WindowDrawImageAlpha
Script function

world.WindowDrawImageAlpha

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Type

Method

Summary

Draws an image into a miniwindow respecting the alpha channel

Prototype

long WindowDrawImageAlpha(BSTR Name, BSTR ImageId, long Left, long Top, long Right, long Bottom, double Opacity, long SrcLeft, long SrcTop);

DOC_data_types View list of data type meanings

Description

This copies an image to the miniwindow, using the alpha channel to show transparent areas.

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.

Parameters:

Name - the name of an existing miniwindow.

ImageId - an image id that you have loaded.

Left, Top, Right, Bottom - describes the rectangle to be drawn to.

Opacity - the amount of opacity, between 0 and 1 (floating-point number). An opacity of 0 means you will not see the drawn image. An opacity of 1 means the image is fully drawn (apart from where the alpha channel makes part of it opaque). An opacity of 0.5 means the image is merged 50% with the original contents of the miniwindow.

SrcLeft, SrcTop - the source offset in the original image (use 0,0 to get the whole image).

The intention of allowing sub-images was so that you could make up a map by having lots of small images (eg. houses, trees, rocks). Now instead of having to load hundreds of tiny image files into memory, which would doubtless take a while to open all those files, you open a single, larger, file in which the various sub-images are "tiled". For example, you might allocate a 32 x 32 pixel square for each image. Now by selecting the appropriate tile you can copy the sub-image from the main image.

For more information, see:

http://www.gammon.com.au/forum/?id=9568

Lua example

WindowDrawImageAlpha (win, "im", 20, 20, 0, 0, 1)


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.

eBadParameter - opacity not in range 0 to 1.

eOK - completed OK


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See Also ...

Topic

DOC_miniwindows Mini Windows

Functions

FNC_GetDeviceCaps GetDeviceCaps (Gets screen device capabilities)
FNC_SetCursor SetCursor (Changes the shape of the mouse cursor)
FNC_TextRectangle TextRectangle (Specifies the size of the rectangle in which text is displayed in the output window.)
FNC_WindowAddHotspot WindowAddHotspot (Adds a hotspot to a miniwindow)
FNC_WindowArc WindowArc (Draws an arc in a miniwindow)
FNC_WindowBezier WindowBezier (Draws a Bézier curve in a miniwindow)
FNC_WindowBlendImage WindowBlendImage (Blends an image into a miniwindow, using a specified blending mode)
FNC_WindowCircleOp WindowCircleOp (Draws ellipses, filled rectangles, round rectangles, chords, pies in a miniwindow)
FNC_WindowCreate WindowCreate (Creates a miniwindow)
FNC_WindowCreateImage WindowCreateImage (Creates an image in a miniwindow)
FNC_WindowDelete WindowDelete (Deletes a miniwindow)
FNC_WindowDeleteAllHotspots WindowDeleteAllHotspots (Deletes all hotspots from a miniwindow)
FNC_WindowDeleteHotspot WindowDeleteHotspot (Deletes a hotspot from a miniwindow)
FNC_WindowDragHandler WindowDragHandler (Adds a drag handler to a miniwindow hotspot)
FNC_WindowDrawImage WindowDrawImage (Draws an image into a miniwindow)
FNC_WindowDrawImageAlpha WindowDrawImageAlpha (Draws an image into a miniwindow respecting the alpha channel)
FNC_WindowFilter WindowFilter (Performs a filtering operation over part of the miniwindow.)
FNC_WindowFont WindowFont (Loads a font into a miniwindow)
FNC_WindowFontInfo WindowFontInfo (Returns information about a font)
FNC_WindowFontList WindowFontList (Lists all fonts loaded into a miniwindow)
FNC_WindowGetPixel WindowGetPixel (Gets the colour of a single pixel in a miniwindow)
FNC_WindowGradient WindowGradient (Draws a gradient in a rectangle)
FNC_WindowHotspotInfo WindowHotspotInfo (Returns information about a hotspot)
FNC_WindowHotspotList WindowHotspotList (Lists all hotspots installed into a miniwindow)
FNC_WindowHotspotTooltip WindowHotspotTooltip (Changes the tooltip text for a hotspot in a miniwindow)
FNC_WindowImageFromWindow WindowImageFromWindow (Creates an image from another miniwindow)
FNC_WindowImageInfo WindowImageInfo (Returns information about an image)
FNC_WindowImageList WindowImageList (Lists all images installed into a miniwindow)
FNC_WindowImageOp WindowImageOp (Draws an ellipse, rectangle or round rectangle, filled with an image)
FNC_WindowInfo WindowInfo (Returns information about a miniwindow)
FNC_WindowLine WindowLine (Draws a line in a miniwindow)
FNC_WindowList WindowList (Lists all miniwindows)
FNC_WindowLoadImage WindowLoadImage (Loads an image into a miniwindow from a disk file)
FNC_WindowMenu WindowMenu (Creates a pop-up menu inside a miniwindow)
FNC_WindowMergeImageAlpha WindowMergeImageAlpha (Merges an image into a miniwindow based on an alpha mask)
FNC_WindowPolygon WindowPolygon (Draws a polygon in a miniwindow)
FNC_WindowPosition WindowPosition (Moves a miniwindow)
FNC_WindowRectOp WindowRectOp (Draws a rectangle in a miniwindow)
FNC_WindowSetPixel WindowSetPixel (Sets a single pixel in a miniwindow to the specified colour)
FNC_WindowShow WindowShow (Shows or hides a miniwindow)
FNC_WindowText WindowText (Draws text into a miniwindow)
FNC_WindowTextWidth WindowTextWidth (Calculates the width of text in a miniwindow)
FNC_WindowWrite WindowWrite (Writes the contents of a miniwindow to disk as a graphics file)

(Help topic: function=WindowDrawImageAlpha)

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