/// <summary>
/// Resizes the SurfaceImage with the given size and redraws the SurfaceImage by loading
/// image from the new Uri.
/// </summary>
/// <param name="uri">Uri of the image to be loaded onto the SurfaceImage.</param>
/// <param name="size">New size of the SurfaceImage</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
/// <returns>Task</returns>
public async Task RedrawAsync(Uri uri, Size size, CompositionSurfaceImageOptions options)
{
// If the given Uri differs from the previously stored Uri
// dispose the existing canvasBitmap
if (!_uri.IsEqualTo(uri))
{
_canvasBitmap?.Dispose();
_canvasBitmap = null;
}
// Set the image options
Options = options;
// Resize the surface only if AutoResize option is disabled
if (!Options.AutoResize)
{
// resize the SurfaceImage
_generator.ResizeDrawingSurface(_surfaceLock, _surface, size);
// Set the size
Size = _surface?.Size ?? new Size(0, 0);
}
// Set the new Uri of the image to be loaded
_uri = uri;
// Reload the SurfaceImage
await RedrawSurfaceImageInternalAsync();
}
/// <summary>
/// Redraws the SurfaceImage with the given image options
/// </summary>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
/// <returns>Task</returns>
public void Redraw(CompositionSurfaceImageOptions options)
{
// Set the image options
Options = options;
// Redraw the SurfaceImage
RedrawSurfaceImageInternal();
}
/// <summary>
/// Disposes the resources used by the SurfaceImage
/// </summary>
public void Dispose()
{
_surface?.Dispose();
if (_generator != null)
{
_generator.DeviceReplaced -= OnDeviceReplaced;
}
_canvasBitmap?.Dispose();
_canvasBitmap = null;
_surface = null;
_generator = null;
_uri = null;
Options = null;
}
/// <summary>
/// Resizes the SurfaceImage to the new size.
/// </summary>
/// <param name="size">New size of the SurfaceImage</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
public void Resize(Size size, CompositionSurfaceImageOptions options)
{
// Set the image options
Options = options;
// Resize the surface only if AutoResize option is disabled
if (!Options.AutoResize)
{
// resize the SurfaceImage
_generator.ResizeDrawingSurface(_surfaceLock, _surface, size);
// Set the size
Size = _surface?.Size ?? new Size(0, 0);
}
// resize the SurfaceImage
RedrawSurfaceImageInternal();
}
/// <summary>
/// Redraws the SurfaceImage by loading image from the new Uri and image options
/// </summary>
/// <param name="uri">Uri of the image to be loaded on to the image surface.</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
/// <returns>Task</returns>
public Task RedrawAsync(Uri uri, CompositionSurfaceImageOptions options)
{
// If the given Uri differs from the previously stored Uri
// dispose the existing canvasBitmap
if (!_uri.IsEqualTo(uri))
{
_canvasBitmap?.Dispose();
_canvasBitmap = null;
}
// Set the new Uri of the image to be loaded
_uri = uri;
// Set the image options
Options = options;
// Reload the SurfaceImage
return(RedrawSurfaceImageInternalAsync());
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="generator">ICompositionMaskGeneratorInternal object</param>
/// <param name="uri">Uri of the image to be loaded onto the SurfaceImage.</param>
/// <param name="size">Size of the SurfaceImage</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
public CompositionSurfaceImage(ICompositionGeneratorInternal generator, Uri uri, Size size, CompositionSurfaceImageOptions options)
{
if (generator == null)
{
throw new ArgumentNullException(nameof(generator), "CompositionGenerator cannot be null!");
}
_generator = generator;
_surfaceLock = new object();
// Create the Surface of the SurfaceImage
_surface = _generator.CreateDrawingSurface(_surfaceLock, size);
Size = _surface?.Size ?? new Size(0, 0);
_uri = uri;
_canvasBitmap = null;
// Set the image options
Options = options;
// Subscribe to DeviceReplaced event
_generator.DeviceReplaced += OnDeviceReplaced;
}
/// <summary>
/// Resizes the SurfaceImage to the given size and redraws the SurfaceImage by loading
/// image from the new Uri. It returns the CanvasBitmap so that it can be cached for efficiency.
