1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
5 *
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:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
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.
23 *
24 * Authors:
25 * Keith Whitwell <keithw@vmware.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 */
TAG(triangle)33 static void TAG(triangle)(struct gl_context *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, oz0, oz1, oz2;
41 GLenum mode = GL_FILL;
42 GLuint facing = 0;
43 GLchan saved_color[3][4] = { { 0 } };
44 GLfloat saved_col0[3][4] = { { 0 } };
45 GLfloat saved_spec[3][4] = { { 0 } };
46
47 v[0] = &verts[e0];
48 v[1] = &verts[e1];
49 v[2] = &verts[e2];
50
51 if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
52 {
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;
58
59 if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
60 {
61 facing = (cc < 0.0F) ^ ctx->Polygon._FrontBit;
62
63 if (IND & SS_UNFILLED_BIT)
64 mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
65
66 if (facing == 1) {
67 if (IND & SS_TWOSIDE_BIT) {
68 if (VB->BackfaceColorPtr) {
69 GLfloat (*vbcolor)[4] = VB->BackfaceColorPtr->data;
70
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);
75 }
76 else {
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]);
80 }
81
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]);
87 }
88 else {
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]);
92 }
93 }
94 else {
95 /* flat shade */
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]);
100 }
101 else {
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]);
105 }
106 }
107 }
108
109 if (VB->BackfaceSecondaryColorPtr) {
110 GLfloat (*vbspec)[4] = VB->BackfaceSecondaryColorPtr->data;
111
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]);
115
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]);
120 }
121 else {
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]);
125 }
126 }
127 }
128 }
129 }
130
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.
139 */
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;
148 }
149 /* new Z values */
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);
153 }
154 }
155
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;
161 }
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;
168 }
169 _swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_line_tri);
170 } else {
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;
175 }
176 _swrast_Triangle( ctx, v[0], v[1], v[2] );
177 }
178
179 /*
180 * Restore original vertex colors, etc.
181 */
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];
186 }
187
188 if (IND & SS_TWOSIDE_BIT) {
189 if (facing == 1) {
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]);
195 }
196 else {
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]);
200 }
201 }
202
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]);
207 }
208 }
209 }
210 }
211
212
213
214 /* Need to fixup edgeflags when decomposing to triangles:
215 */
TAG(quadfunc)216 static void TAG(quadfunc)( struct gl_context *ctx, GLuint v0,
217 GLuint v1, GLuint v2, GLuint v3 )
218 {
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;
230 }
231 } else {
232 TAG(triangle)( ctx, v0, v1, v3 );
233 TAG(triangle)( ctx, v1, v2, v3 );
234 }
235 }
236
237
238
239
TAG(init)240 static void TAG(init)( void )
241 {
242 tri_tab[IND] = TAG(triangle);
243 quad_tab[IND] = TAG(quadfunc);
244 }
245
246
247 #undef IND
248 #undef TAG
249