dPolygon (Function)

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dPolygon (Function)

In french: dPolygone

Draws a polygon:

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.

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. See The drawings for more details.

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. See The drawings for more details.

This function is now available for WEBDEV sites in Linux.

Caution: A specific configuration is required to use this function in Linux. See The drawings for more details.

Versions 16 and later

This function is now available in Browser code.

New in version 16

This function is now available in Browser code.

Example

See additional examples

// Initialize the drawing in an Image control
dStartDrawing(IMG_Drawing)
// Draw a 4-side polygon whose
// background is light yellow and whose border is light blue
dPolygon(4, 10, 20, 20, 50, 40, 60, 50, 10, LightYellow, LightBlue)

Versions 24 and later

// Draw a 4-side polygon whose
// background is light yellow and whose border is light blue
dPolygon(IMG_Drawing, 4, 10, 20, 20, 50, 40, 60, 50, 10, LightYellow, LightBlue)

New in version 24

// Draw a 4-side polygon whose
// background is light yellow and whose border is light blue
dPolygon(IMG_Drawing, 4, 10, 20, 20, 50, 40, 60, 50, 10, LightYellow, LightBlue)

// Draw a polygon from an array of point coordinates
arrCoordinatesXY is array of 0 by 2 int = [[2, 3], [14, 100], [10,70], [50, 80]]
dPolygon(arrCoordinatesXY)
arrCoordinatesXY2 is array of 0 int = [2, 2, 140, 2, 150, 70, 0, 100, 200,100]
dPolygon(arrCoordinatesXY2)
arrCoordinatesXYC is array of 36 by 2 int
Radius is int = 50
FOR I = 1 TO 36
// x
arrCoordinatesXYC[I][1] = 80 + Cos(I*10) * Radius
// y
arrCoordinatesXYC[I][2] = 60 + Sin(I*10) * Radius
END
dPolygon(arrCoordinatesXYC, LightGray, YellowToolhelp)

Syntax

Building a polygon point by point Hide the details

dPolygon([<Image>, ] <Number of sides> , <X1> , <Y1> , <X2> , <Y2> [, <X3> , <Y3> [... [, <Xn> , <Yn>]]] [, <Background color> [, <Side color>]])

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

Versions 24 and later
Image to use. This image can correspond to:
the name of an Image control.
the name of an Image variable.
Versions 25 and later
the name of a WDPic variable. Only the background layer will be handled.
New in version 25
the name of a WDPic variable. Only the background layer will be handled.
the name of a WDPic variable. Only the background layer will be handled.
Versions 25 and later
the name of an picLayer variable.
New in version 25
the name of an picLayer variable.
the name of an picLayer variable.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.
New in version 24
Image to use. This image can correspond to:
the name of an Image control.
the name of an Image variable.
Versions 25 and later
the name of a WDPic variable. Only the background layer will be handled.
New in version 25
the name of a WDPic variable. Only the background layer will be handled.
the name of a WDPic variable. Only the background layer will be handled.
Versions 25 and later
the name of an picLayer variable.
New in version 25
the name of an picLayer variable.
the name of an picLayer variable.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.
Image to use. This image can correspond to:
the name of an Image control.
the name of an Image variable.
Versions 25 and later
the name of a WDPic variable. Only the background layer will be handled.
New in version 25
the name of a WDPic variable. Only the background layer will be handled.
the name of a WDPic variable. Only the background layer will be handled.
Versions 25 and later
the name of an picLayer variable.
New in version 25
the name of an picLayer variable.
the name of an picLayer variable.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.

<Number of sides>: Integer

Number of sides in the polygon (up to 23 sides). This parameter defines the number of <X>, <Y> pairs to specify in the function.

<X1>: Integer

X coordinate of first point of the polygon. These coordinates are expressed in pixels.

<Y1>: Integer

Y coordinate of first point of the polygon. These coordinates are expressed in pixels.

<X2>: Integer

X coordinate of second point of the polygon. These coordinates are expressed in pixels.

<Y2>: Integer

Y coordinate of second point of the polygon. These coordinates are expressed in pixels.

<X3>: Integer

X coordinate of 3rd point of the polygon. These coordinates are expressed in pixels.

<Y3>: Integer

Y coordinate of 3rd point of the polygon. These coordinates are expressed in pixels.

<Xn>: Optional integer

X coordinate of nth point of the polygon. These coordinates are expressed in pixels.

