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/rastpos.h"
  33 #include "main/simple_list.h"
  34 #include "main/mtypes.h"
  35
  36 #include "math/m_matrix.h"
  37 #include "tnl/tnl.h"
  38
  39
  40
  41 /**
  42  * Clip a point against the view volume.
  43  *
  44  * \param v vertex vector describing the point to clip.
  45  *
  46  * \return zero if outside view volume, or one if inside.
  47  */
  48 static GLuint
  49 viewclip_point_xy( const GLfloat v[] )
  50 {
  51    if (   v[0] > v[3] || v[0] < -v[3]
  52        || v[1] > v[3] || v[1] < -v[3] ) {
  53       return 0;
  54    }
  55    else {
  56       return 1;
  57    }
  58 }
  59
  60
  61 /**
  62  * Clip a point against the far/near Z clipping planes.
  63  *
  64  * \param v vertex vector describing the point to clip.
  65  *
  66  * \return zero if outside view volume, or one if inside.
  67  */
  68 static GLuint
  69 viewclip_point_z( const GLfloat v[] )
  70 {
  71    if (v[2] > v[3] || v[2] < -v[3] ) {
  72       return 0;
  73    }
  74    else {
  75       return 1;
  76    }
  77 }
  78
  79
  80 /**
  81  * Clip a point against the user clipping planes.
  82  *
  83  * \param ctx GL context.
  84  * \param v vertex vector describing the point to clip.
  85  *
  86  * \return zero if the point was clipped, or one otherwise.
  87  */
  88 static GLuint
  89 userclip_point( GLcontext *ctx, const GLfloat v[] )
  90 {
  91    GLuint p;
  92
  93    for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
  94       if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
  95          GLfloat dot = v[0] * ctx->Transform._ClipUserPlane[p][0]
  96                      + v[1] * ctx->Transform._ClipUserPlane[p][1]
  97                      + v[2] * ctx->Transform._ClipUserPlane[p][2]
  98                      + v[3] * ctx->Transform._ClipUserPlane[p][3];
  99          if (dot < 0.0F) {
 100             return 0;
 101          }
 102       }
 103    }
 104
 105    return 1;
 106 }
 107
 108
 109 /**
 110  * Compute lighting for the raster position.  Both RGB and CI modes computed.
 111  * \param ctx the context
 112  * \param vertex vertex location
 113  * \param normal normal vector
 114  * \param Rcolor returned color
 115  * \param Rspec returned specular color (if separate specular enabled)
 116  * \param Rindex returned color index
 117  */
 118 static void
 119 shade_rastpos(GLcontext *ctx,
 120               const GLfloat vertex[4],
 121               const GLfloat normal[3],
 122               GLfloat Rcolor[4],
 123               GLfloat Rspec[4],
 124               GLfloat *Rindex)
 125 {
 126    /*const*/ GLfloat (*base)[3] = ctx->Light._BaseColor;
 127    const struct gl_light *light;
 128    GLfloat diffuseColor[4], specularColor[4];  /* for RGB mode only */
 129    GLfloat diffuseCI = 0.0, specularCI = 0.0;  /* for CI mode only */
 130
 131    _mesa_validate_all_lighting_tables( ctx );
 132
 133    COPY_3V(diffuseColor, base[0]);
 134    diffuseColor[3] = CLAMP(
 135       ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3], 0.0F, 1.0F );
 136    ASSIGN_4V(specularColor, 0.0, 0.0, 0.0, 1.0);
 137
 138    foreach (light, &ctx->Light.EnabledList) {
 139       GLfloat attenuation = 1.0;
 140       GLfloat VP[3]; /* vector from vertex to light pos */
 141       GLfloat n_dot_VP;
 142       GLfloat diffuseContrib[3], specularContrib[3];
 143
 144       if (!(light->_Flags & LIGHT_POSITIONAL)) {
