Difference between revisions of "love.graphics.polygon"

(Draw rotated rectangle)
(Draw rotated triangle)
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=== Draw rotated triangle ===
 
=== Draw rotated triangle ===
 
+
[[File:boid.png|upright=0.5|thumb|right|top|Triangle drawn using love.graphics.polygon]]
 
<source lang="lua">
 
<source lang="lua">
 
function drawTriangle (x, y, length, width , angle) -- position, length, width and angle
 
function drawTriangle (x, y, length, width , angle) -- position, length, width and angle

Revision as of 15:17, 19 September 2021

Available since LÖVE 0.4.0
This function is not supported in earlier versions.

Draw a polygon.

Following the mode argument, this function can accept multiple numeric arguments or a single table of numeric arguments. In either case the arguments are interpreted as alternating x and y coordinates of the polygon's vertices.

O.png When in fill mode, the polygon must be convex and simple or rendering artifacts may occur. love.math.triangulate and love.math.isConvex can be used in 0.9.0+.  


Function

Synopsis

love.graphics.polygon( mode, ... )

Arguments

DrawMode mode
How to draw the polygon.
number ...
The vertices of the polygon.

Returns

Nothing.

Function

Synopsis

love.graphics.polygon( mode, vertices )

Arguments

DrawMode mode
How to draw the polygon.
table vertices
The vertices of the polygon as a table.

Returns

Nothing.

Examples

Two ways of drawing the same triangle

Triangle drawn using love.graphics.polygon

This example shows how to give the coordinates explicitly and how to pass a table argument.

-- Giving the coordinates directly.
love.graphics.polygon("fill", 100,100, 200,100, 150,200)

-- Defining a table with the coordinates.
-- This table could be built incrementally too.
local vertices = {100,100, 200,100, 150,200}

-- Passing the table to the function as a second argument.
love.graphics.polygon("fill", vertices)

Draw concave polygon

local vertices  = {100,100, 200,100, 200,200, 300,200, 300,300, 100,300} -- Concave "L" shape.
local triangles = love.math.triangulate(vertices)

for i, triangle in ipairs(triangles) do
	love.graphics.polygon("fill", triangle)
end

Draw rotated rectangle

This is one way to draw a rotated rectangle.

function drawRotatedRectangle(mode, x, y, width, height, angle)
	local cosa, sina = math.cos(angle), math.sin(angle)

	local dx1, dy1 = width*cosa,   width*sina
	local dx2, dy2 = -height*sina, height*cosa

	local px1, py1 = x,         y
	local px2, py2 = x+dx1,     y+dy1
	local px3, py3 = x+dx1+dx2, y+dy1+dy2
	local px4, py4 = x+dx2,     y+dy2
	
	love.graphics.polygon(mode, px1,py1, px2,py2, px3,py3, px4,py4)
end

Draw rotated triangle

Triangle drawn using love.graphics.polygon
function drawTriangle (x, y, length, width , angle) -- position, length, width and angle
	love.graphics.push()
	love.graphics.translate(x, y)
	love.graphics.rotate( angle )
	love.graphics.polygon('fill', -length/2, -width /2, -length/2, width /2, length/2, 0)
	love.graphics.pop() 
end

See Also


Other Languages