src/mesa/tnl/t_rasterpos.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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
  25
  26 #include "main/glheader.h"
  27 #include "main/colormac.h"
  28 #include "main/context.h"
  29 #include "main/feedback.h"
  30 #include "main/light.h"
  31 #include "main/macros.h"
  32 #include "main/simple_list.h"
  33 #include "main/mtypes.h"
  34
  35 #include "math/m_matrix.h"
  36 #include "tnl/tnl.h"
  37
  38
  39
  40 /**
  41  * Clip a point against the view volume.
  42  *
  43  * \param v vertex vector describing the point to clip.
  44  *
  45  * \return zero if outside view volume, or one if inside.
  46  */
  47 static GLuint
  48 viewclip_point_xy( const GLfloat v[] )
  49 {
  50    if (   v[0] > v[3] || v[0] < -v[3]
  51        || v[1] > v[3] || v[1] < -v[3] ) {
  52       return 0;
  53    }
  54    else {
  55       return 1;
  56    }
  57 }
  58
  59
  60 /**
  61  * Clip a point against the far/near Z clipping planes.
  62  *
  63  * \param v vertex vector describing the point to clip.
  64  *
  65  * \return zero if outside view volume, or one if inside.
  66  */
  67 static GLuint
  68 viewclip_point_z( const GLfloat v[] )
  69 {
  70    if (v[2] > v[3] || v[2] < -v[3] ) {
  71       return 0;
  72    }
  73    else {
  74       return 1;
  75    }
  76 }
  77
  78
  79 /**
  80  * Clip a point against the user clipping planes.
  81  *
  82  * \param ctx GL context.
  83  * \param v vertex vector describing the point to clip.
  84  *
  85  * \return zero if the point was clipped, or one otherwise.
  86  */
  87 static GLuint
  88 userclip_point( GLcontext *ctx, const GLfloat v[] )
  89 {
  90    GLuint p;
  91
  92    for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
  93       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
  94          GLfloat dot = v[0] * ctx->Transform._ClipUserPlane[p][0]
  95                      + v[1] * ctx->Transform._ClipUserPlane[p][1]
  96                      + v[2] * ctx->Transform._ClipUserPlane[p][2]
  97                      + v[3] * ctx->Transform._ClipUserPlane[p][3];
  98          if (dot < 0.0F) {
  99             return 0;
 100          }
 101       }
 102    }
 103
 104    return 1;
 105 }
 106
 107
 108 /**
 109  * Compute lighting for the raster position.  Both RGB and CI modes computed.
 110  * \param ctx the context
 111  * \param vertex vertex location
 112  * \param normal normal vector
 113  * \param Rcolor returned color
 114  * \param Rspec returned specular color (if separate specular enabled)
 115  * \param Rindex returned color index
 116  */
 117 static void
 118 shade_rastpos(GLcontext *ctx,
 119               const GLfloat vertex[4],
 120               const GLfloat normal[3],
 121               GLfloat Rcolor[4],
 122               GLfloat Rspec[4],
 123               GLfloat *Rindex)
 124 {
 125    /*const*/ GLfloat (*base)[3] = ctx->Light._BaseColor;
 126    const struct gl_light *light;
 127    GLfloat diffuseColor[4], specularColor[4];  /* for RGB mode only */
 128    GLfloat diffuseCI = 0.0, specularCI = 0.0;  /* for CI mode only */
 129
 130    _mesa_validate_all_lighting_tables( ctx );
 131
 132    COPY_3V(diffuseColor, base[0]);
 133    diffuseColor[3] = CLAMP(
 134       ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3], 0.0F, 1.0F );
 135    ASSIGN_4V(specularColor, 0.0, 0.0, 0.0, 1.0);
 136
 137    foreach (light, &ctx->Light.EnabledList) {
 138       GLfloat attenuation = 1.0;
