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IABSD.fr/xenocara/lib/libGLU/src/libnurbs/interface/incurveeval.cc
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- lib/libGLU/src/libnurbs/interface/incurveeval.cc
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/* ** License Applicability. Except to the extent portions of this file are ** made subject to an alternative license as permitted in the SGI Free ** Software License B, Version 1.1 (the "License"), the contents of this ** file are subject only to the provisions of the License. You may not use ** this file except in compliance with the License. You may obtain a copy ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: ** ** http://oss.sgi.com/projects/FreeB ** ** Note that, as provided in the License, the Software is distributed on an ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT. ** ** Original Code. The Original Code is: OpenGL Sample Implementation, ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. ** Copyright in any portions created by third parties is as indicated ** elsewhere herein. All Rights Reserved. ** ** Additional Notice Provisions: The application programming interfaces ** established by SGI in conjunction with the Original Code are The ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X ** Window System(R) (Version 1.3), released October 19, 1998. This software ** was created using the OpenGL(R) version 1.2.1 Sample Implementation ** published by SGI, but has not been independently verified as being ** compliant with the OpenGL(R) version 1.2.1 Specification. ** */ /* */ #include <stdlib.h> #include <stdio.h> #include "glcurveval.h" /* *compute the Bezier polynomials C[n,j](v) for all j at v with *return values stored in coeff[], where * C[n,j](v) = (n,j) * v^j * (1-v)^(n-j), * j=0,1,2,...,n. *order : n+1 *vprime: v *coeff : coeff[j]=C[n,j](v), this array store the returned values. *The algorithm is a recursive scheme: * C[0,0]=1; * C[n,j](v) = (1-v)*C[n-1,j](v) + v*C[n-1,j-1](v), n>=1 *This code is copied from opengl/soft/so_eval.c:PreEvaluate */ void OpenGLCurveEvaluator::inPreEvaluate(int order, REAL vprime, REAL *coeff) { int i, j; REAL oldval, temp; REAL oneMinusvprime; /* * Minor optimization * Compute orders 1 and 2 outright, and set coeff[0], coeff[1] to * their i==1 loop values to avoid the initialization and the i==1 loop. */ if (order == 1) { coeff[0] = 1.0; return; } oneMinusvprime = 1-vprime; coeff[0] = oneMinusvprime; coeff[1] = vprime; if (order == 2) return; for (i = 2; i < order; i++) { oldval = coeff[0] * vprime; coeff[0] = oneMinusvprime * coeff[0]; for (j = 1; j < i; j++) { temp = oldval; oldval = coeff[j] * vprime; coeff[j] = temp + oneMinusvprime * coeff[j]; } coeff[j] = oldval; } } void OpenGLCurveEvaluator::inMap1f(int which, //0: vert, 1: norm, 2: color, 3: tex int k, //dimension REAL ulower, REAL uupper, int ustride, int uorder, REAL *ctlpoints) { int i,x; curveEvalMachine *temp_em; switch(which){ case 0: //vertex vertex_flag = 1; temp_em = &em_vertex; break; case 1: //normal normal_flag = 1; temp_em = &em_normal; break; case 2: //color color_flag = 1; temp_em = &em_color; break; default: texcoord_flag = 1; temp_em = &em_texcoord; break; } REAL *data = temp_em->ctlpoints; temp_em->uprime = -1; //initialized temp_em->k = k; temp_em->u1 = ulower; temp_em->u2 = uupper; temp_em->ustride = ustride; temp_em->uorder = uorder; /*copy the control points*/ for(i=0; i<uorder; i++){ for(x=0; x<k; x++){ data[x] = ctlpoints[x]; } ctlpoints += ustride; data += k; } } void OpenGLCurveEvaluator::inDoDomain1(curveEvalMachine *em, REAL u, REAL *retPoint) { int j, row; REAL the_uprime; REAL *data; if(em->u2 == em->u1) return; the_uprime = (u-em->u1) / (em->u2-em->u1); /*use already cached values if possible*/ if(em->uprime != the_uprime){ inPreEvaluate(em->uorder, the_uprime, em->ucoeff); em->uprime = the_uprime; } for(j=0; j<em->k; j++){ data = em->ctlpoints+j; retPoint[j] = 0.0; for(row=0; row<em->uorder; row++) { retPoint[j] += em->ucoeff[row] * (*data); data += em->k; } } } void OpenGLCurveEvaluator::inDoEvalCoord1(REAL u) { REAL temp_vertex[4]; REAL temp_normal[3]; REAL temp_color[4]; REAL temp_texcoord[4]; if(texcoord_flag) //there is a texture map { inDoDomain1(&em_texcoord, u, temp_texcoord); texcoordCallBack(temp_texcoord, userData); } #ifdef DEBUG printf("color_flag = %i\n", color_flag); #endif if(color_flag) //there is a color map { inDoDomain1(&em_color, u, temp_color); colorCallBack(temp_color, userData); } if(normal_flag) //there is a normal map { inDoDomain1(&em_normal, u, temp_normal); normalCallBack(temp_normal, userData); } if(vertex_flag) { inDoDomain1(&em_vertex, u, temp_vertex); vertexCallBack(temp_vertex, userData); } } void OpenGLCurveEvaluator::inMapMesh1f(int umin, int umax) { REAL du, u; int i; if(global_grid_nu == 0) return; //no points to output du = (global_grid_u1 - global_grid_u0) / (REAL) global_grid_nu; bgnline(); for(i=umin; i<= umax; i++){ u = (i==global_grid_nu)? global_grid_u1: global_grid_u0 + i*du; inDoEvalCoord1(u); } endline(); }