dArc (Function)

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Coordinates of the arc

Drawing a solid figure

Using the drawing functions

Pattern and PHP

Drawing in Browser code

Related examples

See also

dArc (Function)

In french: dArc

Draws an arc of circle or an arc of ellipse:

in an Image control,
in an Image variable.
This type of variable is not available.
Versions 25 and later
in a WDPic variable (on the background layer),
New in version 25
in a WDPic variable (on the background layer),
in a WDPic variable (on the background layer),
Versions 25 and later
in a picLayer variable.
New in version 25
in a picLayer variable.
in a picLayer variable.

The arc is drawn anticlockwise.

Versions 15 and later

This function is now available for WEBDEV sites in Linux.

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

New in version 15

This function is now available for WEBDEV sites in Linux.

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

This function is now available for WEBDEV sites in Linux.

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

Versions 16 and later

This function is now available for Android applications.

This function is now available in Browser code.

New in version 16

This function is now available for Android applications.

This function is now available in Browser code.

This function is now available for Android applications.

This function is now available in Browser code.

Versions 17 and later

This function is now available for iPhone/iPad applications.

New in version 17

This function is now available for iPhone/iPad applications.

Versions 18 and later

This function is now available in Windows Store apps mode.

New in version 18

This function is now available in Windows Store apps mode.

Versions 21 and later

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Universal Windows 10 App mode.

Versions 24 and later

The syntax that manages the Color type is now available for Android applications.

The syntax that manages the Color type is now available for Java applications.

New in version 24

The syntax that manages the Color type is now available for Android applications.

The syntax that manages the Color type is now available for Java applications.

The syntax that manages the Color type is now available for Android applications.

The syntax that manages the Color type is now available for Java applications.

Example

See additional examples

// Initialize the drawing in the Image control IMG_MyDrawing
dStartDrawing(IMG_MyDrawing)

// Draw an arc of circle in light yellow
dArc(10, 10, 50, 50, 20, 20, 40, 50, LightYellow)

// Draw a light yellow arc of circle in IMG_MyDrawing
dArc(IMG_MyDrawing,10, 10, 50, 50, 20, 20, 40, 50, LightYellow)

Syntax

Drawing an arc Hide the details

dArc([<Image>, ] <X1> , <Y1> , <X2> , <Y2> , <X3> , <Y3> , <X4> , <Y4> [, <Line color> [, <Line thickness>]])

<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.
on behalf of an Variable of type Image.
Versions 25 and later
on behalf of an Variable of type WDPic. Only the background layer will be handled.
New in version 25
on behalf of an Variable of type WDPic. Only the background layer will be handled.
on behalf of an Variable of type WDPic. Only the background layer will be handled.
Versions 25 and later
on behalf of an Variable of type picLayer.
New in version 25
on behalf of an Variable of type picLayer.
on behalf of an Variable of type picLayer.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.

<X1>: entier

X coordinate (in pixels) of top left corner of the rectangle containing the circle.

<Y1>: entier

Y coordinate (in pixels) of top left corner of the rectangle containing the circle.

<X2>: entier

X coordinate (in pixels) of bottom right corner of the rectangle containing the circle.

<Y2>: entier

Y coordinate (in pixels) of bottom right corner of the rectangle containing the circle.

<X3>: entier

X coordinate (in pixels) of start point of the arc of circle.

<Y3>: entier

Y coordinate (in pixels) of start point of the arc of circle.

<X4>: entier

X coordinate (in pixels) of end point of the arc of circle.

<Y4>: entier

Y coordinate (in pixels) of end point of the arc of circle.

<Line color>: Integer or constant (optional)

Color of the arc of circle. This color can correspond to:
an RGB color (returned by RGB),
an HSL color (returned by HSL),
a preset color of WLanguage,
an Variable of the Color type.
If this parameter is not specified, the line color:
is Transparent if dPen has not been used beforehand,
corresponds to the Color specified in the last call to the dPen function..

<Line thickness>: Optional integer

Thickness (in pixels) of the arc of circle to draw. If this parameter is not specified, the value taken into account can be:
the last value specified in the last call to dPen.
1 if dPen was not used beforehand.
Versions 25 and later
This parameter is now available.
New in version 25
This parameter is now available.
This parameter is now available.

Remarks

Coordinates of the arc

If the start and end points are not located on the border of the circle (or on the border of the ellipse), the point taken into account corresponds to the intersection between the circle and the line that joins the specified point and the center of the rectangle (which means the center of the circle).

The origin considered to calculate the coordinates corresponds to the top left corner of the Image (coordinates (0,0)).

Drawing a solid figure

To draw a solid figure (a full arc), use dChord or dSlice.

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
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
This syntax is now available.
New in version 25
This syntax is now available.
This syntax is now available.
New in version 24
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
This syntax is now available.
New in version 25
This syntax is now available.
This syntax is now available.
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
This syntax is now available.
New in version 25
This syntax is now available.
This syntax is now available.

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.

Limitation for dArc: The opacity defined by dBackground is ignored.

Versions 16 and later

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" pane, "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.

New in version 16

Drawing in Browser code

Special case: Drawing in the browser of an Android phone: The browser drawing functions are only available starting with version 3 of Android.

Drawing in Browser code

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: wd260pnt.dll