 139       GLfloat VP[3]; /* vector from vertex to light pos */
 140       GLfloat n_dot_VP;
 141       GLfloat diffuseContrib[3], specularContrib[3];
 142
 143       if (!(light->_Flags & LIGHT_POSITIONAL)) {
 144          /* light at infinity */
 145          COPY_3V(VP, light->_VP_inf_norm);
 146          attenuation = light->_VP_inf_spot_attenuation;
 147       }
 148       else {
 149          /* local/positional light */
 150          GLfloat d;
 151
 152          /* VP = vector from vertex pos to light[i].pos */
 153          SUB_3V(VP, light->_Position, vertex);
 154          /* d = length(VP) */
 155          d = (GLfloat) LEN_3FV( VP );
 156          if (d > 1.0e-6) {
 157             /* normalize VP */
 158             GLfloat invd = 1.0F / d;
 159             SELF_SCALE_SCALAR_3V(VP, invd);
 160          }
 161
 162          /* atti */
 163          attenuation = 1.0F / (light->ConstantAttenuation + d *
 164                                (light->LinearAttenuation + d *
 165                                 light->QuadraticAttenuation));
 166
 167          if (light->_Flags & LIGHT_SPOT) {
 168             GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
 169
 170             if (PV_dot_dir<light->_CosCutoff) {
 171                continue;
 172             }
 173             else {
 174                double x = PV_dot_dir * (EXP_TABLE_SIZE-1);
 175                int k = (int) x;
 176                GLfloat spot = (GLfloat) (light->_SpotExpTable[k][0]
 177                                + (x-k)*light->_SpotExpTable[k][1]);
 178                attenuation *= spot;
 179             }
 180          }
 181       }
 182
 183       if (attenuation < 1e-3)
 184          continue;
 185
 186       n_dot_VP = DOT3( normal, VP );
 187
 188       if (n_dot_VP < 0.0F) {
 189          ACC_SCALE_SCALAR_3V(diffuseColor, attenuation, light->_MatAmbient[0]);
 190          continue;
 191       }
 192
 193       /* Ambient + diffuse */
 194       COPY_3V(diffuseContrib, light->_MatAmbient[0]);
 195       ACC_SCALE_SCALAR_3V(diffuseContrib, n_dot_VP, light->_MatDiffuse[0]);
 196       diffuseCI += n_dot_VP * light->_dli * attenuation;
 197
 198       /* Specular */
 199       {
 200          const GLfloat *h;
 201          GLfloat n_dot_h;
 202
 203          ASSIGN_3V(specularContrib, 0.0, 0.0, 0.0);
 204
 205          if (ctx->Light.Model.LocalViewer) {
 206             GLfloat v[3];
 207             COPY_3V(v, vertex);
 208             NORMALIZE_3FV(v);
 209             SUB_3V(VP, VP, v);
 210             NORMALIZE_3FV(VP);
 211             h = VP;
 212          }
 213          else if (light->_Flags & LIGHT_POSITIONAL) {
 214             ACC_3V(VP, ctx->_EyeZDir);
 215             NORMALIZE_3FV(VP);
 216             h = VP;
 217          }
 218          else {
 219             h = light->_h_inf_norm;
 220          }
 221
 222          n_dot_h = DOT3(normal, h);
 223
 224          if (n_dot_h > 0.0F) {
 225             GLfloat spec_coef;
 226             GET_SHINE_TAB_ENTRY( ctx->_ShineTable[0], n_dot_h, spec_coef );
 227
 228             if (spec_coef > 1.0e-10) {
 229                if (ctx->Light.Model.ColorControl==GL_SEPARATE_SPECULAR_COLOR) {
 230                   ACC_SCALE_SCALAR_3V( specularContrib, spec_coef,
 231                                        light->_MatSpecular[0]);
 232                }
 233                else {
 234                   ACC_SCALE_SCALAR_3V( diffuseContrib, spec_coef,
 235                                        light->_MatSpecular[0]);