 145          /* light at infinity */
 146          COPY_3V(VP, light->_VP_inf_norm);
 147          attenuation = light->_VP_inf_spot_attenuation;
 148       }
 149       else {
 150          /* local/positional light */
 151          GLfloat d;
 152
 153          /* VP = vector from vertex pos to light[i].pos */
 154          SUB_3V(VP, light->_Position, vertex);
 155          /* d = length(VP) */
 156          d = (GLfloat) LEN_3FV( VP );
 157          if (d > 1.0e-6) {
 158             /* normalize VP */
 159             GLfloat invd = 1.0F / d;
 160             SELF_SCALE_SCALAR_3V(VP, invd);
 161          }
 162
 163          /* atti */
 164          attenuation = 1.0F / (light->ConstantAttenuation + d *
 165                                (light->LinearAttenuation + d *
 166                                 light->QuadraticAttenuation));
 167
 168          if (light->_Flags & LIGHT_SPOT) {
 169             GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
 170
 171             if (PV_dot_dir<light->_CosCutoff) {
 172                continue;
 173             }
 174             else {
 175                double x = PV_dot_dir * (EXP_TABLE_SIZE-1);
 176                int k = (int) x;
 177                GLfloat spot = (GLfloat) (light->_SpotExpTable[k][0]
 178                                + (x-k)*light->_SpotExpTable[k][1]);
 179                attenuation *= spot;
 180             }
 181          }
 182       }
 183
 184       if (attenuation < 1e-3)
 185          continue;
 186
 187       n_dot_VP = DOT3( normal, VP );
 188
 189       if (n_dot_VP < 0.0F) {
 190          ACC_SCALE_SCALAR_3V(diffuseColor, attenuation, light->_MatAmbient[0]);
 191          continue;
 192       }
 193
 194       /* Ambient + diffuse */
 195       COPY_3V(diffuseContrib, light->_MatAmbient[0]);
 196       ACC_SCALE_SCALAR_3V(diffuseContrib, n_dot_VP, light->_MatDiffuse[0]);
 197       diffuseCI += n_dot_VP * light->_dli * attenuation;
 198
 199       /* Specular */
 200       {
 201          const GLfloat *h;
 202          GLfloat n_dot_h;
 203
 204          ASSIGN_3V(specularContrib, 0.0, 0.0, 0.0);
 205
 206          if (ctx->Light.Model.LocalViewer) {
 207             GLfloat v[3];
 208             COPY_3V(v, vertex);
 209             NORMALIZE_3FV(v);
 210             SUB_3V(VP, VP, v);
 211             NORMALIZE_3FV(VP);
 212             h = VP;
 213          }
 214          else if (light->_Flags & LIGHT_POSITIONAL) {
 215             ACC_3V(VP, ctx->_EyeZDir);
 216             NORMALIZE_3FV(VP);
 217             h = VP;
 218          }
 219          else {
 220             h = light->_h_inf_norm;
 221          }
 222
 223          n_dot_h = DOT3(normal, h);
 224
 225          if (n_dot_h > 0.0F) {
 226             GLfloat spec_coef;
 227             GET_SHINE_TAB_ENTRY( ctx->_ShineTable[0], n_dot_h, spec_coef );
 228
 229             if (spec_coef > 1.0e-10) {
 230                if (ctx->Light.Model.ColorControl==GL_SEPARATE_SPECULAR_COLOR) {
 231                   ACC_SCALE_SCALAR_3V( specularContrib, spec_coef,
 232                                        light->_MatSpecular[0]);
 233                }
 234                else {
 235                   ACC_SCALE_SCALAR_3V( diffuseContrib, spec_coef,
 236                                        light->_MatSpecular[0]);
 237                }
 238                /*assert(light->_sli > 0.0);*/
 239                specularCI += spec_coef * light->_sli * attenuation;
