Canvas

Available since LÖVE 0.8.0
It has been renamed from Framebuffer.

A Canvas is used for off-screen rendering. Think of it as an invisible screen that you can draw to, but that will not be visible until you draw it to the actual visible screen. It is also known as "render to texture".

By drawing things that do not change position often (such as background items) to the Canvas, and then drawing the entire Canvas instead of each item, you can reduce the number of draw operations performed each frame.

In versions prior to 0.10.0, not all graphics cards that LÖVE supported could use Canvases. love.graphics.isSupported("canvas") could be used to check for support at runtime.

When drawing content to a Canvas using regular alpha blending, the alpha values of the content get multiplied with its RGB values.

Therefore the Canvas' pixel colors will have premultiplied alpha once it has been drawn to, so when drawing the Canvas to the screen or to another Canvas you must use premultiplied alpha blending – love.graphics.setBlendMode("alpha", "premultiplied").

Constructors

love.graphics.newCanvas

Creates a new Canvas.

0.8.0

Functions

Canvas:clear	Clears the contents of a Canvas to a specific color.	0.8.0	0.10.0
Canvas:getDimensions	Gets the width and height of the Canvas.	0.9.0
Canvas:getFSAA	Gets the number of FSAA samples used when drawing to the Canvas.	0.9.1	0.10.0
Canvas:getFilter	Gets the filter mode of the Canvas.	0.8.0
Canvas:getFormat	Gets the texture format of the Canvas.	0.9.1
Canvas:getHeight	Gets the height of the Canvas.
Canvas:getImageData	Generates ImageData from the contents of the Canvas.	0.8.0	0.10.0
Canvas:getMSAA	Gets the number of MSAA samples used when drawing to the Canvas.	0.9.2
Canvas:getPixel	Gets the pixel at the specified position in a Canvas.	0.9.0	0.10.0
Canvas:getWidth	Gets the width of the Canvas.
Canvas:getWrap	Gets the wrapping properties of a Canvas.	0.8.0
Canvas:newImageData	Generates ImageData from the contents of the Canvas.	0.10.0
Canvas:renderTo	Render to a Canvas using a function.	0.8.0
Canvas:setFilter	Sets the filter mode of the Canvas.	0.8.0
Canvas:setWrap	Sets the wrapping properties of a Canvas.	0.8.0
Object:type	Gets the type of the object as a string.
Object:typeOf	Checks whether an object is of a certain type.

Supertypes

• Texture
• Drawable
• Object

Examples

Drawing something to the Canvas and then draw the Canvas to the screen.

function love.load()
    canvas = love.graphics.newCanvas(800, 600)
 
    -- Rectangle is drawn to the canvas with the regular alpha blend mode.
    love.graphics.setCanvas(canvas)
        love.graphics.clear()
        love.graphics.setBlendMode("alpha")
        love.graphics.setColor(255, 0, 0, 128)
        love.graphics.rectangle('fill', 0, 0, 100, 100)
    love.graphics.setCanvas()
end
 
function love.draw()
    love.graphics.setColor(255, 255, 255, 255)
 
    -- The rectangle from the Canvas was already alpha blended.
    -- Use the premultiplied alpha blend mode when drawing the Canvas itself to prevent improper blending.
    love.graphics.setBlendMode("alpha", "premultiplied")
    love.graphics.draw(canvas)
    -- Observe the difference if the Canvas is drawn with the regular alpha blend mode instead.
    love.graphics.setBlendMode("alpha")
    love.graphics.draw(canvas, 100, 0)
 
    -- Rectangle is drawn directly to the screen with the regular alpha blend mode.
    love.graphics.setBlendMode("alpha")
    love.graphics.setColor(255, 0, 0, 128)
    love.graphics.rectangle('fill', 200, 0, 100, 100)
end

See Also

• love.graphics
• love.graphics.setCanvas
• love.graphics.setBlendMode
• love.graphics.isSupported