private void MainCanvas_Paint(object sender, PaintEventArgs e)
{
var graphics = e.Graphics;
graphics.SmoothingMode = SmoothingMode;
// Apply scaling defined by Canvas.ZoomScale
graphics.ScaleTransform(MainCanvas.ZoomScale, MainCanvas.ZoomScale, MatrixOrder.Append);
// Apply the translation defined by the offset values.
graphics.TranslateTransform(MainCanvas.OffsetX, MainCanvas.OffsetY, MatrixOrder.Append);
// All drawing happens when this Canvas is painted on the screen.
// You don't just draw a line and expect it to persist. The drawing will dissapear when you minimise then maximise the form.
// So, if we do all drawing when the containing Panel is drawn, then any time we can see our Panel, all our lines/rectangles will have been drawn too.
// This is a very important concept. When you want to research, do a Google search like: "Drawing Paint event", "Drawing OnPaint override".
foreach (IDrawable drawable in MainCanvas.Drawables)
{
drawable.Draw(graphics);
}
// When you draw a shape, you may drag your mouse to construct the shape. While this happens, IsDrawing will be set to true.
// We want to show the shape being created by the mouse moving, so we draw the Tool's "CreationDrawable" shape.
if (Tool.IsDrawing)
{
Tool.CreationDrawable?.Draw(graphics);
}
MainCanvas.RefreshResizers();
UpdatePeripherals();
}