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
|
/* Copyright (c) 2013, 2015 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 "glwidget.h"
#include <cmath>
#include <algorithm>
#include <QPainter>
#include <QPaintEvent>
#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Wnarrowing"
#endif
GLWidget::GLWidget(QWidget *parent) : QWidget(parent)
{
Q_INIT_RESOURCE(posewidget);
front = QImage(QString(":/images/side1.png"));
back = QImage(QString(":/images/side6.png"));
rotateBy(0, 0, 0, 0, 0, 0);
}
GLWidget::~GLWidget()
{
}
void GLWidget::paintEvent ( QPaintEvent * event ) {
QPainter p(this);
project_quad_texture();
p.drawImage(event->rect(), texture);
}
void GLWidget::rotateBy(float xAngle, float yAngle, float zAngle, float x, float y, float z)
{
float c1 = cos(yAngle / 57.295781);
float s1 = sin(yAngle / 57.295781);
float c2 = cos(xAngle / 57.295781);
float s2 = sin(xAngle / 57.295781);
float c3 = cos(zAngle / 57.295781);
float s3 = sin(zAngle / 57.295781);
float foo[] = {
c2*c3, -c2*s3, s2,
c1*s3+c3*s1*s2, c1*c3-s1*s2*s3, -c2*s1,
s1*s3-c1*c3*s2, c3*s1+c1*s2*s3, c1*c2,
};
rotation = rmat(foo);
translation = vec3({x, y, z});
update();
}
class Triangle {
using num = GLWidget::num;
public:
Triangle(const vec2& p1,
const vec2& p2,
const vec2& p3)
{
origin = p1;
v0 = vec2({ p3.x() - p1.x(), p3.y() - p1.y() });
v1 = vec2({ p2.x() - p1.x(), p2.y() - p1.y() });
dot00 = v0.dot(v0);
dot01 = v0.dot(v1);
dot11 = v1.dot(v1);
invDenom = 1 / (dot00 * dot11 - dot01 * dot01);
}
bool barycentric_coords(const vec2& px, vec2& uv) const
{
vec2 v2 = px - origin;
num dot12 = v1.dot(v2);
num dot02 = v0.dot(v2);
num u = (dot11 * dot02 - dot01 * dot12) * invDenom;
num v = (dot00 * dot12 - dot01 * dot02) * invDenom;
uv = vec2({u, v});
return (u >= 0) && (v >= 0) && (u + v <= 1);
}
private:
num dot00, dot01, dot11, invDenom;
vec2 v0, v1, origin;
};
static __inline vec3 normal(const vec3& p1, const vec3& p2, const vec3& p3)
{
using num = GLWidget::num;
vec3 u = p2 - p1;
vec3 v = p3 - p1;
vec3 tmp = u.cross(v);
num i = 1./sqrt(tmp.dot(tmp));
return tmp * i;
}
void GLWidget::project_quad_texture() {
const int sx = width(), sy = height();
vec2 pt[4];
const vec3 corners[] = {
vec3({0., 0, 0}),
vec3({sx-1, 0, 0}),
vec3({0, sy-1, 0}),
vec3({sx-1, sy-1, 0.})
};
for (int i = 0; i < 4; i++) {
pt[i] = project(vec3({corners[i].x() - sx/2, corners[i].y() - sy/2, 0}));
pt[i].x() += sx/2.;
pt[i].y() += sy/2.;
}
vec3 normal1({0, 0, 1});
vec3 normal2;
{
vec3 foo[3];
for (int i = 0; i < 3; i++)
foo[i] = project2(corners[i]);
normal2 = normal(foo[0], foo[1], foo[2]);
}
num dir = normal1.dot(normal2);
QImage& tex = dir < 0 ? back : front;
int ow = tex.width(), oh = tex.height();
vec2 p2[4];
for (int i = 0; i < 4; i++)
p2[i] = vec2({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 vec2 projected[2][3] = { { p2[0], p2[1], p2[2] }, { p2[3], p2[1], p2[2] } };
const vec2 origs[2][3] = {
{ vec2({0, 0}), vec2({ow-1, 0}), vec2({0, oh-1}) },
{ vec2({ow-1, oh-1}), vec2({ow-1, 0}), vec2({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])
};
const int orig_pitch = tex.bytesPerLine();
const int dest_pitch = texture.bytesPerLine();
const unsigned char* orig = tex.bits();
unsigned char* dest = texture.bits();
const int orig_depth = tex.depth() / 8;
const 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++) {
vec2 pos({(num)x, (num)y});
for (int i = 0; i < 2; i++) {
vec2 uv;
if (triangles[i].barycentric_coords(pos, uv))
{
const int px = origs[i][0].x()
+ uv.x() * (origs[i][2].x() - origs[i][0].x())
+ uv.y() * (origs[i][1].x() - origs[i][0].x());
const int py = origs[i][0].y()
+ uv.x() * (origs[i][2].y() - origs[i][0].y())
+ uv.y() * (origs[i][1].y() - origs[i][0].y());
int r = orig[py * orig_pitch + px * orig_depth + 2];
int g = orig[py * orig_pitch + px * orig_depth + 1];
int b = orig[py * orig_pitch + px * orig_depth + 0];
dest[y * dest_pitch + x * dest_depth + 0] = r;
dest[y * dest_pitch + x * dest_depth + 1] = g;
dest[y * dest_pitch + x * dest_depth + 2] = b;
break;
}
}
}
this->texture = texture;
}
vec2 GLWidget::project(const vec3 &point)
{
vec3 ret = rotation * point;
num z = std::max<num>(.75, 1. + translation.z()/-60);
int w = width(), h = height();
num x = w * translation.x() / 2 / -40;
if (std::abs(x) > w/2)
x = x > 0 ? w/2 : w/-2;
num y = h * translation.y() / 2 / -40;
if (std::abs(y) > h/2)
y = y > 0 ? h/2 : h/-2;
return vec2 { z * (ret.x() + x), z * (ret.y() + y) };
}
vec3 GLWidget::project2(const vec3 &point)
{
return rotation * point;
}
|
