1/*
2 * Mesa 3-D graphics library
3 * Version:  6.5
4 *
5 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 *    Keith Whitwell <keith@tungstengraphics.com>
26 */
27
28
29#include "main/glheader.h"
30#include "main/colormac.h"
31#include "main/macros.h"
32#include "main/imports.h"
33#include "main/mtypes.h"
34
35#include "math/m_xform.h"
36
37#include "t_context.h"
38#include "t_pipeline.h"
39
40
41
42struct vertex_stage_data {
43   GLvector4f eye;
44   GLvector4f clip;
45   GLvector4f proj;
46   GLubyte *clipmask;
47   GLubyte ormask;
48   GLubyte andmask;
49};
50
51#define VERTEX_STAGE_DATA(stage) ((struct vertex_stage_data *)stage->privatePtr)
52
53
54
55
56/* This function implements cliptesting for user-defined clip planes.
57 * The clipping of primitives to these planes is implemented in
58 * t_render_clip.h.
59 */
60#define USER_CLIPTEST(NAME, SZ)					\
61static void NAME( struct gl_context *ctx,				\
62		  GLvector4f *clip,				\
63		  GLubyte *clipmask,				\
64		  GLubyte *clipormask,				\
65		  GLubyte *clipandmask )			\
66{								\
67   GLuint p;							\
68								\
69   for (p = 0; p < ctx->Const.MaxClipPlanes; p++)		\
70      if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {	\
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.DepthClamp) {
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.DepthClamp );
195   }
196   else {
197      VB->NdcPtr = NULL;
198      _mesa_clip_np_tab[VB->ClipPtr->size]( VB->ClipPtr,
199					    NULL,
200					    store->clipmask,
201					    &store->ormask,
202					    &store->andmask,
203					    !ctx->Transform.DepthClamp );
204   }
205
206   if (store->andmask)
207      return GL_FALSE;
208
209
210   /* Test userclip planes.  This contributes to VB->ClipMask, so
211    * is essentially required to be in this stage.
212    */
213   if (ctx->Transform.ClipPlanesEnabled) {
214      usercliptab[VB->ClipPtr->size]( ctx,
215				      VB->ClipPtr,
216				      store->clipmask,
217				      &store->ormask,
218				      &store->andmask );
219
220      if (store->andmask)
221	 return GL_FALSE;
222   }
223
224   VB->ClipAndMask = store->andmask;
225   VB->ClipOrMask = store->ormask;
226   VB->ClipMask = store->clipmask;
227
228   return GL_TRUE;
229}
230
231
232static GLboolean init_vertex_stage( struct gl_context *ctx,
233				    struct tnl_pipeline_stage *stage )
234{
235   struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
236   struct vertex_stage_data *store;
237   GLuint size = VB->Size;
238
239   stage->privatePtr = CALLOC(sizeof(*store));
240   store = VERTEX_STAGE_DATA(stage);
241   if (!store)
242      return GL_FALSE;
243
244   _mesa_vector4f_alloc( &store->eye, 0, size, 32 );
245   _mesa_vector4f_alloc( &store->clip, 0, size, 32 );
246   _mesa_vector4f_alloc( &store->proj, 0, size, 32 );
247
248   store->clipmask = (GLubyte *) _mesa_align_malloc(sizeof(GLubyte)*size, 32 );
249
250   if (!store->clipmask ||
251       !store->eye.data ||
252       !store->clip.data ||
253       !store->proj.data)
254      return GL_FALSE;
255
256   return GL_TRUE;
257}
258
259static void dtr( struct tnl_pipeline_stage *stage )
260{
261   struct vertex_stage_data *store = VERTEX_STAGE_DATA(stage);
262
263   if (store) {
264      _mesa_vector4f_free( &store->eye );
265      _mesa_vector4f_free( &store->clip );
266      _mesa_vector4f_free( &store->proj );
267      _mesa_align_free( store->clipmask );
268      FREE(store);
269      stage->privatePtr = NULL;
270      stage->run = init_vertex_stage;
271   }
272}
273
274
275const struct tnl_pipeline_stage _tnl_vertex_transform_stage =
276{
277   "modelview/project/cliptest/divide",
278   NULL,			/* private data */
279   init_vertex_stage,
280   dtr,				/* destructor */
281   NULL,
282   run_vertex_stage		/* run -- initially set to init */
283};
284