src/mesa/swrast_setup/ss_tritmp.h

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Keith Whitwell <keithw@vmware.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)(struct gl_context *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] = { { 0 } };
  44    GLfloat saved_col0[3][4] = { { 0 } };
  45    GLfloat saved_spec[3][4] = { { 0 } };
  46
  47    v[0] = &verts[e0];
  48    v[1] = &verts[e1];
  49    v[2] = &verts[e2];
  50
  51    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
  52    {
  53       GLfloat ex = v[0]->attrib[VARYING_SLOT_POS][0] - v[2]->attrib[VARYING_SLOT_POS][0];
  54       GLfloat ey = v[0]->attrib[VARYING_SLOT_POS][1] - v[2]->attrib[VARYING_SLOT_POS][1];
  55       GLfloat fx = v[1]->attrib[VARYING_SLOT_POS][0] - v[2]->attrib[VARYING_SLOT_POS][0];
  56       GLfloat fy = v[1]->attrib[VARYING_SLOT_POS][1] - v[2]->attrib[VARYING_SLOT_POS][1];
  57       GLfloat cc  = ex*fy - ey*fx;
  58
  59       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
  60       {
  61          facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
  62
  63          if (IND & SS_UNFILLED_BIT)
  64             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  65
  66          if (facing == 1) {
  67             if (IND & SS_TWOSIDE_BIT) {
  68                if (VB->BackfaceColorPtr) {
  69                   GLfloat (*vbcolor)[4] = VB->BackfaceColorPtr->data;
  70
  71                   if (swsetup->intColors) {
  72                      COPY_CHAN4(saved_color[0], v[0]->color);
  73                      COPY_CHAN4(saved_color[1], v[1]->color);
  74                      COPY_CHAN4(saved_color[2], v[2]->color);
  75                   }
  76                   else {
  77                      COPY_4V(saved_col0[0], v[0]->attrib[VARYING_SLOT_COL0]);
  78                      COPY_4V(saved_col0[1], v[1]->attrib[VARYING_SLOT_COL0]);
  79                      COPY_4V(saved_col0[2], v[2]->attrib[VARYING_SLOT_COL0]);
  80                   }
  81
  82                   if (VB->BackfaceColorPtr->stride) {
  83                      if (swsetup->intColors) {
  84                         SS_COLOR(v[0]->color, vbcolor[e0]);
  85                         SS_COLOR(v[1]->color, vbcolor[e1]);
  86                         SS_COLOR(v[2]->color, vbcolor[e2]);
  87                      }
  88                      else {
  89                         COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], vbcolor[e0]);
  90                         COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], vbcolor[e1]);
  91                         COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], vbcolor[e2]);
  92                      }
  93                   }
  94                   else {
  95                      /* flat shade */
  96                      if (swsetup->intColors) {
  97                         SS_COLOR(v[0]->color, vbcolor[0]);
  98                         SS_COLOR(v[1]->color, vbcolor[0]);
  99                         SS_COLOR(v[2]->color, vbcolor[0]);
 100                      }
 101                      else {
 102                         COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
 103                         COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
 104                         COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
 105                      }
 106                   }
 107                }
 108
 109                if (VB->BackfaceSecondaryColorPtr) {
 110                   GLfloat (*vbspec)[4] = VB->BackfaceSecondaryColorPtr->data;
 111
 112                   COPY_4V(saved_spec[0], v[0]->attrib[VARYING_SLOT_COL1]);
 113                   COPY_4V(saved_spec[1], v[1]->attrib[VARYING_SLOT_COL1]);
 114                   COPY_4V(saved_spec[2], v[2]->attrib[VARYING_SLOT_COL1]);
 115
 116                   if (VB->BackfaceSecondaryColorPtr->stride) {
 117                     SS_SPEC(v[0]->attrib[VARYING_SLOT_COL1], vbspec[e0]);
 118                     SS_SPEC(v[1]->attrib[VARYING_SLOT_COL1], vbspec[e1]);
 119                     SS_SPEC(v[2]->attrib[VARYING_SLOT_COL1], vbspec[e2]);
 120                   }
 121                   else {
 122                     SS_SPEC(v[0]->attrib[VARYING_SLOT_COL1], vbspec[0]);
 123                     SS_SPEC(v[1]->attrib[VARYING_SLOT_COL1], vbspec[0]);
 124                     SS_SPEC(v[2]->attrib[VARYING_SLOT_COL1], vbspec[0]);
 125                   }
 126                }
 127             }
 128          }
 129       }
 130
 131       if (IND & SS_OFFSET_BIT) {
 132          const GLfloat max = ctx->DrawBuffer->_DepthMaxF;
 133          /* save original Z values (restored later) */
 134          z[0] = v[0]->attrib[VARYING_SLOT_POS][2];
 135          z[1] = v[1]->attrib[VARYING_SLOT_POS][2];
 136          z[2] = v[2]->attrib[VARYING_SLOT_POS][2];
 137          /* Note that Z values are already scaled to [0,65535] (for example)
 138           * so no MRD value is used here.