 236                }
 237                /*assert(light->_sli > 0.0);*/
 238                specularCI += spec_coef * light->_sli * attenuation;
 239             }
 240          }
 241       }
 242
 243       ACC_SCALE_SCALAR_3V( diffuseColor, attenuation, diffuseContrib );
 244       ACC_SCALE_SCALAR_3V( specularColor, attenuation, specularContrib );
 245    }
 246
 247    if (ctx->Visual.rgbMode) {
 248       Rcolor[0] = CLAMP(diffuseColor[0], 0.0F, 1.0F);
 249       Rcolor[1] = CLAMP(diffuseColor[1], 0.0F, 1.0F);
 250       Rcolor[2] = CLAMP(diffuseColor[2], 0.0F, 1.0F);
 251       Rcolor[3] = CLAMP(diffuseColor[3], 0.0F, 1.0F);
 252       Rspec[0] = CLAMP(specularColor[0], 0.0F, 1.0F);
 253       Rspec[1] = CLAMP(specularColor[1], 0.0F, 1.0F);
 254       Rspec[2] = CLAMP(specularColor[2], 0.0F, 1.0F);
 255       Rspec[3] = CLAMP(specularColor[3], 0.0F, 1.0F);
 256    }
 257    else {
 258       GLfloat *ind = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_INDEXES];
 259       GLfloat d_a = ind[MAT_INDEX_DIFFUSE] - ind[MAT_INDEX_AMBIENT];
 260       GLfloat s_a = ind[MAT_INDEX_SPECULAR] - ind[MAT_INDEX_AMBIENT];
 261       GLfloat i = (ind[MAT_INDEX_AMBIENT]
 262                    + diffuseCI * (1.0F-specularCI) * d_a
 263                    + specularCI * s_a);
 264       if (i > ind[MAT_INDEX_SPECULAR]) {
 265          i = ind[MAT_INDEX_SPECULAR];
 266       }
 267       *Rindex = i;
 268    }
 269 }
 270
 271
 272 /**
 273  * Do texgen needed for glRasterPos.
 274  * \param ctx  rendering context
 275  * \param vObj  object-space vertex coordinate
 276  * \param vEye  eye-space vertex coordinate
 277  * \param normal  vertex normal
 278  * \param unit  texture unit number
 279  * \param texcoord  incoming texcoord and resulting texcoord
 280  */
 281 static void
 282 compute_texgen(GLcontext *ctx, const GLfloat vObj[4], const GLfloat vEye[4],
 283                const GLfloat normal[3], GLuint unit, GLfloat texcoord[4])
 284 {
 285    const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 286
 287    /* always compute sphere map terms, just in case */
 288    GLfloat u[3], two_nu, rx, ry, rz, m, mInv;
 289    COPY_3V(u, vEye);
 290    NORMALIZE_3FV(u);
 291    two_nu = 2.0F * DOT3(normal, u);
 292    rx = u[0] - normal[0] * two_nu;
 293    ry = u[1] - normal[1] * two_nu;
 294    rz = u[2] - normal[2] * two_nu;
 295    m = rx * rx + ry * ry + (rz + 1.0F) * (rz + 1.0F);
 296    if (m > 0.0F)
 297       mInv = 0.5F * _mesa_inv_sqrtf(m);
 298    else
 299       mInv = 0.0F;
 300
 301    if (texUnit->TexGenEnabled & S_BIT) {
 302       switch (texUnit->GenS.Mode) {
 303          case GL_OBJECT_LINEAR:
 304             texcoord[0] = DOT4(vObj, texUnit->GenS.ObjectPlane);
 305             break;
 306          case GL_EYE_LINEAR:
 307             texcoord[0] = DOT4(vEye, texUnit->GenS.EyePlane);
 308             break;
 309          case GL_SPHERE_MAP:
 310             texcoord[0] = rx * mInv + 0.5F;
 311             break;
 312          case GL_REFLECTION_MAP:
 313             texcoord[0] = rx;
 314             break;
 315          case GL_NORMAL_MAP:
 316             texcoord[0] = normal[0];
 317             break;
 318          default:
 319             _mesa_problem(ctx, "Bad S texgen in compute_texgen()");
 320             return;
 321       }
 322    }
 323
 324    if (texUnit->TexGenEnabled & T_BIT) {
 325       switch (texUnit->GenT.Mode) {
 326          case GL_OBJECT_LINEAR:
 327             texcoord[1] = DOT4(vObj, texUnit->GenT.ObjectPlane);
