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Merge branch 'mesa_7_6_branch'
[mesa.git] / src / mesa / tnl / t_vb_cliptmp.h
1 /*
2 * Mesa 3-D graphics library
3 * Version: 6.5.2
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 #define CLIP_DOTPROD(K, A, B, C, D) X(K)*A + Y(K)*B + Z(K)*C + W(K)*D
30
31 #define POLY_CLIP( PLANE_BIT, A, B, C, D ) \
32 do { \
33 if (mask & PLANE_BIT) { \
34 GLuint idxPrev = inlist[0]; \
35 GLfloat dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D ); \
36 GLuint outcount = 0; \
37 GLuint i; \
38 \
39 inlist[n] = inlist[0]; /* prevent rotation of vertices */ \
40 for (i = 1; i <= n; i++) { \
41 GLuint idx = inlist[i]; \
42 GLfloat dp = CLIP_DOTPROD(idx, A, B, C, D ); \
43 \
44 if (!IS_NEGATIVE(dpPrev)) { \
45 outlist[outcount++] = idxPrev; \
46 } \
47 \
48 if (DIFFERENT_SIGNS(dp, dpPrev)) { \
49 if (IS_NEGATIVE(dp)) { \
50 /* Going out of bounds. Avoid division by zero as we \
51 * know dp != dpPrev from DIFFERENT_SIGNS, above. \
52 */ \
53 GLfloat t = dp / (dp - dpPrev); \
54 INTERP_4F( t, coord[newvert], coord[idx], coord[idxPrev]); \
55 interp( ctx, t, newvert, idx, idxPrev, GL_TRUE ); \
56 } else { \
57 /* Coming back in. \
58 */ \
59 GLfloat t = dpPrev / (dpPrev - dp); \
60 INTERP_4F( t, coord[newvert], coord[idxPrev], coord[idx]); \
61 interp( ctx, t, newvert, idxPrev, idx, GL_FALSE ); \
62 } \
63 outlist[outcount++] = newvert++; \
64 } \
65 \
66 idxPrev = idx; \
67 dpPrev = dp; \
68 } \
69 \
70 if (outcount < 3) \
71 return; \
72 \
73 { \
74 GLuint *tmp = inlist; \
75 inlist = outlist; \
76 outlist = tmp; \
77 n = outcount; \
78 } \
79 } \
80 } while (0)
81
82
83 #define POLY_USERCLIP(PLANE) \
84 do { \
85 if (mask & CLIP_USER_BIT) { \
86 GLuint idxPrev = inlist[0]; \
87 GLfloat dpPrev = VB->ClipDistancePtr[PLANE][idxPrev]; \
88 GLuint outcount = 0; \
89 GLuint i; \
90 \
91 inlist[n] = inlist[0]; /* prevent rotation of vertices */ \
92 for (i = 1; i <= n; i++) { \
93 GLuint idx = inlist[i]; \
94 GLfloat dp = VB->ClipDistancePtr[PLANE][idx]; \
95 \
96 if (!IS_NEGATIVE(dpPrev)) { \
97 outlist[outcount++] = idxPrev; \
98 } \
99 \
100 if (DIFFERENT_SIGNS(dp, dpPrev)) { \
101 if (IS_NEGATIVE(dp)) { \
102 /* Going out of bounds. Avoid division by zero as we \
103 * know dp != dpPrev from DIFFERENT_SIGNS, above. \
104 */ \
105 GLfloat t = dp / (dp - dpPrev); \
106 INTERP_4F( t, coord[newvert], coord[idx], coord[idxPrev]); \
107 interp( ctx, t, newvert, idx, idxPrev, GL_TRUE ); \
108 } else { \
109 /* Coming back in. \
110 */ \
111 GLfloat t = dpPrev / (dpPrev - dp); \
112 INTERP_4F( t, coord[newvert], coord[idxPrev], coord[idx]); \
113 interp( ctx, t, newvert, idxPrev, idx, GL_FALSE ); \
114 } \
115 outlist[outcount++] = newvert++; \
116 } \
117 \
118 idxPrev = idx; \
119 dpPrev = dp; \
120 } \
121 \
122 if (outcount < 3) \
123 return; \
124 \
125 { \
126 GLuint *tmp = inlist; \
127 inlist = outlist; \
128 outlist = tmp; \
129 n = outcount; \
130 } \
131 } \
132 } while (0)
133
134
135 #define LINE_CLIP(PLANE_BIT, A, B, C, D ) \
136 do { \
137 if (mask & PLANE_BIT) { \
138 const GLfloat dp0 = CLIP_DOTPROD( v0, A, B, C, D ); \
139 const GLfloat dp1 = CLIP_DOTPROD( v1, A, B, C, D ); \
140 const GLboolean neg_dp0 = IS_NEGATIVE(dp0); \
141 const GLboolean neg_dp1 = IS_NEGATIVE(dp1); \
142 \
143 /* For regular clipping, we know from the clipmask that one \
144 * (or both) of these must be negative (otherwise we wouldn't \
145 * be here). \
146 * For userclip, there is only a single bit for all active \
