| /* |
| * Mesa 3-D graphics library |
| * Version: 6.5 |
| * |
| * Copyright (C) 1999-2006 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 <keith@tungstengraphics.com> |
| */ |
| |
| |
| #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->AttribPtr[_TNL_ATTRIB_NORMAL]->data; |
| GLuint stride = VB->AttribPtr[_TNL_ATTRIB_NORMAL]->stride; |
| GLuint count = VB->Count; |
| GLuint i; |
| |
| if (ctx->VertexProgram._Current || |
| !ctx->Transform.CullVertexFlag) |
| return GL_TRUE; |
| |
| 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); |
| } |
| |
| |
| |
| const struct tnl_pipeline_stage _tnl_vertex_cull_stage = |
| { |
| "EXT_cull_vertex", |
| NULL, /* private data */ |
| NULL, /* ctr */ |
| NULL, /* destructor */ |
| NULL, |
| run_cull_stage /* run -- initially set to init */ |
| }; |