1 /* 2 ** License Applicability. Except to the extent portions of this file are 3 ** made subject to an alternative license as permitted in the SGI Free 4 ** Software License B, Version 1.1 (the "License"), the contents of this 5 ** file are subject only to the provisions of the License. You may not use 6 ** this file except in compliance with the License. You may obtain a copy 7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: 9 ** 10 ** http://oss.sgi.com/projects/FreeB 11 ** 12 ** Note that, as provided in the License, the Software is distributed on an 13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS 14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND 15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A 16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT. 17 ** 18 ** Original Code. The Original Code is: OpenGL Sample Implementation, 19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, 20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. 21 ** Copyright in any portions created by third parties is as indicated 22 ** elsewhere herein. All Rights Reserved. 23 ** 24 ** Additional Notice Provisions: The application programming interfaces 25 ** established by SGI in conjunction with the Original Code are The 26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released 27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version 28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X 29 ** Window System(R) (Version 1.3), released October 19, 1998. This software 30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation 31 ** published by SGI, but has not been independently verified as being 32 ** compliant with the OpenGL(R) version 1.2.1 Specification. 33 ** 34 */ 35 /* 36 */ 37 38 //#include <stdlib.h> 39 //#include <stdio.h> 40 41 #include "glcurveval.h" 42 43 44 /* 45 *compute the Bezier polynomials C[n,j](v) for all j at v with 46 *return values stored in coeff[], where 47 * C[n,j](v) = (n,j) * v^j * (1-v)^(n-j), 48 * j=0,1,2,...,n. 49 *order : n+1 50 *vprime: v 51 *coeff : coeff[j]=C[n,j](v), this array store the returned values. 52 *The algorithm is a recursive scheme: 53 * C[0,0]=1; 54 * C[n,j](v) = (1-v)*C[n-1,j](v) + v*C[n-1,j-1](v), n>=1 55 *This code is copied from opengl/soft/so_eval.c:PreEvaluate 56 */ 57 void OpenGLCurveEvaluator::inPreEvaluate(int order, REAL vprime, REAL *coeff) 58 { 59 int i, j; 60 REAL oldval, temp; 61 REAL oneMinusvprime; 62 63 /* 64 * Minor optimization 65 * Compute orders 1 and 2 outright, and set coeff[0], coeff[1] to 66 * their i==1 loop values to avoid the initialization and the i==1 loop. 67 */ 68 if (order == 1) { 69 coeff[0] = 1.0; 70 return; 71 } 72 73 oneMinusvprime = 1-vprime; 74 coeff[0] = oneMinusvprime; 75 coeff[1] = vprime; 76 if (order == 2) return; 77 78 for (i = 2; i < order; i++) { 79 oldval = coeff[0] * vprime; 80 coeff[0] = oneMinusvprime * coeff[0]; 81 for (j = 1; j < i; j++) { 82 temp = oldval; 83 oldval = coeff[j] * vprime; 84 coeff[j] = temp + oneMinusvprime * coeff[j]; 85 } 86 coeff[j] = oldval; 87 } 88 } 89 90 void OpenGLCurveEvaluator::inMap1f(int which, //0: vert, 1: norm, 2: color, 3: tex 91 int k, //dimension 92 REAL ulower, 93 REAL uupper, 94 int ustride, 95 int uorder, 96 REAL *ctlpoints) 97 { 98 int i,x; 99 curveEvalMachine *temp_em; 100 switch(which){ 101 case 0: //vertex 102 vertex_flag = 1; 103 temp_em = &em_vertex; 104 break; 105 case 1: //normal 106 normal_flag = 1; 107 temp_em = &em_normal; 108 break; 109 case 2: //color 110 color_flag = 1; 111 temp_em = &em_color; 112 break; 113 default: 114 texcoord_flag = 1; 115 temp_em = &em_texcoord; 116 break; 117 } 118 119 REAL *data = temp_em->ctlpoints; 120 temp_em->uprime = -1; //initialized 121 temp_em->k = k; 122 temp_em->u1 = ulower; 123 temp_em->u2 = uupper; 124 temp_em->ustride = ustride; 125 temp_em->uorder = uorder; 126 /*copy the control points*/ 127 for(i=0; i<uorder; i++){ 128 for(x=0; x<k; x++){ 129 data[x] = ctlpoints[x]; 130 } 131 ctlpoints += ustride; 132 data += k; 133 } 134 } 135 136 void OpenGLCurveEvaluator::inDoDomain1(curveEvalMachine *em, REAL u, REAL *retPoint) 137 { 138 int j, row; 139 REAL the_uprime; 140 REAL *data; 141 142 if(em->u2 == em->u1) 143 return; 144 the_uprime = (u-em->u1) / (em->u2-em->u1); 145 /*use already cached values if possible*/ 146 if(em->uprime != the_uprime){ 147 inPreEvaluate(em->uorder, the_uprime, em->ucoeff); 148 em->uprime = the_uprime; 149 } 150 151 for(j=0; j<em->k; j++){ 152 data = em->ctlpoints+j; 153 retPoint[j] = 0.0; 154 for(row=0; row<em->uorder; row++) 155 { 156 retPoint[j] += em->ucoeff[row] * (*data); 157 data += em->k; 158 } 159 } 160 } 161 162 void OpenGLCurveEvaluator::inDoEvalCoord1(REAL u) 163 { 164 REAL temp_vertex[4]; 165 REAL temp_normal[3]; 166 REAL temp_color[4]; 167 REAL temp_texcoord[4]; 168 if(texcoord_flag) //there is a texture map 169 { 170 inDoDomain1(&em_texcoord, u, temp_texcoord); 171 texcoordCallBack(temp_texcoord, userData); 172 } 173 #ifdef DEBUG 174 printf("color_flag = %i\n", color_flag); 175 #endif 176 if(color_flag) //there is a color map 177 { 178 inDoDomain1(&em_color, u, temp_color); 179 colorCallBack(temp_color, userData); 180 } 181 if(normal_flag) //there is a normal map 182 { 183 inDoDomain1(&em_normal, u, temp_normal); 184 normalCallBack(temp_normal, userData); 185 } 186 if(vertex_flag) 187 { 188 inDoDomain1(&em_vertex, u, temp_vertex); 189 vertexCallBack(temp_vertex, userData); 190 } 191 } 192 193 void OpenGLCurveEvaluator::inMapMesh1f(int umin, int umax) 194 { 195 REAL du, u; 196 int i; 197 if(global_grid_nu == 0) 198 return; //no points to output 199 du = (global_grid_u1 - global_grid_u0) / (REAL) global_grid_nu; 200 bgnline(); 201 for(i=umin; i<= umax; i++){ 202 u = (i==global_grid_nu)? global_grid_u1: global_grid_u0 + i*du; 203 inDoEvalCoord1(u); 204 } 205 endline(); 206 } 207