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  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *    Keith Whitwell <keith@tungstengraphics.com>
  27  */
  28
  29
  30 /**
  31  * This is where we handle assigning vertex colors based on front/back
  32  * facing, compute polygon offset and handle glPolygonMode().
  33  */
  34 static void TAG(triangle)(struct gl_context *ctx, GLuint e0, GLuint e1, GLuint e2 )
  35 {
  36    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  37    SScontext *swsetup = SWSETUP_CONTEXT(ctx);
  38    SWvertex *verts = SWSETUP_CONTEXT(ctx)->verts;
  39    SWvertex *v[3];
  40    GLfloat z[3];
  41    GLfloat offset, oz0, oz1, oz2;
  42    GLenum mode = GL_FILL;
  43    GLuint facing = 0;
  44    GLchan saved_color[3][4] = { { 0 } };
  45    GLfloat saved_col0[3][4] = { { 0 } };
  46    GLfloat saved_spec[3][4] = { { 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[VARYING_SLOT_POS][0] - v[2]->attrib[VARYING_SLOT_POS][0];
  55       GLfloat ey = v[0]->attrib[VARYING_SLOT_POS][1] - v[2]->attrib[VARYING_SLOT_POS][1];
  56       GLfloat fx = v[1]->attrib[VARYING_SLOT_POS][0] - v[2]->attrib[VARYING_SLOT_POS][0];
  57       GLfloat fy = v[1]->attrib[VARYING_SLOT_POS][1] - v[2]->attrib[VARYING_SLOT_POS][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 (VB->BackfaceColorPtr) {
  70                   GLfloat (*vbcolor)[4] = VB->BackfaceColorPtr->data;
  71
  72                   if (swsetup->intColors) {
  73                      COPY_CHAN4(saved_color[0], v[0]->color);
  74                      COPY_CHAN4(saved_color[1], v[1]->color);
  75                      COPY_CHAN4(saved_color[2], v[2]->color);
  76                   }
  77                   else {
  78                      COPY_4V(saved_col0[0], v[0]->attrib[VARYING_SLOT_COL0]);
  79                      COPY_4V(saved_col0[1], v[1]->attrib[VARYING_SLOT_COL0]);
  80                      COPY_4V(saved_col0[2], v[2]->attrib[VARYING_SLOT_COL0]);
  81                   }
  82
  83                   if (VB->BackfaceColorPtr->stride) {
  84                      if (swsetup->intColors) {
  85                         SS_COLOR(v[0]->color, vbcolor[e0]);
  86                         SS_COLOR(v[1]->color, vbcolor[e1]);
  87                         SS_COLOR(v[2]->color, vbcolor[e2]);
  88                      }
  89                      else {
  90                         COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], vbcolor[e0]);
  91                         COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], vbcolor[e1]);
  92                         COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], vbcolor[e2]);
  93                      }
  94                   }
  95                   else {
  96                      /* flat shade */
  97                      if (swsetup->intColors) {
  98                         SS_COLOR(v[0]->color, vbcolor[0]);
  99                         SS_COLOR(v[1]->color, vbcolor[0]);
 100                         SS_COLOR(v[2]->color, vbcolor[0]);
 101                      }
 102                      else {
 103                         COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
 104                         COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
 105                         COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
 106                      }
 107                   }
 108                }
 109
 110                if (VB->BackfaceSecondaryColorPtr) {
 111                   GLfloat (*vbspec)[4] = VB->BackfaceSecondaryColorPtr->data;
 112
 113                   COPY_4V(saved_spec[0], v[0]->attrib[VARYING_SLOT_COL1]);
 114                   COPY_4V(saved_spec[1], v[1]->attrib[VARYING_SLOT_COL1]);
 115                   COPY_4V(saved_spec[2], v[2]->attrib[VARYING_SLOT_COL1]);
 116
 117                   if (VB->BackfaceSecondaryColorPtr->stride) {
 118                     SS_SPEC(v[0]->attrib[VARYING_SLOT_COL1], vbspec[e0]);
 119                     SS_SPEC(v[1]->attrib[VARYING_SLOT_COL1], vbspec[e1]);
 120                     SS_SPEC(v[2]->attrib[VARYING_SLOT_COL1], vbspec[e2]);
 121                   }
 122                   else {
 123                     SS_SPEC(v[0]->attrib[VARYING_SLOT_COL1], vbspec[0]);
 124                     SS_SPEC(v[1]->attrib[VARYING_SLOT_COL1], vbspec[0]);
 125                     SS_SPEC(v[2]->attrib[VARYING_SLOT_COL1], vbspec[0]);
 126                   }
 127                }
 128             }
 129          }
 130       }
 131
 132       if (IND & SS_OFFSET_BIT) {
 133          const GLfloat max = ctx->DrawBuffer->_DepthMaxF;
 134          /* save original Z values (restored later) */
 135          z[0] = v[0]->attrib[VARYING_SLOT_POS][2];
 136          z[1] = v[1]->attrib[VARYING_SLOT_POS][2];
 137          z[2] = v[2]->attrib[VARYING_SLOT_POS][2];
 138          /* Note that Z values are already scaled to [0,65535] (for example)
 139           * so no MRD value is used here.
