src/mesa/main/clip.c

   1 /* $Id: clip.c,v 1.13 2000/11/05 18:40:57 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.3
   6  *
   7  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 #ifdef PC_HEADER
  29 #include "all.h"
  30 #else
  31 #include "glheader.h"
  32 #include "clip.h"
  33 #include "colormac.h"
  34 #include "context.h"
  35 #include "macros.h"
  36 #include "matrix.h"
  37 #include "mmath.h"
  38 #include "types.h"
  39 #include "vb.h"
  40 #include "xform.h"
  41 #endif
  42
  43
  44
  45
  46 #define CLIP_RGBA0    0x1
  47 #define CLIP_RGBA1    0x2
  48 #define CLIP_TEX0     0x4
  49 #define CLIP_TEX1     0x8
  50 #define CLIP_INDEX0   0x10
  51 #define CLIP_INDEX1   0x20
  52 #define CLIP_FOG_COORD 0x40
  53
  54
  55 /* Linear interpolation between A and B: */
  56 #define LINTERP( T, A, B )   ( (A) + (T) * ( (B) - (A) ) )
  57
  58
  59
  60 #define INTERP_SZ( t, vec, to, a, b, sz )                       \
  61 do {                                                            \
  62    switch (sz) {                                                \
  63    case 4: vec[to][3] = LINTERP( t, vec[a][3], vec[b][3] );     \
  64    case 3: vec[to][2] = LINTERP( t, vec[a][2], vec[b][2] );     \
  65    case 2: vec[to][1] = LINTERP( t, vec[a][1], vec[b][1] );     \
  66    case 1: vec[to][0] = LINTERP( t, vec[a][0], vec[b][0] );     \
  67    }                                                            \
  68 } while(0)
  69
  70
  71 static clip_interp_func clip_interp_tab[0x80];
  72
  73 #define IND 0
  74 #define NAME clip_nil
  75 #include "interp_tmp.h"
  76
  77 #define IND (CLIP_RGBA0)
  78 #define NAME clipRGBA0
  79 #include "interp_tmp.h"
  80
  81 #define IND (CLIP_RGBA0|CLIP_RGBA1)
  82 #define NAME clipRGBA0_RGBA1
  83 #include "interp_tmp.h"
  84
  85 #define IND (CLIP_TEX0|CLIP_RGBA0)
  86 #define NAME clipTEX0_RGBA0
  87 #include "interp_tmp.h"
  88
  89 #define IND (CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1)
  90 #define NAME clipTEX0_RGBA0_RGBA1
  91 #include "interp_tmp.h"
  92
  93 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0)
  94 #define NAME clipTEX1_TEX0_RGBA0
  95 #include "interp_tmp.h"
  96
  97 #define IND (CLIP_TEX0)
  98 #define NAME clipTEX0
  99 #include "interp_tmp.h"
 100
 101 #define IND (CLIP_TEX1|CLIP_TEX0)
 102 #define NAME clipTEX1_TEX0
 103 #include "interp_tmp.h"
 104
 105 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1)
 106 #define NAME clipTEX1_TEX0_RGBA0_RGBA1
 107 #include "interp_tmp.h"
 108
 109 #define IND (CLIP_INDEX0)
 110 #define NAME clipINDEX0
 111 #include "interp_tmp.h"
 112
 113 #define IND (CLIP_INDEX0|CLIP_INDEX1)
 114 #define NAME clipINDEX0_INDEX1
 115 #include "interp_tmp.h"
 116
 117 #define IND (CLIP_FOG_COORD)
 118 #define NAME clip_FOG
 119 #include "interp_tmp.h"
 120
 121 #define IND (CLIP_RGBA0|CLIP_FOG_COORD)
 122 #define NAME clipRGBA0_FOG
 123 #include "interp_tmp.h"
 124
 125 #define IND (CLIP_RGBA0|CLIP_RGBA1|CLIP_FOG_COORD)
 126 #define NAME clipRGBA0_RGBA1_FOG
 127 #include "interp_tmp.h"
 128
 129 #define IND (CLIP_TEX0|CLIP_RGBA0|CLIP_FOG_COORD)
 130 #define NAME clipTEX0_RGBA0_FOG
 131 #include "interp_tmp.h"
 132
 133 #define IND (CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1|CLIP_FOG_COORD)
 134 #define NAME clipTEX0_RGBA0_RGBA1_FOG
 135 #include "interp_tmp.h"
 136
 137 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_FOG_COORD)
 138 #define NAME clipTEX1_TEX0_RGBA0_FOG
 139 #include "interp_tmp.h"
 140
 141 #define IND (CLIP_TEX0|CLIP_FOG_COORD)
 142 #define NAME clipTEX0_FOG
 143 #include "interp_tmp.h"
 144
 145 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_FOG_COORD)
 146 #define NAME clipTEX1_TEX0_FOG