 328             break;
 329          case GL_EYE_LINEAR:
 330             texcoord[1] = DOT4(vEye, texUnit->GenT.EyePlane);
 331             break;
 332          case GL_SPHERE_MAP:
 333             texcoord[1] = ry * mInv + 0.5F;
 334             break;
 335          case GL_REFLECTION_MAP:
 336             texcoord[1] = ry;
 337             break;
 338          case GL_NORMAL_MAP:
 339             texcoord[1] = normal[1];
 340             break;
 341          default:
 342             _mesa_problem(ctx, "Bad T texgen in compute_texgen()");
 343             return;
 344       }
 345    }
 346
 347    if (texUnit->TexGenEnabled & R_BIT) {
 348       switch (texUnit->GenR.Mode) {
 349          case GL_OBJECT_LINEAR:
 350             texcoord[2] = DOT4(vObj, texUnit->GenR.ObjectPlane);
 351             break;
 352          case GL_EYE_LINEAR:
 353             texcoord[2] = DOT4(vEye, texUnit->GenR.EyePlane);
 354             break;
 355          case GL_REFLECTION_MAP:
 356             texcoord[2] = rz;
 357             break;
 358          case GL_NORMAL_MAP:
 359             texcoord[2] = normal[2];
 360             break;
 361          default:
 362             _mesa_problem(ctx, "Bad R texgen in compute_texgen()");
 363             return;
 364       }
 365    }
 366
 367    if (texUnit->TexGenEnabled & Q_BIT) {
 368       switch (texUnit->GenQ.Mode) {
 369          case GL_OBJECT_LINEAR:
 370             texcoord[3] = DOT4(vObj, texUnit->GenQ.ObjectPlane);
 371             break;
 372          case GL_EYE_LINEAR:
 373             texcoord[3] = DOT4(vEye, texUnit->GenQ.EyePlane);
 374             break;
 375          default:
 376             _mesa_problem(ctx, "Bad Q texgen in compute_texgen()");
 377             return;
 378       }
 379    }
 380 }
 381
 382
 383 /**
 384  * glRasterPos transformation.  Typically called via ctx->Driver.RasterPos().
 385  * XXX some of this code (such as viewport xform, clip testing and setting
 386  * of ctx->Current.Raster* fields) could get lifted up into the
 387  * main/rasterpos.c code.
 388  *
 389  * \param vObj  vertex position in object space
 390  */
 391 void
 392 _tnl_RasterPos(GLcontext *ctx, const GLfloat vObj[4])
 393 {
 394    if (ctx->VertexProgram._Enabled) {
 395       /* XXX implement this */
 396       _mesa_problem(ctx, "Vertex programs not implemented for glRasterPos");
 397       return;
 398    }
 399    else {
 400       GLfloat eye[4], clip[4], ndc[3], d;
 401       GLfloat *norm, eyenorm[3];
 402       GLfloat *objnorm = ctx->Current.Attrib[VERT_ATTRIB_NORMAL];
 403
 404       /* apply modelview matrix:  eye = MV * obj */
 405       TRANSFORM_POINT( eye, ctx->ModelviewMatrixStack.Top->m, vObj );
 406       /* apply projection matrix:  clip = Proj * eye */
 407       TRANSFORM_POINT( clip, ctx->ProjectionMatrixStack.Top->m, eye );
 408
 409       /* clip to view volume. */
 410       if (!ctx->Transform.DepthClamp) {
 411          if (viewclip_point_z(clip) == 0) {
 412             ctx->Current.RasterPosValid = GL_FALSE;
 413             return;
 414          }
 415       }
 416       if (!ctx->Transform.RasterPositionUnclipped) {
 417          if (viewclip_point_xy(clip) == 0) {
 418             ctx->Current.RasterPosValid = GL_FALSE;
 419             return;
 420          }
 421       }
 422
 423       /* clip to user clipping planes */
 424       if (ctx->Transform.ClipPlanesEnabled && !userclip_point(ctx, clip)) {
 425          ctx->Current.RasterPosValid = GL_FALSE;
