Difference between revisions of "love.graphics.draw"

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(Improved explanation on coordinate systems and transformations)
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Draws a [[Drawable]] object (an [[Image]], [[Canvas]], [[SpriteBatch]] or [[ParticleSystem]]) on the screen with optional rotation, scaling and shearing.
 
Draws a [[Drawable]] object (an [[Image]], [[Canvas]], [[SpriteBatch]] or [[ParticleSystem]]) on the screen with optional rotation, scaling and shearing.
  
The object is drawn with its top-left corner at the given position on the screen, minus the offset.
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All objects have a local and global coordinate system. The object is positioned relative to the local coordinate system (LCS), and the LCS is positioned relative to the origin of the global coordinate system (GCS). The origin of the LCS is by default located at the top left corner of the object. All scaling, shearing, and rotation arguments transform the object relative to that point.
  
Rotation is given in radians, which can be converted to from degrees using Lua's <tt>math.rad</tt> function.
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One can offset the origin of the LCS to achieve a desired effect. For example, offsetting the origin to the object's center allows one to rotate an object about its center. Angles must given in radians for rotation. With the origin at the center of the object, one can also use a negative scaling factor to flip about its centerline.
 
 
The width and height of the object are multiplied by the scaling factors. A negative scaling factor will result in the drawing being flipped.
 
 
 
The origin is a point relative to the object, where the object is positioned, scaled, and rotated from. For example, with an origin point at half the object's width and height it can be rotated around its center.
 
  
 
The right and bottom edges of the object are shifted at an angle defined by the shearing factors.
 
The right and bottom edges of the object are shifted at an angle defined by the shearing factors.

Revision as of 03:25, 29 March 2013

Draws a Drawable object (an Image, Canvas, SpriteBatch or ParticleSystem) on the screen with optional rotation, scaling and shearing.

All objects have a local and global coordinate system. The object is positioned relative to the local coordinate system (LCS), and the LCS is positioned relative to the origin of the global coordinate system (GCS). The origin of the LCS is by default located at the top left corner of the object. All scaling, shearing, and rotation arguments transform the object relative to that point.

One can offset the origin of the LCS to achieve a desired effect. For example, offsetting the origin to the object's center allows one to rotate an object about its center. Angles must given in radians for rotation. With the origin at the center of the object, one can also use a negative scaling factor to flip about its centerline.

The right and bottom edges of the object are shifted at an angle defined by the shearing factors.

Function

Synopsis

love.graphics.draw( drawable, x, y, r, sx, sy, ox, oy, kx, ky )

Arguments

Drawable drawable
A drawable object.
number x (0)
The position to draw the object (x-axis).
number y (0)
The position to draw the object (y-axis).
number r (0)
Orientation (radians).
number sx (1)
Scale factor (x-axis).
number sy (sx)
Scale factor (y-axis).
number ox (0)
Origin offset (x-axis).
number oy (0)
Origin offset (y-axis).
Available since LÖVE 0.8.0
number kx (0)
Shearing factor (x-axis).
number ky (0)
Shearing factor (y-axis).

Returns

Nothing.

Examples

Draw an image (the Hamster Ball) at 100 by 100 pixels

function love.load()
   hamster = love.graphics.newImage("hamster.png")
end
function love.draw()
   love.graphics.draw(hamster, 100, 100)
end

Draw an image (the Hamster Ball) from the center at 100 by 100 pixels, rotated by 90 degrees

function love.load()
   hamster = love.graphics.newImage("hamster.png")
   width = hamster:getWidth()
   height = hamster:getHeight()
end
function love.draw()
   love.graphics.draw(hamster, 100, 100, math.rad(90), 1, 1, width / 2, height / 2)
end

See Also


Other Languages