 147 #include "interp_tmp.h"
 148
 149 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1|CLIP_FOG_COORD)
 150 #define NAME clipTEX1_TEX0_RGBA0_RGBA1_FOG
 151 #include "interp_tmp.h"
 152
 153 #define IND (CLIP_INDEX0|CLIP_FOG_COORD)
 154 #define NAME clipINDEX0_FOG
 155 #include "interp_tmp.h"
 156
 157 #define IND (CLIP_INDEX0|CLIP_INDEX1|CLIP_FOG_COORD)
 158 #define NAME clipINDEX0_INDEX1_FOG
 159 #include "interp_tmp.h"
 160
 161
 162
 163
 164 /**********************************************************************/
 165 /*                     Get/Set User clip-planes.                      */
 166 /**********************************************************************/
 167
 168
 169
 170 void
 171 _mesa_ClipPlane( GLenum plane, const GLdouble *eq )
 172 {
 173    GET_CURRENT_CONTEXT(ctx);
 174    GLint p;
 175    GLfloat equation[4];
 176
 177    equation[0] = eq[0];
 178    equation[1] = eq[1];
 179    equation[2] = eq[2];
 180    equation[3] = eq[3];
 181
 182    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glClipPlane");
 183
 184    p = (GLint) plane - (GLint) GL_CLIP_PLANE0;
 185    if (p<0 || p>=MAX_CLIP_PLANES) {
 186       gl_error( ctx, GL_INVALID_ENUM, "glClipPlane" );
 187       return;
 188    }
 189
 190    /*
 191     * The equation is transformed by the transpose of the inverse of the
 192     * current modelview matrix and stored in the resulting eye coordinates.
 193     *
 194     * KW: Eqn is then transformed to the current clip space, where user
 195     * clipping now takes place.  The clip-space equations are recalculated
 196     * whenever the projection matrix changes.
 197     */
 198    if (ctx->ModelView.flags & MAT_DIRTY_ALL_OVER) {
 199       gl_matrix_analyze( &ctx->ModelView );
 200    }
 201    gl_transform_vector( ctx->Transform.EyeUserPlane[p], equation,
 202                         ctx->ModelView.inv );
 203
 204
 205    if (ctx->Transform.ClipEnabled[p]) {
 206       if (ctx->ProjectionMatrix.flags & MAT_DIRTY_ALL_OVER) {
 207          gl_matrix_analyze( &ctx->ProjectionMatrix );
 208       }
 209       gl_transform_vector( ctx->Transform._ClipUserPlane[p],
 210                            ctx->Transform.EyeUserPlane[p],
 211                            ctx->ProjectionMatrix.inv );
 212    }
 213
 214    ctx->NewState |= _NEW_TRANSFORM;
 215 }
 216
 217
 218 void gl_update_userclip( GLcontext *ctx )
 219 {
 220    GLuint p;
 221
 222    for (p = 0 ; p < MAX_CLIP_PLANES ; p++) {
 223       if (ctx->Transform.ClipEnabled[p]) {
 224          gl_transform_vector( ctx->Transform._ClipUserPlane[p],
 225                               ctx->Transform.EyeUserPlane[p],
 226                               ctx->ProjectionMatrix.inv );
 227       }
 228    }
 229 }
 230
 231 void
 232 _mesa_GetClipPlane( GLenum plane, GLdouble *equation )
 233 {
 234    GET_CURRENT_CONTEXT(ctx);
 235    GLint p;
 236
 237    ASSERT_OUTSIDE_BEGIN_END(ctx, "glGetClipPlane");
 238
 239
 240    p = (GLint) (plane - GL_CLIP_PLANE0);
 241    if (p<0 || p>=MAX_CLIP_PLANES) {
 242       gl_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" );
 243       return;
 244    }
 245
 246    equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0];
 247    equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1];
 248    equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2];
 249    equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3];
 250 }
 251
 252
 253
 254
 255 /**********************************************************************/
 256 /*                         View volume clipping.                      */
 257 /**********************************************************************/
 258
 259
 260 /*
 261  * Clip a point against the view volume.
