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;
  41    GLenum mode = GL_FILL;
  42    GLuint facing = 0;
  43    GLchan saved_color[3][4];
  44    GLfloat saved_col0[3][4];
  45    GLfloat saved_spec[3][4];
  46    GLfloat saved_index[3];
  47
  48    v[0] = &verts[e0];
  49    v[1] = &verts[e1];
  50    v[2] = &verts[e2];
  51
  52
  53    if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
  54    {
  55       GLfloat ex = v[0]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
  56       GLfloat ey = v[0]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
  57       GLfloat fx = v[1]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
  58       GLfloat fy = v[1]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
  59       GLfloat cc  = ex*fy - ey*fx;
  60
  61       if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
  62       {
  63          facing = (cc < 0.0) ^ ctx->Polygon._FrontBit;
  64          ctx->_Facing = facing;
  65
  66          if (IND & SS_UNFILLED_BIT)
  67             mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
  68
  69          if (facing == 1) {
  70             if (IND & SS_TWOSIDE_BIT) {
  71                if (IND & SS_RGBA_BIT) {
  72                   if (VB->ColorPtr[1]) {
  73                      GLfloat (*vbcolor)[4] = VB->ColorPtr[1]->data;
  74
  75                      if (swsetup->intColors) {
  76                         COPY_CHAN4(saved_color[0], v[0]->color);
  77                         COPY_CHAN4(saved_color[1], v[1]->color);
  78                         COPY_CHAN4(saved_color[2], v[2]->color);
  79                      }
  80                      else {
  81                         COPY_4V(saved_col0[0], v[0]->attrib[FRAG_ATTRIB_COL0]);
  82                         COPY_4V(saved_col0[1], v[1]->attrib[FRAG_ATTRIB_COL0]);
  83                         COPY_4V(saved_col0[2], v[2]->attrib[FRAG_ATTRIB_COL0]);
  84                      }
  85
  86                      if (VB->ColorPtr[1]->stride) {
  87                         if (swsetup->intColors) {
  88                            SS_COLOR(v[0]->color, vbcolor[e0]);
  89                            SS_COLOR(v[1]->color, vbcolor[e1]);
  90                            SS_COLOR(v[2]->color, vbcolor[e2]);
  91                         }
  92                         else {
  93                            COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL0], vbcolor[e0]);
  94                            COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], vbcolor[e1]);
  95                            COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], vbcolor[e2]);
  96                         }
  97                      }
  98                      else {
  99                         /* flat shade */
 100                         if (swsetup->intColors) {
 101                            SS_COLOR(v[0]->color, vbcolor[0]);
 102                            SS_COLOR(v[1]->color, vbcolor[0]);
 103                            SS_COLOR(v[2]->color, vbcolor[0]);
 104                         }
 105                         else {
 106                            COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
 107                            COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
 108                            COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
 109                         }
 110                      }
 111                   }
 112
 113                   if (VB->SecondaryColorPtr[1]) {
 114                      GLfloat (*vbspec)[4] = VB->SecondaryColorPtr[1]->data;
 115
 116                      COPY_4V(saved_spec[0], v[0]->attrib[FRAG_ATTRIB_COL1]);
 117                      COPY_4V(saved_spec[1], v[1]->attrib[FRAG_ATTRIB_COL1]);
 118                      COPY_4V(saved_spec[2], v[2]->attrib[FRAG_ATTRIB_COL1]);
 119
 120                      if (VB->SecondaryColorPtr[1]->stride) {
 121                         SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[e0]);
 122                         SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[e1]);
 123                         SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[e2]);
 124                      }
 125                      else {
 126                         SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 127                         SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 128                         SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
 129                      }
 130                   }
 131                } else {
 132                   GLfloat *vbindex = (GLfloat *)VB->IndexPtr[1]->data;
 133                   saved_index[0] = v[0]->attrib[FRAG_ATTRIB_CI][0];
 134                   saved_index[1] = v[1]->attrib[FRAG_ATTRIB_CI][0];
 135                   saved_index[2] = v[2]->attrib[FRAG_ATTRIB_CI][0];
 136
 137                   SS_IND(v[0]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e0]);
 138                   SS_IND(v[1]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e1]);
 139                   SS_IND(v[2]->attrib[FRAG_ATTRIB_CI][0], (GLuint) vbindex[e2]);
 140                }
 141             }
 142          }
 143       }
 144
 145       if (IND & SS_OFFSET_BIT)
 146       {
 147          offset = ctx->Polygon.OffsetUnits * ctx->DrawBuffer->_MRD;
 148          z[0] = v[0]->attrib[FRAG_ATTRIB_WPOS][2];
 149          z[1] = v[1]->attrib[FRAG_ATTRIB_WPOS][2];
 150          z[2] = v[2]->attrib[FRAG_ATTRIB_WPOS][2];
 151          if (cc * cc > 1e-16) {
 152             const GLfloat ez = z[0] - z[2];
 153             const GLfloat fz = z[1] - z[2];
 154             const GLfloat oneOverArea = 1.0F / cc;
 155             const GLfloat dzdx = FABSF((ey * fz - ez * fy) * oneOverArea);
 156             const GLfloat dzdy = FABSF((ez * fx - ex * fz) * oneOverArea);
 157             offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
 158             /* Unfortunately, we need to clamp to prevent negative Zs below.
 159              * Technically, we should do the clamping per-fragment.
 160              */
 161             offset = MAX2(offset, -v[0]->attrib[FRAG_ATTRIB_WPOS][2]);
 162             offset = MAX2(offset, -v[1]->attrib[FRAG_ATTRIB_WPOS][2]);
 163             offset = MAX2(offset, -v[2]->attrib[FRAG_ATTRIB_WPOS][2]);
 164          }
 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] += offset;
 171          v[1]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 172          v[2]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 173       }
 174       _swsetup_render_point_tri( ctx, e0, e1, e2, facing );
 175    } else if (mode == GL_LINE) {
 176       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
 177          v[0]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 178          v[1]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 179          v[2]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 180       }
 181       _swsetup_render_line_tri( ctx, e0, e1, e2, facing );
 182    } else {
 183       if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
 184          v[0]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 185          v[1]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 186          v[2]->attrib[FRAG_ATTRIB_WPOS][2] += offset;
 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->ColorPtr[1]) {
 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->SecondaryColorPtr[1]) {
 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       GLubyte ef1 = VB->EdgeFlag[v1];
 240       GLubyte ef3 = VB->EdgeFlag[v3];
 241       VB->EdgeFlag[v1] = 0;
 242       TAG(triangle)( ctx, v0, v1, v3 );
 243       VB->EdgeFlag[v1] = ef1;
 244       VB->EdgeFlag[v3] = 0;
 245       TAG(triangle)( ctx, v1, v2, v3 );
 246       VB->EdgeFlag[v3] = ef3;
 247    } else {
 248       TAG(triangle)( ctx, v0, v1, v3 );
 249       TAG(triangle)( ctx, v1, v2, v3 );
 250    }
 251 }
 252
 253
 254
 255
 256 static void TAG(init)( void )
 257 {
 258    tri_tab[IND] = TAG(triangle);
 259    quad_tab[IND] = TAG(quadfunc);
 260 }
 261
 262
 263 #undef IND
 264 #undef TAG