 240             }
 241          }
 242       }
 243
 244       ACC_SCALE_SCALAR_3V( diffuseColor, attenuation, diffuseContrib );
 245       ACC_SCALE_SCALAR_3V( specularColor, attenuation, specularContrib );
 246    }
 247
 248    if (ctx->Visual.rgbMode) {
 249       Rcolor[0] = CLAMP(diffuseColor[0], 0.0F, 1.0F);
 250       Rcolor[1] = CLAMP(diffuseColor[1], 0.0F, 1.0F);
 251       Rcolor[2] = CLAMP(diffuseColor[2], 0.0F, 1.0F);
 252       Rcolor[3] = CLAMP(diffuseColor[3], 0.0F, 1.0F);
 253       Rspec[0] = CLAMP(specularColor[0], 0.0F, 1.0F);
 254       Rspec[1] = CLAMP(specularColor[1], 0.0F, 1.0F);
 255       Rspec[2] = CLAMP(specularColor[2], 0.0F, 1.0F);
 256       Rspec[3] = CLAMP(specularColor[3], 0.0F, 1.0F);
 257    }
 258    else {
 259       GLfloat *ind = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_INDEXES];
 260       GLfloat d_a = ind[MAT_INDEX_DIFFUSE] - ind[MAT_INDEX_AMBIENT];
 261       GLfloat s_a = ind[MAT_INDEX_SPECULAR] - ind[MAT_INDEX_AMBIENT];
 262       GLfloat i = (ind[MAT_INDEX_AMBIENT]
 263                    + diffuseCI * (1.0F-specularCI) * d_a
 264                    + specularCI * s_a);
 265       if (i > ind[MAT_INDEX_SPECULAR]) {
 266          i = ind[MAT_INDEX_SPECULAR];
 267       }
 268       *Rindex = i;
 269    }
 270 }
 271
 272
 273 /**
 274  * Do texgen needed for glRasterPos.
 275  * \param ctx  rendering context
 276  * \param vObj  object-space vertex coordinate
 277  * \param vEye  eye-space vertex coordinate
 278  * \param normal  vertex normal
 279  * \param unit  texture unit number
 280  * \param texcoord  incoming texcoord and resulting texcoord
 281  */
 282 static void
 283 compute_texgen(GLcontext *ctx, const GLfloat vObj[4], const GLfloat vEye[4],
 284                const GLfloat normal[3], GLuint unit, GLfloat texcoord[4])
 285 {
 286    const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
 287
 288    /* always compute sphere map terms, just in case */
 289    GLfloat u[3], two_nu, rx, ry, rz, m, mInv;
 290    COPY_3V(u, vEye);
 291    NORMALIZE_3FV(u);
 292    two_nu = 2.0F * DOT3(normal, u);
 293    rx = u[0] - normal[0] * two_nu;
 294    ry = u[1] - normal[1] * two_nu;
 295    rz = u[2] - normal[2] * two_nu;
 296    m = rx * rx + ry * ry + (rz + 1.0F) * (rz + 1.0F);
 297    if (m > 0.0F)
 298       mInv = 0.5F * _mesa_inv_sqrtf(m);
 299    else
 300       mInv = 0.0F;
 301
 302    if (texUnit->TexGenEnabled & S_BIT) {
 303       switch (texUnit->GenS.Mode) {
 304          case GL_OBJECT_LINEAR:
 305             texcoord[0] = DOT4(vObj, texUnit->GenS.ObjectPlane);
 306             break;
 307          case GL_EYE_LINEAR:
 308             texcoord[0] = DOT4(vEye, texUnit->GenS.EyePlane);
 309             break;
 310          case GL_SPHERE_MAP:
 311             texcoord[0] = rx * mInv + 0.5F;
 312             break;
 313          case GL_REFLECTION_MAP:
 314             texcoord[0] = rx;
 315             break;
 316          case GL_NORMAL_MAP:
 317             texcoord[0] = normal[0];
 318             break;
 319          default:
 320             _mesa_problem(ctx, "Bad S texgen in compute_texgen()");
 321             return;
 322       }
 323    }
 324
 325    if (texUnit->TexGenEnabled & T_BIT) {
 326       switch (texUnit->GenT.Mode) {
 327          case GL_OBJECT_LINEAR:
 328             texcoord[1] = DOT4(vObj, texUnit->GenT.ObjectPlane);
 329             break;
 330          case GL_EYE_LINEAR:
