aboutsummaryrefslogtreecommitdiff
path: root/src/math/Quaternion.cpp
blob: b0e782e20ca7c3ddba57ace575202cf9ffb9df3a (plain) (blame)
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
#include "common.h"
#include "Quaternion.h"

void
CQuaternion::Normalise(void)
{
	float sq = MagnitudeSqr();
	if (sq == 0.0f)
		w = 1.0f;
	else {
		float invsqrt = RecipSqrt(sq);
		x *= invsqrt;
		y *= invsqrt;
		z *= invsqrt;
		w *= invsqrt;
	}
}

void
CQuaternion::Slerp(const CQuaternion &q1, const CQuaternion &q2, float theta, float invSin, float t)
{
	if (theta == 0.0f)
		*this = q2;
	else {
		float w1, w2;
		if (theta > PI / 2) {
			theta = PI - theta;
			w1 = Sin((1.0f - t) * theta) * invSin;
			w2 = -Sin(t * theta) * invSin;
		} else {
			w1 = Sin((1.0f - t) * theta) * invSin;
			w2 = Sin(t * theta) * invSin;
		}
		// TODO: VU0 code
		*this = w1 * q1 + w2 * q2;
	}
}

void
CQuaternion::Multiply(const CQuaternion &q1, const CQuaternion &q2)
{
	x = (q2.z * q1.y) - (q1.z * q2.y) + (q1.x * q2.w) + (q2.x * q1.w);
	y = (q2.x * q1.z) - (q1.x * q2.z) + (q1.y * q2.w) + (q2.y * q1.w);
	z = (q2.y * q1.x) - (q1.y * q2.x) + (q1.z * q2.w) + (q2.z * q1.w);
	w = (q2.w * q1.w) - (q2.x * q1.x) - (q2.y * q1.y) - (q2.z * q1.z);
}

void
CQuaternion::Get(RwV3d *axis, float *angle)
{
	*angle = Acos(w);
	float s = Sin(*angle);

	axis->x = x * (1.0f / s);
	axis->y = y * (1.0f / s);
	axis->z = z * (1.0f / s);
}

void
CQuaternion::Set(RwV3d *axis, float angle)
{
	float halfCos = Cos(angle * 0.5f);
	float halfSin = Sin(angle * 0.5f);
	x = axis->x * halfSin;
	y = axis->y * halfSin;
	z = axis->z * halfSin;
	w = halfCos;
}

void
CQuaternion::Get(RwMatrix *matrix)
{
	float x2 = x + x;
	float y2 = y + y;
	float z2 = z + z;

	float x_2x = x * x2;
	float x_2y = x * y2;
	float x_2z = x * z2;
	float y_2y = y * y2;
	float y_2z = y * z2;
	float z_2z = z * z2;
	float w_2x = w * x2;
	float w_2y = w * y2;
	float w_2z = w * z2;

	matrix->right.x = 1.0f - (y_2y + z_2z);
	matrix->up.x = x_2y - w_2z;
	matrix->at.x = x_2z + w_2y;
	matrix->right.y = x_2y + w_2z;
	matrix->up.y = 1.0f - (x_2x + z_2z);
	matrix->at.y = y_2z - w_2x;
	matrix->right.z = x_2z - w_2y;
	matrix->up.z = y_2z + w_2x;
	matrix->at.z = 1.0f - (x_2x + y_2y);
}

void
CQuaternion::Set(const RwMatrix &matrix)
{
	float f, s, m;

	f = matrix.up.y + matrix.right.x + matrix.at.z;
	if (f >= 0.0f) {
		s = Sqrt(f + 1.0f);
		w = 0.5f * s;
		m = 0.5f / s;
		x = (matrix.up.z - matrix.at.y) * m;
		y = (matrix.at.x - matrix.right.z) * m;
		z = (matrix.right.y - matrix.up.x) * m;
		return;
	}

	f = matrix.right.x - matrix.up.y - matrix.at.z;
	if (f >= 0.0f) {
		s = Sqrt(f + 1.0f);
		x = 0.5f * s;
		m = 0.5f / s;
		y = (matrix.up.x + matrix.right.y) * m;
		z = (matrix.at.x + matrix.right.z) * m;
		w = (matrix.up.z - matrix.at.y) * m;
		return;
	}

	f = matrix.up.y - matrix.right.x - matrix.at.z;
	if (f >= 0.0f) {
		s = Sqrt(f + 1.0f);
		y = 0.5f * s;
		m = 0.5f / s;
		w = (matrix.at.x - matrix.right.z) * m;
		x = (matrix.up.x - matrix.right.y) * m;
		z = (matrix.at.y + matrix.up.z) * m;
		return;
	}

	f = matrix.at.z - (matrix.up.y + matrix.right.x);
	s = Sqrt(f + 1.0f);
	z = 0.5f * s;
	m = 0.5f / s;
	w = (matrix.right.y - matrix.up.x) * m;
	x = (matrix.at.x + matrix.right.z) * m;
	y = (matrix.at.y + matrix.up.z) * m;
}

void
CQuaternion::Get(float *f1, float *f2, float *f3)
{
	RwMatrix matrix;

	Get(&matrix);
	*f3 = Atan2(matrix.right.y, matrix.up.y);
	if (*f3 < 0.0f)
		*f3 += TWOPI;
	float s = Sin(*f3);
	float c = Cos(*f3);
	*f1 = Atan2(-matrix.at.y, s * matrix.right.y + c * matrix.up.y);
	if (*f1 < 0.0f)
		*f1 += TWOPI;
	*f2 = Atan2(-(matrix.right.z * c - matrix.up.z * s), matrix.right.x * c - matrix.up.x * s);
	if (*f2 < 0.0f)
		*f2 += TWOPI;
}

void
CQuaternion::Set(float f1, float f2, float f3)
{
	float c1 = Cos(f1 * 0.5f);
	float c2 = Cos(f2 * 0.5f);
	float c3 = Cos(f3 * 0.5f);
	float s1 = Sin(f1 * 0.5f);
	float s2 = Sin(f2 * 0.5f);
	float s3 = Sin(f3 * 0.5f);
	x = ((c2 * c1) * s3) - ((s2 * s1) * c3);
	y = ((s1 * c2) * c3) + ((s2 * c1) * s3);
	z = ((s2 * c1) * c3) - ((s1 * c2) * s3);
	w = ((c2 * c1) * c3) + ((s2 * s1) * s3);
}