void IMTKViewDelegate.Draw(MTKView view)
{
if (designMode)
{
return;
}
if (backendContext.Device == null || backendContext.Queue == null || CurrentDrawable?.Texture == null)
{
return;
}
CanvasSize = DrawableSize.ToSKSize();
if (CanvasSize.Width <= 0 || CanvasSize.Height <= 0)
{
return;
}
// create the contexts if not done already
context ??= GRContext.CreateMetal(backendContext);
const SKColorType colorType = SKColorType.Bgra8888;
const GRSurfaceOrigin surfaceOrigin = GRSurfaceOrigin.TopLeft;
// create the render target
var metalInfo = new GRMtlTextureInfo(CurrentDrawable.Texture);
using var renderTarget = new GRBackendRenderTarget((int)CanvasSize.Width, (int)CanvasSize.Height, (int)SampleCount, metalInfo);
// create the surface
using var surface = SKSurface.Create(context, renderTarget, surfaceOrigin, colorType);
using var canvas = surface.Canvas;
// start drawing
var e = new SKPaintMetalSurfaceEventArgs(surface, renderTarget, surfaceOrigin, colorType);
OnPaintSurface(e);
// flush the SkiaSharp contents
canvas.Flush();
surface.Flush();
context.Flush();
// present
using var commandBuffer = backendContext.Queue.CommandBuffer();
commandBuffer.PresentDrawable(CurrentDrawable);
commandBuffer.Commit();
}
protected virtual void OnPaintSurface(SKPaintMetalSurfaceEventArgs e)
{
PaintSurface?.Invoke(this, e);
}