 331             texcoord[1] = DOT4(vEye, texUnit->GenT.EyePlane);
 332             break;
 333          case GL_SPHERE_MAP:
 334             texcoord[1] = ry * mInv + 0.5F;
 335             break;
 336          case GL_REFLECTION_MAP:
 337             texcoord[1] = ry;
 338             break;
 339          case GL_NORMAL_MAP:
 340             texcoord[1] = normal[1];
 341             break;
 342          default:
 343             _mesa_problem(ctx, "Bad T texgen in compute_texgen()");
 344             return;
 345       }
 346    }
 347
 348    if (texUnit->TexGenEnabled & R_BIT) {
 349       switch (texUnit->GenR.Mode) {
 350          case GL_OBJECT_LINEAR:
 351             texcoord[2] = DOT4(vObj, texUnit->GenR.ObjectPlane);
 352             break;
 353          case GL_EYE_LINEAR:
 354             texcoord[2] = DOT4(vEye, texUnit->GenR.EyePlane);
 355             break;
 356          case GL_REFLECTION_MAP:
 357             texcoord[2] = rz;
 358             break;
 359          case GL_NORMAL_MAP:
 360             texcoord[2] = normal[2];
 361             break;
 362          default:
 363             _mesa_problem(ctx, "Bad R texgen in compute_texgen()");
 364             return;
 365       }
 366    }
 367
 368    if (texUnit->TexGenEnabled & Q_BIT) {
 369       switch (texUnit->GenQ.Mode) {
 370          case GL_OBJECT_LINEAR:
 371             texcoord[3] = DOT4(vObj, texUnit->GenQ.ObjectPlane);
 372             break;
 373          case GL_EYE_LINEAR:
 374             texcoord[3] = DOT4(vEye, texUnit->GenQ.EyePlane);
 375             break;
 376          default:
 377             _mesa_problem(ctx, "Bad Q texgen in compute_texgen()");
 378             return;
 379       }
 380    }
 381 }
 382
 383
 384 /**
 385  * glRasterPos transformation.  Typically called via ctx->Driver.RasterPos().
 386  * XXX some of this code (such as viewport xform, clip testing and setting
 387  * of ctx->Current.Raster* fields) could get lifted up into the
 388  * main/rasterpos.c code.
 389  *
 390  * \param vObj  vertex position in object space
 391  */
 392 void
 393 _tnl_RasterPos(GLcontext *ctx, const GLfloat vObj[4])
 394 {
 395    if (ctx->VertexProgram._Enabled) {
 396       /* XXX implement this */
 397       _mesa_problem(ctx, "Vertex programs not implemented for glRasterPos");
 398       return;
 399    }
 400    else {
 401       GLfloat eye[4], clip[4], ndc[3], d;
 402       GLfloat *norm, eyenorm[3];
 403       GLfloat *objnorm = ctx->Current.Attrib[VERT_ATTRIB_NORMAL];
 404
 405       /* apply modelview matrix:  eye = MV * obj */
 406       TRANSFORM_POINT( eye, ctx->ModelviewMatrixStack.Top->m, vObj );
 407       /* apply projection matrix:  clip = Proj * eye */
 408       TRANSFORM_POINT( clip, ctx->ProjectionMatrixStack.Top->m, eye );
 409
 410       /* clip to view volume. */
 411       if (!ctx->Transform.DepthClamp) {
 412          if (viewclip_point_z(clip) == 0) {
 413             ctx->Current.RasterPosValid = GL_FALSE;
 414             return;
 415          }
 416       }
 417       if (!ctx->Transform.RasterPositionUnclipped) {
 418          if (viewclip_point_xy(clip) == 0) {
 419             ctx->Current.RasterPosValid = GL_FALSE;
 420             return;
 421          }
 422       }
 423
 424       /* clip to user clipping planes */
 425       if (ctx->Transform.ClipPlanesEnabled && !userclip_point(ctx, clip)) {
 426          ctx->Current.RasterPosValid = GL_FALSE;
 427          return;
 428       }
 429
