- Coordinates of the arc
- Drawing a solid figure
- Using the drawing functions
- Drawing in PHP
- Drawing in Browser code
In french: dArc
// Initialize the drawing in the Image control IMG_MyDrawing
// Draw an arc of circle in light yellow
dArc(10, 10, 50, 50, 20, 20, 40, 50, LightYellow)
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
X-coordinate (in pixels) of the upper-left corner of the rectangle containing the circle.
Y-coordinate (in pixels) of the upper-left corner of the rectangle containing the circle.
X-coordinate (in pixels) of the lower-right corner of the rectangle containing the circle.
Y-coordinate (in pixels) of the lower-right corner of the rectangle containing the circle.
X-coordinate (in pixels) of the starting point of the arc.
Y-coordinate (in pixels) of the starting point of the arc.
X-coordinate (in pixels) of the end point of the arc.
Y-coordinate (in pixels) of the end point of the arc.
<Line color>: Integer or constant (optional)
Color of the arc of circle. This color can correspond to: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 dPen.
<Line thickness>: Optional integer
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 used to calculate the coordinates corresponds to the upper-left corner of the image (coordinates: (0,0)).
Limitation for dArc
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.
: The opacity defined by dBackground
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.
Unit examples (WINDEV): The drawing functions
Business / UI classification: Neutral code
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