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