src/mesa/main/clip.c

   1 /* $Id: clip.c,v 1.2 1999/09/18 20:41:22 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.1
   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
  29
  30
  31 #ifdef PC_HEADER
  32 #include "all.h"
  33 #else
  34 #include <string.h>
  35 #include <stdlib.h>
  36 #include <stdio.h>
  37 #include "clip.h"
  38 #include "context.h"
  39 #include "macros.h"
  40 #include "matrix.h"
  41 #include "mmath.h"
  42 #include "types.h"
  43 #include "vb.h"
  44 #include "xform.h"
  45 #ifdef XFree86Server
  46 #include "GL/xf86glx.h"
  47 #endif
  48 #endif
  49
  50
  51
  52
  53 /* Linear interpolation between A and B: */
  54 #define LINTERP( T, A, B )   ( (A) + (T) * ( (B) - (A) ) )
  55
  56
  57
  58 #define INTERP_SZ( t, vec, to, a, b, sz )                       \
  59 do {                                                            \
  60    switch (sz) {                                                \
  61    case 4: vec[to][3] = LINTERP( t, vec[a][3], vec[b][3] );     \
  62    case 3: vec[to][2] = LINTERP( t, vec[a][2], vec[b][2] );     \
  63    case 2: vec[to][1] = LINTERP( t, vec[a][1], vec[b][1] );     \
  64    case 1: vec[to][0] = LINTERP( t, vec[a][0], vec[b][0] );     \
  65    }                                                            \
  66 } while(0)
  67
  68
  69
  70
  71 #define CLIP_RGBA0    0x1
  72 #define CLIP_RGBA1    0x2
  73 #define CLIP_TEX0     0x4
  74 #define CLIP_TEX1     0x8
  75 #define CLIP_INDEX0   0x10
  76 #define CLIP_INDEX1   0x20
  77
  78 static clip_interp_func clip_interp_tab[0x40];
  79
  80 #define IND 0
  81 #define NAME clip_nil
  82 #include "interp_tmp.h"
  83
  84 #define IND (CLIP_RGBA0)
  85 #define NAME clipRGBA0
  86 #include "interp_tmp.h"
  87
  88 #define IND (CLIP_RGBA0|CLIP_RGBA1)
  89 #define NAME clipRGBA0_RGBA1
  90 #include "interp_tmp.h"
  91
  92 #define IND (CLIP_TEX0|CLIP_RGBA0)
  93 #define NAME clipTEX0_RGBA0
  94 #include "interp_tmp.h"
  95
  96 #define IND (CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1)
  97 #define NAME clipTEX0_RGBA0_RGBA1
  98 #include "interp_tmp.h"
  99
 100 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0)
 101 #define NAME clipTEX1_TEX0_RGBA0
 102 #include "interp_tmp.h"
 103
 104 #define IND (CLIP_TEX0)
 105 #define NAME clipTEX0
 106 #include "interp_tmp.h"
 107
 108 #define IND (CLIP_TEX1|CLIP_TEX0)
 109 #define NAME clipTEX1_TEX0
 110 #include "interp_tmp.h"
 111
 112 #define IND (CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1)
 113 #define NAME clipTEX1_TEX0_RGBA0_RGBA1
 114 #include "interp_tmp.h"
 115
 116 #define IND (CLIP_INDEX0)
 117 #define NAME clipINDEX0
 118 #include "interp_tmp.h"
 119
 120 #define IND (CLIP_INDEX0|CLIP_INDEX1)
 121 #define NAME clipINDEX0_INDEX1
 122 #include "interp_tmp.h"
 123
 124
 125
 126
 127 /**********************************************************************/
 128 /*                     Get/Set User clip-planes.                      */
 129 /**********************************************************************/
 130
 131
 132
 133 void gl_ClipPlane( GLcontext* ctx, GLenum plane, const GLfloat *equation )
 134 {
 135    GLint p;
 136
 137    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx, "glClipPlane");
 138
 139    p = (GLint) plane - (GLint) GL_CLIP_PLANE0;
 140    if (p<0 || p>=MAX_CLIP_PLANES) {
 141       gl_error( ctx, GL_INVALID_ENUM, "glClipPlane" );
 142       return;
 143    }
 144
 145    /*
 146     * The equation is transformed by the transpose of the inverse of the
 147     * current modelview matrix and stored in the resulting eye coordinates.
