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 * 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. 23 * 24 * Authors: 25 * Keith Whitwell <keith@tungstengraphics.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 */ 33static 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[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; 58 59 if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT)) 60 { 61 facing = (cc < 0.0) ^ 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[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]); 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[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]); 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[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]); 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[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]); 115 116 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]); 120 } 121 else { 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]); 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[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. 139 */ 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; 148 } 149 /* new Z values */ 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); 153 } 154 } 155 156 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; 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[FRAG_ATTRIB_WPOS][2] = oz0; 166 v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1; 167 v[2]->attrib[FRAG_ATTRIB_WPOS][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[FRAG_ATTRIB_WPOS][2] = oz0; 173 v[1]->attrib[FRAG_ATTRIB_WPOS][2] = oz1; 174 v[2]->attrib[FRAG_ATTRIB_WPOS][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[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]; 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[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]); 200 } 201 } 202 203 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]); 207 } 208 } 209 } 210} 211 212 213 214/* Need to fixup edgeflags when decomposing to triangles: 215 */ 216static 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 240static 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