 426          return;
 427       }
 428
 429       /* ndc = clip / W */
 430       d = (clip[3] == 0.0F) ? 1.0F : 1.0F / clip[3];
 431       ndc[0] = clip[0] * d;
 432       ndc[1] = clip[1] * d;
 433       ndc[2] = clip[2] * d;
 434       /* wincoord = viewport_mapping(ndc) */
 435       ctx->Current.RasterPos[0] = (ndc[0] * ctx->Viewport._WindowMap.m[MAT_SX]
 436                                    + ctx->Viewport._WindowMap.m[MAT_TX]);
 437       ctx->Current.RasterPos[1] = (ndc[1] * ctx->Viewport._WindowMap.m[MAT_SY]
 438                                    + ctx->Viewport._WindowMap.m[MAT_TY]);
 439       ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport._WindowMap.m[MAT_SZ]
 440                                    + ctx->Viewport._WindowMap.m[MAT_TZ])
 441                                   / ctx->DrawBuffer->_DepthMaxF;
 442       ctx->Current.RasterPos[3] = clip[3];
 443
 444       if (ctx->Transform.DepthClamp) {
 445          ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
 446                                            ctx->Viewport.Near,
 447                                            ctx->Viewport.Far);
 448       }
 449
 450       /* compute raster distance */
 451       if (ctx->Fog.FogCoordinateSource == GL_FOG_COORDINATE_EXT)
 452          ctx->Current.RasterDistance = ctx->Current.Attrib[VERT_ATTRIB_FOG][0];
 453       else
 454          ctx->Current.RasterDistance =
 455                         SQRTF( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
 456
 457       /* compute transformed normal vector (for lighting or texgen) */
 458       if (ctx->_NeedEyeCoords) {
 459          const GLfloat *inv = ctx->ModelviewMatrixStack.Top->inv;
 460          TRANSFORM_NORMAL( eyenorm, objnorm, inv );
 461          norm = eyenorm;
 462       }
 463       else {
 464          norm = objnorm;
 465       }
 466
 467       /* update raster color */
 468       if (ctx->Light.Enabled) {
 469          /* lighting */
 470          shade_rastpos( ctx, vObj, norm,
 471                         ctx->Current.RasterColor,
 472                         ctx->Current.RasterSecondaryColor,
 473                         &ctx->Current.RasterIndex );
 474       }
 475       else {
 476          /* use current color or index */
 477          if (ctx->Visual.rgbMode) {
 478             COPY_4FV(ctx->Current.RasterColor,
 479                      ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
 480             COPY_4FV(ctx->Current.RasterSecondaryColor,
 481                      ctx->Current.Attrib[VERT_ATTRIB_COLOR1]);
 482          }
 483          else {
 484             ctx->Current.RasterIndex
 485                = ctx->Current.Attrib[VERT_ATTRIB_COLOR_INDEX][0];
 486          }
 487       }
 488
 489       /* texture coords */
 490       {
 491          GLuint u;
 492          for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
 493             GLfloat tc[4];
 494             COPY_4V(tc, ctx->Current.Attrib[VERT_ATTRIB_TEX0 + u]);
 495             if (ctx->Texture.Unit[u].TexGenEnabled) {
 496                compute_texgen(ctx, vObj, eye, norm, u, tc);
 497             }
 498             TRANSFORM_POINT(ctx->Current.RasterTexCoords[u],
 499                             ctx->TextureMatrixStack[u].Top->m, tc);
 500          }
 501       }
 502
 503       ctx->Current.RasterPosValid = GL_TRUE;
 504    }
 505
 506    if (ctx->RenderMode == GL_SELECT) {
 507       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 508    }
 509 }