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    GLfloat 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]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
  50       GLfloat ey = v[0]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
  51       GLfloat fx = v[1]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
  52       GLfloat fy = v[1]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][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                   if (VB->ColorPtr[1]) {
  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                      if (VB->ColorPtr[1]->stride) {
  74                         SS_COLOR(v[0]->color, vbcolor[e0]);
  75                         SS_COLOR(v[1]->color, vbcolor[e1]);
  76                         SS_COLOR(v[2]->color, vbcolor[e2]);
  77                      }
  78                      else {
  79                         SS_COLOR(v[0]->color, vbcolor[0]);
  80                         SS_COLOR(v[1]->color, vbcolor[0]);
  81                         SS_COLOR(v[2]->color, vbcolor[0]);
  82                      }
  83                   }
  84
  85                   if (VB->SecondaryColorPtr[1]) {
  86                      GLfloat (*vbspec)[4] = VB->SecondaryColorPtr[1]->data;
  87
  88                      COPY_4V(saved_spec[0], v[0]->attrib[FRAG_ATTRIB_COL1]);
  89                      COPY_4V(saved_spec[1], v[1]->attrib[FRAG_ATTRIB_COL1]);
  90                      COPY_4V(saved_spec[2], v[2]->attrib[FRAG_ATTRIB_COL1]);
  91
  92                      if (VB->SecondaryColorPtr[1]->stride) {
  93                         SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[e0]);
  94                         SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[e1]);
  95                         SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[e2]);
  96                      }
  97                      else {
  98                         SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
  99                         SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 100                         SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 101                      }
 102                   }
 103                } else {
 104                   GLfloat *vbindex = (GLfloat *)VB->IndexPtr[1]->data;
 105                   saved_index[0] = v[0]->attrib[FRAG_ATTRIB_CI][0];
 106                   saved_index[1] = v[1]->attrib[FRAG_ATTRIB_CI][0];
 107                   saved_index[2] = v[2]->attrib[FRAG_ATTRIB_CI][0];
 108
 109                   SS_IND(v[0]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e0]);
 110                   SS_IND(v[1]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e1]);
 111                   SS_IND(v[2]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e2]);
 112                }
 113             }
 114          }
 115       }
 116
 117       if (IND & SS_OFFSET_BIT)
 118       {
 119          offset = ctx->Polygon.OffsetUnits * ctx->DrawBuffer->_MRD;
 120          z[0] = v[0]->attrib[FRAG_ATTRIB_WPOS][2];
 121          z[1] = v[1]->attrib[FRAG_ATTRIB_WPOS][2];
 122          z[2] = v[2]->attrib[FRAG_ATTRIB_WPOS][2];
 123          if (cc * cc > 1e-16) {
 124             const GLfloat ez = z[0] - z[2];
 125             const GLfloat fz = z[1] - z[2];
 126             const GLfloat oneOverArea = 1.0F / cc;
 127             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 128             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 129             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 130             /* Unfortunately, we need to clamp to prevent negative Zs below.
 131              * Technically, we should do the clamping per-fragment.
 132              */
 133             offset = MAX2(offset, -v[0]->attrib[FRAG_ATTRIB_WPOS][2]);
 134             offset = MAX2(offset, -v[1]->attrib[FRAG_ATTRIB_WPOS][2]);
 135             offset = MAX2(offset, -v[2]->attrib[FRAG_ATTRIB_WPOS][2]);
 136          }
 137       }
 138    }
 139
 140    if (mode == GL_POINT) {
 141       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 142          v[0]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 143          v[1]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 144          v[2]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 145       }
 146       _swsetup_render_point_tri( ctx, e0, e1, e2, facing );
 147    } else if (mode == GL_LINE) {
 148       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 149          v[0]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 150          v[1]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 151          v[2]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 152       }
 153       _swsetup_render_line_tri( ctx, e0, e1, e2, facing );
 154    } else {
 155       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 156          v[0]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 157          v[1]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 158          v[2]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 159       }
 160       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 161    }
 162
 163    if (IND & SS_OFFSET_BIT) {
 164       v[0]->attrib[FRAG_ATTRIB_WPOS][2] = z[0];
 165       v[1]->attrib[FRAG_ATTRIB_WPOS][2] = z[1];
 166       v[2]->attrib[FRAG_ATTRIB_WPOS][2] = z[2];
 167    }
 168
 169    if (IND & SS_TWOSIDE_BIT) {
 170       if (facing == 1) {
 171          if (IND & SS_RGBA_BIT) {
 172             if (VB->ColorPtr[1]) {
 173                COPY_CHAN4(v[0]->color, saved_color[0]);
 174                COPY_CHAN4(v[1]->color, saved_color[1]);
 175                COPY_CHAN4(v[2]->color, saved_color[2]);
 176             }
 177
 178             if (VB->SecondaryColorPtr[1]) {
 179                COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL1], saved_spec[0]);
 180                COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL1], saved_spec[1]);
 181                COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL1], saved_spec[2]);
 182             }
 183          } else {
 184             v[0]->attrib[FRAG_ATTRIB_CI][0] = saved_index[0];
 185             v[1]->attrib[FRAG_ATTRIB_CI][0] = saved_index[1];
 186             v[2]->attrib[FRAG_ATTRIB_CI][0] = saved_index[2];
 187          }
 188       }
 189    }
 190 }
 191
 192
 193
 194 /* Need to fixup edgeflags when decomposing to triangles:
 195  */
 196 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 197                        GLuint v1, GLuint v2, GLuint v3 )
 198 {
 199    if (IND & SS_UNFILLED_BIT) {
 200       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 201       GLubyte ef1 = VB->EdgeFlag[v1];
 202       GLubyte ef3 = VB->EdgeFlag[v3];
 203       VB->EdgeFlag[v1] = 0;
 204       TAG(triangle)( ctx, v0, v1, v3 );
 205       VB->EdgeFlag[v1] = ef1;
 206       VB->EdgeFlag[v3] = 0;
 207       TAG(triangle)( ctx, v1, v2, v3 );
 208       VB->EdgeFlag[v3] = ef3;
 209    } else {
 210       TAG(triangle)( ctx, v0, v1, v3 );
 211       TAG(triangle)( ctx, v1, v2, v3 );
 212    }
 213 }
 214
 215
 216
 217
 218 static void TAG(init)( void )
 219 {
 220    tri_tab[IND] = TAG(triangle);
 221    quad_tab[IND] = TAG(quadfunc);
 222 }
 223
 224
 225 #undef IND
 226 #undef TAG