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/mtypes.h"
32
33 #include "math/m_xform.h"
34
35 #include "util/bitscan.h"
36 #include "util/u_memory.h"
37
38 #include "t_context.h"
39 #include "t_pipeline.h"
40
41
42
43 struct 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) \
62 static 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
104 USER_CLIPTEST(userclip2, 2)
105 USER_CLIPTEST(userclip3, 3)
106 USER_CLIPTEST(userclip4, 4)
107
108 static 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
120 void
tnl_clip_prepare(struct gl_context * ctx)121 tnl_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
run_vertex_stage(struct gl_context * ctx,struct tnl_pipeline_stage * stage)137 static 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
init_vertex_stage(struct gl_context * ctx,struct tnl_pipeline_stage * stage)234 static 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 = 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
dtr(struct tnl_pipeline_stage * stage)261 static 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 align_free( store->clipmask );
270 free(store);
271 stage->privatePtr = NULL;
272 stage->run = init_vertex_stage;
273 }
274 }
275
276
277 const 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