147 * planes, so we can end up here when there is nothing to do, \
148 * hence the second IS_NEGATIVE() test: \
149 */ \
150 if (neg_dp0 && neg_dp1) \
151 return; /* both vertices outside clip plane: discard */ \
152 \
153 if (neg_dp1) { \
154 GLfloat t = dp1 / (dp1 - dp0); \
155 if (t > t1) t1 = t; \
156 } else if (neg_dp0) { \
157 GLfloat t = dp0 / (dp0 - dp1); \
158 if (t > t0) t0 = t; \
159 } \
160 if (t0 + t1 >= 1.0) \
161 return; /* discard */ \
162 } \
163 } while (0)
164
165
166 #define LINE_USERCLIP(PLANE) \
167 do { \
168 if (mask & CLIP_USER_BIT) { \
169 const GLfloat dp0 = VB->ClipDistancePtr[PLANE][v0]; \
170 const GLfloat dp1 = VB->ClipDistancePtr[PLANE][v1]; \
171 const GLboolean neg_dp0 = IS_NEGATIVE(dp0); \
172 const GLboolean neg_dp1 = IS_NEGATIVE(dp1); \
173 \
174 /* For regular clipping, we know from the clipmask that one \
175 * (or both) of these must be negative (otherwise we wouldn't \
176 * be here). \
177 * For userclip, there is only a single bit for all active \
178 * planes, so we can end up here when there is nothing to do, \
179 * hence the second IS_NEGATIVE() test: \
180 */ \
181 if (neg_dp0 && neg_dp1) \
182 return; /* both vertices outside clip plane: discard */ \
183 \
184 if (neg_dp1) { \
185 GLfloat t = dp1 / (dp1 - dp0); \
186 if (t > t1) t1 = t; \
187 } else if (neg_dp0) { \
188 GLfloat t = dp0 / (dp0 - dp1); \
189 if (t > t0) t0 = t; \
190 } \
191 if (t0 + t1 >= 1.0) \
192 return; /* discard */ \
193 } \
194 } while (0)
195
196
197
198 /* Clip a line against the viewport and user clip planes.
199 */
200 static INLINE void
201 TAG(clip_line)( GLcontext *ctx, GLuint v0, GLuint v1, GLubyte mask )
202 {
203 TNLcontext *tnl = TNL_CONTEXT(ctx);
204 struct vertex_buffer *VB = &tnl->vb;
205 tnl_interp_func interp = tnl->Driver.Render.Interp;
206 GLfloat (*coord)[4] = VB->ClipPtr->data;
207 GLuint newvert = VB->Count;
208 GLfloat t0 = 0;
209 GLfloat t1 = 0;
210 GLuint p;
211 const GLuint v0_orig = v0;
212
213 if (mask & CLIP_FRUSTUM_BITS) {
214 LINE_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 );
215 LINE_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 );
216 LINE_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 );
217 LINE_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 );
218 LINE_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 );
219 LINE_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 );
220 }
221
222 if (mask & CLIP_USER_BIT) {
223 for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
224 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
225 LINE_USERCLIP(p);
226 }
227 }
228 }
229
230 if (VB->ClipMask[v0]) {
231 INTERP_4F( t0, coord[newvert], coord[v0], coord[v1] );
232 interp( ctx, t0, newvert, v0, v1, GL_FALSE );
233 v0 = newvert;
234 newvert++;
235 }
236 else {
237 ASSERT(t0 == 0.0);
238 }
239
240 /* Note: we need to use vertex v0_orig when computing the new
241 * interpolated/clipped vertex position, not the current v0 which
242 * may have got set when we clipped the other end of the line!
243 */
244 if (VB->ClipMask[v1]) {
245 INTERP_4F( t1, coord[newvert], coord[v1], coord[v0_orig] );
246 interp( ctx, t1, newvert, v1, v0_orig, GL_FALSE );
247
248 if (ctx->Light.ShadeModel == GL_FLAT)
249 tnl->Driver.Render.CopyPV( ctx, newvert, v1 );
250
251 v1 = newvert;
252
253 newvert++;
254 }
255 else {
256 ASSERT(t1 == 0.0);
257 }
258
259 tnl->Driver.Render.ClippedLine( ctx, v0, v1 );
260 }
261
262
263 /* Clip a triangle against the viewport and user clip planes.
