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  • Use in prefix syntax
  • Drawing with opacity
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Stored procedures
Indicates that the drawing functions that will be used are intended for a variable of type picLayer.
Remark: <picLayer variable>.StartDrawing initializes all the parameters required to create a drawing for a given element.
Example
MyImage is WDPic = "Test.gif"
MyLayer is picLayer
// Start drawing in the layer
ResDrawing = MyLayer.StartDrawing()
// Drawings in MyLayer
...
// End of drawings in MyLayer
IMG_MyDrawing = MyImage
MyWDPic is WDPic = "Test.gif"
MyLayer is picLayer
 
MyLayer.StartDrawing()
MyLayer.Font("Arial", 12, iNormal, 0)
MyLayer.DrawText(4, 0, "I'm writing in a picLayer variable!")
IMG_MyDrawing = MyWDPic
<Result> = <picLayer image>.StartDrawing([<Options>])
<Result>: Boolean
  • True if the drawing was initialized,
  • False otherwise.
<picLayer image>: picLayer variable
Name of the picLayer variable to be used.
<Options>: Optional Integer constant (or combination of constants)
Drawing options:
dGridlinesOpacityThe drawing is displayed over gridlines in order to highlight the transparent or semi-transparent sections of the drawing. The gridlines are not saved in the image.
dNoEraseDoes not erase the drawing in the variable.
dOnChartUsed to draw in a variable in which a chart has already been drawn. In this case, the chart drawing is not erased.
dWithOpacityAllows managing opacity in the different drawing functions used with the variable. Used for example to create a PNG drawing with an Alpha channel.

No drawing option is used if this parameter is not specified.
Remarks

Use in prefix syntax

<picLayer variable>.StartDrawing must be called before the other drawing functions. <picLayer variable>.StartDrawing makes it possible to define the drawing options used on the picLayer variable.
Reports and Queries

Drawing with opacity

By creating a drawing that supports opacity, you can easily save PNG images with an Alpha channel.
To save a PNG drawing with an Alpha channel:
  1. Use the <picLayer variable>.StartDrawing function. This function is used to define, if necessary, the element onto which the drawing functions will be applied as well as the drawing mode. The dWithOpacity constant is used to indicate that the drawing will manage the opacity. The dGridlinesOpacity constant is used to display gridlines underneath the different drawing areas.
  2. Configure the opacity of your drawings with the following functions:
    <picLayer variable>.BackgroundDeclares the background color and its opacity for the next drawings.
    <picLayer variable>.DrawPointDeclares the color of the points and their opacity for the next drawings.
    <Image>.PenDeclares the color of the lines and their opacity for the next drawings.

    Remark: <picLayer variable>.PixelOpacity is used to find out the opacity of a point.
  3. Use <Image>.SavePNG to save your drawing in PNG format with alpha channel (opacity).
Limit: In "Management of opacity" mode, <picLayer variable>.DrawText is limited to the use of True Type fonts.
Related Examples:
The drawing functions Unit examples (WINDEV): The drawing functions
[ + ] Using the main drawing functions of WINDEV to:
- Initialize an Image control for drawing
- Draw simple shapes
- Write a text into a drawing
- Change the color in a drawing
Component: wd270pnt.dll
Minimum version required
  • Version 25
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