 262  * Input:  v - vertex-vector describing the point to clip
 263  * Return:  0 = outside view volume
 264  *          1 = inside view volume
 265  */
 266 GLuint gl_viewclip_point( const GLfloat v[] )
 267 {
 268    if (   v[0] > v[3] || v[0] < -v[3]
 269        || v[1] > v[3] || v[1] < -v[3]
 270        || v[2] > v[3] || v[2] < -v[3] ) {
 271       return 0;
 272    }
 273    else {
 274       return 1;
 275    }
 276 }
 277
 278 /*
 279  * Clip a point against the user clipping planes.
 280  * Input:  v - vertex-vector describing the point to clip.
 281  * Return:  0 = point was clipped
 282  *          1 = point not clipped
 283  */
 284 GLuint gl_userclip_point( GLcontext* ctx, const GLfloat v[] )
 285 {
 286    GLuint p;
 287
 288    for (p=0;p<MAX_CLIP_PLANES;p++) {
 289       if (ctx->Transform.ClipEnabled[p]) {
 290          GLfloat dot = v[0] * ctx->Transform._ClipUserPlane[p][0]
 291                      + v[1] * ctx->Transform._ClipUserPlane[p][1]
 292                      + v[2] * ctx->Transform._ClipUserPlane[p][2]
 293                      + v[3] * ctx->Transform._ClipUserPlane[p][3];
 294          if (dot < 0.0F) {
 295             return 0;
 296          }
 297       }
 298    }
 299
 300    return 1;
 301 }
 302
 303
 304
 305
 306 #if 0
 307 #define NEGATIVE(x) ((*(int *)&x)<0)
 308 #define DIFFERENT_SIGNS(a,b) ((a*b) < 0)
 309 #else
 310 #define NEGATIVE(x) (x < 0)
 311 #define DIFFERENT_SIGNS(a,b) ((a*b) < 0)
 312 #endif
 313
 314
 315 static clip_poly_func gl_poly_clip_tab[2][5];
 316 static clip_line_func gl_line_clip_tab[2][5];
 317
 318 #define W(i) coord[i][3]
 319 #define Z(i) coord[i][2]
 320 #define Y(i) coord[i][1]
 321 #define X(i) coord[i][0]
 322 #define SIZE 4
 323 #define IND 0
 324 #define TAG(x) x##_4
 325 #include "clip_funcs.h"
 326
 327 #define W(i) 1.0
 328 #define Z(i) coord[i][2]
 329 #define Y(i) coord[i][1]
 330 #define X(i) coord[i][0]
 331 #define SIZE 3
 332 #define IND 0
 333 #define TAG(x) x##_3
 334 #include "clip_funcs.h"
 335
 336 #define W(i) 1.0
 337 #define Z(i) 0.0
 338 #define Y(i) coord[i][1]
 339 #define X(i) coord[i][0]
 340 #define SIZE 2
 341 #define IND 0
 342 #define TAG(x) x##_2
 343 #include "clip_funcs.h"
 344
 345 #define W(i) coord[i][3]
 346 #define Z(i) coord[i][2]
 347 #define Y(i) coord[i][1]
 348 #define X(i) coord[i][0]
 349 #define SIZE 4
 350 #define IND CLIP_TAB_EDGEFLAG
 351 #define TAG(x) x##_4_edgeflag
 352 #include "clip_funcs.h"
 353
 354 #define W(i) 1.0
 355 #define Z(i) coord[i][2]
 356 #define Y(i) coord[i][1]
 357 #define X(i) coord[i][0]
 358 #define SIZE 3
 359 #define IND CLIP_TAB_EDGEFLAG
 360 #define TAG(x) x##_3_edgeflag
 361 #include "clip_funcs.h"
 362
 363 #define W(i) 1.0
 364 #define Z(i) 0.0
 365 #define Y(i) coord[i][1]
 366 #define X(i) coord[i][0]
 367 #define SIZE 2
 368 #define IND CLIP_TAB_EDGEFLAG
 369 #define TAG(x) x##_2_edgeflag
 370 #include "clip_funcs.h"
 371
 372
 373
 374
 375 void gl_update_clipmask( GLcontext *ctx )
 376 {
 377    GLuint mask = 0;
 378
 379    if (ctx->Visual.RGBAflag)
 380    {
 381       mask |= CLIP_RGBA0;
 382
 383       if (ctx->_TriangleCaps & (DD_TRI_LIGHT_TWOSIDE|DD_SEPERATE_SPECULAR))
 384          mask |= CLIP_RGBA1;
 385
 386       if (ctx->Texture._ReallyEnabled & 0xf0)
