### Description

With this function you can draw either an outline of a triangle
or a filled triangle.

**NOTE**: If you are wanting to draw a shape
using a shader, you should be aware that most shaders expect the
following inputs: vertex, texture, colour. However, when using this
function, only vertex and colour data are being passed in, and so
the shader may not draw anything (or draw something but not
correctly). If you need to draw shapes in this way then the shader
should be customised with this in mind.

### Syntax:

draw_triangle(x1, y1, x2, y2, x3, y3, outline);

Argument |
Description |

x1 |
The x coordinate of the triangle's first corner. |

y1 |
The y coordinate of the triangle's first corner. |

x2 |
The x coordinate of the triangle's second corner. |

y2 |
The y coordinate of the triangle's second corner. |

x3 |
The x coordinate of the triangle's third corner. |

y3 |
The y coordinate of the triangle's third corner. |

outline |
Whether the triangle is drawn filled (false) or as a one pixel
wide outline (true). |

### Returns:

N/A

### Example:

draw_set_colour(c_aqua);

draw_triangle(50, 50, 200, 50, 50, 200, 0);

This will draw a filled aquamarine-coloured isosceles
right-angled triangle, with its first corner at (50,50), its second
at (200,50) and its third at (50,200).