Deletes all the drawings made since the last call to dStartDrawing
In the case of an Image control, the current drawing is deleted.
In the case of a variable, the memory used is released.Remark
: The call to dEndDrawing
is optional. The resources are automatically released when the window or page is closed.
: A specific configuration is required to use this function in Linux. For more details, see The drawings
// Destroy the drawing found in the "IMG_Drawing" control
- dStartDrawing must be called before using the drawing functions. dStartDrawing is used to define the element (Image control or Image variable) onto which the drawing functions will be applied.
- For 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 Windows 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.
Drawing functions, zoom and automatic scrollbars
The "Automatic scrollbars and zoom" option, available for Image controls, is not compatible with dStartDrawing
. If this option is used on the Image control, dStartDrawing
freezes the image in the control. The zoom and the scrollbars are also frozen. The standard behavior is restored when dEndDrawing
Drawing in 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.
Drawing in Browser code
Some drawing functions are available in Browser code. The drawing functions in Browser code are based on the HTML 5 standard. More specifically, these functions are based on the "canvas" tag of HTML 5.
The drawing features in browser code are available for the recent browsers only (supporting the HTML 5 standard). To find out whether the drawing features are proposed by your browser, use DrawingAvailable
Caution: To use the drawing functions with Internet Explorer 9, the project must include the reference to the DTD file. To do so, the HTML mode must be "HTML 4.01 Transitional + DTD". This option is available in the "Advanced" tab of the description window of project.
Reminder: To open the project description window, go to the "Project" tab, "Project" group and click "Description".
Special case: Drawing in the browser of an Android phone: The browser drawing functions are only available starting with version 3 of Android.
Complete examples (WINDEV): WD Magnifier