Difference between revisions of "Canvas"
m (Reworded compatibility warning a bit)
m (Added Texture parent)
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== Supertypes ==
== Supertypes ==
Revision as of 08:34, 30 January 2014
|Some older graphics cards do not support canvases, and will throw an error if you attempt to use them. You should try to avoid using canvases for non-optional effects unless necessary, to avoid excluding users. Use love.graphics.isSupported("canvas") to check for support.|
|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.
Canvases can be susceptible to power of 2 syndrome. Most graphics cards that support Canvas should have non-PO2 texture support. However, there are some old cards that do not. Check with love.graphics.isSupported("npot") if it is supported.
|love.graphics.newCanvas||Creates a new Canvas.||0.8.0|
|Canvas:clear||Clears the contents of a Canvas to a specific color.||0.8.0||0.10.0|
|Canvas:generateMipmaps||Generates mipmaps for the Canvas, based on the contents of the highest-resolution mipmap level.||11.0|
|Canvas:getFSAA||Gets the number of FSAA samples used when drawing to the Canvas.||0.9.1||0.10.0|
|Canvas:getFormat||Gets the texture format of the Canvas.||0.9.1||11.0|
|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:getMipmapMode||Gets the MipmapMode this Canvas was created with.||11.0|
|Canvas:getPixel||Gets the pixel at the specified position in a Canvas.||0.9.0||0.10.0|
|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|
|Object:release||Immediately destroys the object's Lua reference.||11.0|
|Object:type||Gets the type of the object as a string.|
|Object:typeOf||Checks whether an object is of a certain type.|
Drawing something to the Canvas and then the Canvas itself.
function love.load() canvas = love.graphics.newCanvas(800, 600) -- Rectangle is drawn to the canvas with the alpha blend mode. love.graphics.setCanvas(canvas) canvas: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 blend mode when drawing the Canvas itself to prevent another blending. love.graphics.setBlendMode('premultiplied') love.graphics.draw(canvas) -- Observe the difference if the Canvas is drawn with the alpha blend mode instead. love.graphics.setBlendMode('alpha') love.graphics.draw(canvas, 100, 0) -- Rectangle is drawn directly to the screen with the alpha blend mode. love.graphics.setBlendMode('alpha') love.graphics.setColor(255, 0, 0, 128) love.graphics.rectangle('fill', 200, 0, 100, 100) end
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