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  • Coordinates
  • Using the drawing functions
  • Drawing in an image with opacity
  • Pattern and PHP
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Stored procedures
Identifies the opacity of a pixel in an image that supports the Alpha layer. This image can be:
  • an Image control,
  • in an Image variable.
    PHP This type of variable is not available.
Versions 15 and later
Java This function is now available for Java applications.
New in version 15
Java This function is now available for Java applications.
Java This function is now available for Java applications.
Versions 16 and later
Android This function is now available for Android applications.
New in version 16
Android This function is now available for Android applications.
Android This function is now available for Android applications.
Versions 17 and later
iPhone/iPad This function is now available for iPhone/iPad applications.
New in version 17
iPhone/iPad This function is now available for iPhone/iPad applications.
iPhone/iPad This function is now available for iPhone/iPad applications.
Example
// Identify the opacity of the pixel (15, 25)
// on the "IMG_ImageDrawing" control
ResOpacity = dPixelOpacity(IMG_ImageDrawing, 15, 25)
Syntax
<Result> = dPixelOpacity([<Image>, ] <X coordinate> , <Y coordinate>)
<Result>: Integer
Opacity of specified pixel (included between 0 for transparent and 255 for opaque).
<Image>: Optional control name or optional Image, WDPic or picLayer variable
Image to use. This image can correspond to:
  • the name of an Image control.
  • the name of an Image variable.
    PHP This type of variable is not available.
If this parameter is not specified, the Image used is the one handled by the dStartDrawing function.
<X coordinate>: Integer
Horizontal position of pixel to use.
<Y coordinate>: Integer
Vertical position of pixel to use.
Remarks

Coordinates

Coordinates are given in pixels with respect to the top left corner of the image (coordinates: (0.0)).
To retrieve the position of a mouse click in an Image control, use MouseXPos and MouseYPos.

Using the drawing functions

The drawing functions can be used according to 2 methods:
  • Method 1: Using dStartDrawing
    • dStartDrawing must be called before any other drawing function. dStartDrawing is used to define the element (Image control or variable) to which the drawing functions will be applied.
    • When drawing on an Image control:
      • The drawing functions operate on a copy ("bitmap") of the image. You can use the drawing functions of Windows (via API or CallDLL32) but these functions must use the DC (Device Context) returned by dStartDrawing.
      • dEndDrawing and dStartDrawing must not be called in the same process.
        The drawing will not be displayed if dEndDrawing and dStartDrawing are called in the same process: it will be automatically erased.
  • Versions 24 and later
    AndroidiPhone/iPadJavaUser code (UMC) Method 2: indicating the drawing target directly in the syntax (via a parameter)
    The <Image> parameter is used to specify directly the target of the drawing. The dStartDrawing function becomes unnecessary. This function must be deleted.
    Versions 25 and later
    AndroidJava This syntax is now available.
    New in version 25
    AndroidJava This syntax is now available.
    AndroidJava This syntax is now available.
    New in version 24
    AndroidiPhone/iPadJavaUser code (UMC) Method 2: indicating the drawing target directly in the syntax (via a parameter)
    The <Image> parameter is used to specify directly the target of the drawing. The dStartDrawing function becomes unnecessary. This function must be deleted.
    Versions 25 and later
    AndroidJava This syntax is now available.
    New in version 25
    AndroidJava This syntax is now available.
    AndroidJava This syntax is now available.
    AndroidiPhone/iPadJavaUser code (UMC) Method 2: indicating the drawing target directly in the syntax (via a parameter)
    The <Image> parameter is used to specify directly the target of the drawing. The dStartDrawing function becomes unnecessary. This function must be deleted.
    Versions 25 and later
    AndroidJava This syntax is now available.
    New in version 25
    AndroidJava This syntax is now available.
    AndroidJava This syntax is now available.

Drawing in an image with opacity

To specify that the drawing in the image supports opacity (Alpha layer), use dStartDrawing and the dWithOpacity constant.
PHP

Pattern and PHP

In PHP, the drawing functions are based on the graphic library GD. This library is commonly used by the PHP hosting companies and therefore it is always enabled. The version of the GD library must be version 2.0.28 (or later). This library can be downloaded from the PHP site.
To enable (if necessary) this library locally, the following elements are required:
  • PHP installed.
  • the PHP.INI file found in the Windows directory must contain the following line: "extension=php_gd2.dll" (instead of ";extension=php_gd2.dll").
  • the php_gd2.dll file must exist in the directory of PHP extensions. This directory is defined in the PHP.INI file by the "extension_dir" variable.
Component: wd260obj.dll
Minimum version required
  • Version 12
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