 148     *
 149     * KW: Eqn is then transformed to the current clip space, where user
 150     * clipping now takes place.  The clip-space equations are recalculated
 151     * whenever the projection matrix changes.
 152     */
 153    if (ctx->ModelView.flags & MAT_DIRTY_ALL_OVER) {
 154       gl_matrix_analyze( &ctx->ModelView );
 155    }
 156    gl_transform_vector( ctx->Transform.EyeUserPlane[p], equation,
 157                         ctx->ModelView.inv );
 158
 159
 160    if (ctx->Transform.ClipEnabled[p]) {
 161       ctx->NewState |= NEW_USER_CLIP;
 162
 163       if (ctx->ProjectionMatrix.flags & MAT_DIRTY_ALL_OVER) {
 164          gl_matrix_analyze( &ctx->ProjectionMatrix );
 165       }
 166       gl_transform_vector( ctx->Transform.ClipUserPlane[p],
 167                            ctx->Transform.EyeUserPlane[p],
 168                            ctx->ProjectionMatrix.inv );
 169    }
 170 }
 171
 172
 173 void gl_update_userclip( GLcontext *ctx )
 174 {
 175    GLuint p;
 176
 177    for (p = 0 ; p < MAX_CLIP_PLANES ; p++) {
 178       if (ctx->Transform.ClipEnabled[p]) {
 179          gl_transform_vector( ctx->Transform.ClipUserPlane[p],
 180                               ctx->Transform.EyeUserPlane[p],
 181                               ctx->ProjectionMatrix.inv );
 182       }
 183    }
 184 }
 185
 186 void gl_GetClipPlane( GLcontext* ctx, GLenum plane, GLdouble *equation )
 187 {
 188    GLint p;
 189
 190    ASSERT_OUTSIDE_BEGIN_END(ctx, "glGetClipPlane");
 191
 192
 193    p = (GLint) (plane - GL_CLIP_PLANE0);
 194    if (p<0 || p>=MAX_CLIP_PLANES) {
 195       gl_error( ctx, GL_INVALID_ENUM, "glGetClipPlane" );
 196       return;
 197    }
 198
 199    equation[0] = (GLdouble) ctx->Transform.EyeUserPlane[p][0];
 200    equation[1] = (GLdouble) ctx->Transform.EyeUserPlane[p][1];
 201    equation[2] = (GLdouble) ctx->Transform.EyeUserPlane[p][2];
 202    equation[3] = (GLdouble) ctx->Transform.EyeUserPlane[p][3];
 203 }
 204
 205
 206
 207
 208 /**********************************************************************/
 209 /*                         View volume clipping.                      */
 210 /**********************************************************************/
 211
 212
 213 /*
 214  * Clip a point against the view volume.
 215  * Input:  v - vertex-vector describing the point to clip
 216  * Return:  0 = outside view volume
 217  *          1 = inside view volume
 218  */
 219 GLuint gl_viewclip_point( const GLfloat v[] )
 220 {
 221    if (   v[0] > v[3] || v[0] < -v[3]
 222        || v[1] > v[3] || v[1] < -v[3]
 223        || v[2] > v[3] || v[2] < -v[3] ) {
 224       return 0;
 225    }
 226    else {
 227       return 1;
 228    }
 229 }
 230
 231 /*
 232  * Clip a point against the user clipping planes.
 233  * Input:  v - vertex-vector describing the point to clip.
