src/mesa/swrast_setup/ss_tritmp.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Keith Whitwell <keith@tungstengraphics.com>
  26  */
  27
  28
  29 static void TAG(triangle)(GLcontext *ctx, GLuint e0, GLuint e1, GLuint e2 )
  30 {
  31    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  32    SWvertex *verts = SWSETUP_CONTEXT(ctx)->verts;
  33    SWvertex *v[3];
  34    GLfloat z[3];
  35    GLfloat offset;
  36    GLenum mode = GL_FILL;
  37    GLuint facing = 0;
  38    GLchan saved_color[3][4];
  39    GLchan saved_spec[3][4];
  40    GLfloat saved_index[3];
  41
  42    v[0] = &verts[e0];
  43    v[1] = &verts[e1];
  44    v[2] = &verts[e2];
  45
  46
  47    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
  48    {
  49       GLfloat ex = v[0]->win[0] - v[2]->win[0];
  50       GLfloat ey = v[0]->win[1] - v[2]->win[1];
  51       GLfloat fx = v[1]->win[0] - v[2]->win[0];
  52       GLfloat fy = v[1]->win[1] - v[2]->win[1];
  53       GLfloat cc  = ex*fy - ey*fx;
  54
  55       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
  56       {
  57          facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
  58          ctx->_Facing = facing;
  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                   GLfloat (*vbcolor)[4] = VB->ColorPtr[1]->data;
  67
  68                   COPY_CHAN4(saved_color[0], v[0]->color);
  69                   COPY_CHAN4(saved_color[1], v[1]->color);
  70                   COPY_CHAN4(saved_color[2], v[2]->color);
  71
  72                   if (VB->ColorPtr[1]->stride) {
  73                      SS_COLOR(v[0]->color, vbcolor[e0]);
  74                      SS_COLOR(v[1]->color, vbcolor[e1]);
  75                      SS_COLOR(v[2]->color, vbcolor[e2]);
  76                   }
  77                   else {
  78                      SS_COLOR(v[0]->color, vbcolor[0]);
  79                      SS_COLOR(v[1]->color, vbcolor[0]);
  80                      SS_COLOR(v[2]->color, vbcolor[0]);
  81                   }
  82
  83                   if (VB->SecondaryColorPtr[1]) {
  84                      GLfloat (*vbspec)[4] = VB->SecondaryColorPtr[1]->data;
  85
  86                      COPY_CHAN4(saved_spec[0], v[0]->specular);
  87                      COPY_CHAN4(saved_spec[1], v[1]->specular);
  88                      COPY_CHAN4(saved_spec[2], v[2]->specular);
  89
  90                      if (VB->SecondaryColorPtr[1]->stride) {
  91                         SS_SPEC(v[0]->specular, vbspec[e0]);
  92                         SS_SPEC(v[1]->specular, vbspec[e1]);
  93                         SS_SPEC(v[2]->specular, vbspec[e2]);
  94                      }
  95                      else {
  96                         SS_SPEC(v[0]->specular, vbspec[0]);
  97                         SS_SPEC(v[1]->specular, vbspec[0]);
  98                         SS_SPEC(v[2]->specular, vbspec[0]);
  99                      }
 100                   }
 101                } else {
 102                   GLfloat *vbindex = (GLfloat *)VB->IndexPtr[1]->data;
 103                   saved_index[0] = v[0]->index;
 104                   saved_index[1] = v[1]->index;
 105                   saved_index[2] = v[2]->index;
 106
 107                   SS_IND(v[0]->index, (GLuint) vbindex[e0]);
 108                   SS_IND(v[1]->index, (GLuint) vbindex[e1]);
 109                   SS_IND(v[2]->index, (GLuint) vbindex[e2]);
 110                }
 111             }
 112          }
 113       }
 114
 115       if (IND & SS_OFFSET_BIT)
 116       {
 117          offset = ctx->Polygon.OffsetUnits * ctx->DrawBuffer->_MRD;
 118          z[0] = v[0]->win[2];
 119          z[1] = v[1]->win[2];
 120          z[2] = v[2]->win[2];
 121          if (cc * cc > 1e-16) {
 122             const GLfloat ez = z[0] - z[2];
 123             const GLfloat fz = z[1] - z[2];
 124             const GLfloat oneOverArea = 1.0F / cc;
 125             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 126             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 127             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 128             /* Unfortunately, we need to clamp to prevent negative Zs below.
