void ScalePartAndFixPosition(MouseEventArgs mouseEvent, double scaleAmount)
{
Vector2 mousePreScale = new Vector2(mouseEvent.X, mouseEvent.Y);
TotalTransform.inverse_transform(ref mousePreScale);
layerScale = scaleAmount;
Vector2 mousePostScale = new Vector2(mouseEvent.X, mouseEvent.Y);
TotalTransform.inverse_transform(ref mousePostScale);
unscaledRenderOffset += (mousePostScale - mousePreScale);
}
public override void OnMouseMove(MouseEventArgs mouseEvent)
{
base.OnMouseMove(mouseEvent);
Vector2 mousePos = new Vector2(mouseEvent.X, mouseEvent.Y);
if (MouseCaptured)
{
Vector2 mouseDelta = mousePos - lastMousePosition;
switch (TransformState)
{
case ETransformState.Move:
ScallingTransform.inverse_transform(ref mouseDelta);
unscaledRenderOffset += mouseDelta;
break;
case ETransformState.Scale:
double zoomDelta = 1;
if (mouseDelta.y < 0)
{
zoomDelta = 1 - (-1 * mouseDelta.y / 100);
}
else if (mouseDelta.y > 0)
{
zoomDelta = 1 + (1 * mouseDelta.y / 100);
}
Vector2 mousePreScale = mouseDownPosition;
TotalTransform.inverse_transform(ref mousePreScale);
layerScale *= zoomDelta;
Vector2 mousePostScale = mouseDownPosition;
TotalTransform.inverse_transform(ref mousePostScale);
unscaledRenderOffset += (mousePostScale - mousePreScale);
break;
default:
throw new NotImplementedException();
}
Invalidate();
}
lastMousePosition = mousePos;
}
public override void OnMouseWheel(MouseEventArgs mouseEvent)
{
base.OnMouseWheel(mouseEvent);
if (FirstWidgetUnderMouse) // TODO: find a good way to decide if you are what the wheel is trying to do
{
Vector2 mousePreScale = new Vector2(mouseEvent.X, mouseEvent.Y);
TotalTransform.inverse_transform(ref mousePreScale);
const double deltaFor1Click = 120;
layerScale = layerScale + layerScale * (mouseEvent.WheelDelta / deltaFor1Click) * .1;
Vector2 mousePostScale = new Vector2(mouseEvent.X, mouseEvent.Y);
TotalTransform.inverse_transform(ref mousePostScale);
unscaledRenderOffset += (mousePostScale - mousePreScale);
Invalidate();
}
}
public override void PostProcess(SKRect?viewport, SKMatrix totalMatrix)
{
var element = Element;
if (element is null)
{
return;
}
var enableOpacity = !IgnoreAttributes.HasFlag(DrawAttributes.Opacity);
ClipPath = null;
MaskDrawable = null;
Opacity = enableOpacity ? SvgExtensions.GetOpacityPaint(element) : null;
Filter = null;
TotalTransform = totalMatrix.PreConcat(Transform);
TransformedBounds = TotalTransform.MapRect(GeometryBounds);
foreach (var child in ChildrenDrawables)
{
child.PostProcess(viewport, totalMatrix);
}
}
public override void OnMouseMove(MouseEventArgs mouseEvent)
{
base.OnMouseMove(mouseEvent);
Vector2 mousePos = new Vector2();
if (mouseEvent.NumPositions == 1)
{
mousePos = new Vector2(mouseEvent.X, mouseEvent.Y);
}
else
{
Vector2 centerPosition = (mouseEvent.GetPosition(1) + mouseEvent.GetPosition(0)) / 2;
mousePos = centerPosition;
}
if (MouseCaptured)
{
Vector2 mouseDelta = mousePos - lastMousePosition;
switch (TransformState)
{
case ETransformState.Move:
ScalingTransform.inverse_transform(ref mouseDelta);
unscaledRenderOffset += mouseDelta;
break;
case ETransformState.Scale:
double zoomDelta = 1;
if (mouseDelta.y < 0)
{
zoomDelta = 1 - (-1 * mouseDelta.y / 100);
}
else if (mouseDelta.y > 0)
{
zoomDelta = 1 + (1 * mouseDelta.y / 100);
}
Vector2 mousePreScale = mouseDownPosition;
TotalTransform.inverse_transform(ref mousePreScale);
layerScale *= zoomDelta;
Vector2 mousePostScale = mouseDownPosition;
TotalTransform.inverse_transform(ref mousePostScale);
unscaledRenderOffset += (mousePostScale - mousePreScale);
break;
default:
throw new NotImplementedException();
}
Invalidate();
}
lastMousePosition = mousePos;
// check if we should do some scaling
if (TransformState == ETransformState.Move &&
mouseEvent.NumPositions > 1 &&
startDistanceBetweenPoints > 0)
{
double curDistanceBetweenPoints = (mouseEvent.GetPosition(1) - mouseEvent.GetPosition(0)).Length;
double scaleAmount = pinchStartScale * curDistanceBetweenPoints / startDistanceBetweenPoints;
ScalePartAndFixPosition(mouseEvent, scaleAmount);
}
}
