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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/* Copyright (c) 2013 Stanislaw Halik <sthalik@misaki.pl>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*/
#include <QtGui>
#include "glwidget.h"
#include <QWidget>
#include <cmath>
#include <algorithm>
GLWidget::GLWidget(QWidget *parent) : QWidget(parent)
{
front = QImage(QString(":/images/side1.png"));
back = QImage(QString(":/images/side6.png"));
rotateBy(0, 0, 0);
}
GLWidget::~GLWidget()
{
}
void GLWidget::paintEvent ( QPaintEvent * event ) {
QWidget::paintEvent(event);
QPainter p(this);
project_quad_texture();
p.drawImage(event->rect(), texture);
}
void GLWidget::rotateBy(double xAngle, double yAngle, double zAngle)
{
double ch = cos(xAngle / 57.295781);
double sh = sin(xAngle / 57.295781);
double ca = cos(yAngle / 57.295781);
double sa = sin(yAngle / 57.295781);
double cb = cos(zAngle / 57.295781);
double sb = sin(zAngle / 57.295781);
matrix[0 * 3 + 0] = ch * ca;
matrix[0 * 3 + 1]= sh*sb - ch*sa*cb;
matrix[0 * 3 + 2]= ch*sa*sb + sh*cb;
matrix[1 * 3 + 0]= sa;
matrix[1 * 3 + 1]= ca*cb;
matrix[1 * 3 + 2]= -ca*sb;
matrix[2 * 3 + 0]= -sh*ca;
matrix[2 * 3 + 1]= sh*sa*cb + ch*sb;
matrix[2 * 3 + 2]= -sh*sa*sb + ch*cb;
update();
}
class Triangle {
public:
Triangle(const Vec2f& p1,
const Vec2f& p2,
const Vec2f& p3)
{
origin = p1;
v0 = Vec2f(p3.x - p1.x, p3.y - p1.y);
v1 = Vec2f(p2.x - p1.x, p2.y - p1.y);
dot00 = dot(v0, v0);
dot01 = dot(v0, v1);
dot11 = dot(v1, v1);
invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
}
bool barycentric_coords(const Vec2f& px, Vec2f& uv) const
{
Vec2f v2(px.x - origin.x, px.y - origin.y);
double dot12 = dot(v1, v2);
double dot02 = dot(v0, v2);
double u = (dot11 * dot02 - dot01 * dot12) * invDenom;
double v = (dot00 * dot12 - dot01 * dot02) * invDenom;
uv.x = u;
uv.y = v;
return (u >= 0) && (v >= 0) && (u + v <= 1);
}
private:
double dot00, dot01, dot11, invDenom;
Vec2f v0, v1, origin;
double dot(const Vec2f& p1, const Vec2f& p2) const {
return p1.x * p2.x + p1.y * p2.y;
}
};
static __inline Vec3f cross(const Vec3f& p1, const Vec3f& p2)
{
return Vec3f(p1.y * p2.z - p2.y * p1.z,
p2.x * p1.z - p1.x * p2.z,
p1.x * p2.y - p1.y * p2.x);
}
static __inline Vec3f normal(const Vec3f& p1, const Vec3f& p2, const Vec3f& p3)
{
Vec3f u(p2.x - p1.x, p2.y - p1.y, p2.z - p1.z);
Vec3f v(p3.x - p1.x, p3.y - p1.y, p3.z - p1.z);
Vec3f tmp = cross(u, v);
double i = 1./sqrt(tmp.x * tmp.x + tmp.y * tmp.y + tmp.z * tmp.z);
return Vec3f(i * tmp.x, i * tmp.y, i * tmp.z);
}
void GLWidget::project_quad_texture() {
const int sx = width(), sy = height();
Point pt[4];
static Vec3f corners[] = {
Vec3f(0, 0, 0),
Vec3f(sx-1, 0, 0),
Vec3f(0, sy-1, 0),
Vec3f(sx-1, sy-1, 0)
};
for (int i = 0; i < 4; i++) {
pt[i] = project(Vec3f(corners[i].x - sx/2, corners[i].y - sy/2, 0));
pt[i].x += sx/2;
pt[i].y += sy/2;
}
Vec3f normal1(0, 0, 1);
Vec3f normal2;
{
Vec3f foo[3];
for (int i = 0; i < 3; i++)
foo[i] = project2(corners[i]);
normal2 = normal(foo[0], foo[1], foo[2]);
}
double dir = normal1.x * normal2.x + normal1.y * normal2.y + normal1.z * normal2.z;