<Yn>: Optional integer

Y coordinate of nth point of the polygon. These coordinates are expressed in pixels.

<Background color>: Integer or constant (optional)

Background color of polygon. This color can correspond to:
an RGB color (returned by RGB),
an HSL color (returned by HSL),
a preset color of WLanguage.
If this parameter is not specified, the background color:
is Transparent if dBackground was not used beforehand,
corresponds to the color specified in the last call to dBackground.

<Side color>: Integer or constant (optional)

Color of polygon sides. This color can correspond to:
an RGB color (returned by RGB),
an HSL color (returned by HSL),
a preset color of WLanguage.
If this parameter is not specified, the line color:
corresponds to the color specified in the last call to dPen,
is identical to the color used for the background if dPen has not been used.

Building a polygon via an array of X and Y coordinates Hide the details

dPolygon([<Image>, ] <Array of coordinates> [, <Background color> [, <Side color>]])

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

Versions 24 and later
Image to use. This image can correspond to:
the name of an Image control.
the name of an Image variable.
Versions 25 and later
the name of a WDPic variable. Only the background layer will be handled.
New in version 25
the name of a WDPic variable. Only the background layer will be handled.
the name of a WDPic variable. Only the background layer will be handled.
Versions 25 and later
the name of a picLayer variable.
New in version 25
the name of a picLayer variable.
the name of a picLayer variable.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.
New in version 24
Image to use. This image can correspond to:
the name of an Image control.
the name of an Image variable.
Versions 25 and later
the name of a WDPic variable. Only the background layer will be handled.
New in version 25
the name of a WDPic variable. Only the background layer will be handled.
the name of a WDPic variable. Only the background layer will be handled.
Versions 25 and later
the name of a picLayer variable.
New in version 25
the name of a picLayer variable.
the name of a picLayer variable.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.
Image to use. This image can correspond to:
the name of an Image control.
the name of an Image variable.
Versions 25 and later
the name of a WDPic variable. Only the background layer will be handled.
New in version 25
the name of a WDPic variable. Only the background layer will be handled.
the name of a WDPic variable. Only the background layer will be handled.
Versions 25 and later
the name of a picLayer variable.
New in version 25
the name of a picLayer variable.
the name of a picLayer variable.
If this parameter is not specified, it is necessary to define the drawing destination with dStartDrawing.

<Array of coordinates>: Array of integers or array of points

WLanguage array of integers containing the coordinates of polygon points. The even subscript represent the X coordinates while the odd subscripts represent the Y coordinates of points. These coordinates are expressed in pixels.
WLanguage array of Point variables containing the coordinates of polygon points. These coordinates are expressed in pixels.

<Background color>: Integer or constant (optional)

Background color of polygon. This color can correspond to:
an RGB color (returned by RGB),
an HSL color (returned by HSL),
a preset color of WLanguage,
a Color variable.
If this parameter is not specified, the background color:
is Transparent if dBackground was not used beforehand,
corresponds to the color specified in the last call to dBackground.

<Side color>: Integer or constant (optional)

Color of polygon sides. This color can correspond to:
an RGB color (returned by RGB),
an HSL color (returned by HSL),
a preset color of WLanguage,
a Color variable.
If this parameter is not specified, the line color:
corresponds to the color specified during the last call to dPen,
is identical to the color used for the background if dPen has not been used.

Remarks

Coordinates

Drawing a polygon:

dPolygon(5, 80, 10, 10, 150, 100, 200, 160, 80, 140, 40)

Coordinates are given with respect to the top left corner of the image (coordinates: (0.0)).

Important: There is no need to close the polygon (the coordinates of last point do not have to be equal to the coordinates of first point). The polygon is automatically "closed".

Limits: a polygon can contain up to 100 000 points in WINDEV, WEBDEV and Java, and up to 1000 points in Windows CE.

Drawing with opacity or anti-aliasing

In the case of a drawing with opacity (dStartDrawing with the dWithOpacity constant) or anti-aliasing (dChangeMode with the drawAntiAliasing constant), the outline is drawn over the inside of the polygon: therefore, the line is partly combined with the inside of the polygon. If the line is very thick, it will be displayed in two colors.

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. dStartDrawing becomes useless. This function must be deleted.

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. dStartDrawing becomes useless. This function must be deleted.

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 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.

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 display the description window of project, on the "Project" pane, in the "Project" group, 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 : wd250pnt.dll