24 lines
597 B
Go
24 lines
597 B
Go
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package vertex
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import "zworld/plugins/math/vec3"
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type Triangle struct {
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A, B, C vec3.T
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}
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func (t *Triangle) Normal() vec3.T {
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// Set Vector U to (Triangle.p2 minus Triangle.p1)
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u := t.B.Sub(t.A)
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// Set Vector V to (Triangle.p3 minus Triangle.p1)
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v := t.C.Sub(t.A)
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// Set Normal.x to (multiply U.y by V.z) minus (multiply U.z by V.y)
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x := u.Y*v.Z - u.Z*v.Y
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// Set Normal.y to (multiply U.z by V.x) minus (multiply U.x by V.z)
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y := u.Z*v.X - u.X*v.Z
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// Set Normal.z to (multiply U.x by V.y) minus (multiply U.y by V.x)
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z := u.X*v.Y - u.Y*v.X
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return vec3.New(x, y, z).Normalized()
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}
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