, winpos
+    */
+   emit_vertex_attr(vinfo, TGSI_ATTRIB_VERTEX_HEADER, FORMAT_1F, INTERP_NONE);
+   emit_vertex_attr(vinfo, TGSI_ATTRIB_CLIP_POS, FORMAT_4F, INTERP_LINEAR);
+   emit_vertex_attr(vinfo, TGSI_ATTRIB_POS, FORMAT_4F_VIEWPORT, INTERP_LINEAR);
+
+   /*
+    * Remaining attribs (color, texcoords, etc)
+    */
+   for (i = 1; i < nr_attrs; i++) {
+      emit_vertex_attr(vinfo, slot_to_vf_attr[i], FORMAT_4F, interp_mode[i]);
+   }
+
+   draw_compute_vertex_size(vinfo);
+}
+
+
+/**
+ * This function is used to tell the draw module about attributes
+ * (like colors) that need to be selected based on front/back face
+ * orientation.
+ *
+ * The logic is:
+ *    if (polygon is back-facing) {
+ *       vertex->attrib[front0] = vertex->attrib[back0];
+ *       vertex->attrib[front1] = vertex->attrib[back1];
+ *    }
+ *
+ * \param front0  first attrib to replace if the polygon is back-facing
+ * \param back0  first attrib to copy if the polygon is back-facing
+ * \param front1  second attrib to replace if the polygon is back-facing
+ * \param back1  second attrib to copy if the polygon is back-facing
+ *
+ * Pass -1 to disable two-sided attributes.
+ */
+void
+draw_set_twoside_attributes(struct draw_context *draw,
+                            uint front0, uint back0,
+                            uint front1, uint back1)
+{
+   /* XXX we could alternately pass an array of front/back attribs if there's
+    * ever need for more than two.  One could imagine a shader extension
+    * that allows arbitrary attributes to be selected based on polygon
+    * orientation...
+    */
+   draw->attrib_front0 = front0;
+   draw->attrib_back0 = back0;
+   draw->attrib_front1 = front1;
+   draw->attrib_back1 = back1;
+}