src/mesa/swrast_setup/ss_tritmp.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  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 /**
  30  * This is where we handle assigning vertex colors based on front/back
  31  * facing, compute polygon offset and handle glPolygonMode().
  32  */
  33 static void TAG(triangle)(GLcontext *ctx, GLuint e0, GLuint e1, GLuint e2 )
  34 {
  35    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  36    SScontext *swsetup = SWSETUP_CONTEXT(ctx);
  37    SWvertex *verts = SWSETUP_CONTEXT(ctx)->verts;
  38    SWvertex *v[3];
  39    GLfloat z[3];
  40    GLfloat offset, oz0, oz1, oz2;
  41    GLenum mode = GL_FILL;
  42    GLuint facing = 0;
  43    GLchan saved_color[3][4];
  44    GLfloat saved_col0[3][4] = { { 0 } };
  45    GLfloat saved_spec[3][4] = { { 0 } };
  46    GLfloat saved_index[3] = { 0 };
  47
  48    v[0] = &verts[e0];
  49    v[1] = &verts[e1];
  50    v[2] = &verts[e2];
  51
  52    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
  53    {
  54       GLfloat ex = v[0]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
  55       GLfloat ey = v[0]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
  56       GLfloat fx = v[1]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
  57       GLfloat fy = v[1]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
  58       GLfloat cc  = ex*fy - ey*fx;
  59
  60       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
  61       {
  62          facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
  63
  64          if (IND & SS_UNFILLED_BIT)
  65             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  66
  67          if (facing == 1) {
  68             if (IND & SS_TWOSIDE_BIT) {
  69                if (IND & SS_RGBA_BIT) {
  70                   if (VB->BackfaceColorPtr) {
  71                      GLfloat (*vbcolor)[4] = VB->BackfaceColorPtr->data;
  72
  73                      if (swsetup->intColors) {
  74                         COPY_CHAN4(saved_color[0], v[0]->color);
  75                         COPY_CHAN4(saved_color[1], v[1]->color);
  76                         COPY_CHAN4(saved_color[2], v[2]->color);
  77                      }
  78                      else {
  79                         COPY_4V(saved_col0[0], v[0]->attrib[FRAG_ATTRIB_COL0]);
  80                         COPY_4V(saved_col0[1], v[1]->attrib[FRAG_ATTRIB_COL0]);
  81                         COPY_4V(saved_col0[2], v[2]->attrib[FRAG_ATTRIB_COL0]);
  82                      }
  83
  84                      if (VB->BackfaceColorPtr->stride) {
  85                         if (swsetup->intColors) {
  86                            SS_COLOR(v[0]->color, vbcolor[e0]);
  87                            SS_COLOR(v[1]->color, vbcolor[e1]);
  88                            SS_COLOR(v[2]->color, vbcolor[e2]);
  89                         }
  90                         else {
  91                            COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL0], vbcolor[e0]);
  92                            COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], vbcolor[e1]);
  93                            COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], vbcolor[e2]);
  94                         }
  95                      }
  96                      else {
  97                         /* flat shade */
  98                         if (swsetup->intColors) {
  99                            SS_COLOR(v[0]->color, vbcolor[0]);
 100                            SS_COLOR(v[1]->color, vbcolor[0]);
 101                            SS_COLOR(v[2]->color, vbcolor[0]);
 102                         }
 103                         else {
 104                            COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
 105                            COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
 106                            COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
 107                         }
 108                      }
 109                   }
 110
 111                   if (VB->BackfaceSecondaryColorPtr) {
 112                      GLfloat (*vbspec)[4] = VB->BackfaceSecondaryColorPtr->data;
 113
 114                      COPY_4V(saved_spec[0], v[0]->attrib[FRAG_ATTRIB_COL1]);
 115                      COPY_4V(saved_spec[1], v[1]->attrib[FRAG_ATTRIB_COL1]);
 116                      COPY_4V(saved_spec[2], v[2]->attrib[FRAG_ATTRIB_COL1]);
 117
 118                      if (VB->BackfaceSecondaryColorPtr->stride) {
 119                         SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[e0]);
 120                         SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[e1]);
 121                         SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[e2]);
 122                      }
 123                      else {
 124                         SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 125                         SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 126                         SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 127                      }
 128                   }
 129                } else {
 130                   GLfloat *vbindex = (GLfloat *)VB->BackfaceIndexPtr->data;
 131                   saved_index[0] = v[0]->attrib[FRAG_ATTRIB_CI][0];
 132                   saved_index[1] = v[1]->attrib[FRAG_ATTRIB_CI][0];
 133                   saved_index[2] = v[2]->attrib[FRAG_ATTRIB_CI][0];
 134
 135                   SS_IND(v[0]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e0]);
 136                   SS_IND(v[1]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e1]);
 137                   SS_IND(v[2]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e2]);
 138                }
 139             }
 140          }
 141       }
 142
 143       if (IND & SS_OFFSET_BIT) {
 144          const GLfloat max = ctx->DrawBuffer->_DepthMaxF;
 145          /* save original Z values (restored later) */
 146          z[0] = v[0]->attrib[FRAG_ATTRIB_WPOS][2];
 147          z[1] = v[1]->attrib[FRAG_ATTRIB_WPOS][2];
 148          z[2] = v[2]->attrib[FRAG_ATTRIB_WPOS][2];
 149          /* Note that Z values are already scaled to [0,65535] (for example)
 150           * so no MRD value is used here.
