draw_primitive_begin

This function must be called before you can define any primitives. There are 6 types of primitives you can define with the following constants:

• pr_pointlist
• pr_linelist
• pr_linestrip
• pr_trianglelist
• pr_trianglestrip
• pr_trianglefan

The following image illustrates basically how these should look and also the order in which you should define the vertexes:

Please note that on some platforms (Windows, UWP, XBox) the pr_trianglefan type is not natively supported and so GameMaker Studio 2 does a conversion when the game is compiled to make them work. This means that on those platforms the pr_trianglefan type will be much slower to use than the others. This Also note that to use this function on HTML5, you must enable WebGL in the Game Options.

Syntax:

draw_primitive_begin(kind)

Returns:

N/A

Example:

var _steps = 20;
var _xx = 50;
var _yy = 50;
var _radius = 30;
draw_primitive_begin(pr_trianglefan);
draw_vertex(_xx, _yy);
for(var i = 0; i <= _steps; ++i;)
    {
    draw_vertex(_xx + lengthdir_x(_radius, 270 * i / _steps), _yy + lengthdir_y(_radius, 270 * i / _steps));
    }
draw_primitive_end();

The above code will draw three quarters of a circle made from primitives.