Canvas (Русский)

Available since LÖVE 0.8.0
It has been renamed from Framebuffer.

Холст пре-рендера используется для внеэкранного рендеринга. Это невидимый экран на которым вы можете нарисовать то что будет отображено позже. Известен так же как "Рендер в текстуру"

Одно из практических применений это оптимизация рендера, ведь рисуя на таком холсте объекты, которые меняются не часто, например фон, можно заметно увеличить производительность.

В версиях до 0.10.0 не на всех видеокартах LOVE поддерживает Canvases love.graphics.isSupported("canvas") проверка поддержки видеокартой подобного рендера.

O.png При рисовании содержимого на холсте с использованием обычного Альфа-смешивания Альфа-значения содержимого умножаются на значения RGB. Поэтому цвета пикселей холста будут иметь" предварительно умноженную Альфа", как только он будет нарисован, поэтому при рисовании холста на экран или на другой холст вы должны использовать предварительно умноженное Альфа – смешивание - love.graphics.setBlendMode(""alpha", "premultiplied").  

Конструкторы

love.graphics.newCanvas Creates a new Canvas. Added since 0.8.0

Functions

Canvas:clear Clears the contents of a Canvas to a specific color. Added since 0.8.0 Removed in 0.10.0
Canvas:getFSAA Gets the number of FSAA samples used when drawing to the Canvas. Added since 0.9.1 Removed in 0.10.0
Canvas:getFormat Gets the texture format of the Canvas. Added since 0.9.1 Removed in 11.0
Canvas:getImageData Generates ImageData from the contents of the Canvas. Added since 0.8.0 Removed in 0.10.0
Canvas:getMSAA Gets the number of MSAA samples used when drawing to the Canvas. Added since 0.9.2
Canvas:getPixel Gets the pixel at the specified position in a Canvas. Added since 0.9.0 Removed in 0.10.0
Canvas:newImageData Generates ImageData from the contents of the Canvas. Added since 0.10.0
Canvas:renderTo Render to a Canvas using a function. Added since 0.8.0
Object:release Immediately destroys the object's Lua reference. Added since 11.0
Object:type Gets the type of the object as a string.
Object:typeOf Checks whether an object is of a certain type.
Texture:getDPIScale Gets the DPI scale factor of the Texture. Added since 11.0
Texture:getDepth Gets the depth of a Volume Texture. Added since 11.0
Texture:getDepthSampleMode Gets the comparison mode used when sampling from a depth texture in a shader. Added since 11.0
Texture:getDimensions Gets the width and height of the Texture. Added since 0.9.0
Texture:getFilter Gets the filter mode of the Texture.
Texture:getFormat Gets the pixel format of the Texture. Added since 11.0
Texture:getHeight Gets the height of the Texture.
Texture:getLayerCount Gets the number of layers / slices in an Array Texture. Added since 11.0
Texture:getMipmapCount Gets the number of mipmaps contained in the Texture. Added since 11.0
Texture:getMipmapFilter Gets the mipmap filter mode for a Texture. Added since 0.9.0
Texture:getPixelDimensions Gets the width and height in pixels of the Texture. Added since 11.0
Texture:getPixelHeight Gets the height in pixels of the Texture. Added since 11.0
Texture:getPixelWidth Gets the width in pixels of the Texture. Added since 11.0
Texture:getTextureType Gets the type of the Texture. Added since 11.0
Texture:getWidth Gets the width of the Texture.
Texture:getWrap Gets the wrapping properties of a Texture.
Texture:isReadable Gets whether the Texture can be drawn sent to a Shader. Added since 11.0
Texture:setDepthSampleMode Sets the comparison mode used when sampling from a depth texture in a shader. Added since 11.0
Texture:setFilter Sets the filter mode of the Texture.
Texture:setMipmapFilter Sets the mipmap filter mode for a Texture. Added since 0.9.0
Texture:setWrap Sets the wrapping properties of a Texture.

Supertypes

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(1, 0, 0, 0.5)
        love.graphics.rectangle('fill', 0, 0, 100, 100)
    love.graphics.setCanvas()
end
 
function love.draw()
    -- very important!: reset color before drawing to canvas to have colors properly displayed
    -- see discussion here: https://love2d.org/forums/viewtopic.php?f=4&p=211418#p211418
    love.graphics.setColor(1, 1, 1, 1)
 
    -- 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(1, 0, 0, 0.5)
    love.graphics.rectangle('fill', 200, 0, 100, 100)
end

See Also


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