2 * Mesa 3-D graphics library
4 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
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:
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
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.
25 * Keith Whitwell <keithw@vmware.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
)(struct gl_context
*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] = { { 0 } };
44 GLfloat saved_col0
[3][4] = { { 0 } };
45 GLfloat saved_spec
[3][4] = { { 0 } };
51 if (IND
& (SS_TWOSIDE_BIT
| SS_OFFSET_BIT
| SS_UNFILLED_BIT
))
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
;
59 if (IND
& (SS_TWOSIDE_BIT
| SS_UNFILLED_BIT
))
61 facing
= (cc
< 0.0F
) ^ ctx
->Polygon
._FrontBit
;
63 if (IND
& SS_UNFILLED_BIT
)
64 mode
= facing
? ctx
->Polygon
.BackMode
: ctx
->Polygon
.FrontMode
;
67 if (IND
& SS_TWOSIDE_BIT
) {
68 if (VB
->BackfaceColorPtr
) {
69 GLfloat (*vbcolor
)[4] = VB
->BackfaceColorPtr
->data
;
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
);
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
]);
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
]);
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
]);
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]);
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]);
109 if (VB
->BackfaceSecondaryColorPtr
) {
110 GLfloat (*vbspec
)[4] = VB
->BackfaceSecondaryColorPtr
->data
;
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
]);
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
]);
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]);
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.
140 offset
= ctx
->Polygon
.OffsetUnits
;
141 if (cc
* cc
> 1e-16F
) {
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
;
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
);
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
;
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
;
169 _swsetup_render_tri(ctx
, e0
, e1
, e2
, facing
, _swsetup_edge_render_line_tri
);
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
;
176 _swrast_Triangle( ctx
, v
[0], v
[1], v
[2] );
180 * Restore original vertex colors, etc.
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];
188 if (IND
& SS_TWOSIDE_BIT
) {
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]);
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]);
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]);
214 /* Need to fixup edgeflags when decomposing to triangles:
216 static void TAG(quadfunc
)( struct gl_context
*ctx
, GLuint v0
,
217 GLuint v1
, GLuint v2
, GLuint v3
)
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
;
232 TAG(triangle
)( ctx
, v0
, v1
, v3
);
233 TAG(triangle
)( ctx
, v1
, v2
, v3
);
240 static void TAG(init
)( void )
242 tri_tab
[IND
] = TAG(triangle
);
243 quad_tab
[IND
] = TAG(quadfunc
);