File size: 4,806 Bytes
898c672
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
local math3d = {}

math3d.projection_constant = 0.7071067811865

function math3d.project_vec3(vec3)
  return
  {
    vec3[1],
    (vec3[2] + vec3[3]) * math3d.projection_constant
  }
end

math3d.vector4 = {}
math3d.vector4.zero = {0, 0, 0, 0}

function math3d.vector4.dot_product(u, v)
  return u[1] * v[1] + u[2] * v[2] + u[3] * v[3] + u[4] * v[4]
end

function math3d.vector4.add(u, v)
  return { u[1]+v[1], u[2]+v[2], u[3]+v[3], u[4]+v[4] }
end

function math3d.vector4.sub(u, v)
  return { u[1]-v[1], u[2]-v[2], u[3]-v[3], u[4]-v[4] }
end

function math3d.vector4.from_vec3(u)
  return { u[1], u[2], u[3], 1 }
end

math3d.vector3 = {}
math3d.vector3.zero = {0, 0, 0}

function math3d.vector3.dot_product(u, v)
  return u[1] * v[1] + u[2] * v[2] + u[3] * v[3]
end

function math3d.vector3.add(u, v)
  return { u[1]+v[1], u[2]+v[2], u[3]+v[3] }
end

function math3d.vector3.sub(u, v)
  return { u[1]-v[1], u[2]-v[2], u[3]-v[3] }
end

function math3d.vector3.mul(u, k)
  return { u[1]*k, u[2]*k, u[3]*k }
end

function math3d.vector3.cross_product(u, v)
  return {u[2]*v[3] - u[3]*v[2],u[3]*v[1] - u[1]*v[3],u[1]*v[2] - u[2]*v[1]}
end

function math3d.vector3.angle(u, v)
  local len = math.sqrt(math3d.vector3.dot_product(u,u) * math3d.vector3.dot_product(v,v))
  local cos_phi = math3d.vector3.dot_product(u, v) / len
  return math.acos(cos_phi)
end

math3d.vector2 = {}
math3d.vector2.zero = {0, 0}

function math3d.vector2.dot_product(u, v)
  return u[1] * v[1] + u[2] * v[2]
end

function math3d.vector2.add(u, v)
  return { u[1]+v[1], u[2]+v[2] }
end

function math3d.vector2.sub(u, v)
  return { u[1]-v[1], u[2]-v[2] }
end

function math3d.vector2.mul(u, k)
  return { u[1]*k, u[2]*k }
end

function math3d.vector2.rotate(v, phi)
  local sin_phi = math.sin(phi)
  local cos_phi = math.cos(phi)
  return
  {
    v[1] * cos_phi - v[2] * sin_phi,
    v[1] * sin_phi + v[2] * cos_phi
  }
end

math3d.matrix4x4 = {}
math3d.matrix4x4.identity =
{
  { 1, 0, 0, 0 },
  { 0, 1, 0, 0 },
  { 0, 0, 1, 0 },
  { 0, 0, 0, 1 }
}

function math3d.matrix4x4.rotation_x(phi)
  local sin_phi = math.sin(phi)
  local cos_phi = math.cos(phi)
  return
  {
     {       1,        0,        0,     0 },
     {       0,  cos_phi, -sin_phi,     0 },
     {       0,  sin_phi,  cos_phi,     0 },
     {       0,        0,        0,     1 }
  }
end

function math3d.matrix4x4.rotation_y(phi)
  local sin_phi = math.sin(phi)
  local cos_phi = math.cos(phi)
  return
  {
     { cos_phi,        0,  sin_phi,     0 },
     {       0,        1,        0,     0 },
     {-sin_phi,        0,  cos_phi,     0 },
     {       0,        0,        0,     1 }
  }
end

function math3d.matrix4x4.rotation_z(phi)
  local sin_phi = math.sin(phi)
  local cos_phi = math.cos(phi)
  return
  {
     { cos_phi, -sin_phi,        0,     0 },
     { sin_phi,  cos_phi,        0,     0 },
     {       0,        0,        1,     0 },
     {       0,        0,        0,     1 }
  }
end

function math3d.matrix4x4.translation(x, y, z)
  return
  {
     {       1,        0,        0,     x },
     {       0,        1,        0,     y },
     {       0,        0,        1,     z },
     {       0,        0,        0,     1 }
  }
end

function math3d.matrix4x4.translation_vec3(vec3)
  return math3d.matrix4x4.translation(vec3[1], vec3[2], vec3[3])
end

function math3d.matrix4x4.scale(x, y, z)
  return
  {
     {       x,        0,        0,     0 },
     {       0,        y,        0,     0 },
     {       0,        0,        z,     0 },
     {       0,        0,        0,     1 }
  }
end

function math3d.matrix4x4.column(mat, index)
   return { mat[1][index], mat[2][index], mat[3][index], mat[4][index] }
end

function math3d.matrix4x4.transpose(mat)
   return
   {
     math3d.matrix4x4.column(mat, 1),
     math3d.matrix4x4.column(mat, 2),
     math3d.matrix4x4.column(mat, 3),
     math3d.matrix4x4.column(mat, 4)
   }
end

function math3d.matrix4x4.mul_mat(m1, m2)
  local dot = math3d.vector4.dot_product
  local t = math3d.matrix4x4.transpose(m2)
  return
  {
     { dot(m1[1], t[1]), dot(m1[1], t[2]), dot(m1[1], t[3]), dot(m1[1], t[4]) },
     { dot(m1[2], t[1]), dot(m1[2], t[2]), dot(m1[2], t[3]), dot(m1[2], t[4]) },
     { dot(m1[3], t[1]), dot(m1[3], t[2]), dot(m1[3], t[3]), dot(m1[3], t[4]) },
     { dot(m1[4], t[1]), dot(m1[4], t[2]), dot(m1[4], t[3]), dot(m1[4], t[4]) }
  }
end

function math3d.matrix4x4.mul_vec3(mat, vec3)
  return
  {
    math3d.vector3.dot_product(vec3, mat[1]) + mat[1][4],
    math3d.vector3.dot_product(vec3, mat[2]) + mat[2][4],
    math3d.vector3.dot_product(vec3, mat[3]) + mat[3][4]
  }
end

function math3d.matrix4x4.compose(list)
  local retval = math3d.matrix4x4.identity
  for i,m in ipairs(list) do
    retval = math3d.matrix4x4.mul_mat(m, retval)
  end
  return retval
end

return math3d