# surface/DrawPoly

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{{Example | {{Example | ||

|Description=A helper function to draw a circle using surface.DrawPoly. | |Description=A helper function to draw a circle using surface.DrawPoly. | ||

− | |Code= | + | |Code=function draw.Circle( x, y, radius, seg ) |

− | + | ||

− | + | ||

− | function draw.Circle( x, y, radius, seg ) | + | |

local cir = {} | local cir = {} | ||

## Latest revision as of 05:33, 19 September 2019

## Contents |

# Description

Draws a textured polygon (secretly a triangle fan) with a maximum of 256 vertices. Only works properly with convex polygons. You may try to render concave polygons, but there is no guarantee that things wont get messed up.

Unlike most surface library functions, non-integer coordinates are not rounded.

WARNING |
You must reset the drawing color and texture before calling the function to ensure consistent results. See examples below. |

NOTE |
This is a rendering function that requires a 2D rendering context. |

# Arguments

table vertices

A table containing integer vertices. See the PolygonVertex structure.

**The vertices must be in clockwise order.**

# Examples

## Example

Draws a red triangle in the top left corner of the screen.

local triangle = { { x = 100, y = 200 }, { x = 150, y = 100 }, { x = 200, y = 200 } } hook.Add("HUDPaint", "PolygonTest", function() surface.SetDrawColor( 255, 0, 0, 255 ) draw.NoTexture() surface.DrawPoly( triangle ) end )

**Output:**

# Examples

## Example

A helper function to draw a circle using surface.DrawPoly.

function draw.Circle( x, y, radius, seg ) local cir = {} table.insert( cir, { x = x, y = y, u = 0.5, v = 0.5 } ) for i = 0, seg do local a = math.rad( ( i / seg ) * -360 ) table.insert( cir, { x = x + math.sin( a ) * radius, y = y + math.cos( a ) * radius, u = math.sin( a ) / 2 + 0.5, v = math.cos( a ) / 2 + 0.5 } ) end local a = math.rad( 0 ) -- This is needed for non absolute segment counts table.insert( cir, { x = x + math.sin( a ) * radius, y = y + math.cos( a ) * radius, u = math.sin( a ) / 2 + 0.5, v = math.cos( a ) / 2 + 0.5 } ) surface.DrawPoly( cir ) end hook.Add("HUDPaint", "PolygonCircleTest", function() surface.SetDrawColor( 0, 0, 0, 200) draw.NoTexture() draw.Circle( ScrW() / 2, ScrH() / 2, 200, math.sin( CurTime() ) * 20 + 25 ) --Usage: --draw.Circle( x, y, radius, segments ) end )