class PNG::Canvas

• PNG::Canvas
• Reference
• Object

Overview

A canvas holds all of the PNG data including the header and other chunk information

Included Modules

• Drawable

Defined in:

png/canvas.cr

Constructors

• .new(width : UInt32, height : UInt32, palette : PNG::Palette | Nil = nil)
• .new(header : PNG::Header, data : Bytes | Nil = nil, palette : PNG::Palette | Nil = nil)

Class Method Summary

• .make(width : UInt32, height : UInt32, palette : Palette | Nil = nil, &)
• .make(header : Header, palette : Palette | Nil = nil, &)

Instance Method Summary

• #[](x : UInt32, y : UInt32)

  Get the data at x, y into the canvas.

• #[](x : Number, y : Number)

  Get the data at x, y into the canvas.

• #[]=(x : UInt32, y : UInt32, c : Int, value : UInt8)
• #[]=(x : UInt32, y : UInt32, values : Indexable(UInt8))

  Set the pixel at x, y on the canvas via bytes that correspond to the color type and bit depth.

• #[]=(x, y, values : Indexable(UInt8))
• #[]=(x, y, values : Indexable(UInt16))
• #[]=(x, y, values : Indexable(Number))
• #[]=(x, y, value : Int)
• #bg_color : Bytes | Nil
• #bg_color=(bg_color : Bytes | Nil)
• #bit_depth(*args, **options)
• #bit_depth(*args, **options, &)
• #bit_index(x : UInt32, y : UInt32)

  Calculates the index into the canvas that a value would be at, accounting for padding that would exist at the end of a scanline where bit depth < 8

• #bits_per_pixel(*args, **options)
• #bits_per_pixel(*args, **options, &)
• #byte_index(x : UInt32, y : UInt32)
• #bytes_per_pixel(*args, **options)
• #bytes_per_pixel(*args, **options, &)
• #bytes_per_row(*args, **options)
• #bytes_per_row(*args, **options, &)
• #clone

  Return a deep clone of this canvas

• #color(x, y) : Enumerable

  Get the color at x, y

• #color_type(*args, **options)
• #color_type(*args, **options, &)
• #copy_ancilarry(to : Canvas)

  Copy the ancillarry data to a new canvas

• #crop(start_x : Int, start_y : Int, end_x : Int, end_y : Int)

  Crop a canvas in absolute coordinates

• #data : Bytes
• #data=(data : Bytes)
• #gama : UInt32 | Nil
• #gama=(gama : UInt32 | Nil)
• #header : Header
• #header=(header : Header)
• #height(*args, **options)
• #height(*args, **options, &)
• #interlaced? : Bool
• #last_modified : Time | Nil
• #last_modified=(last_modified : Time | Nil)
• #palette : Palette | Nil
• #palette=(palette : Palette | Nil)
• #pixel_size : PixelSize | Nil
• #pixel_size=(pixel_size : PixelSize | Nil)
• #resize_bilinear(width, height)
• #resize_nearest_neighbor(width, height)
• #scanline(y)

  Return the bytes corresponding to scanline

• #set_color(x, y, color : Enumerable)

  Set a color at x, y

• #transparency : Bytes | Nil
• #transparency=(transparency : Bytes | Nil)
• #width(*args, **options)
• #width(*args, **options, &)

Constructor Detail

Class Method Detail

Instance Method Detail