52d35457e3
Also fix the f32_test. LGTM=crawshaw R=crawshaw CC=golang-codereviews https://golang.org/cl/149310043
48 lines
1.2 KiB
Go
48 lines
1.2 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package f32
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import "fmt"
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// An Affine is a 3x3 matrix of float32 values for which the bottom row is
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// implicitly always equal to [0 0 1].
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// Elements are indexed first by row then column, i.e. m[row][column].
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type Affine [2]Vec3
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func (m *Affine) String() string {
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return fmt.Sprintf(`Affine[% 0.3f, % 0.3f, % 0.3f,
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% 0.3f, % 0.3f, % 0.3f]`,
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m[0][0], m[0][1], m[0][2],
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m[1][0], m[1][1], m[1][2])
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}
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func (m *Affine) Identity() {
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*m = Affine{
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{1, 0, 0},
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{0, 1, 0},
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}
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}
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func (m *Affine) Eq(n *Affine, epsilon float32) bool {
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for i := range m {
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for j := range m[i] {
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diff := m[i][j] - n[i][j]
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if diff < -epsilon || +epsilon < diff {
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return false
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}
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}
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}
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return true
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}
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func (m *Affine) Mul(m0, m1 *Affine) {
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m[0][0] = m0[0][0]*m1[0][0] + m0[0][1]*m1[1][0]
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m[0][1] = m0[0][0]*m1[0][1] + m0[0][1]*m1[1][1]
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m[0][2] = m0[0][0]*m1[0][2] + m0[0][1]*m1[1][2] + m0[0][2]
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m[1][0] = m0[1][0]*m1[0][0] + m0[1][1]*m1[1][0]
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m[1][1] = m0[1][0]*m1[0][1] + m0[1][1]*m1[1][1]
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m[1][2] = m0[1][0]*m1[0][2] + m0[1][1]*m1[1][2] + m0[1][2]
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}
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