 140           */
 141          offset = ctx->Polygon.OffsetUnits;
 142          if (cc * cc > 1e-16) {
 143             const GLfloat ez = z[0] - z[2];
 144             const GLfloat fz = z[1] - z[2];
 145             const GLfloat oneOverArea = 1.0F / cc;
 146             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 147             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 148             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 149          }
 150          /* new Z values */
 151          oz0 = CLAMP(v[0]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
 152          oz1 = CLAMP(v[1]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
 153          oz2 = CLAMP(v[2]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
 154       }
 155    }
 156
 157    if (mode == GL_POINT) {
 158       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
 159          v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
 160          v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
 161          v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
 162       }
 163       _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_point_tri);
 164    } else if (mode == GL_LINE) {
 165       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 166          v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
 167          v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
 168          v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
 169       }
 170       _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_line_tri);
 171    } else {
 172       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 173          v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
 174          v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
 175          v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
 176       }
 177       _swrast_Triangle( ctx, v[0], v[1], v[2] );
 178    }
 179
 180    /*
 181     * Restore original vertex colors, etc.
 182     */
 183    if (IND & SS_OFFSET_BIT) {
 184       v[0]->attrib[VARYING_SLOT_POS][2] = z[0];
 185       v[1]->attrib[VARYING_SLOT_POS][2] = z[1];
 186       v[2]->attrib[VARYING_SLOT_POS][2] = z[2];
 187    }
 188
 189    if (IND & SS_TWOSIDE_BIT) {
 190       if (facing == 1) {
 191         if (VB->BackfaceColorPtr) {
 192           if (swsetup->intColors) {
 193             COPY_CHAN4(v[0]->color, saved_color[0]);
 194             COPY_CHAN4(v[1]->color, saved_color[1]);
 195             COPY_CHAN4(v[2]->color, saved_color[2]);
 196           }
 197           else {
 198             COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], saved_col0[0]);
 199             COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], saved_col0[1]);
 200             COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], saved_col0[2]);
 201           }
 202         }
 203
 204         if (VB->BackfaceSecondaryColorPtr) {
 205           COPY_4V(v[0]->attrib[VARYING_SLOT_COL1], saved_spec[0]);
 206           COPY_4V(v[1]->attrib[VARYING_SLOT_COL1], saved_spec[1]);
 207           COPY_4V(v[2]->attrib[VARYING_SLOT_COL1], saved_spec[2]);
 208         }
 209       }
 210    }
 211 }
 212
 213
 214
 215 /* Need to fixup edgeflags when decomposing to triangles:
 216  */
 217 static void TAG(quadfunc)( struct gl_context *ctx, GLuint v0,
 218                        GLuint v1, GLuint v2, GLuint v3 )
 219 {
 220    if (IND & SS_UNFILLED_BIT) {
 221       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
 222       if (VB->EdgeFlag) { /* XXX this test shouldn't be needed (bug 12614) */
 223          GLubyte ef1 = VB->EdgeFlag[v1];
 224          GLubyte ef3 = VB->EdgeFlag[v3];
 225          VB->EdgeFlag[v1] = 0;
 226          TAG(triangle)( ctx, v0, v1, v3 );
 227          VB->EdgeFlag[v1] = ef1;
 228          VB->EdgeFlag[v3] = 0;
 229          TAG(triangle)( ctx, v1, v2, v3 );
 230          VB->EdgeFlag[v3] = ef3;
 231       }
 232    } else {
 233       TAG(triangle)( ctx, v0, v1, v3 );
 234       TAG(triangle)( ctx, v1, v2, v3 );
 235    }
 236 }
 237
 238
 239
 240
 241 static void TAG(init)( void )
 242 {
 243    tri_tab[IND] = TAG(triangle);
 244    quad_tab[IND] = TAG(quadfunc);
 245 }
 246
 247
 248 #undef IND
 249 #undef TAG