QImage& tex = dir < 0 ? back : front;
int ow = tex.width(), oh = tex.height();
Vec2f p2[4];
for (int i = 0; i < 4; i++)
p2[i] = Vec2f(pt[i].x, pt[i].y);
QImage texture(QSize(sx, sy), QImage::Format_RGB888);
QColor bgColor = palette().color(QPalette::Current, QPalette::Window);
texture.fill(bgColor);
const Vec2f projected[2][3] = { { p2[0], p2[1], p2[2] }, { p2[3], p2[1], p2[2] } };
const Vec2f origs[2][3] = {
{ Vec2f(0, 0), Vec2f(ow-1, 0), Vec2f(0, oh-1) },
{ Vec2f(ow-1, oh-1), Vec2f(ow-1, 0), Vec2f(0, oh-1) }
};
const Triangle triangles[2] = {
Triangle(projected[0][0], projected[0][1], projected[0][2]),
Triangle(projected[1][0], projected[1][1], projected[1][2])
};
int orig_pitch = tex.bytesPerLine();
int dest_pitch = texture.bytesPerLine();
const unsigned char* orig = tex.bits();
unsigned char* dest = texture.bits();
int orig_depth = tex.depth() / 8;
int dest_depth = texture.depth() / 8;
/* image breakage? */
if (orig_depth < 3)
return;
for (int y = 0; y < sy; y++)
for (int x = 0; x < sx; x++) {
Vec2f pos;
pos.x = x;
pos.y = y;
for (int i = 0; i < 2; i++) {
Vec2f coords;
if (triangles[i].barycentric_coords(pos, coords))
{
double qx = origs[i][0].x
+ coords.x * (origs[i][2].x - origs[i][0].x)
+ coords.y * (origs[i][1].x - origs[i][0].x);
double qy = origs[i][0].y
+ coords.x * (origs[i][2].y - origs[i][0].y)
+ coords.y * (origs[i][1].y - origs[i][0].y);
int qx1 = std::min<int>(ow - 1, std::max<int>(0, qx - 0.5));
int qy1 = std::min<int>(oh - 1, std::max<int>(0, qy - 0.5));
int qx2 = std::min<int>(ow - 1, std::max<int>(0, qx + 0.5));
int qy2 = std::min<int>(oh - 1, std::max<int>(0, qy + 0.5));
double dx1 = qx1 - qx;
double dy1 = qy1 - qy;
double dx2 = qx2 - qx;
double dy2 = qy2 - qy;
double d1 = 2 - (dx1 * dx1 + dy1 * dy1);
double d2 = 2 - (dx2 * dx2 + dy2 * dy2);
double d3 = 2 - (dx2 * dx2 + dy1 * dy1);
double d4 = 2 - (dx1 * dx1 + dy2 * dy2);
double inv_norm = 1. / (d1 + d2 + d3 + d4);
d1 *= inv_norm;
d2 *= inv_norm;
d3 *= inv_norm;
d4 *= inv_norm;
double r = d1 * (double) orig[qy1 * orig_pitch + qx1 * orig_depth + 2]
+ d2 * (double) orig[qy2 * orig_pitch + qx2 * orig_depth + 2]
+ d3 * (double) orig[qy1 * orig_pitch + qx2 * orig_depth + 2]
+ d4 * (double) orig[qy2 * orig_pitch + qx1 * orig_depth + 2];
double g = d1 * (double) orig[qy1 * orig_pitch + qx1 * orig_depth + 1]
+ d2 * (double) orig[qy2 * orig_pitch + qx2 * orig_depth + 1]
+ d3 * (double) orig[qy1 * orig_pitch + qx2 * orig_depth + 1]
+ d4 * (double) orig[qy2 * orig_pitch + qx1 * orig_depth + 1];
double b = d1 * (double) orig[qy1 * orig_pitch + qx1 * orig_depth + 0]
+ d2 * (double) orig[qy2 * orig_pitch + qx2 * orig_depth + 0]
+ d3 * (double) orig[qy1 * orig_pitch + qx2 * orig_depth + 0]
+ d4 * (double) orig[qy2 * orig_pitch + qx1 * orig_depth + 0];
dest[y * dest_pitch + x * dest_depth + 0] = std::max<int>(0, std::min<int>(255, r));
dest[y * dest_pitch + x * dest_depth + 1] = std::max<int>(0, std::min<int>(255, g));
dest[y * dest_pitch + x * dest_depth + 2] = std::max<int>(0, std::min<int>(255, b));
break;
}
}
}
this->texture = texture;
}
|
