src/mesa/main/rastpos.c

   1 /* $Id: rastpos.c,v 1.2 1999/10/08 09:27:11 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.1
   6  *
   7  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28
  29
  30
  31 #ifdef PC_HEADER
  32 #include "all.h"
  33 #else
  34 #ifndef XFree86Server
  35 #include <assert.h>
  36 #include <math.h>
  37 #else
  38 #include "GL/xf86glx.h"
  39 #endif
  40 #include "clip.h"
  41 #include "context.h"
  42 #include "feedback.h"
  43 #include "light.h"
  44 #include "macros.h"
  45 #include "matrix.h"
  46 #include "mmath.h"
  47 #include "rastpos.h"
  48 #include "shade.h"
  49 #include "types.h"
  50 #include "xform.h"
  51 #endif
  52
  53
  54 /*
  55  * Caller:  context->API.RasterPos4f
  56  */
  57 void gl_RasterPos4f( GLcontext *ctx,
  58                      GLfloat x, GLfloat y, GLfloat z, GLfloat w )
  59 {
  60    GLfloat v[4], eye[4], clip[4], ndc[3], d;
  61
  62    /* KW: Added this test, which is in the spec.  We can't do this
  63     *     outside begin/end any more because the ctx->Current values
  64     *     aren't uptodate during that period.
  65     */
  66    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx, "glRasterPos" );
  67
  68    if (ctx->NewState)
  69       gl_update_state( ctx );
  70
  71    ASSIGN_4V( v, x, y, z, w );
  72    TRANSFORM_POINT( eye, ctx->ModelView.m, v );
  73
  74    /* raster color */
  75    if (ctx->Light.Enabled)
  76    {
  77       /*GLfloat *vert;*/
  78       GLfloat *norm, eyenorm[3];
  79       GLfloat *objnorm = ctx->Current.Normal;
  80
  81           /* Not needed???
  82       vert = (ctx->NeedEyeCoords ? eye : v);
  83           */
  84
  85       if (ctx->NeedEyeNormals) {
  86          GLfloat *inv = ctx->ModelView.inv;
  87          TRANSFORM_NORMAL( eyenorm, objnorm, inv );
  88          norm = eyenorm;
  89       } else {
  90          norm = objnorm;
  91       }
  92
  93       gl_shade_rastpos( ctx, v, norm,
  94                         ctx->Current.RasterColor,
  95                         &ctx->Current.RasterIndex );
  96
  97    }
  98    else {
  99       /* use current color or index */
 100       if (ctx->Visual->RGBAflag) {
 101          UBYTE_RGBA_TO_FLOAT_RGBA(ctx->Current.RasterColor,
 102                                   ctx->Current.ByteColor);
 103       }
 104       else {
 105          ctx->Current.RasterIndex = ctx->Current.Index;
 106       }
 107    }
 108
 109    /* compute raster distance */
 110    ctx->Current.RasterDistance =
 111                       GL_SQRT( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
 112
 113    /* apply projection matrix:  clip = Proj * eye */
 114    TRANSFORM_POINT( clip, ctx->ProjectionMatrix.m, eye );
 115
 116    /* clip to view volume */
 117    if (gl_viewclip_point( clip )==0) {
 118       ctx->Current.RasterPosValid = GL_FALSE;
 119       return;
 120    }
 121
 122    /* clip to user clipping planes */
 123    if ( ctx->Transform.AnyClip &&
 124         gl_userclip_point(ctx, clip) == 0)
 125    {
 126       ctx->Current.RasterPosValid = GL_FALSE;
 127       return;
 128    }
 129
 130    /* ndc = clip / W */
 131    ASSERT( clip[3]!=0.0 );
 132    d = 1.0F / clip[3];
 133    ndc[0] = clip[0] * d;
 134    ndc[1] = clip[1] * d;
 135    ndc[2] = clip[2] * d;
 136
 137    ctx->Current.RasterPos[0] = (ndc[0] * ctx->Viewport.WindowMap.m[MAT_SX] +
 138                                 ctx->Viewport.WindowMap.m[MAT_TX]);
 139    ctx->Current.RasterPos[1] = (ndc[1] * ctx->Viewport.WindowMap.m[MAT_SY] +
 140                                 ctx->Viewport.WindowMap.m[MAT_TY]);
 141    ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport.WindowMap.m[MAT_SZ] +
 142                                 ctx->Viewport.WindowMap.m[MAT_TZ]) / DEPTH_SCALE;
 143    ctx->Current.RasterPos[3] = clip[3];
 144    ctx->Current.RasterPosValid = GL_TRUE;
 145
 146    /* FOG??? */
 147
 148    {
 149       GLuint texSet;
 150       for (texSet=0; texSet<MAX_TEXTURE_UNITS; texSet++) {
 151          COPY_4FV( ctx->Current.RasterMultiTexCoord[texSet],
 152                   ctx->Current.Texcoord[texSet] );
 153       }
 154    }
 155
 156    if (ctx->RenderMode==GL_SELECT) {
 157       gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 158    }
 159
 160 }
 161
 162
 163
 164 /*
 165  * This is a MESA extension function.  Pretty much just like glRasterPos
 166  * except we don't apply the modelview or projection matrices; specify a
 167  * window coordinate directly.
 168  * Caller:  context->API.WindowPos4fMESA pointer.
 169  */
 170 void gl_windowpos( GLcontext *ctx, GLfloat x, GLfloat y, GLfloat z, GLfloat w )
 171 {
 172    /* KW: Assume that like rasterpos, this must be outside begin/end.
 173     */
 174    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx, "glWindowPosMESA" );
 175
 176    /* set raster position */
 177    ctx->Current.RasterPos[0] = x;
 178    ctx->Current.RasterPos[1] = y;
 179    ctx->Current.RasterPos[2] = CLAMP( z, 0.0F, 1.0F );
 180    ctx->Current.RasterPos[3] = w;
 181
 182    ctx->Current.RasterPosValid = GL_TRUE;
 183
 184    /* raster color */
 185    if (0 && ctx->Light.Enabled) {
 186
 187       /* KW: I don't see how this can work - would have to take the
 188        *     inverse of the projection matrix or the combined
 189        *     modelProjection matrix, transform point and normal, and
 190        *     do the lighting.  Those inverses are not used for
 191        *     anything else.  This is not an object-space lighting
 192        *     issue - what this is trying to do is something like
 193        *     clip-space or window-space lighting...
 194        *
 195        *     Anyway, since the implementation was never correct, I'm
 196        *     not fixing it now - just use the unlit color.
 197        */
 198
 199       /* KW:  As a reprise, we now *do* keep the inverse of the projection
 200        *      matrix, so it is not infeasible to try to swim up stream
 201        *      in this manner.  I still don't want to implement it,
 202        *      however.
 203        */
 204    }
 205    else {
 206       /* use current color or index */
 207       if (ctx->Visual->RGBAflag) {
 208          UBYTE_RGBA_TO_FLOAT_RGBA(ctx->Current.RasterColor,
 209                                   ctx->Current.ByteColor);
 210       }
 211       else {
 212          ctx->Current.RasterIndex = ctx->Current.Index;
 213       }
 214    }
 215
 216    ctx->Current.RasterDistance = 0.0;
 217
 218    {
 219       GLuint texSet;
 220       for (texSet=0; texSet<MAX_TEXTURE_UNITS; texSet++) {
 221          COPY_4FV( ctx->Current.RasterMultiTexCoord[texSet],
 222                   ctx->Current.Texcoord[texSet] );
 223       }
 224    }
 225
 226    if (ctx->RenderMode==GL_SELECT) {
 227       gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 228    }
 229 }