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