ss_tritmp.h revision 3d8d5b298a268b119d840bc9bae0ee9e0c9244a9
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 */
34static 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 */
217static 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
241static 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
250