 139           */
 140          offset = ctx->Polygon.OffsetUnits;
 141          if (cc * cc > 1e-16) {
 142             const GLfloat ez = z[0] - z[2];
 143             const GLfloat fz = z[1] - z[2];
 144             const GLfloat oneOverArea = 1.0F / cc;
 145             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 146             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 147             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 148          }
 149          /* new Z values */
 150          oz0 = CLAMP(v[0]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
 151          oz1 = CLAMP(v[1]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
 152          oz2 = CLAMP(v[2]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
 153       }
 154    }
 155
 156    if (mode == GL_POINT) {
 157       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 158          v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
 159          v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
 160          v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
 161       }
 162       _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_point_tri);
 163    } else if (mode == GL_LINE) {
 164       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 165          v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
 166          v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
 167          v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
 168       }
 169       _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_line_tri);
 170    } else {
 171       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 172          v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
 173          v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
 174          v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
 175       }
 176       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 177    }
 178
 179    /*
 180     * Restore original vertex colors, etc.
 181     */
 182    if (IND & SS_OFFSET_BIT) {
 183       v[0]->attrib[VARYING_SLOT_POS][2] = z[0];
 184       v[1]->attrib[VARYING_SLOT_POS][2] = z[1];
 185       v[2]->attrib[VARYING_SLOT_POS][2] = z[2];
 186    }
 187
 188    if (IND & SS_TWOSIDE_BIT) {
 189       if (facing == 1) {
 190         if (VB->BackfaceColorPtr) {
 191           if (swsetup->intColors) {
 192             COPY_CHAN4(v[0]->color, saved_color[0]);
 193             COPY_CHAN4(v[1]->color, saved_color[1]);
 194             COPY_CHAN4(v[2]->color, saved_color[2]);
 195           }
 196           else {
 197             COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], saved_col0[0]);
 198             COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], saved_col0[1]);
 199             COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], saved_col0[2]);
 200           }
 201         }
 202
 203         if (VB->BackfaceSecondaryColorPtr) {
 204           COPY_4V(v[0]->attrib[VARYING_SLOT_COL1], saved_spec[0]);
 205           COPY_4V(v[1]->attrib[VARYING_SLOT_COL1], saved_spec[1]);
 206           COPY_4V(v[2]->attrib[VARYING_SLOT_COL1], saved_spec[2]);
 207         }
 208       }
 209    }
 210 }
 211
 212
 213
 214 /* Need to fixup edgeflags when decomposing to triangles:
 215  */
 216 static void TAG(quadfunc)( struct gl_context *ctx, GLuint v0,
 217                        GLuint v1, GLuint v2, GLuint v3 )
 218 {
 219    if (IND & SS_UNFILLED_BIT) {
 220       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 221       if (VB->EdgeFlag) { /* XXX this test shouldn't be needed (bug 12614) */
 222          GLubyte ef1 = VB->EdgeFlag[v1];
 223          GLubyte ef3 = VB->EdgeFlag[v3];
 224          VB->EdgeFlag[v1] = 0;
 225          TAG(triangle)( ctx, v0, v1, v3 );
 226          VB->EdgeFlag[v1] = ef1;
 227          VB->EdgeFlag[v3] = 0;
 228          TAG(triangle)( ctx, v1, v2, v3 );
 229          VB->EdgeFlag[v3] = ef3;
 230       }
 231    } else {
 232       TAG(triangle)( ctx, v0, v1, v3 );
 233       TAG(triangle)( ctx, v1, v2, v3 );
 234    }
 235 }
 236
 237
 238
 239
 240 static void TAG(init)( void )
 241 {
 242    tri_tab[IND] = TAG(triangle);
 243    quad_tab[IND] = TAG(quadfunc);
 244 }
 245
 246
 247 #undef IND
 248 #undef TAG