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    GLuint 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          if (ctx->Stencil.TestTwoSide)
  59             ctx->_Facing = facing; /* for 2-sided stencil test */
  60
  61          if (IND & SS_UNFILLED_BIT)
  62             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  63
  64          if (facing == 1) {
  65             if (IND & SS_TWOSIDE_BIT) {
  66                if (IND & SS_RGBA_BIT) {
  67                   GLfloat (*vbcolor)[4] = VB->ColorPtr[1]->data;
  68
  69                   COPY_CHAN4(saved_color[0], v[0]->color);
  70                   COPY_CHAN4(saved_color[1], v[1]->color);
  71                   COPY_CHAN4(saved_color[2], v[2]->color);
  72
  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                   if (VB->SecondaryColorPtr[1]) {
  78                      GLfloat (*vbspec)[4] = VB->SecondaryColorPtr[1]->data;
  79
  80                      COPY_CHAN4(saved_spec[0], v[0]->specular);
  81                      COPY_CHAN4(saved_spec[1], v[1]->specular);
  82                      COPY_CHAN4(saved_spec[2], v[2]->specular);
  83
  84                      SS_SPEC(v[0]->specular, vbspec[e0]);
  85                      SS_SPEC(v[1]->specular, vbspec[e1]);
  86                      SS_SPEC(v[2]->specular, vbspec[e2]);
  87                   }
  88                } else {
  89                   GLfloat *vbindex = (GLfloat *)VB->IndexPtr[1]->data;
  90                   saved_index[0] = v[0]->index;
  91                   saved_index[1] = v[1]->index;
  92                   saved_index[2] = v[2]->index;
  93
  94                   SS_IND(v[0]->index, (GLuint) vbindex[e0]);
  95                   SS_IND(v[1]->index, (GLuint) vbindex[e1]);
  96                   SS_IND(v[2]->index, (GLuint) vbindex[e2]);
  97                }
  98             }
  99          }
 100       }
 101
 102       if (IND & SS_OFFSET_BIT)
 103       {
 104          offset = ctx->Polygon.OffsetUnits * ctx->MRD;
 105          z[0] = v[0]->win[2];
 106          z[1] = v[1]->win[2];
 107          z[2] = v[2]->win[2];
 108          if (cc * cc > 1e-16) {
 109             const GLfloat ez = z[0] - z[2];
 110             const GLfloat fz = z[1] - z[2];
 111             const GLfloat oneOverArea = 1.0F / cc;
 112             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 113             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 114             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 115             /* Unfortunately, we need to clamp to prevent negative Zs below.
 116              * Technically, we should do the clamping per-fragment.
 117              */
 118             offset = MAX2(offset, -v[0]->win[2]);
 119             offset = MAX2(offset, -v[1]->win[2]);
 120             offset = MAX2(offset, -v[2]->win[2]);
 121          }
 122       }
 123    }
 124
 125    if (mode == GL_POINT) {
 126       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 127          v[0]->win[2] += offset;
 128          v[1]->win[2] += offset;
 129          v[2]->win[2] += offset;
 130       }
 131       _swsetup_render_point_tri( ctx, e0, e1, e2, facing );
 132    } else if (mode == GL_LINE) {
 133       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 134          v[0]->win[2] += offset;
 135          v[1]->win[2] += offset;
 136          v[2]->win[2] += offset;
 137       }
 138       _swsetup_render_line_tri( ctx, e0, e1, e2, facing );
 139    } else {
 140       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 141          v[0]->win[2] += offset;
 142          v[1]->win[2] += offset;
 143          v[2]->win[2] += offset;
 144       }
 145       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 146    }
 147
 148    if (IND & SS_OFFSET_BIT) {
 149       v[0]->win[2] = z[0];
 150       v[1]->win[2] = z[1];
 151       v[2]->win[2] = z[2];
 152    }
 153
 154    if (IND & SS_TWOSIDE_BIT) {
 155       if (facing == 1) {
 156          if (IND & SS_RGBA_BIT) {
 157             COPY_CHAN4(v[0]->color, saved_color[0]);
 158             COPY_CHAN4(v[1]->color, saved_color[1]);
 159             COPY_CHAN4(v[2]->color, saved_color[2]);
 160             if (VB->SecondaryColorPtr[1]) {
 161                COPY_CHAN4(v[0]->specular, saved_spec[0]);
 162                COPY_CHAN4(v[1]->specular, saved_spec[1]);
 163                COPY_CHAN4(v[2]->specular, saved_spec[2]);
 164             }
 165          } else {
 166             v[0]->index = saved_index[0];
 167             v[1]->index = saved_index[1];
 168             v[2]->index = saved_index[2];
 169          }
 170       }
 171    }
 172 }
 173
 174
 175
 176 /* Need to fixup edgeflags when decomposing to triangles:
 177  */
 178 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 179                        GLuint v1, GLuint v2, GLuint v3 )
 180 {
 181    if (IND & SS_UNFILLED_BIT) {
 182       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 183       GLubyte ef1 = VB->EdgeFlag[v1];
 184       GLubyte ef3 = VB->EdgeFlag[v3];
 185       VB->EdgeFlag[v1] = 0;
 186       TAG(triangle)( ctx, v0, v1, v3 );
 187       VB->EdgeFlag[v1] = ef1;
 188       VB->EdgeFlag[v3] = 0;
 189       TAG(triangle)( ctx, v1, v2, v3 );
 190       VB->EdgeFlag[v3] = ef3;
 191    } else {
 192       TAG(triangle)( ctx, v0, v1, v3 );
 193       TAG(triangle)( ctx, v1, v2, v3 );
 194    }
 195 }
 196
 197
 198
 199
 200 static void TAG(init)( void )
 201 {
 202    tri_tab[IND] = TAG(triangle);
 203    quad_tab[IND] = TAG(quadfunc);
 204 }
 205
 206
 207 #undef IND
 208 #undef TAG