Script function
world.WindowGetImageAlpha
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Type
Method
Summary
Draws the alpha channel of an image into a miniwindow
Prototype
long WindowGetImageAlpha(BSTR WindowName, BSTR ImageId, long Left, long Top, long Right, long Bottom, long SrcLeft, long SrcTop);
View list of data type meanings
Description
This copies the alpha channel of an image to the miniwindow, showing the alpha information as grayscale.
The alpha channel could be used when copying an image onto the miniwindow using the WindowMergeImageAlpha function.
Thus you could use WindowGetImageAlpha to create a scratch window (one not visible to the player) which holds the alpha information. This could then be turned into another image by using WindowImageFromWindow. This image is now available for use with WindowMergeImageAlpha to selectively copy the image to another miniwindow (this image would be used as the MaskId).
Note that changes to miniwindows will not become visible until the output window is redrawn. This happens when new (visible) lines arrive from the MUD, or if you call WindowShow, or Redraw. (In the case of WindowGetImageAlpha you would probably never want to actually show the image, as it is just the alpha, or mask, channel).
Parameters:
WindowName - the name of an existing miniwindow.
ImageId - an image id that you have loaded (which must have an alpha channel - generally this means it will be 32 bits per pixel, which is 8 bits for each of red, green and blue, and 8 bits for the alpha information).
Left, Top, Right, Bottom - describes the rectangle to be drawn to.
SrcLeft, SrcTop - the source offset in the original image (use 0,0 to get the whole image).
Available in MUSHclient version 4.52 onwards.
Lua example
WindowGetImageAlpha (win, "im", 20, 20, 0, 0)
Return value
eNoSuchWindow - no such miniwindow
eImageNotInstalled - that image was not loaded with WindowLoadImage (or WindowLoadImageMemory), or the image does not have an alpha channel.
eOK - completed OK
View list of return code meanings
See Also ...
Topic
MiniWindows
Functions
(GetDeviceCaps) Gets screen device capabilities
(SetCursor) Changes the shape of the mouse cursor
(TextRectangle) Specifies the size of the rectangle in which text is displayed in the output window.
(WindowAddHotspot) Adds a hotspot to a miniwindow
(WindowArc) Draws an arc in a miniwindow
(WindowBezier) Draws a Bézier curve in a miniwindow
(WindowBlendImage) Blends an image into a miniwindow, using a specified blending mode
(WindowCircleOp) Draws ellipses, filled rectangles, round rectangles, chords, pies in a miniwindow
(WindowCreate) Creates a miniwindow
(WindowCreateImage) Creates an image in a miniwindow
(WindowDelete) Deletes a miniwindow
(WindowDeleteAllHotspots) Deletes all hotspots from a miniwindow
(WindowDeleteHotspot) Deletes a hotspot from a miniwindow
(WindowDragHandler) Adds a drag handler to a miniwindow hotspot
(WindowDrawImage) Draws an image into a miniwindow
(WindowDrawImageAlpha) Draws an image into a miniwindow respecting the alpha channel
(WindowFilter) Performs a filtering operation over part of the miniwindow.
(WindowFont) Loads a font into a miniwindow
(WindowFontInfo) Returns information about a font
(WindowFontList) Lists all fonts loaded into a miniwindow
(WindowGetPixel) Gets the colour of a single pixel in a miniwindow
(WindowGradient) Draws a gradient in a rectangle
(WindowHotspotInfo) Returns information about a hotspot
(WindowHotspotList) Lists all hotspots installed into a miniwindow
(WindowHotspotTooltip) Changes the tooltip text for a hotspot in a miniwindow
(WindowImageFromWindow) Creates an image from another miniwindow
(WindowImageInfo) Returns information about an image
(WindowImageList) Lists all images installed into a miniwindow
(WindowImageOp) Draws an ellipse, rectangle or round rectangle, filled with an image
(WindowInfo) Returns information about a miniwindow
(WindowLine) Draws a line in a miniwindow
(WindowList) Lists all miniwindows
(WindowLoadImage) Loads an image into a miniwindow from a disk file
(WindowMenu) Creates a pop-up menu inside a miniwindow
(WindowMergeImageAlpha) Merges an image into a miniwindow based on an alpha mask
(WindowMoveHotspot) Moves a hotspot in a miniwindow
(WindowPolygon) Draws a polygon in a miniwindow
(WindowPosition) Moves a miniwindow
(WindowRectOp) Draws a rectangle in a miniwindow
(WindowResize) Resizes a miniwindow
(WindowScrollwheelHandler) Adds a scroll-wheel handler to a miniwindow hotspot
(WindowSetPixel) Sets a single pixel in a miniwindow to the specified colour
(WindowSetZOrder) Sets the Z-Order for a miniwindow
(WindowShow) Shows or hides a miniwindow
(WindowText) Draws text into a miniwindow
(WindowTextWidth) Calculates the width of text in a miniwindow
(WindowTransformImage) Draws an image into a miniwindow with optional rotation, scaling, reflection and shearing
(WindowWrite) Writes the contents of a miniwindow to disk as a graphics file
(Help topic: function=WindowGetImageAlpha)