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