/// </summary>
/// <param name="surfaceLock">The object to lock to prevent multiple threads
/// from accessing the surface at the same time.</param>
/// <param name="surface">CompositionDrawingSurface</param>
/// <param name="uri">Uri of the image to be loaded onto the SurfaceImage.</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
/// <param name="canvasBitmap">The CanvasBitmap on which the image is loaded.</param>
/// <returns>CanvasBitmap</returns>
public async Task <CanvasBitmap> RedrawSurfaceImageAsync(object surfaceLock, CompositionDrawingSurface surface,
Uri uri, CompositionSurfaceImageOptions options, CanvasBitmap canvasBitmap)
{
if ((canvasBitmap == null) && (uri != null))
{
try
{
canvasBitmap = await CanvasBitmap.LoadAsync(_canvasDevice, uri);
}
catch (IOException)
{
// Do nothing here as RenderBitmap method will fill the surface
// with options.SurfaceBackgroundColor as the image failed to load
// from Uri
}
}
// Render the image to the surface
RenderBitmap(surfaceLock, surface, canvasBitmap, options);
return(canvasBitmap);
}
/// <summary>
/// Renders the CanvasBitmap on the CompositionDrawingSurface based on the given options.
/// </summary>
/// <param name="surfaceLock">The object to lock to prevent multiple threads
/// from accessing the surface at the same time.</param>
/// <param name="surface">CompositionDrawingSurface on which the CanvasBitmap has to be rendered.</param>
/// <param name="canvasBitmap">CanvasBitmap created by loading the image from the Uri</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
private static void RenderBitmap(object surfaceLock, CompositionDrawingSurface surface, CanvasBitmap canvasBitmap,
CompositionSurfaceImageOptions options)
{
var surfaceSize = surface.Size;
// If the canvasBitmap is null, then just fill the surface with the SurfaceBackgroundColor
if (canvasBitmap == null)
{
// No need to render if the width and/or height of the surface is zero
if (surfaceSize.IsEmpty || surfaceSize.Width.IsZero() || surfaceSize.Height.IsZero())
{
return;
}
//
// Since multiple threads could be trying to get access to the device/surface
// at the same time, we need to do any device/surface work under a lock.
//
lock (surfaceLock)
{
using (var session = CanvasComposition.CreateDrawingSession(surface))
{
// Clear the surface with the SurfaceBackgroundColor
session.Clear(options.SurfaceBackgroundColor);
}
// No need to proceed further
return;
}
}
//
// Since multiple threads could be trying to get access to the device/surface
// at the same time, we need to do any device/surface work under a lock.
//
lock (surfaceLock)
{
// Is AutoResize Enabled?
if (options.AutoResize)
{
// If AutoResize is allowed and the canvasBitmap size and surface size are
// not matching then resize the surface to match the canvasBitmap size.
//
// NOTE: HorizontalAlignment, Vertical Alignment and Stretch will be
// handled by the CompositionSurfaceBrush created using this surface.
