* Allow to set the scale (versus multiplication with a scale).

* Added commented versions for translation, rotation and shear, which would
   work similar.
 * Added B_AFFINE_IDENTITY_TRANSFORM constant similar to B_ORIGIN.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36401 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/interface/AffineTransform.h

@@ -81,6 +81,8 @@ public:
 			BAffineTransform		TranslateByCopy(double x, double y) const;
 			BAffineTransform		TranslateByCopy(const BPoint& delta) const;
 
+//			const BAffineTransform&	SetTranslation(double x, double y);
+
 	// Rotation
 	inline	const BAffineTransform&	RotateBy(double angle);
 			const BAffineTransform&	RotateBy(const BPoint& center,
@@ -90,6 +92,8 @@ public:
 			BAffineTransform		RotateByCopy(const BPoint& center,
 										double angle) const;
 
+//			const BAffineTransform&	SetRotation(double angle);
+
 	// Scaling
 	inline	const BAffineTransform&	ScaleBy(double scale);
 			const BAffineTransform&	ScaleBy(const BPoint& center,
@@ -111,6 +115,9 @@ public:
 			BAffineTransform		ScaleByCopy(const BPoint& center,
 										const BPoint& scale) const;
 
+			const BAffineTransform&	SetScale(double scale);
+			const BAffineTransform&	SetScale(double x, double y);
+
 	// Shearing
 	inline	const BAffineTransform&	ShearBy(double x, double y);
 			const BAffineTransform&	ShearBy(const BPoint& center, double x,
@@ -126,6 +133,8 @@ public:
 			BAffineTransform		ShearByCopy(const BPoint& center,
 										const BPoint& shear) const;
 
+//			const BAffineTransform&	SetShear(double x, double y);
+
 	// Multiplication
 	inline	const BAffineTransform&	Multiply(const BAffineTransform& other);
 			const BAffineTransform&	PreMultiply(const BAffineTransform& other);
@@ -191,6 +200,9 @@ public:
 };
 
 
+extern const BAffineTransform B_AFFINE_IDENTITY_TRANSFORM;
+
+
 // #pragma mark - inline methods
 
 

src/kits/interface/AffineTransform.cpp

@@ -26,6 +26,9 @@
 #include <TypeConstants.h>
 
 
+const BAffineTransform B_AFFINE_IDENTITY_TRANSFORM;
+
+
 BAffineTransform::BAffineTransform()
 	:
 	sx(1.0),
@@ -373,6 +376,36 @@ BAffineTransform::ScaleByCopy(const BPoint& center, const BPoint& scale) const
 }
 
 
+const BAffineTransform&
+BAffineTransform::SetScale(double scale)
+{
+	return SetScale(scale, scale);
+}
+
+
+const BAffineTransform&
+BAffineTransform::SetScale(double x, double y)
+{
+	double tx;
+	double ty;
+	double rotation;
+	double shearX;
+	double shearY;
+	if (!GetAffineParameters(&tx, &ty, &rotation, NULL, NULL,
+			&shearX, &shearY)) {
+		return *this;
+	}
+
+	BAffineTransform result;
+	result.ShearBy(shearX, shearY);
+	result.ScaleBy(x, y);
+	result.RotateBy(rotation);
+	result.TranslateBy(tx, ty);
+
+	return *this = result;
+}
+
+
 // #pragma mark -