1 files changed, 157 insertions, 0 deletions
diff --git a/src/mesa/pipe/softpipe/g_prim_offset.c b/src/mesa/pipe/softpipe/g_prim_offset.c
new file mode 100644
index 0000000000..801ce9a441
--- /dev/null
+++ b/src/mesa/pipe/softpipe/g_prim_offset.c
@@ -0,0 +1,157 @@
+/**************************************************************************
+ * 
+ * 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>
+ */
+#include "imports.h"
+#include "macros.h"
+
+#include "g_context.h"
+#include "g_prim.h"
+
+
+
+struct offset_stage {
+   struct prim_stage stage;
+
+   GLuint hw_data_offset;
+
+   GLfloat scale;
+   GLfloat units;
+};
+
+
+
+static INLINE struct offset_stage *offset_stage( struct prim_stage *stage )
+{
+   return (struct offset_stage *)stage;
+}
+
+
+static void offset_begin( struct prim_stage *stage )
+{
+   struct offset_stage *offset = offset_stage(stage);
+
+   offset->units = stage->generic->setup.offset_units;
+   offset->scale = stage->generic->setup.offset_scale;
+
+   stage->next->begin( stage->next );
+}
+
+
+/* Offset tri.  Some hardware can handle this, but not usually when
+ * doing unfilled rendering.
+ */
+static void do_offset_tri( struct prim_stage *stage,
+			   struct prim_header *header )
+{
+   struct offset_stage *offset = offset_stage(stage);   
+   GLfloat inv_det = 1.0 / header->det;
+
+   /* Window coords:
+    */
+   GLfloat *v0 = (GLfloat *)&(header->v[0]->data[0]);
+   GLfloat *v1 = (GLfloat *)&(header->v[1]->data[0]);
+   GLfloat *v2 = (GLfloat *)&(header->v[2]->data[0]);
+   
+   GLfloat ex = v0[0] - v2[2];
+   GLfloat fx = v1[0] - v2[2];
+   GLfloat ey = v0[1] - v2[2];
+   GLfloat fy = v1[1] - v2[2];
+   GLfloat ez = v0[2] - v2[2];
+   GLfloat fz = v1[2] - v2[2];
+
+   GLfloat a = ey*fz - ez*fy;
+   GLfloat b = ez*fx - ex*fz;
+
+   GLfloat ac = a * inv_det;
+   GLfloat bc = b * inv_det;
+   GLfloat zoffset;
+
+   if ( ac < 0.0f ) ac = -ac;
+   if ( bc < 0.0f ) bc = -bc;
+
+   zoffset = offset->units + MAX2( ac, bc ) * offset->scale;
+
+   v0[2] += zoffset;
+   v1[2] += zoffset;
+   v2[2] += zoffset;
+
+   stage->next->tri( stage->next, header );
+}
+
+
+static void offset_tri( struct prim_stage *stage,
+			struct prim_header *header )
+{
+   struct prim_header tmp;
+
+   tmp.det = header->det;
+   tmp.v[0] = dup_vert(stage, header->v[0], 0);
+   tmp.v[1] = dup_vert(stage, header->v[1], 1);
+   tmp.v[2] = dup_vert(stage, header->v[2], 2);
+
+   do_offset_tri( stage->next, &tmp );
+}
+
+
+
+static void offset_line( struct prim_stage *stage,
+		       struct prim_header *header )
+{
+   stage->next->line( stage->next, header );
+}
+
+
+static void offset_point( struct prim_stage *stage,
+			struct prim_header *header )
+{
+   stage->next->point( stage->next, header );
+}
+
+
+static void offset_end( struct prim_stage *stage )
+{
+   stage->next->end( stage->next );
+}
+
+struct prim_stage *prim_offset( struct generic_context *generic )
+{
+   struct offset_stage *offset = CALLOC_STRUCT(offset_stage);
+
+   prim_alloc_tmps( &offset->stage, 3 );
+
+   offset->stage.generic = generic;
+   offset->stage.next = NULL;
+   offset->stage.begin = offset_begin;
+   offset->stage.point = offset_point;
+   offset->stage.line = offset_line;
+   offset->stage.tri = offset_tri;
+   offset->stage.end = offset_end;
+
+   return &offset->stage;
+}