t_vb_vertex.c revision b8e80941 
1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 *    Keith Whitwell <keithw@vmware.com>
26 */
27
28
29#include "main/glheader.h"
30#include "main/macros.h"
31#include "main/imports.h"
32#include "main/mtypes.h"
33
34#include "math/m_xform.h"
35
36#include "util/bitscan.h"
37
38#include "t_context.h"
39#include "t_pipeline.h"
40
41
42
43struct vertex_stage_data {
44   GLvector4f eye;
45   GLvector4f clip;
46   GLvector4f proj;
47   GLubyte *clipmask;
48   GLubyte ormask;
49   GLubyte andmask;
50};
51
52#define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
53
54
55
56
57/* This function implements cliptesting for user-defined clip planes.
58 * The clipping of primitives to these planes is implemented in
59 * t_render_clip.h.
60 */
61#define USER_CLIPTEST(NAME, SZ)					\
62static void NAME( struct gl_context *ctx,				\
63		  GLvector4f *clip,				\
64		  GLubyte *clipmask,				\
65		  GLubyte *clipormask,				\
66		  GLubyte *clipandmask )			\
67{								\
68   GLbitfield mask = ctx->Transform.ClipPlanesEnabled;          \
69   while (mask) {                                               \
70      const int p = u_bit_scan(&mask);                          \
71      GLuint nr, i;						\
72      const GLfloat a = ctx->Transform._ClipUserPlane[p][0];	\
73      const GLfloat b = ctx->Transform._ClipUserPlane[p][1];	\
74      const GLfloat c = ctx->Transform._ClipUserPlane[p][2];	\
75      const GLfloat d = ctx->Transform._ClipUserPlane[p][3];	\
76      GLfloat *coord = (GLfloat *)clip->data;                   \
77      GLuint stride = clip->stride;				\
78      GLuint count = clip->count;				\
79								\
80      for (nr = 0, i = 0 ; i < count ; i++) {                   \
81         GLfloat dp = coord[0] * a + coord[1] * b;		\
82         if (SZ > 2) dp += coord[2] * c;			\
83         if (SZ > 3) dp += coord[3] * d; else dp += d;          \
84								\
85         if (dp < 0) {                                          \
86            nr++;						\
87            clipmask[i] |= CLIP_USER_BIT;			\
88         }							\
89								\
90         STRIDE_F(coord, stride);				\
91      }                                                         \
92								\
93      if (nr > 0) {						\
94         *clipormask |= CLIP_USER_BIT;                          \
95         if (nr == count) {					\
96            *clipandmask |= CLIP_USER_BIT;			\
97            return;						\
98         }							\
99      }								\
100   }								\
101}
102
103
104USER_CLIPTEST(userclip2, 2)
105USER_CLIPTEST(userclip3, 3)
106USER_CLIPTEST(userclip4, 4)
107
108static void (*(usercliptab[5]))( struct gl_context *,
109				 GLvector4f *, GLubyte *,
110				 GLubyte *, GLubyte * ) =
111{
112   NULL,
113   NULL,
114   userclip2,
115   userclip3,
116   userclip4
117};
118
119
120void
121tnl_clip_prepare(struct gl_context *ctx)
122{
123   /* Neither the x86 nor sparc asm cliptest functions have been updated
124    * for ARB_depth_clamp, so force the C paths.
125    */
126   if (ctx->Transform.DepthClampNear && ctx->Transform.DepthClampFar) {
127      static GLboolean c_funcs_installed = GL_FALSE;
128      if (!c_funcs_installed) {
129         init_c_cliptest();
130         c_funcs_installed = GL_TRUE;
131      }
132   }
133}
134
135
136
137static GLboolean run_vertex_stage( struct gl_context *ctx,
138				   struct tnl_pipeline_stage *stage )
139{
140   struct vertex_stage_data *store = (struct vertex_stage_data *)stage->privatePtr;
141   TNLcontext *tnl = TNL_CONTEXT(ctx);
142   struct vertex_buffer *VB = &tnl->vb;
143
144   if (ctx->VertexProgram._Current)
145      return GL_TRUE;
146
147   tnl_clip_prepare(ctx);
148
149   if (ctx->_NeedEyeCoords) {
150      /* Separate modelview transformation:
151       * Use combined ModelProject to avoid some depth artifacts
152       */
153      if (ctx->ModelviewMatrixStack.Top->type == MATRIX_IDENTITY)
154	 VB->EyePtr = VB->AttribPtr[_TNL_ATTRIB_POS];
155      else
156	 VB->EyePtr = TransformRaw( &store->eye,
157				    ctx->ModelviewMatrixStack.Top,
158				    VB->AttribPtr[_TNL_ATTRIB_POS]);
159   }
160
161   VB->ClipPtr = TransformRaw( &store->clip,
162			       &ctx->_ModelProjectMatrix,
163			       VB->AttribPtr[_TNL_ATTRIB_POS] );
164
165   /* Drivers expect this to be clean to element 4...