 151           */
 152          offset = ctx->Polygon.OffsetUnits;
 153          if (cc * cc > 1e-16) {
 154             const GLfloat ez = z[0] - z[2];
 155             const GLfloat fz = z[1] - z[2];
 156             const GLfloat oneOverArea = 1.0F / cc;
 157             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 158             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 159             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 160          }
 161          /* new Z values */
 162          oz0 = CLAMP(v[0]->attrib[FRAG_ATTRIB_WPOS][2] + offset, 0.0, max);
 163          oz1 = CLAMP(v[1]->attrib[FRAG_ATTRIB_WPOS][2] + offset, 0.0, max);
 164          oz2 = CLAMP(v[2]->attrib[FRAG_ATTRIB_WPOS][2] + offset, 0.0, max);
 165       }
 166    }
 167
 168    if (mode == GL_POINT) {
 169       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 170          v[0]->attrib[FRAG_ATTRIB_WPOS][2] = oz0;
 171          v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1;
 172          v[2]->attrib[FRAG_ATTRIB_WPOS][2] = oz2;
 173       }
 174       _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_point_tri);
 175    } else if (mode == GL_LINE) {
 176       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 177          v[0]->attrib[FRAG_ATTRIB_WPOS][2] = oz0;
 178          v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1;
 179          v[2]->attrib[FRAG_ATTRIB_WPOS][2] = oz2;
 180       }
 181       _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_line_tri);
 182    } else {
 183       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 184          v[0]->attrib[FRAG_ATTRIB_WPOS][2] = oz0;
 185          v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1;
 186          v[2]->attrib[FRAG_ATTRIB_WPOS][2] = oz2;
 187       }
 188       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 189    }
 190
 191    /*
 192     * Restore original vertex colors, etc.
 193     */
 194    if (IND & SS_OFFSET_BIT) {
 195       v[0]->attrib[FRAG_ATTRIB_WPOS][2] = z[0];
 196       v[1]->attrib[FRAG_ATTRIB_WPOS][2] = z[1];
 197       v[2]->attrib[FRAG_ATTRIB_WPOS][2] = z[2];
 198    }
 199
 200    if (IND & SS_TWOSIDE_BIT) {
 201       if (facing == 1) {
 202          if (IND & SS_RGBA_BIT) {
 203             if (VB->BackfaceColorPtr) {
 204                if (swsetup->intColors) {
 205                   COPY_CHAN4(v[0]->color, saved_color[0]);
 206                   COPY_CHAN4(v[1]->color, saved_color[1]);
 207                   COPY_CHAN4(v[2]->color, saved_color[2]);
 208                }
 209                else {
 210                   COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL0], saved_col0[0]);
 211                   COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], saved_col0[1]);
 212                   COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], saved_col0[2]);
 213                }
 214             }
 215
 216             if (VB->BackfaceSecondaryColorPtr) {
 217                COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL1], saved_spec[0]);
 218                COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL1], saved_spec[1]);
 219                COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL1], saved_spec[2]);
 220             }
 221          } else {
 222             v[0]->attrib[FRAG_ATTRIB_CI][0] = saved_index[0];
 223             v[1]->attrib[FRAG_ATTRIB_CI][0] = saved_index[1];
 224             v[2]->attrib[FRAG_ATTRIB_CI][0] = saved_index[2];
 225          }
 226       }
 227    }
 228 }
 229
 230
 231
 232 /* Need to fixup edgeflags when decomposing to triangles:
 233  */
 234 static void TAG(quadfunc)( GLcontext *ctx, GLuint v0,
 235                        GLuint v1, GLuint v2, GLuint v3 )
 236 {
 237    if (IND & SS_UNFILLED_BIT) {
 238       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 239       if (VB->EdgeFlag) { /* XXX this test shouldn't be needed (bug 12614) */
 240          GLubyte ef1 = VB->EdgeFlag[v1];
 241          GLubyte ef3 = VB->EdgeFlag[v3];
 242          VB->EdgeFlag[v1] = 0;
 243          TAG(triangle)( ctx, v0, v1, v3 );
 244          VB->EdgeFlag[v1] = ef1;
 245          VB->EdgeFlag[v3] = 0;
 246          TAG(triangle)( ctx, v1, v2, v3 );
 247          VB->EdgeFlag[v3] = ef3;
 248       }
 249    } else {
 250       TAG(triangle)( ctx, v0, v1, v3 );
 251       TAG(triangle)( ctx, v1, v2, v3 );
 252    }
 253 }
 254
 255
 256
 257
 258 static void TAG(init)( void )
 259 {
 260    tri_tab[IND] = TAG(triangle);
 261    quad_tab[IND] = TAG(quadfunc);
 262 }
 263
 264
 265 #undef IND
 266 #undef TAG