 387          mask |= CLIP_TEX1|CLIP_TEX0;
 388
 389       if (ctx->Texture._ReallyEnabled & 0xf)
 390          mask |= CLIP_TEX0;
 391    }
 392    else if (ctx->Light.ShadeModel==GL_SMOOTH)
 393    {
 394       mask |= CLIP_INDEX0;
 395
 396       if (ctx->_TriangleCaps & DD_TRI_LIGHT_TWOSIDE)
 397          mask |= CLIP_INDEX1;
 398    }
 399
 400    if (ctx->Fog.Enabled)
 401       mask |= CLIP_FOG_COORD;
 402
 403    ctx->_ClipInterpFunc = clip_interp_tab[mask];
 404    ctx->_poly_clip_tab = gl_poly_clip_tab[0];
 405    ctx->_line_clip_tab = gl_line_clip_tab[0];
 406
 407    if (ctx->_TriangleCaps & DD_TRI_UNFILLED) {
 408       ctx->_poly_clip_tab = gl_poly_clip_tab[1];
 409       ctx->_line_clip_tab = gl_line_clip_tab[0];
 410    }
 411 }
 412
 413
 414 #define USER_CLIPTEST(NAME, SZ)                                         \
 415 static void NAME( struct vertex_buffer *VB )                            \
 416 {                                                                       \
 417    GLcontext *ctx = VB->ctx;                                            \
 418    GLubyte *clipMask = VB->ClipMask;                                    \
 419    GLubyte *userClipMask = VB->UserClipMask;                            \
 420    GLuint start = VB->Start;                                            \
 421    GLuint count = VB->Count;                                            \
 422    GLuint p, i;                                                         \
 423    GLubyte bit;                                                         \
 424                                                                         \
 425                                                                         \
 426    for (bit = 1, p = 0; p < MAX_CLIP_PLANES ; p++, bit *=2)             \
 427       if (ctx->Transform.ClipEnabled[p]) {                              \
 428          GLuint nr = 0;                                                 \
 429          const GLfloat a = ctx->Transform._ClipUserPlane[p][0];         \
 430          const GLfloat b = ctx->Transform._ClipUserPlane[p][1];         \
 431          const GLfloat c = ctx->Transform._ClipUserPlane[p][2];         \
 432          const GLfloat d = ctx->Transform._ClipUserPlane[p][3];         \
 433          GLfloat *coord = VB->ClipPtr->start;                           \
 434          GLuint stride = VB->ClipPtr->stride;                           \
 435                                                                         \
 436          for (i = start ; i < count ; i++, STRIDE_F(coord, stride)) {   \
 437             GLfloat dp = coord[0] * a + coord[1] * b;                   \
 438             if (SZ > 2) dp += coord[2] * c;                             \
 439             if (SZ > 3) dp += coord[3] * d; else dp += d;               \
 440                                                                         \
 441             if (dp < 0) {                                               \
 442                clipMask[i] |= CLIP_USER_BIT;                            \
 443                userClipMask[i] |= bit;                                  \
 444                nr++;                                                    \
 445             }                                                           \
