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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.
**
** $Date: 2001/03/17 00:25:40 $ $Revision: 1.1 $
*/
/*
** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/interface/incurveeval.cc,v 1.1 2001/03/17 00:25:40 brianp Exp $
*/
#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,j,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 p;
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();
}
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