src/mesa/swrast_setup/ss_tritmp.h

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  5.0
   5  *
   6  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *    Keith Whitwell <keith@tungstengraphics.com>
  27  */
  28
  29
  30 static void TAG(triangle)(GLcontext *ctx, GLuint e0, GLuint e1, GLuint e2 )
  31 {
  32    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  33    SWvertex *verts = SWSETUP_CONTEXT(ctx)->verts;
  34    SWvertex *v[3];
  35    GLfloat z[3];
  36    GLfloat offset;
  37    GLenum mode = GL_FILL;
  38    GLuint facing = 0;
  39
  40    v[0] = &verts[e0];
  41    v[1] = &verts[e1];
  42    v[2] = &verts[e2];
  43
  44
  45    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
  46    {
  47       GLfloat ex = v[0]->win[0] - v[2]->win[0];
  48       GLfloat ey = v[0]->win[1] - v[2]->win[1];
  49       GLfloat fx = v[1]->win[0] - v[2]->win[0];
  50       GLfloat fy = v[1]->win[1] - v[2]->win[1];
  51       GLfloat cc  = ex*fy - ey*fx;
  52
  53       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
  54       {
  55          facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
  56          if (ctx->Stencil.TestTwoSide)
  57             ctx->_Facing = facing; /* for 2-sided stencil test */
  58
  59          if (IND & SS_UNFILLED_BIT)
  60             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  61
  62          if (facing == 1) {
  63             if (IND & SS_TWOSIDE_BIT) {
  64                if (IND & SS_RGBA_BIT) {
  65                   GLfloat (*vbcolor)[4] = VB->ColorPtr[1]->data;
  66                   SS_COLOR(v[0]->color, vbcolor[e0]);
  67                   SS_COLOR(v[1]->color, vbcolor[e1]);
  68                   SS_COLOR(v[2]->color, vbcolor[e2]);
  69                   if (VB->SecondaryColorPtr[1]) {
  70                      GLfloat (*vbspec)[4] = VB->SecondaryColorPtr[1]->data;
  71                      SS_SPEC(v[0]->specular, vbspec[e0]);
  72                      SS_SPEC(v[1]->specular, vbspec[e1]);
  73                      SS_SPEC(v[2]->specular, vbspec[e2]);
  74                   }
  75                } else {
  76                   GLfloat *vbindex = (GLfloat *)VB->IndexPtr[1]->data;
  77                   SS_IND(v[0]->index, vbindex[e0]);
  78                   SS_IND(v[1]->index, vbindex[e1]);
  79                   SS_IND(v[2]->index, vbindex[e2]);
  80                }
  81             }
  82          }
  83       }
  84
  85       if (IND & SS_OFFSET_BIT)
  86       {
  87          offset = ctx->Polygon.OffsetUnits;
  88          z[0] = v[0]->win[2];
  89          z[1] = v[1]->win[2];
  90          z[2] = v[2]->win[2];
  91          if (cc * cc > 1e-16) {
  92             GLfloat ez = z[0] - z[2];
  93             GLfloat fz = z[1] - z[2];
  94             GLfloat a = ey*fz - ez*fy;
  95             GLfloat b = ez*fx - ex*fz;
  96             GLfloat ic = 1.0F / cc;
  97             GLfloat ac = a * ic;
  98             GLfloat bc = b * ic;
  99             if (ac < 0.0F) ac = -ac;
 100             if (bc < 0.0F) bc = -bc;
 101             offset += MAX2(ac, bc) * ctx->Polygon.OffsetFactor;
 102          }
 103          offset *= ctx->MRD;
 104          /*printf("offset %g\n", offset);*/
 105       }
 106    }
 107
 108    if (mode == GL_POINT) {
 109       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 110          v[0]->win[2] += offset;
 111          v[1]->win[2] += offset;
 112          v[2]->win[2] += offset;
 113       }
 114       _swsetup_render_point_tri( ctx, e0, e1, e2, facing );
 115    } else if (mode == GL_LINE) {
 116       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 117          v[0]->win[2] += offset;
 118          v[1]->win[2] += offset;
 119          v[2]->win[2] += offset;
 120       }
 121       _swsetup_render_line_tri( ctx, e0, e1, e2, facing );
 122    } else {
 123       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 124          v[0]->win[2] += offset;
 125          v[1]->win[2] += offset;
 126          v[2]->win[2] += offset;
 127       }
 128       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 129    }
 130
 131    if (IND & SS_OFFSET_BIT) {
 132       v[0]->win[2] = z[0];
 133       v[1]->win[2] = z[1];
 134       v[2]->win[2] = z[2];
 135    }
 136
 137    if (IND & SS_TWOSIDE_BIT) {
 138       if (facing == 1) {
 139          if (IND & SS_RGBA_BIT) {
 140             GLfloat (*vbcolor)[4] = VB->ColorPtr[0]->data;
 141             SS_COLOR(v[0]->color, vbcolor[e0]);
 142             SS_COLOR(v[1]->color, vbcolor[e1]);
 143             SS_COLOR(v[2]->color, vbcolor[e2]);
 144             if (VB->SecondaryColorPtr[0]) {
 145                GLfloat (*vbspec)[4] = VB->SecondaryColorPtr[0]->data;
 146                SS_SPEC(v[0]->specular, vbspec[e0]);
 147                SS_SPEC(v[1]->specular, vbspec[e1]);
 148                SS_SPEC(v[2]->specular, vbspec[e2]);
 149             }
 150          } else {
 151             GLfloat *vbindex = (GLfloat *)VB->IndexPtr[0]->data;
 152             SS_IND(v[0]->index, vbindex[e0]);
 153             SS_IND(v[1]->index, vbindex[e1]);
 154             SS_IND(v[2]->index, vbindex[e2]);
 155          }
 156       }
 157    }
 158 }
 159
 160
 161
 162 /* Need to fixup edgeflags when decomposing to triangles:
 163  */
 164 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 165                        GLuint v1, GLuint v2, GLuint v3 )
 166 {
 167    if (IND & SS_UNFILLED_BIT) {
 168       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 169       GLubyte ef1 = VB->EdgeFlag[v1];
 170       GLubyte ef3 = VB->EdgeFlag[v3];
 171       VB->EdgeFlag[v1] = 0;
 172       TAG(triangle)( ctx, v0, v1, v3 );
 173       VB->EdgeFlag[v1] = ef1;
 174       VB->EdgeFlag[v3] = 0;
 175       TAG(triangle)( ctx, v1, v2, v3 );
 176       VB->EdgeFlag[v3] = ef3;
 177    } else {
 178       TAG(triangle)( ctx, v0, v1, v3 );
 179       TAG(triangle)( ctx, v1, v2, v3 );
 180    }
 181 }
 182
 183
 184
 185
 186 static void TAG(init)( void )
 187 {
 188    tri_tab[IND] = TAG(triangle);
 189    quad_tab[IND] = TAG(quadfunc);
 190 }
 191
 192
 193 #undef IND
 194 #undef TAG