From 21733d0858db0722bf0855851cd7a34c001da05e Mon Sep 17 00:00:00 2001
From: faiface <faiface@ksp.sk>
Date: Fri, 2 Dec 2016 17:36:36 +0100
Subject: [PATCH] add Transform.ScaleXY method
---
transform.go | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/transform.go b/transform.go
index a88c09c..5e96fab 100644
--- a/transform.go
+++ b/transform.go
@@ -15,15 +15,15 @@ import "github.com/go-gl/mathgl/mgl32"
//
// pixel.Position(pixel.V(100, 100)).Rotate(math.Pi / 3).Scale(1.5)
type Transform struct {
- pos, anc Vec
- sca, rot float64
+ pos, anc, sca Vec
+ rot float64
}
// Position creates a Transformation object with specified position. Anchor is (0, 0), rotation is 0 and scale is 1.
func Position(position Vec) Transform {
return Transform{
pos: position,
- sca: 1,
+ sca: V(1, 1),
}
}
@@ -50,6 +50,15 @@ func (t Transform) MoveAnchor(delta Vec) Transform {
// Note, that subsequent calls to this method accumulate the final scale factor. Scaling two times by 2 is equivalent
// to scaling once by 4.
func (t Transform) Scale(scale float64) Transform {
+ t.sca *= V(scale, scale)
+ return t
+}
+
+// ScaleXY scales the transform by the supplied X and Y factor. Note, that scale is applied before rotation.
+//
+// Note, that subsequent calls to this method accumulate the final scale factor. Scaling two times by 2 is equivalent
+// to scaling once by 4.
+func (t Transform) ScaleXY(scale Vec) Transform {
t.sca *= scale
return t
}
@@ -67,8 +76,8 @@ func (t Transform) Rotate(angle float64) Transform {
func (t Transform) Mat3() mgl32.Mat3 {
mat := mgl32.Ident3()
mat = mat.Mul3(mgl32.Translate2D(float32(t.pos.X()), float32(t.pos.Y())))
- mat = mat.Mul3(mgl32.Scale2D(float32(t.sca), float32(t.sca)))
mat = mat.Mul3(mgl32.Rotate3DZ(float32(t.rot)))
+ mat = mat.Mul3(mgl32.Scale2D(float32(t.sca.X()), float32(t.sca.Y())))
mat = mat.Mul3(mgl32.Translate2D(float32(t.anc.X()), float32(t.anc.Y())))
return mat
}
--
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