src/mesa/swrast_setup/ss_tritmp.h

   1 /* $Id: ss_tritmp.h,v 1.13 2001/07/12 22:09:21 keithw Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.5
   6  *
   7  * Copyright (C) 1999-2001  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 <keithw@valinux.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;
  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
  58          if (IND & SS_UNFILLED_BIT)
  59             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  60
  61          if (facing == 1) {
  62             if (IND & SS_TWOSIDE_BIT) {
  63                if (IND & SS_RGBA_BIT) {
  64                   GLfloat (*vbcolor)[4] = (GLfloat (*)[4])VB->ColorPtr[1]->Ptr;
  65                   SS_COLOR(v[0]->color, vbcolor[e0]);
  66                   SS_COLOR(v[1]->color, vbcolor[e1]);
  67                   SS_COLOR(v[2]->color, vbcolor[e2]);
  68                   if (VB->SecondaryColorPtr[1]) {
  69                      GLfloat (*vbspec)[4] = (GLfloat (*)[4])VB->SecondaryColorPtr[1]->Ptr;
  70                      SS_SPEC(v[0]->specular, vbspec[e0]);
  71                      SS_SPEC(v[1]->specular, vbspec[e1]);
  72                      SS_SPEC(v[2]->specular, vbspec[e2]);
  73                   }
  74                } else {
  75                   GLuint *vbindex = VB->IndexPtr[1]->data;
  76                   SS_IND(v[0]->index, vbindex[e0]);
  77                   SS_IND(v[1]->index, vbindex[e1]);
  78                   SS_IND(v[2]->index, vbindex[e2]);
  79                }
  80             }
  81          }
  82       }
  83
  84       if (IND & SS_OFFSET_BIT)
  85       {
  86          offset = ctx->Polygon.OffsetUnits;
  87          z[0] = v[0]->win[2];
  88          z[1] = v[1]->win[2];
  89          z[2] = v[2]->win[2];
  90          if (cc * cc > 1e-16) {
  91             GLfloat ez = z[0] - z[2];
  92             GLfloat fz = z[1] - z[2];
  93             GLfloat a = ey*fz - ez*fy;
  94             GLfloat b = ez*fx - ex*fz;
  95             GLfloat ic = 1.0 / cc;
  96             GLfloat ac = a * ic;
  97             GLfloat bc = b * ic;
  98             if (ac < 0.0f) ac = -ac;
  99             if (bc < 0.0f) bc = -bc;
 100             offset += MAX2(ac, bc) * ctx->Polygon.OffsetFactor;
 101          }
 102          offset *= ctx->MRD;
 103          /*printf("offset %g\n", offset);*/
 104       }
 105    }
 106
 107    if (mode == GL_POINT) {
 108       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 109          v[0]->win[2] += offset;
 110          v[1]->win[2] += offset;
 111          v[2]->win[2] += offset;
 112       }
 113       _swsetup_render_point_tri( ctx, e0, e1, e2 );
 114    } else if (mode == GL_LINE) {
 115       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 116          v[0]->win[2] += offset;
 117          v[1]->win[2] += offset;
 118          v[2]->win[2] += offset;
 119       }
 120       _swsetup_render_line_tri( ctx, e0, e1, e2 );
 121    } else {
 122       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 123          v[0]->win[2] += offset;
 124          v[1]->win[2] += offset;
 125          v[2]->win[2] += offset;
 126       }
 127       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 128    }
 129
 130    if (IND & SS_OFFSET_BIT) {
 131       v[0]->win[2] = z[0];
 132       v[1]->win[2] = z[1];
 133       v[2]->win[2] = z[2];
 134    }
 135
 136    if (IND & SS_TWOSIDE_BIT) {
 137       if (facing == 1) {
 138          if (IND & SS_RGBA_BIT) {
 139             GLfloat (*vbcolor)[4] = (GLfloat (*)[4])VB->ColorPtr[0]->Ptr;
 140             SS_COLOR(v[0]->color, vbcolor[e0]);
 141             SS_COLOR(v[1]->color, vbcolor[e1]);
 142             SS_COLOR(v[2]->color, vbcolor[e2]);
 143             if (VB->SecondaryColorPtr[0]) {
 144                GLfloat (*vbspec)[4] = (GLfloat (*)[4])VB->SecondaryColorPtr[0]->Ptr;
 145                SS_SPEC(v[0]->specular, vbspec[e0]);
 146                SS_SPEC(v[1]->specular, vbspec[e1]);
 147                SS_SPEC(v[2]->specular, vbspec[e2]);
 148             }
 149          } else {
 150             GLuint *vbindex = VB->IndexPtr[0]->data;
 151             SS_IND(v[0]->index, vbindex[e0]);
 152             SS_IND(v[1]->index, vbindex[e1]);
 153             SS_IND(v[2]->index, vbindex[e2]);
 154          }
 155       }
 156    }
 157 }
 158
 159
 160
 161 /* Need to fixup edgeflags when decomposing to triangles:
 162  */
 163 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 164                        GLuint v1, GLuint v2, GLuint v3 )
 165 {
 166    if (IND & SS_UNFILLED_BIT) {
 167       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 168       GLubyte ef1 = VB->EdgeFlag[v1];
 169       GLubyte ef3 = VB->EdgeFlag[v3];
 170       VB->EdgeFlag[v1] = 0;
 171       TAG(triangle)( ctx, v0, v1, v3 );
 172       VB->EdgeFlag[v1] = ef1;
 173       VB->EdgeFlag[v3] = 0;
 174       TAG(triangle)( ctx, v1, v2, v3 );
 175       VB->EdgeFlag[v3] = ef3;
 176    } else {
 177       TAG(triangle)( ctx, v0, v1, v3 );
 178       TAG(triangle)( ctx, v1, v2, v3 );
 179    }
 180 }
 181
 182
 183
 184
 185 static void TAG(init)( void )
 186 {
 187    tri_tab[IND] = TAG(triangle);
 188    quad_tab[IND] = TAG(quadfunc);
 189 }
 190
 191
 192 #undef IND
 193 #undef TAG