 234  * Return:  0 = point was clipped
 235  *          1 = point not clipped
 236  */
 237 GLuint gl_userclip_point( GLcontext* ctx, const GLfloat v[] )
 238 {
 239    GLuint p;
 240
 241    for (p=0;p<MAX_CLIP_PLANES;p++) {
 242       if (ctx->Transform.ClipEnabled[p]) {
 243          GLfloat dot = v[0] * ctx->Transform.ClipUserPlane[p][0]
 244                      + v[1] * ctx->Transform.ClipUserPlane[p][1]
 245                      + v[2] * ctx->Transform.ClipUserPlane[p][2]
 246                      + v[3] * ctx->Transform.ClipUserPlane[p][3];
 247          if (dot < 0.0F) {
 248             return 0;
 249          }
 250       }
 251    }
 252
 253    return 1;
 254 }
 255
 256
 257
 258
 259 #if defined(__i386__)
 260 #define NEGATIVE(x) ((*(int *)&x)<0)
 261 #else
 262 #define NEGATIVE(x) (x < 0)
 263 #endif
 264
 265
 266 static clip_poly_func gl_poly_clip_tab[2][5];
 267 static clip_line_func gl_line_clip_tab[2][5];
 268
 269 #define W(i) coord[i][3]
 270 #define Z(i) coord[i][2]
 271 #define Y(i) coord[i][1]
 272 #define X(i) coord[i][0]
 273 #define SIZE 4
 274 #define IND 0
 275 #define TAG(x) x##_4
 276 #include "clip_funcs.h"
 277
 278 #define W(i) 1.0
 279 #define Z(i) coord[i][2]
 280 #define Y(i) coord[i][1]
 281 #define X(i) coord[i][0]
 282 #define SIZE 3
 283 #define IND 0
 284 #define TAG(x) x##_3
 285 #include "clip_funcs.h"
 286
 287 #define W(i) 1.0
 288 #define Z(i) 0.0
 289 #define Y(i) coord[i][1]
 290 #define X(i) coord[i][0]
 291 #define SIZE 2
 292 #define IND 0
 293 #define TAG(x) x##_2
 294 #include "clip_funcs.h"
 295
 296 #define W(i) coord[i][3]
 297 #define Z(i) coord[i][2]
 298 #define Y(i) coord[i][1]
 299 #define X(i) coord[i][0]
 300 #define SIZE 4
 301 #define IND CLIP_TAB_EDGEFLAG
 302 #define TAG(x) x##_4_edgeflag
 303 #include "clip_funcs.h"
 304
 305 #define W(i) 1.0
 306 #define Z(i) coord[i][2]
 307 #define Y(i) coord[i][1]
 308 #define X(i) coord[i][0]
 309 #define SIZE 3
 310 #define IND CLIP_TAB_EDGEFLAG
 311 #define TAG(x) x##_3_edgeflag
 312 #include "clip_funcs.h"
 313
 314 #define W(i) 1.0
 315 #define Z(i) 0.0
 316 #define Y(i) coord[i][1]
 317 #define X(i) coord[i][0]
 318 #define SIZE 2
 319 #define IND CLIP_TAB_EDGEFLAG
 320 #define TAG(x) x##_2_edgeflag
 321 #include "clip_funcs.h"
 322
 323
 324
 325
 326 void gl_update_clipmask( GLcontext *ctx )
 327 {
 328    GLuint mask = 0;
 329
 330    if (ctx->Visual->RGBAflag)
 331    {
 332       if (ctx->Light.ShadeModel==GL_SMOOTH)
 333       {
 334          mask |= CLIP_RGBA0;
 335
 336          if (ctx->TriangleCaps & (DD_TRI_LIGHT_TWOSIDE|DD_SEPERATE_SPECULAR))
 337             mask |= CLIP_RGBA1;
 338       }
 339
 340       if (ctx->Texture.ReallyEnabled & 0xf0)
 341          mask |= CLIP_TEX1|CLIP_TEX0;
 342
 343       if (ctx->Texture.ReallyEnabled & 0xf)
 344          mask |= CLIP_TEX0;
 345    }
 346    else if (ctx->Light.ShadeModel==GL_SMOOTH)
 347    {
 348       mask |= CLIP_INDEX0;
 349
 350       if (ctx->TriangleCaps & DD_TRI_LIGHT_TWOSIDE)
 351          mask |= CLIP_INDEX1;
 352    }
 353
 354
 355    ctx->ClipInterpFunc = clip_interp_tab[mask];
 356    ctx->poly_clip_tab = gl_poly_clip_tab[0];
 357    ctx->line_clip_tab = gl_line_clip_tab[0];
 358
 359    if (ctx->TriangleCaps & DD_TRI_UNFILLED) {
 360       ctx->poly_clip_tab = gl_poly_clip_tab[1];
 361       ctx->line_clip_tab = gl_line_clip_tab[0];
 362    }
 363 }
 364
 365
 366 #define USER_CLIPTEST(NAME, SZ)                                         \
 367 static void NAME( struct vertex_buffer *VB )                            \
 368 {                                                                       \
 369    GLcontext *ctx = VB->ctx;                                            \
 370    GLubyte *clipMask = VB->ClipMask;                                    \
 371    GLubyte *userClipMask = VB->UserClipMask;                            \
 372    GLuint start = VB->Start;                                            \
 373    GLuint count = VB->Count;                                            \
 374    GLuint p, i;                                                         \
