Add EXT_vertex_cull support to mesa

1 files changed, 111 insertions, 0 deletions

diff --git a/src/mesa/tnl/t_vb_cull.c b/src/mesa/tnl/t_vb_cull.c
new file mode 100644
index 00000000000..9527ead9430
--- /dev/null
+++ b/src/mesa/tnl/t_vb_cull.c
@@ -0,0 +1,111 @@
+/*
+ * Mesa 3-D graphics library
+ * Version:  6.1
+ *
+ * Copyright (C) 1999-2004  Brian Paul   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, sublicense,
+ * 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 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL 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 <[email protected]>
+ */
+
+
+#include "glheader.h"
+#include "colormac.h"
+#include "context.h"
+#include "macros.h"
+#include "imports.h"
+#include "mtypes.h"
+
+#include "math/m_xform.h"
+
+#include "t_context.h"
+#include "t_pipeline.h"
+
+
+
+/* EXT_vertex_cull.  Not really a big win, but probably depends on
+ * your application.  This stage not included in the default pipeline.
+ */
+static GLboolean run_cull_stage( GLcontext *ctx,
+				 struct tnl_pipeline_stage *stage )
+{
+   TNLcontext *tnl = TNL_CONTEXT(ctx);
+   struct vertex_buffer *VB = &tnl->vb;
+
+   const GLfloat a = ctx->Transform.CullObjPos[0];
+   const GLfloat b = ctx->Transform.CullObjPos[1];
+   const GLfloat c = ctx->Transform.CullObjPos[2];
+   GLfloat *norm = (GLfloat *)VB->NormalPtr->data;
+   GLuint stride = VB->NormalPtr->stride;
+   GLuint count = VB->Count;
+   GLuint i;
+
+   VB->ClipOrMask &= ~CLIP_CULL_BIT;
+   VB->ClipAndMask |= CLIP_CULL_BIT;
+
+   for (i = 0 ; i < count ; i++) {
+      GLfloat dp = (norm[0] * a + 
+		    norm[1] * b +
+		    norm[2] * c);
+
+      if (dp < 0) {
+	 VB->ClipMask[i] |= CLIP_CULL_BIT;
+	 VB->ClipOrMask |= CLIP_CULL_BIT;
+      }
+      else {
+	 VB->ClipMask[i] &= ~CLIP_CULL_BIT;
+	 VB->ClipAndMask &= ~CLIP_CULL_BIT;
+      }
+
+      STRIDE_F(norm, stride);
+   }
+
+   return !(VB->ClipAndMask & CLIP_CULL_BIT);
+}
+
+
+static void check_cull( GLcontext *ctx, struct tnl_pipeline_stage *stage )
+{
+   stage->active = (!ctx->VertexProgram._Enabled &&
+		    ctx->Transform.CullVertexFlag);
+}
+
+
+static void dtr( struct tnl_pipeline_stage *stage )
+{
+}
+
+
+const struct tnl_pipeline_stage _tnl_vertex_cull_stage =
+{
+   "EXT_cull_vertex",
+   _NEW_PROGRAM | 
+   _NEW_TRANSFORM,  
+   _NEW_TRANSFORM,
+   GL_TRUE,			/* active */
+   _TNL_BIT_NORMAL | 
+   _TNL_BIT_POS,		/* inputs */
+   _TNL_BIT_POS,		/* outputs */
+   0,				/* changed_inputs */
+   NULL,			/* private data */
+   dtr,				/* destructor */
+   check_cull,		/* check */
+   run_cull_stage		/* run -- initially set to init */
+};