src/mesa/main/rastpos.c

   1 /* $Id: rastpos.c,v 1.1 1999/08/19 00:55:41 jtg 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 #include <assert.h>
  35 #include "clip.h"
  36 #include "feedback.h"
  37 #include "light.h"
  38 #include "macros.h"
  39 #include "matrix.h"
  40 #include "mmath.h"
  41 #include "shade.h"
  42 #include "types.h"
  43 #include "xform.h"
  44 #include "context.h"
  45 #ifdef XFree86Server
  46 #include "GL/xf86glx.h"
  47 #endif
  48 #endif
  49
  50
  51
  52 /*
  53  * Caller:  context->API.RasterPos4f
  54  */
  55 void gl_RasterPos4f( GLcontext *ctx,
  56                      GLfloat x, GLfloat y, GLfloat z, GLfloat w )
  57 {
  58    GLfloat v[4], eye[4], clip[4], ndc[3], d;
  59
  60    /* KW: Added this test, which is in the spec.  We can't do this
  61     *     outside begin/end any more because the ctx->Current values
  62     *     aren't uptodate during that period.
  63     */
  64    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx, "glRasterPos" );
  65
  66    if (ctx->NewState)
  67       gl_update_state( ctx );
  68
  69    ASSIGN_4V( v, x, y, z, w );
  70    TRANSFORM_POINT( eye, ctx->ModelView.m, v );
  71
  72    /* raster color */
  73    if (ctx->Light.Enabled)
  74    {
  75       /*GLfloat *vert;*/
  76       GLfloat *norm, eyenorm[3];
  77       GLfloat *objnorm = ctx->Current.Normal;
  78
  79           /* Not needed???
  80       vert = (ctx->NeedEyeCoords ? eye : v);
  81           */
  82
  83       if (ctx->NeedEyeNormals) {
  84          GLfloat *inv = ctx->ModelView.inv;
  85          TRANSFORM_NORMAL( eyenorm, objnorm, inv );
  86          norm = eyenorm;
  87       } else {
  88          norm = objnorm;
  89       }
  90
  91       gl_shade_rastpos( ctx, v, norm,
  92                         ctx->Current.RasterColor,
  93                         &ctx->Current.RasterIndex );
  94
  95    }
  96    else {
  97       /* use current color or index */
  98       if (ctx->Visual->RGBAflag) {
  99          UBYTE_RGBA_TO_FLOAT_RGBA(ctx->Current.RasterColor,
 100                                   ctx->Current.ByteColor);
 101       }
 102       else {
 103          ctx->Current.RasterIndex = ctx->Current.Index;
 104       }
 105    }
 106
 107    /* compute raster distance */
 108    ctx->Current.RasterDistance =
 109                       GL_SQRT( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
 110
 111    /* apply projection matrix:  clip = Proj * eye */
 112    TRANSFORM_POINT( clip, ctx->ProjectionMatrix.m, eye );
 113
 114    /* clip to view volume */
 115    if (gl_viewclip_point( clip )==0) {
 116       ctx->Current.RasterPosValid = GL_FALSE;
 117       return;
 118    }
 119
 120    /* clip to user clipping planes */
 121    if ( ctx->Transform.AnyClip &&
 122         gl_userclip_point(ctx, clip) == 0)
 123    {
 124       ctx->Current.RasterPosValid = GL_FALSE;
 125       return;
 126    }
 127
 128    /* ndc = clip / W */
 129    ASSERT( clip[3]!=0.0 );
 130    d = 1.0F / clip[3];
 131    ndc[0] = clip[0] * d;
 132    ndc[1] = clip[1] * d;
 133    ndc[2] = clip[2] * d;
 134
 135    ctx->Current.RasterPos[0] = (ndc[0] * ctx->Viewport.WindowMap.m[MAT_SX] +
 136                                 ctx->Viewport.WindowMap.m[MAT_TX]);
 137    ctx->Current.RasterPos[1] = (ndc[1] * ctx->Viewport.WindowMap.m[MAT_SY] +
 138                                 ctx->Viewport.WindowMap.m[MAT_TY]);
 139    ctx->Current.RasterPos[2] = (ndc[2] * ctx->Viewport.WindowMap.m[MAT_SZ] +
 140                                 ctx->Viewport.WindowMap.m[MAT_TZ]) / DEPTH_SCALE;
 141    ctx->Current.RasterPos[3] = clip[3];
 142    ctx->Current.RasterPosValid = GL_TRUE;
 143
 144    /* FOG??? */
 145
 146    {
 147       GLuint texSet;
 148       for (texSet=0; texSet<MAX_TEXTURE_UNITS; texSet++) {
 149          COPY_4FV( ctx->Current.RasterMultiTexCoord[texSet],
 150                   ctx->Current.Texcoord[texSet] );
 151       }
 152    }
 153
 154    if (ctx->RenderMode==GL_SELECT) {
 155       gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 156    }
 157
 158 }
 159
 160
 161
 162 /*
 163  * This is a MESA extension function.  Pretty much just like glRasterPos
 164  * except we don't apply the modelview or projection matrices; specify a
 165  * window coordinate directly.
 166  * Caller:  context->API.WindowPos4fMESA pointer.
 167  */
 168 void gl_windowpos( GLcontext *ctx, GLfloat x, GLfloat y, GLfloat z, GLfloat w )
 169 {
 170    /* KW: Assume that like rasterpos, this must be outside begin/end.
 171     */
 172    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx, "glWindowPosMESA" );
 173
 174    /* set raster position */
 175    ctx->Current.RasterPos[0] = x;
 176    ctx->Current.RasterPos[1] = y;
 177    ctx->Current.RasterPos[2] = CLAMP( z, 0.0F, 1.0F );
 178    ctx->Current.RasterPos[3] = w;
 179
 180    ctx->Current.RasterPosValid = GL_TRUE;
 181
 182    /* raster color */
 183    if (0 && ctx->Light.Enabled) {
 184
 185       /* KW: I don't see how this can work - would have to take the
 186        *     inverse of the projection matrix or the combined
 187        *     modelProjection matrix, transform point and normal, and
 188        *     do the lighting.  Those inverses are not used for
 189        *     anything else.  This is not an object-space lighting
 190        *     issue - what this is trying to do is something like
 191        *     clip-space or window-space lighting...
 192        *
 193        *     Anyway, since the implementation was never correct, I'm
 194        *     not fixing it now - just use the unlit color.
 195        */
 196
 197       /* KW:  As a reprise, we now *do* keep the inverse of the projection
 198        *      matrix, so it is not infeasible to try to swim up stream
 199        *      in this manner.  I still don't want to implement it,
 200        *      however.
 201        */
 202    }
 203    else {
 204       /* use current color or index */
 205       if (ctx->Visual->RGBAflag) {
 206          UBYTE_RGBA_TO_FLOAT_RGBA(ctx->Current.RasterColor,
 207                                   ctx->Current.ByteColor);
 208       }
 209       else {
 210          ctx->Current.RasterIndex = ctx->Current.Index;
 211       }
 212    }
 213
 214    ctx->Current.RasterDistance = 0.0;
 215
 216    {
 217       GLuint texSet;
 218       for (texSet=0; texSet<MAX_TEXTURE_UNITS; texSet++) {
 219          COPY_4FV( ctx->Current.RasterMultiTexCoord[texSet],
 220                   ctx->Current.Texcoord[texSet] );
 221       }
 222    }
 223
 224    if (ctx->RenderMode==GL_SELECT) {
 225       gl_update_hitflag( ctx, ctx->Current.RasterPos[2] );
 226    }
 227 }