1 /* $Id: quads.c,v 1.5 1997/08/19 02:44:18 brianp Exp $ */ 2 3 /* 4 * Mesa 3-D graphics library 5 * Version: 2.4 6 * Copyright (C) 1995-1997 Brian Paul 7 * 8 * This library is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Library General Public 10 * License as published by the Free Software Foundation; either 11 * version 2 of the License, or (at your option) any later version. 12 * 13 * This library is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Library General Public License for more details. 17 * 18 * You should have received a copy of the GNU Library General Public 19 * License along with this library; if not, write to the Free 20 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21 */ 22 23 24 /* 25 * $Log: quads.c,v $ 26 * Revision 1.5 1997/08/19 02:44:18 brianp 27 * added null_quad() and re-implemented gl_set_quad_function() 28 * 29 * Revision 1.4 1997/07/24 01:23:44 brianp 30 * changed precompiled header symbol from PCH to PC_HEADER 31 * 32 * Revision 1.3 1997/05/28 03:26:18 brianp 33 * added precompiled header (PCH) support 34 * 35 * Revision 1.2 1997/04/20 19:45:46 brianp 36 * added a comment 37 * 38 * Revision 1.1 1997/04/12 12:24:07 brianp 39 * Initial revision 40 * 41 */ 42 43 44 /* 45 * Quadrilateral rendering functions. 46 */ 47 48 49 #ifdef PC_HEADER 50 #include "all.h" 51 #else 52 #include "types.h" 53 #include "quads.h" 54 #endif 55 56 57 58 /* 59 * At this time there is no quadrilateral optimization. Just call the 60 * triangle function twice. 61 * v0, v1, v2, v3 in CCW order = front facing. 62 */ 63 static void quad( GLcontext *ctx, 64 GLuint v0, GLuint v1, GLuint v2, GLuint v3, GLuint pv ) 65 { 66 (*ctx->Driver.TriangleFunc)( ctx, v0, v1, v3, pv ); 67 (*ctx->Driver.TriangleFunc)( ctx, v1, v2, v3, pv ); 68 } 69 70 71 72 /* 73 * Draw nothing (NULL raster mode) 74 */ 75 static void null_quad( GLcontext *ctx, 76 GLuint v0, GLuint v1, GLuint v2, GLuint v3, GLuint pv ) 77 { 78 } 79 80 81 82 void gl_set_quad_function( GLcontext *ctx ) 83 { 84 if (ctx->RenderMode==GL_RENDER) { 85 if (ctx->NoRaster) { 86 ctx->Driver.QuadFunc = null_quad; 87 } 88 else if (ctx->Driver.QuadFunc) { 89 /* Device driver will draw quads. */ 90 } 91 else { 92 ctx->Driver.QuadFunc = quad; 93 } 94 } 95 else { 96 /* if in feedback or selection mode we can fall back to triangle code */ 97 ctx->Driver.QuadFunc = quad; 98 } 99 } 100 101 102