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)(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[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
54 GLfloat ey = v[0]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
55 GLfloat fx = v[1]->attrib[FRAG_ATTRIB_WPOS][0] - v[2]->attrib[FRAG_ATTRIB_WPOS][0];
56 GLfloat fy = v[1]->attrib[FRAG_ATTRIB_WPOS][1] - v[2]->attrib[FRAG_ATTRIB_WPOS][1];
57 GLfloat cc = ex*fy - ey*fx;
59 if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
61 facing = (cc < 0.0) ^ 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[FRAG_ATTRIB_COL0]);
78 COPY_4V(saved_col0[1], v[1]->attrib[FRAG_ATTRIB_COL0]);
79 COPY_4V(saved_col0[2], v[2]->attrib[FRAG_ATTRIB_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[FRAG_ATTRIB_COL0], vbcolor[e0]);
90 COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], vbcolor[e1]);
91 COPY_4V(v[2]->attrib[FRAG_ATTRIB_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[FRAG_ATTRIB_COL0], vbcolor[0]);
103 COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
104 COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], vbcolor[0]);
109 if (VB->BackfaceSecondaryColorPtr) {
110 GLfloat (*vbspec)[4] = VB->BackfaceSecondaryColorPtr->data;
112 COPY_4V(saved_spec[0], v[0]->attrib[FRAG_ATTRIB_COL1]);
113 COPY_4V(saved_spec[1], v[1]->attrib[FRAG_ATTRIB_COL1]);
114 COPY_4V(saved_spec[2], v[2]->attrib[FRAG_ATTRIB_COL1]);
116 if (VB->BackfaceSecondaryColorPtr->stride) {
117 SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[e0]);
118 SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[e1]);
119 SS_SPEC(v[2]->attrib[FRAG_ATTRIB_COL1], vbspec[e2]);
122 SS_SPEC(v[0]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
123 SS_SPEC(v[1]->attrib[FRAG_ATTRIB_COL1], vbspec[0]);
124 SS_SPEC(v[2]->attrib[FRAG_ATTRIB_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[FRAG_ATTRIB_WPOS][2];
135 z[1] = v[1]->attrib[FRAG_ATTRIB_WPOS][2];
136 z[2] = v[2]->attrib[FRAG_ATTRIB_WPOS][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-16) {
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[FRAG_ATTRIB_WPOS][2] + offset, 0.0F, max);
151 oz1 = CLAMP(v[1]->attrib[FRAG_ATTRIB_WPOS][2] + offset, 0.0F, max);
152 oz2 = CLAMP(v[2]->attrib[FRAG_ATTRIB_WPOS][2] + offset, 0.0F, max);
156 if (mode == GL_POINT) {
157 if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
158 v[0]->attrib[FRAG_ATTRIB_WPOS][2] = oz0;
159 v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1;
160 v[2]->attrib[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][2] = oz0;
166 v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1;
167 v[2]->attrib[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][2] = oz0;
173 v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1;
174 v[2]->attrib[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][2] = z[0];
184 v[1]->attrib[FRAG_ATTRIB_WPOS][2] = z[1];
185 v[2]->attrib[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_COL0], saved_col0[0]);
198 COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL0], saved_col0[1]);
199 COPY_4V(v[2]->attrib[FRAG_ATTRIB_COL0], saved_col0[2]);
203 if (VB->BackfaceSecondaryColorPtr) {
204 COPY_4V(v[0]->attrib[FRAG_ATTRIB_COL1], saved_spec[0]);
205 COPY_4V(v[1]->attrib[FRAG_ATTRIB_COL1], saved_spec[1]);
206 COPY_4V(v[2]->attrib[FRAG_ATTRIB_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);