async void mainCanvas_CreateResources(Microsoft.Graphics.Canvas.CanvasControl sender, object args)
{
m_isResourceLoadingDone = false;
// WIN2D: resource loading from WinRT types including StorageFile and IRAS
m_sourceBitmap = await CanvasBitmap.LoadAsync(sender, "Chrysanthemum.jpg");
var sourceFile = await Package.Current.InstalledLocation.GetFileAsync("Chrysanthemum.jpg");
// Win2D: because we can't lock/read pixels we rely on BitmapDecoder
var stream = await sourceFile.OpenReadAsync();
var decoder = await BitmapDecoder.CreateAsync(stream);
// Technically these should always be identical to m_sourceBitmap.SizeInPixels;
m_pixelArrayHeight = decoder.PixelHeight;
m_pixelArrayWidth = decoder.PixelWidth;
var pixelProvider = await decoder.GetPixelDataAsync(
BitmapPixelFormat.Bgra8,
BitmapAlphaMode.Premultiplied,
new BitmapTransform(),
ExifOrientationMode.IgnoreExifOrientation, // Must do this.
ColorManagementMode.ColorManageToSRgb
);
m_pixelArray = pixelProvider.DetachPixelData();
m_targetBitmap = new CanvasRenderTarget(sender, new Size(m_pixelArrayWidth, m_pixelArrayHeight));
m_rnd = new Random();
m_isResourceLoadingDone = true;
mainCanvas.Invalidate();
}
void mainCanvas_Draw(Microsoft.Graphics.Canvas.CanvasControl sender, Microsoft.Graphics.Canvas.CanvasDrawEventArgs args)
{
if (m_isResourceLoadingDone)
{
//args.DrawingSession.DrawImage(m_sourceBitmap);
using (var ds = m_targetBitmap.CreateDrawingSession())
{
// Draw a bunch of solid color strokes.
// - Centered at a random point
// - Color is determined by the bitmap value at that point
// - Fixed stroke length and width
// - Random angle
for (int i = 0; i < m_numStrokes; i++)
{
double centerXFactor = m_rnd.NextDouble();
double centerYFactor = m_rnd.NextDouble();
float centerX = (float)(centerXFactor * m_sourceBitmap.Size.Width);
float centerY = (float)(centerYFactor * m_sourceBitmap.Size.Height);
float angle = (float)(m_rnd.NextDouble() * 2 * Math.PI);
Color color = getColorFromBitmapCoordinates(centerXFactor, centerYFactor);
// Convert the stroke definition to bounding box for line.
float x1 = centerX + (float)Math.Cos(angle) * m_strokeLength / 2;
// Technically the coordinate systems don't match for Y, but it doesn't matter here.
float y1 = centerY + (float)Math.Sin(angle) * m_strokeLength / 2;
float x2 = 2 * centerX - x1;
float y2 = 2 * centerY - y1;
ds.DrawLine(x1, y1, x2, y2, color, m_strokeWidth);
}
}
args.DrawingSession.DrawImage(m_targetBitmap);
}
// Render looping.
mainCanvas.Invalidate();
}