 446          }                                                              \
 447                                                                         \
 448          if (nr > 0) {                                                  \
 449             VB->ClipOrMask |= CLIP_USER_BIT;                            \
 450             VB->CullMode |= CLIP_MASK_ACTIVE;                           \
 451             if (nr == count - start) {                                  \
 452                VB->ClipAndMask |= CLIP_USER_BIT;                        \
 453                VB->Culled = 1;                                          \
 454                return;                                                  \
 455             }                                                           \
 456          }                                                              \
 457       }                                                                 \
 458 }
 459
 460
 461 USER_CLIPTEST(userclip2, 2)
 462 USER_CLIPTEST(userclip3, 3)
 463 USER_CLIPTEST(userclip4, 4)
 464
 465 static void (*(usercliptab[5]))( struct vertex_buffer * ) = {
 466    0,
 467    0,
 468    userclip2,
 469    userclip3,
 470    userclip4
 471 };
 472
 473 void gl_user_cliptest( struct vertex_buffer *VB )
 474 {
 475    usercliptab[VB->ClipPtr->size]( VB );
 476 }
 477
 478
 479 void gl_init_clip(void)
 480 {
 481    init_clip_funcs_4();
 482    init_clip_funcs_3();
 483    init_clip_funcs_2();
 484
 485    init_clip_funcs_4_edgeflag();
 486    init_clip_funcs_3_edgeflag();
 487    init_clip_funcs_2_edgeflag();
 488
 489    clip_interp_tab[0] = clip_nil;
 490    clip_interp_tab[CLIP_RGBA0] = clipRGBA0;
 491    clip_interp_tab[CLIP_RGBA0|CLIP_RGBA1] = clipRGBA0_RGBA1;
 492    clip_interp_tab[CLIP_TEX0|CLIP_RGBA0] = clipTEX0_RGBA0;
 493    clip_interp_tab[CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1] = clipTEX0_RGBA0_RGBA1;
 494    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0] = clipTEX1_TEX0_RGBA0;
 495    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1] =
 496       clipTEX1_TEX0_RGBA0_RGBA1;
 497    clip_interp_tab[CLIP_TEX0] = clipTEX0;
 498    clip_interp_tab[CLIP_TEX1|CLIP_TEX0] = clipTEX1_TEX0;
 499    clip_interp_tab[CLIP_INDEX0] = clipINDEX0;
 500    clip_interp_tab[CLIP_INDEX0|CLIP_INDEX1] = clipINDEX0_INDEX1;
 501
 502    clip_interp_tab[CLIP_FOG_COORD] = clip_FOG;
 503    clip_interp_tab[CLIP_RGBA0|CLIP_FOG_COORD] = clipRGBA0_FOG;
 504    clip_interp_tab[CLIP_RGBA0|CLIP_RGBA1|CLIP_FOG_COORD] = clipRGBA0_RGBA1_FOG;
 505    clip_interp_tab[CLIP_TEX0|CLIP_RGBA0|CLIP_FOG_COORD] = clipTEX0_RGBA0_FOG;
 506    clip_interp_tab[CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1|CLIP_FOG_COORD] = clipTEX0_RGBA0_RGBA1_FOG;
 507    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_FOG_COORD] = clipTEX1_TEX0_RGBA0_FOG;
 508    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1|CLIP_FOG_COORD] =
 509       clipTEX1_TEX0_RGBA0_RGBA1_FOG;
 510    clip_interp_tab[CLIP_TEX0|CLIP_FOG_COORD] = clipTEX0_FOG;
 511    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_FOG_COORD] = clipTEX1_TEX0_FOG;
 512    clip_interp_tab[CLIP_INDEX0|CLIP_FOG_COORD] = clipINDEX0_FOG;
 513    clip_interp_tab[CLIP_INDEX0|CLIP_INDEX1|CLIP_FOG_COORD] = clipINDEX0_INDEX1_FOG;
 514 }
 515