Difference between revisions of "love.graphics.polygon"

(→‎Rectangle with angle)
(→‎Examples: Cleaned up examples.)
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Nothing.
 
Nothing.
 
== Examples ==
 
== Examples ==
 +
 +
 
=== Two ways of drawing the same triangle ===
 
=== Two ways of drawing the same triangle ===
 
[[File:Polygon_triangle.png|upright=0.5|thumb|right|top|Triangle drawn using love.graphics.polygon]]
 
[[File:Polygon_triangle.png|upright=0.5|thumb|right|top|Triangle drawn using love.graphics.polygon]]
 
This example shows how to give the coordinates explicitly and how to pass a table argument.
 
This example shows how to give the coordinates explicitly and how to pass a table argument.
 +
 
<source lang="lua">
 
<source lang="lua">
−
-- giving the coordinates directly
+
-- Giving the coordinates directly.
−
love.graphics.polygon('fill', 100, 100, 200, 100, 150, 200)
+
love.graphics.polygon("fill", 100,100, 200,100, 150,200)
  
−
-- defining a table with the coordinates
+
-- Defining a table with the coordinates.
−
-- this table could be built incrementally too
+
-- This table could be built incrementally too.
−
local vertices = {100, 100, 200, 100, 150, 200}
+
local vertices = {100,100, 200,100, 150,200}
  
−
-- passing the table to the function as a second argument
+
-- Passing the table to the function as a second argument.
−
love.graphics.polygon('fill', vertices)
+
love.graphics.polygon("fill", vertices)
 
</source>
 
</source>
  
  
−
=== Concave polygon ===
+
=== Draw concave polygon ===
−
 
 
 
<source lang="lua">
 
<source lang="lua">
−
local vertices = {100,100,200,100,200,200,300,200,300,300,100,300} -- concave
+
local vertices = {100,100, 200,100, 200,200, 300,200, 300,300, 100,300} -- Concave "L" shape.
 
local triangles = love.math.triangulate(vertices)
 
local triangles = love.math.triangulate(vertices)
−
for i, triangle in pairs (triangles) do
+
 
−
love.graphics.polygon( 'fill', triangle)
+
for i, triangle in ipairs(triangles) do
 +
love.graphics.polygon("fill", triangle)
 
end
 
end
−
love.graphics.setColor(1, 1, 0, 1)
 
−
love.graphics.polygon('line', vertices)
 
 
</source>
 
</source>
  
  
−
=== Rectangle with angle ===
+
=== Draw rotated rectangle ===
−
There is no easy way to draw [[love.graphics.rectangle|the tilted rectangle]], but it can be done with polygon:
+
This is one way to draw a rotated [[love.graphics.rectangle|rectangle]].
  
 
<source lang="lua">
 
<source lang="lua">
−
function draw_tilted_rectangle ( mode, x, y, width, height, angle )
+
function drawRotatedRectangle(mode, x, y, width, height, angle)
−
angle = angle or 0 -- angle in radians
 
 
local cosa, sina = math.cos(angle), math.sin(angle)
 
local cosa, sina = math.cos(angle), math.sin(angle)
−
local dx1, dy1 = width*cosa, width*sina
+
 
 +
local dx1, dy1 = width*cosa,   width*sina
 
local dx2, dy2 = -height*sina, height*cosa
 
local dx2, dy2 = -height*sina, height*cosa
−
local px1, py1 = x, y
+
 
−
local px2, py2 = x + dx1, y + dy1
+
local px1, py1 = x,         y
−
local px3, py3 = x + dx1 + dx2, y + dy1 + dy2
+
local px2, py2 = x+dx1,     y+dy1
−
local px4, py4 = x + dx2, y + dy2
+
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)
+
love.graphics.polygon(mode, px1,py1, px2,py2, px3,py3, px4,py4)
 
end
 
end
 
</source>
 
</source>

Revision as of 02:38, 16 July 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

See Also


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