image: Deprecate ScaleGeo, TranslateGeo and RotateGeo

geom.go

@@ -91,7 +91,14 @@ func (g *GeoM) Translate(tx, ty float64) {
 }
 
 func (g *GeoM) Rotate(theta float64) {
-	g.Concat(RotateGeo(theta))
+	sin, cos := math.Sincos(theta)
+	g.Concat(GeoM{
+		initialized: true,
+		es: [2][3]float64{
+			{cos, -sin, 0},
+			{sin, cos, 0},
+		},
+	})
 }
 
 // SetElement sets an element at (i, j).
@@ -102,7 +109,7 @@ func (g *GeoM) SetElement(i, j int, element float64) {
 	g.es[i][j] = element
 }
 
-// ScaleGeo returns a matrix that scales a geometry matrix by (x, y).
+// Deprecated as of 1.2.0-alpha. Use Scale instead.
 func ScaleGeo(x, y float64) GeoM {
 	return GeoM{
 		initialized: true,
@@ -113,7 +120,7 @@ func ScaleGeo(x, y float64) GeoM {
 	}
 }
 
-// TranslateGeo returns a matrix that translates a geometry matrix by (tx, ty).
+// Deprecated as of 1.2.0-alpha. Use Translate instead.
 func TranslateGeo(tx, ty float64) GeoM {
 	return GeoM{
 		initialized: true,
@@ -124,7 +131,7 @@ func TranslateGeo(tx, ty float64) GeoM {
 	}
 }
 
-// RotateGeo returns a matrix that rotates a geometry matrix by theta.
+// Deprecated as of 1.2.0-alpha. Use Rotate instead.
 func RotateGeo(theta float64) GeoM {
 	sin, cos := math.Sincos(theta)
 	return GeoM{

geom_test.go

@@ -50,8 +50,9 @@ func TestGeometryInit(t *testing.T) {
 }
 
 func TestGeometryAssign(t *testing.T) {
-	m := ScaleGeo(1, 1) // Create elements explicitly
-	m2 := m
+	m := &GeoM{}
+	m.Scale(1, 1) // Create elements explicitly
+	m2 := *m
 	m.SetElement(0, 0, 0)
 	got := m2.Element(0, 0)
 	want := 1.0
@@ -61,8 +62,10 @@ func TestGeometryAssign(t *testing.T) {
 }
 
 func TestGeometryConcat(t *testing.T) {
-	matrix1 := ScaleGeo(2, 2)
-	matrix2 := TranslateGeo(1, 1)
+	matrix1 := GeoM{}
+	matrix1.Scale(2, 2)
+	matrix2 := GeoM{}
+	matrix2.Translate(1, 1)
 
 	matrix3 := matrix1
 	matrix3.Concat(matrix2)