//
if (canvasBitmap.Size != surfaceSize)
{
// Resize the surface
CanvasComposition.Resize(surface, canvasBitmap.Size);
surfaceSize = canvasBitmap.Size;
}
// No need to render if the width and/or height of the surface is zero
if (surfaceSize.IsEmpty || surface.Size.Width.IsZero() || surface.Size.Height.IsZero())
{
return;
}
// Draw the image to the surface
using (var session = CanvasComposition.CreateDrawingSession(surface))
{
// Render the image
session.DrawImage(canvasBitmap, // CanvasBitmap
new Rect(0, 0, surfaceSize.Width, surfaceSize.Height), // Target Rectangle
new Rect(0, 0, canvasBitmap.Size.Width, canvasBitmap.Size.Height), // Source Rectangle
options.Opacity, // Opacity
options.Interpolation); // Interpolation
}
}
else
{
// No need to render if the width and/or height of the surface is zero
if (surfaceSize.IsEmpty || surface.Size.Width.IsZero() || surface.Size.Height.IsZero())
{
return;
}
var bitmapSize = canvasBitmap.Size;
var sourceWidth = bitmapSize.Width;
var sourceHeight = bitmapSize.Height;
var ratio = sourceWidth / sourceHeight;
var targetWidth = 0d;
var targetHeight = 0d;
var left = 0d;
var top = 0d;
// Stretch Mode
switch (options.Stretch)
{
case Stretch.None:
targetWidth = sourceWidth;
targetHeight = sourceHeight;
break;
case Stretch.Fill:
targetWidth = surfaceSize.Width;
targetHeight = surfaceSize.Height;
break;
case Stretch.Uniform:
// If width is greater than height
if (ratio > 1.0)
{
targetHeight = Math.Min(surfaceSize.Width / ratio, surfaceSize.Height);
targetWidth = targetHeight * ratio;
}
else
{
targetWidth = Math.Min(surfaceSize.Height * ratio, surfaceSize.Width);
targetHeight = targetWidth / ratio;
}
break;
case Stretch.UniformToFill:
// If width is greater than height
if (ratio > 1.0)
{
targetHeight = Math.Max(surfaceSize.Width / ratio, surfaceSize.Height);
targetWidth = targetHeight * ratio;
}
else
{
targetWidth = Math.Max(surfaceSize.Height * ratio, surfaceSize.Width);
targetHeight = targetWidth / ratio;
}
break;
}
// Horizontal Alignment
switch (options.HorizontalAlignment)
{
case AlignmentX.Left:
left = 0;
break;
case AlignmentX.Center:
left = (surfaceSize.Width - targetWidth) / 2.0;
break;
case AlignmentX.Right:
left = surfaceSize.Width - targetWidth;
break;
}
// Vertical Alignment
switch (options.VerticalAlignment)
{
case AlignmentY.Top:
top = 0;
break;
case AlignmentY.Center:
top = (surfaceSize.Height - targetHeight) / 2.0;
break;
case AlignmentY.Bottom:
top = surfaceSize.Height - targetHeight;
break;
}
// Draw the image to the surface
using (var session = CanvasComposition.CreateDrawingSession(surface))
{
// Clear the surface with the SurfaceBackgroundColor
session.Clear(options.SurfaceBackgroundColor);
// Render the image
session.DrawImage(canvasBitmap, // CanvasBitmap
new Rect(left, top, targetWidth, targetHeight), // Target Rectangle
new Rect(0, 0, sourceWidth, sourceHeight), // Source Rectangle
options.Opacity, // Opacity
options.Interpolation); // Interpolation
}
}
}
}
/// <summary>
/// Resizes the SurfaceImage to the given size and redraws the SurfaceImage
/// by resizing the existing canvasBitmap
/// </summary>
/// <param name="surfaceLock">The object to lock to prevent multiple threads
/// from accessing the surface at the same time.</param>
/// <param name="surface">CompositionDrawingSurface</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
/// <param name="canvasBitmap">The CanvasBitmap on which the image is loaded.</param>
public void RedrawSurfaceImage(object surfaceLock, CompositionDrawingSurface surface,
CompositionSurfaceImageOptions options, CanvasBitmap canvasBitmap)
{
// Render the image to the surface
RenderBitmap(surfaceLock, surface, canvasBitmap, options);
}
/// <summary>
/// Creates a CompositionSurfaceImage having the given size onto which an image (based on the Uri
/// and the options) is loaded.
/// </summary>
/// <param name="uri">Uri of the image to be loaded onto the SurfaceImage.</param>
/// <param name="size">New size of the SurfaceImage</param>
/// <param name="options">Describes the image's resize and alignment options in the allocated space.</param>
/// <returns>ICompositionSurfaceImage</returns>
public async Task <ICompositionSurfaceImage> CreateSurfaceImageAsync(Uri uri, Size size, CompositionSurfaceImageOptions options)
{
// Initialize the SurfaceImage
ICompositionSurfaceImage surfaceImage = new CompositionSurfaceImage(this, uri, size, options);
// Render the image onto the surface
await surfaceImage.RedrawAsync();
return(surfaceImage);
}
