dBackground (Function)

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dBackground (Function)

In french: dFond

Declares the default background color for the rectangles, circles, etc.::

in an Image control,
in a variable of type Image.
This type of variable is not available.
in a variable of type WDPic (on the background layer),
in a variable of type picLayer.

Caution: A specific configuration is required to use this function in Linux. For more details, see The drawings.

Example

See additional examples

// Initialize the drawing in an Image control
dStartDrawing(IMG_Drawing)

// Declare the background color of the different drawings in an Image control
dBackground(LightGreen)

// Declare the background color of the different drawings in the IMG_Drawing control
dBackground(IMG_Drawing, LightGreen)

Syntax

dBackground([<Image>, ] <Color> [, <Fill style> [, <Type of hatching> [, <Opacity>]]])

<Image>: Optional control name or optional Image, WDPic or picLayer variable

Image to use. The image can correspond to:
the name of an Image control.
the name of a variable of type Image.
the name of a variable of type WDPic. Only the background layer will be handled.
the name of a variable of type picLayer.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.

<Color>: Integer or constant

Default background color of different drawings. This color can correspond to:
an RGB color (returned by RGB),
an HSL color (returned by HSL),
a WLanguage preset color.
a variable of type Color. In this case, the opacity specified in the variable is taken into account.
Not available.

<Fill style>: Optional integer or Integer constant

Default background fill of different drawings:
BackgroundHatched Background filled with hatching.
Corresponds to value 2 for compatibility.
BackgroundSolid
(Default value) Solid background.
Corresponds to value 0 for compatibility.
BackgroundTransparent Transparent background (<Color> is ignored).
Corresponds to value 1 for compatibility.

This value is ignored. In this version, you cannot hatch the background of a drawing.
The drawing of hatching is not supported.

<Type of hatching>: Optional integer

Type of background hatching used by default in the different drawings. To use this parameter, the value of <Fill style> must be equal to 2. If the value of <Fill style> is different from 2, <Type of hatching> is ignored. The different types of hatching are:
0: Horizontal hatching
1: Vertical hatching
2: Diagonal hatching at 60%
3: Diagonal hatching at 120%
4 (by default): Criss-crossed hatching
5: Diagonal crossed hatching
This value is ignored. In this version, you cannot hatch the background of a drawing.

<Opacity>: Optional integer

Opacity of color, included between 0 (transparent) and 255 (opaque). An opacity set to 128 is used to blend 50% of the color with the existing color found in the control.
Remarks:
This opacity will be taken into account if the drawing was initialized with the dWithOpacity constant (dStartDrawing).
If the <Color> parameter corresponds to a variable of type Color, this parameter must not be specified: the opacity specified in the variable will be taken into account.

Remarks

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.
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. dStartDrawing becomes useless. This function must be deleted.

Drawing in PHP

In PHP, the drawing functions are based on the graphic library GD. This library is commonly used by the PHP hosting providers 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 project description window.
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.

Related Examples:

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

Business / UI classification: Neutral code

Component: wd300pnt.dll