166    */
167   switch (VB->ClipPtr->size) {
168   case 1:
169      /* impossible */
170   case 2:
171      _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 2 );
172      /* fall-through */
173   case 3:
174      _mesa_vector4f_clean_elem( VB->ClipPtr, VB->Count, 3 );
175      /* fall-through */
176   case 4:
177      break;
178   }
179
180
181   /* Cliptest and perspective divide.  Clip functions must clear
182    * the clipmask.
183    */
184   store->ormask = 0;
185   store->andmask = CLIP_FRUSTUM_BITS;
186
187   if (tnl->NeedNdcCoords) {
188      VB->NdcPtr =
189	 _mesa_clip_tab[VB->ClipPtr->size]( VB->ClipPtr,
190					    &store->proj,
191					    store->clipmask,
192					    &store->ormask,
193					    &store->andmask,
194					    !(ctx->Transform.DepthClampNear &&
195                                              ctx->Transform.DepthClampFar) );
196   }
197   else {
198      VB->NdcPtr = NULL;
199      _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
200					    NULL,
201					    store->clipmask,
202					    &store->ormask,
203					    &store->andmask,
204					    !(ctx->Transform.DepthClampNear &&
205                                              ctx->Transform.DepthClampFar) );
206   }
207
208   if (store->andmask)
209      return GL_FALSE;
210
211
212   /* Test userclip planes.  This contributes to VB->ClipMask, so
213    * is essentially required to be in this stage.
214    */
215   if (ctx->Transform.ClipPlanesEnabled) {
216      usercliptab[VB->ClipPtr->size]( ctx,
217				      VB->ClipPtr,
218				      store->clipmask,
219				      &store->ormask,
220				      &store->andmask );
221
222      if (store->andmask)
223	 return GL_FALSE;
224   }
225
226   VB->ClipAndMask = store->andmask;
227   VB->ClipOrMask = store->ormask;
228   VB->ClipMask = store->clipmask;
229
230   return GL_TRUE;
231}
232
233
234static GLboolean init_vertex_stage( struct gl_context *ctx,
235				    struct tnl_pipeline_stage *stage )
236{
237   struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
238   struct vertex_stage_data *store;
239   GLuint size = VB->Size;
240
241   stage->privatePtr = calloc(1, sizeof(*store));
242   store = VERTEX_STAGE_DATA(stage);
243   if (!store)
244      return GL_FALSE;
245
246   _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
247   _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
248   _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
249
250   store->clipmask = _mesa_align_malloc(sizeof(GLubyte)*size, 32 );
251
252   if (!store->clipmask ||
253       !store->eye.data ||
254       !store->clip.data ||
255       !store->proj.data)
256      return GL_FALSE;
257
258   return GL_TRUE;
259}
260
261static void dtr( struct tnl_pipeline_stage *stage )
262{
263   struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
264
265   if (store) {
266      _mesa_vector4f_free( &store->eye );
267      _mesa_vector4f_free( &store->clip );
268      _mesa_vector4f_free( &store->proj );
269      _mesa_align_free( store->clipmask );
270      free(store);
271      stage->privatePtr = NULL;
272      stage->run = init_vertex_stage;
273   }
274}
275
276
277const struct tnl_pipeline_stage _tnl_vertex_transform_stage =
278{
279   "modelview/project/cliptest/divide",
280   NULL,			/* private data */
281   init_vertex_stage,
282   dtr,				/* destructor */
283   NULL,
284   run_vertex_stage		/* run -- initially set to init */
285};
286