2 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
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:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
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.
25 * Keith Whitwell <keith@tungstengraphics.com>
30 * This is where we handle assigning vertex colors based on front/back
31 * facing, compute polygon offset and handle glPolygonMode().
33 static void TAG(triangle
)(GLcontext
*ctx
, GLuint e0
, GLuint e1
, GLuint e2
)
35 struct vertex_buffer
*VB
= &TNL_CONTEXT(ctx
)->vb
;
36 SScontext
*swsetup
= SWSETUP_CONTEXT(ctx
);
37 SWvertex
*verts
= SWSETUP_CONTEXT(ctx
)->verts
;
40 GLfloat offset
, oz0
, oz1
, oz2
;
41 GLenum mode
= GL_FILL
;
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 };
52 if (IND
& (SS_TWOSIDE_BIT
| SS_OFFSET_BIT
| SS_UNFILLED_BIT
))
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
;
60 if (IND
& (SS_TWOSIDE_BIT
| SS_UNFILLED_BIT
))
62 facing
= (cc
< 0.0) ^ ctx
->Polygon
._FrontBit
;
64 if (IND
& SS_UNFILLED_BIT
)
65 mode
= facing
? ctx
->Polygon
.BackMode
: ctx
->Polygon
.FrontMode
;
68 if (IND
& SS_TWOSIDE_BIT
) {
69 if (IND
& SS_RGBA_BIT
) {
70 if (VB
->BackfaceColorPtr
) {
71 GLfloat (*vbcolor
)[4] = VB
->BackfaceColorPtr
->data
;
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
);
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
]);
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
]);
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
]);
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]);
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]);
111 if (VB
->BackfaceSecondaryColorPtr
) {
112 GLfloat (*vbspec
)[4] = VB
->BackfaceSecondaryColorPtr
->data
;
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
]);
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
]);
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]);
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];
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
]);
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.
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
;
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
);
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
;
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
;
181 _swsetup_render_tri(ctx
, e0
, e1
, e2
, facing
, _swsetup_edge_render_line_tri
);
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
;
188 _swrast_Triangle( ctx
, v
[0], v
[1], v
[2] );
192 * Restore original vertex colors, etc.
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];
200 if (IND
& SS_TWOSIDE_BIT
) {
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]);
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]);
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]);
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];
232 /* Need to fixup edgeflags when decomposing to triangles:
234 static void TAG(quadfunc
)( GLcontext
*ctx
, GLuint v0
,
235 GLuint v1
, GLuint v2
, GLuint v3
)
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
;
250 TAG(triangle
)( ctx
, v0
, v1
, v3
);
251 TAG(triangle
)( ctx
, v1
, v2
, v3
);
258 static void TAG(init
)( void )
260 tri_tab
[IND
] = TAG(triangle
);
261 quad_tab
[IND
] = TAG(quadfunc
);