 430       /* ndc = clip / W */
 431       d = (clip[3] == 0.0F) ? 1.0F : 1.0F / clip[3];
 432       ndc[0] = clip[0] * d;
 433       ndc[1] = clip[1] * d;
 434       ndc[2] = clip[2] * d;
 435       /* wincoord = viewport_mapping(ndc) */
 436       ctx->Current.RasterPos[0] = (ndc[0] * ctx->Viewport._WindowMap.m[MAT_SX]
 437                                    + ctx->Viewport._WindowMap.m[MAT_TX]);
 438       ctx->Current.RasterPos[1] = (ndc[1] * ctx->Viewport._WindowMap.m[MAT_SY]
 439                                    + ctx->Viewport._WindowMap.m[MAT_TY]);
 440       ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport._WindowMap.m[MAT_SZ]
 441                                    + ctx->Viewport._WindowMap.m[MAT_TZ])
 442                                   / ctx->DrawBuffer->_DepthMaxF;
 443       ctx->Current.RasterPos[3] = clip[3];
 444
 445       if (ctx->Transform.DepthClamp) {
 446          ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
 447                                            ctx->Viewport.Near,
 448                                            ctx->Viewport.Far);
 449       }
 450
 451       /* compute raster distance */
 452       if (ctx->Fog.FogCoordinateSource == GL_FOG_COORDINATE_EXT)
 453          ctx->Current.RasterDistance = ctx->Current.Attrib[VERT_ATTRIB_FOG][0];
 454       else
 455          ctx->Current.RasterDistance =
 456                         SQRTF( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
 457
 458       /* compute transformed normal vector (for lighting or texgen) */
 459       if (ctx->_NeedEyeCoords) {
 460          const GLfloat *inv = ctx->ModelviewMatrixStack.Top->inv;
 461          TRANSFORM_NORMAL( eyenorm, objnorm, inv );
 462          norm = eyenorm;
 463       }
 464       else {
 465          norm = objnorm;
 466       }
 467
 468       /* update raster color */
 469       if (ctx->Light.Enabled) {
 470          /* lighting */
 471          shade_rastpos( ctx, vObj, norm,
 472                         ctx->Current.RasterColor,
 473                         ctx->Current.RasterSecondaryColor,
 474                         &ctx->Current.RasterIndex );
 475       }
 476       else {
 477          /* use current color or index */
 478          if (ctx->Visual.rgbMode) {
 479             COPY_4FV(ctx->Current.RasterColor,
 480                      ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
 481             COPY_4FV(ctx->Current.RasterSecondaryColor,
 482                      ctx->Current.Attrib[VERT_ATTRIB_COLOR1]);
 483          }
 484          else {
 485             ctx->Current.RasterIndex
 486                = ctx->Current.Attrib[VERT_ATTRIB_COLOR_INDEX][0];
 487          }
 488       }
 489
 490       /* texture coords */
 491       {
 492          GLuint u;
 493          for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
 494             GLfloat tc[4];
 495             COPY_4V(tc, ctx->Current.Attrib[VERT_ATTRIB_TEX0 + u]);
 496             if (ctx->Texture.Unit[u].TexGenEnabled) {
 497                compute_texgen(ctx, vObj, eye, norm, u, tc);
 498             }
 499             TRANSFORM_POINT(ctx->Current.RasterTexCoords[u],
 500                             ctx->TextureMatrixStack[u].Top->m, tc);
 501          }
 502       }
 503
 504       ctx->Current.RasterPosValid = GL_TRUE;
 505    }
 506
 507    if (ctx->RenderMode == GL_SELECT) {
 508       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 509    }
 510 }