src/mesa/swrast_setup/ss_tritmp.h

   1 /* $Id: ss_tritmp.h,v 1.20 2002/11/13 15:04:29 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  5.0
   6  *
   7  * Copyright (C) 1999-2002  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  * Authors:
  27  *    Keith Whitwell <keith@tungstengraphics.com>
  28  */
  29
  30
  31 static void TAG(triangle)(GLcontext *ctx, GLuint e0, GLuint e1, GLuint e2 )
  32 {
  33    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  34    SWvertex *verts = SWSETUP_CONTEXT(ctx)->verts;
  35    SWvertex *v[3];
  36    GLfloat z[3];
  37    GLfloat offset;
  38    GLenum mode = GL_FILL;
  39    GLuint facing = 0;
  40
  41    v[0] = &verts[e0];
  42    v[1] = &verts[e1];
  43    v[2] = &verts[e2];
  44
  45
  46    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
  47    {
  48       GLfloat ex = v[0]->win[0] - v[2]->win[0];
  49       GLfloat ey = v[0]->win[1] - v[2]->win[1];
  50       GLfloat fx = v[1]->win[0] - v[2]->win[0];
  51       GLfloat fy = v[1]->win[1] - v[2]->win[1];
  52       GLfloat cc  = ex*fy - ey*fx;
  53
  54       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
  55       {
  56          facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
  57          if (ctx->Stencil.TestTwoSide)
  58             ctx->_Facing = facing; /* for 2-sided stencil test */
  59
  60          if (IND & SS_UNFILLED_BIT)
  61             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  62
  63          if (facing == 1) {
  64             if (IND & SS_TWOSIDE_BIT) {
  65                if (IND & SS_RGBA_BIT) {
  66                   GLchan (*vbcolor)[4] = (GLchan (*)[4])VB->ColorPtr[1]->Ptr;
  67                   SS_COLOR(v[0]->color, vbcolor[e0]);
  68                   SS_COLOR(v[1]->color, vbcolor[e1]);
  69                   SS_COLOR(v[2]->color, vbcolor[e2]);
  70                   if (VB->SecondaryColorPtr[1]) {
  71                      GLchan (*vbspec)[4] = (GLchan (*)[4])VB->SecondaryColorPtr[1]->Ptr;
  72                      SS_SPEC(v[0]->specular, vbspec[e0]);
  73                      SS_SPEC(v[1]->specular, vbspec[e1]);
  74                      SS_SPEC(v[2]->specular, vbspec[e2]);
  75                   }
  76                } else {
  77                   GLuint *vbindex = VB->IndexPtr[1]->data;
  78                   SS_IND(v[0]->index, vbindex[e0]);
  79                   SS_IND(v[1]->index, vbindex[e1]);
  80                   SS_IND(v[2]->index, vbindex[e2]);
  81                }
  82             }
  83          }
  84       }
  85
  86       if (IND & SS_OFFSET_BIT)
  87       {
  88          offset = ctx->Polygon.OffsetUnits;
  89          z[0] = v[0]->win[2];
  90          z[1] = v[1]->win[2];
  91          z[2] = v[2]->win[2];
  92          if (cc * cc > 1e-16) {
  93             GLfloat ez = z[0] - z[2];
  94             GLfloat fz = z[1] - z[2];
  95             GLfloat a = ey*fz - ez*fy;
  96             GLfloat b = ez*fx - ex*fz;
  97             GLfloat ic = 1.0F / cc;
  98             GLfloat ac = a * ic;
  99             GLfloat bc = b * ic;
 100             if (ac < 0.0F) ac = -ac;
 101             if (bc < 0.0F) bc = -bc;
 102             offset += MAX2(ac, bc) * ctx->Polygon.OffsetFactor;
 103          }
 104          offset *= ctx->MRD;
 105          /*printf("offset %g\n", offset);*/
 106       }
 107    }
 108
 109    if (mode == GL_POINT) {
 110       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 111          v[0]->win[2] += offset;
 112          v[1]->win[2] += offset;
 113          v[2]->win[2] += offset;
 114       }
 115       _swsetup_render_point_tri( ctx, e0, e1, e2, facing );
 116    } else if (mode == GL_LINE) {
 117       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 118          v[0]->win[2] += offset;
 119          v[1]->win[2] += offset;
 120          v[2]->win[2] += offset;
 121       }
 122       _swsetup_render_line_tri( ctx, e0, e1, e2, facing );
 123    } else {
 124       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 125          v[0]->win[2] += offset;
 126          v[1]->win[2] += offset;
 127          v[2]->win[2] += offset;
 128       }
 129       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 130    }
 131
 132    if (IND & SS_OFFSET_BIT) {
 133       v[0]->win[2] = z[0];
 134       v[1]->win[2] = z[1];
 135       v[2]->win[2] = z[2];
 136    }
 137
 138    if (IND & SS_TWOSIDE_BIT) {
 139       if (facing == 1) {
 140          if (IND & SS_RGBA_BIT) {
 141             GLchan (*vbcolor)[4] = (GLchan (*)[4])VB->ColorPtr[0]->Ptr;
 142             SS_COLOR(v[0]->color, vbcolor[e0]);
 143             SS_COLOR(v[1]->color, vbcolor[e1]);
 144             SS_COLOR(v[2]->color, vbcolor[e2]);
 145             if (VB->SecondaryColorPtr[0]) {
 146                GLchan (*vbspec)[4] = (GLchan (*)[4])VB->SecondaryColorPtr[0]->Ptr;
 147                SS_SPEC(v[0]->specular, vbspec[e0]);
 148                SS_SPEC(v[1]->specular, vbspec[e1]);
 149                SS_SPEC(v[2]->specular, vbspec[e2]);
 150             }
 151          } else {
 152             GLuint *vbindex = VB->IndexPtr[0]->data;
 153             SS_IND(v[0]->index, vbindex[e0]);
 154             SS_IND(v[1]->index, vbindex[e1]);
 155             SS_IND(v[2]->index, vbindex[e2]);
 156          }
 157       }
 158    }
 159 }
 160
 161
 162
 163 /* Need to fixup edgeflags when decomposing to triangles:
 164  */
 165 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 166                        GLuint v1, GLuint v2, GLuint v3 )
 167 {
 168    if (IND & SS_UNFILLED_BIT) {
 169       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 170       GLubyte ef1 = VB->EdgeFlag[v1];
 171       GLubyte ef3 = VB->EdgeFlag[v3];
 172       VB->EdgeFlag[v1] = 0;
 173       TAG(triangle)( ctx, v0, v1, v3 );
 174       VB->EdgeFlag[v1] = ef1;
 175       VB->EdgeFlag[v3] = 0;
 176       TAG(triangle)( ctx, v1, v2, v3 );
 177       VB->EdgeFlag[v3] = ef3;
 178    } else {
 179       TAG(triangle)( ctx, v0, v1, v3 );
 180       TAG(triangle)( ctx, v1, v2, v3 );
 181    }
 182 }
 183
 184
 185
 186
 187 static void TAG(init)( void )
 188 {
 189    tri_tab[IND] = TAG(triangle);
 190    quad_tab[IND] = TAG(quadfunc);
 191 }
 192
 193
 194 #undef IND
 195 #undef TAG