44 lines
806 B
Go
44 lines
806 B
Go
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package pixelgl
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import (
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"github.com/faiface/pixel"
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"github.com/go-gl/mathgl/mgl32"
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)
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func clamp(x, low, high float64) float64 {
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if x < low {
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return low
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}
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if x > high {
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return high
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}
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return x
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}
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func lerp(x float64, a, b pixel.Vec) pixel.Vec {
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return a.Scaled(1-x) + b.Scaled(x)
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}
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func lerp2d(x, a, b pixel.Vec) pixel.Vec {
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return pixel.V(
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lerp(x.X(), a, b).X(),
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lerp(x.Y(), a, b).Y(),
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)
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}
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func transformToMat(t ...pixel.Transform) mgl32.Mat3 {
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mat := mgl32.Ident3()
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for i := range t {
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mat = mat.Mul3(t[i].Mat())
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}
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return mat
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}
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func pictureBounds(p *pixel.Picture, v pixel.Vec) pixel.Vec {
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w, h := float64(p.Texture().Width()), float64(p.Texture().Height())
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a := p.Bounds().Pos
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b := p.Bounds().Pos + p.Bounds().Size
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u := lerp2d(v, a, b)
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return pixel.V(u.X()/w, u.Y()/h)
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}
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