264 */
265 static INLINE void
266 TAG(clip_tri)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask )
267 {
268 TNLcontext *tnl = TNL_CONTEXT(ctx);
269 struct vertex_buffer *VB = &tnl->vb;
270 tnl_interp_func interp = tnl->Driver.Render.Interp;
271 GLuint newvert = VB->Count;
272 GLfloat (*coord)[4] = VB->ClipPtr->data;
273 GLuint pv = v2;
274 GLuint vlist[2][MAX_CLIPPED_VERTICES];
275 GLuint *inlist = vlist[0], *outlist = vlist[1];
276 GLuint p;
277 GLuint n = 3;
278
279 ASSIGN_3V(inlist, v2, v0, v1 ); /* pv rotated to slot zero */
280
281 if (0) {
282 /* print pre-clip vertex coords */
283 GLuint i, j;
284 _mesa_printf("pre clip:\n");
285 for (i = 0; i < n; i++) {
286 j = inlist[i];
287 _mesa_printf(" %u: %u: %f, %f, %f, %f\n",
288 i, j,
289 coord[j][0], coord[j][1], coord[j][2], coord[j][3]);
290 assert(!IS_INF_OR_NAN(coord[j][0]));
291 assert(!IS_INF_OR_NAN(coord[j][1]));
292 assert(!IS_INF_OR_NAN(coord[j][2]));
293 assert(!IS_INF_OR_NAN(coord[j][3]));
294 }
295 }
296
297
298 if (mask & CLIP_FRUSTUM_BITS) {
299 POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 );
300 POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 );
301 POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 );
302 POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 );
303 POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 );
304 POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 );
305 }
306
307 if (mask & CLIP_USER_BIT) {
308 for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
309 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
310 POLY_USERCLIP(p);
311 }
312 }
313 }
314
315 if (ctx->Light.ShadeModel == GL_FLAT) {
316 if (pv != inlist[0]) {
317 ASSERT( inlist[0] >= VB->Count );
318 tnl->Driver.Render.CopyPV( ctx, inlist[0], pv );
319 }
320 }
321
322 if (0) {
323 /* print post-clip vertex coords */
324 GLuint i, j;
325 _mesa_printf("post clip:\n");
326 for (i = 0; i < n; i++) {
327 j = inlist[i];
328 _mesa_printf(" %u: %u: %f, %f, %f, %f\n",
329 i, j,
330 coord[j][0], coord[j][1], coord[j][2], coord[j][3]);
331 }
332 }
333
334 tnl->Driver.Render.ClippedPolygon( ctx, inlist, n );
335 }
336
337
338 /* Clip a quad against the viewport and user clip planes.
339 */
340 static INLINE void
341 TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3,
342 GLubyte mask )
343 {
344 TNLcontext *tnl = TNL_CONTEXT(ctx);
345 struct vertex_buffer *VB = &tnl->vb;
346 tnl_interp_func interp = tnl->Driver.Render.Interp;
347 GLuint newvert = VB->Count;
348 GLfloat (*coord)[4] = VB->ClipPtr->data;
349 GLuint pv = v3;
350 GLuint vlist[2][MAX_CLIPPED_VERTICES];
351 GLuint *inlist = vlist[0], *outlist = vlist[1];
352 GLuint p;
353 GLuint n = 4;
354
355 ASSIGN_4V(inlist, v3, v0, v1, v2 ); /* pv rotated to slot zero */
356
357 if (mask & CLIP_FRUSTUM_BITS) {
358 POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 );
359 POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 );
360 POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 );
361 POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 );
362 POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 );
363 POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 );
364 }
365
366 if (mask & CLIP_USER_BIT) {
367 for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
368 if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
369 POLY_USERCLIP(p);
370 }
371 }
372 }
373
374 if (ctx->Light.ShadeModel == GL_FLAT) {
375 if (pv != inlist[0]) {
376 ASSERT( inlist[0] >= VB->Count );
377 tnl->Driver.Render.CopyPV( ctx, inlist[0], pv );
378 }
379 }
380
381 tnl->Driver.Render.ClippedPolygon( ctx, inlist, n );
382 }
383
384 #undef W
385 #undef Z
386 #undef Y
387 #undef X
388 #undef SIZE
389 #undef TAG
390 #undef POLY_CLIP
391 #undef POLY_USERCLIP
392 #undef LINE_CLIP
393 #undef LINE_USERCLIP