1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/*
** 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();
}
|
