Class SKImagePyramidViewport
Manages the Deep Zoom viewport — the logical window into the image. Handles coordinate conversions between element (screen), logical (0-1 normalized), and image pixel spaces. Mirrors Silverlight's MultiScaleImage viewport behavior.
public class SKImagePyramidViewport- Inheritance
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SKImagePyramidViewport
- Inherited Members
Constructors
Fields
- MinViewportWidth
Minimum viewport width to prevent extreme zoom (corresponds to ~1,000,000x zoom).
Properties
- AspectRatio
Image aspect ratio (width/height).
- ControlHeight
Height of the control in screen pixels.
- ControlWidth
Width of the control in screen pixels.
- MaxViewportWidth
Maximum viewport width (minimum zoom level). Default 1.0 means the image fills the control. Set higher (e.g., 10.0) to allow zooming out so the image appears as a small thumbnail.
- Scale
Pixels per logical unit — the effective scale factor.
- ViewportHeight
The logical height visible, derived from ViewportWidth and control aspect ratio.
- ViewportOriginX
Top-left X in logical coordinates (0-1 normalized to image width).
- ViewportOriginY
Top-left Y in logical coordinates.
- ViewportWidth
Logical width of the visible area. 1.0 = full image width fits in control. Less than 1.0 = zoomed in. Greater than 1.0 = zoomed out. Minimum width is clamped to prevent extreme zoom levels.
- Zoom
Current zoom level (1.0 = fits width, higher = zoomed in).
Methods
- Constrain()
Constrains the viewport. When zoomed out past the image, the image is centered within the viewport.
- ElementToLogicalPoint(double, double)
Converts a screen-space point to logical coordinates.
- FitToView()
Sets the viewport to "fit" mode — the entire image is visible and centered. Does not alter MaxViewportWidth; callers may zoom out past fit.
- GetLogicalBounds()
Gets the logical bounds of the current viewport (Left, Top, Right, Bottom).
- GetState()
Creates a snapshot of the current viewport state.
- GetZoomRect(double)
Returns the logical rectangle that is currently visible in the control at the given viewport width. Height is derived from the control's pixel dimensions, not the image aspect ratio, so that the returned rect always matches the visible area regardless of control shape.
- LogicalToElementPoint(double, double)
Converts a logical point to screen-space coordinates.
- PanByScreenDelta(double, double)
Pans by a delta in screen pixels.
- SetState(SKImagePyramidViewportState)
Restores a previously captured viewport state.
- ZoomAboutLogicalPoint(double, double, double)
Zooms about a logical point. The point under the cursor stays fixed on screen. This is the core zoom algorithm from Silverlight's MultiScaleImage.ZoomAboutLogicalPoint.