Split out imgutil

1 files changed, 57 insertions, 0 deletions

diff --git a/imgutil/imgutil.go b/imgutil/imgutil.go
new file mode 100644
index 0000000..bd9122b
--- /dev/null
+++ b/imgutil/imgutil.go
@@ -0,0 +1,57 @@
+package imgutil
+
+import (
+	"image"
+	"image/color"
+)
+
+// Scale is a scaling image.Image wrapper.
+type Scale struct {
+	Image image.Image
+	Scale int
+}
+
+// ColorModel implements image.Image.
+func (s *Scale) ColorModel() color.Model {
+	return s.Image.ColorModel()
+}
+
+// Bounds implements image.Image.
+func (s *Scale) Bounds() image.Rectangle {
+	r := s.Image.Bounds()
+	return image.Rect(r.Min.X*s.Scale, r.Min.Y*s.Scale,
+		r.Max.X*s.Scale, r.Max.Y*s.Scale)
+}
+
+// At implements image.Image.
+func (s *Scale) At(x, y int) color.Color {
+	if x < 0 {
+		x = x - s.Scale + 1
+	}
+	if y < 0 {
+		y = y - s.Scale + 1
+	}
+	return s.Image.At(x/s.Scale, y/s.Scale)
+}
+
+// LeftRotate is a 90 degree rotating image.Image wrapper.
+type LeftRotate struct {
+	Image image.Image
+}
+
+// ColorModel implements image.Image.
+func (lr *LeftRotate) ColorModel() color.Model {
+	return lr.Image.ColorModel()
+}
+
+// Bounds implements image.Image.
+func (lr *LeftRotate) Bounds() image.Rectangle {
+	r := lr.Image.Bounds()
+	// Min is inclusive, Max is exclusive.
+	return image.Rect(r.Min.Y, -(r.Max.X - 1), r.Max.Y, -(r.Min.X - 1))
+}
+
+// At implements image.Image.
+func (lr *LeftRotate) At(x, y int) color.Color {
+	return lr.Image.At(-y, x)
+}