 129              * Technically, we should do the clamping per-fragment.
 130              */
 131             offset = MAX2(offset, -v[0]->win[2]);
 132             offset = MAX2(offset, -v[1]->win[2]);
 133             offset = MAX2(offset, -v[2]->win[2]);
 134          }
 135       }
 136    }
 137
 138    if (mode == GL_POINT) {
 139       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 140          v[0]->win[2] += offset;
 141          v[1]->win[2] += offset;
 142          v[2]->win[2] += offset;
 143       }
 144       _swsetup_render_point_tri( ctx, e0, e1, e2, facing );
 145    } else if (mode == GL_LINE) {
 146       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 147          v[0]->win[2] += offset;
 148          v[1]->win[2] += offset;
 149          v[2]->win[2] += offset;
 150       }
 151       _swsetup_render_line_tri( ctx, e0, e1, e2, facing );
 152    } else {
 153       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 154          v[0]->win[2] += offset;
 155          v[1]->win[2] += offset;
 156          v[2]->win[2] += offset;
 157       }
 158       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 159    }
 160
 161    if (IND & SS_OFFSET_BIT) {
 162       v[0]->win[2] = z[0];
 163       v[1]->win[2] = z[1];
 164       v[2]->win[2] = z[2];
 165    }
 166
 167    if (IND & SS_TWOSIDE_BIT) {
 168       if (facing == 1) {
 169          if (IND & SS_RGBA_BIT) {
 170             COPY_CHAN4(v[0]->color, saved_color[0]);
 171             COPY_CHAN4(v[1]->color, saved_color[1]);
 172             COPY_CHAN4(v[2]->color, saved_color[2]);
 173             if (VB->SecondaryColorPtr[1]) {
 174                COPY_CHAN4(v[0]->specular, saved_spec[0]);
 175                COPY_CHAN4(v[1]->specular, saved_spec[1]);
 176                COPY_CHAN4(v[2]->specular, saved_spec[2]);
 177             }
 178          } else {
 179             v[0]->index = saved_index[0];
 180             v[1]->index = saved_index[1];
 181             v[2]->index = saved_index[2];
 182          }
 183       }
 184    }
 185 }
 186
 187
 188
 189 /* Need to fixup edgeflags when decomposing to triangles:
 190  */
 191 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 192                        GLuint v1, GLuint v2, GLuint v3 )
 193 {
 194    if (IND & SS_UNFILLED_BIT) {
 195       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 196       GLubyte ef1 = VB->EdgeFlag[v1];
 197       GLubyte ef3 = VB->EdgeFlag[v3];
 198       VB->EdgeFlag[v1] = 0;
 199       TAG(triangle)( ctx, v0, v1, v3 );
 200       VB->EdgeFlag[v1] = ef1;
 201       VB->EdgeFlag[v3] = 0;
 202       TAG(triangle)( ctx, v1, v2, v3 );
 203       VB->EdgeFlag[v3] = ef3;
 204    } else {
 205       TAG(triangle)( ctx, v0, v1, v3 );
 206       TAG(triangle)( ctx, v1, v2, v3 );
 207    }
 208 }
 209
 210
 211
 212
 213 static void TAG(init)( void )
 214 {
 215    tri_tab[IND] = TAG(triangle);
 216    quad_tab[IND] = TAG(quadfunc);
 217 }
 218
 219
 220 #undef IND
 221 #undef TAG