 375    GLubyte bit;                                                         \
 376                                                                         \
 377                                                                         \
 378    for (bit = 1, p = 0; p < MAX_CLIP_PLANES ; p++, bit *=2)             \
 379       if (ctx->Transform.ClipEnabled[p]) {                              \
 380          GLuint nr = 0;                                                 \
 381          const GLfloat a = ctx->Transform.ClipUserPlane[p][0];          \
 382          const GLfloat b = ctx->Transform.ClipUserPlane[p][1];          \
 383          const GLfloat c = ctx->Transform.ClipUserPlane[p][2];          \
 384          const GLfloat d = ctx->Transform.ClipUserPlane[p][3];          \
 385          GLfloat *coord = VB->ClipPtr->start;                           \
 386          GLuint stride = VB->ClipPtr->stride;                           \
 387                                                                         \
 388          for (i = start ; i < count ; i++, STRIDE_F(coord, stride)) {   \
 389             GLfloat dp = coord[0] * a + coord[1] * b;                   \
 390             if (SZ > 2) dp += coord[2] * c;                             \
 391             if (SZ > 3) dp += coord[3] * d; else dp += d;               \
 392                                                                         \
 393             if (dp < 0) {                                               \
 394                clipMask[i] |= CLIP_USER_BIT;                            \
 395                userClipMask[i] |= bit;                                  \
 396                nr++;                                                    \
 397             }                                                           \
 398          }                                                              \
 399                                                                         \
 400          if (nr > 0) {                                                  \
 401             VB->ClipOrMask |= CLIP_USER_BIT;                            \
 402             VB->CullMode |= CLIP_MASK_ACTIVE;                           \
 403             if (nr == count - start) {                                  \
 404                VB->ClipAndMask |= CLIP_USER_BIT;                        \
 405                VB->Culled = 1;                                          \
 406                return;                                                  \
 407             }                                                           \
 408          }                                                              \
 409       }                                                                 \
 410 }
 411
 412
 413 USER_CLIPTEST(userclip2, 2)
 414 USER_CLIPTEST(userclip3, 3)
 415 USER_CLIPTEST(userclip4, 4)
 416
 417 static void (*(usercliptab[5]))( struct vertex_buffer * ) = {
 418    0,
 419    0,
 420    userclip2,
 421    userclip3,
 422    userclip4
 423 };
 424
 425 void gl_user_cliptest( struct vertex_buffer *VB )
 426 {
 427    usercliptab[VB->ClipPtr->size]( VB );
 428 }
 429
 430
 431 void gl_init_clip(void)
 432 {
 433    init_clip_funcs_4();
 434    init_clip_funcs_3();
 435    init_clip_funcs_2();
 436
 437    init_clip_funcs_4_edgeflag();
 438    init_clip_funcs_3_edgeflag();
 439    init_clip_funcs_2_edgeflag();
 440
 441    clip_interp_tab[0] = clip_nil;
 442    clip_interp_tab[CLIP_RGBA0] = clipRGBA0;
 443    clip_interp_tab[CLIP_RGBA0|CLIP_RGBA1] = clipRGBA0_RGBA1;
 444    clip_interp_tab[CLIP_TEX0|CLIP_RGBA0] = clipTEX0_RGBA0;
 445    clip_interp_tab[CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1] = clipTEX0_RGBA0_RGBA1;
 446    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0] = clipTEX1_TEX0_RGBA0;
 447    clip_interp_tab[CLIP_TEX1|CLIP_TEX0|CLIP_RGBA0|CLIP_RGBA1] =
 448       clipTEX1_TEX0_RGBA0_RGBA1;
 449
 450    clip_interp_tab[CLIP_TEX0] = clipTEX0;
 451    clip_interp_tab[CLIP_TEX1|CLIP_TEX0] = clipTEX1_TEX0;
 452
 453    clip_interp_tab[CLIP_INDEX0] = clipINDEX0;
 454    clip_interp_tab[CLIP_INDEX0|CLIP_INDEX1] = clipINDEX0_INDEX1;
 455 }
 456