Sha256: 34954ae99c9f04f66015f44ebe7ba284d61b8f31083996a91d918b7925a923de
Contents?: true
Size: 1.83 KB
Versions: 15
Compression:
Stored size: 1.83 KB
Contents
module ZPNG
class ScanLine
module Mixins
# scanline decoding
module Interlaced
def prev_scanline_byte x
# When the image is interlaced, each pass of the interlace pattern is
# treated as an independent image for filtering purposes
image.adam7.pass_start?(@idx) ? 0 : image.scanlines[@idx-1].decoded_bytes.getbyte(x)
end
end
module NotFirstLine
def prev_scanline_byte x
image.scanlines[@idx-1].decoded_bytes.getbyte(x)
end
end
module FirstLine
def prev_scanline_byte x
0
end
end
# pixel access
# RGB 8 bits per sample = 24bpp
module RGB24
def [] x
t = x*3
# color_class is for (limited) BMP support
image.color_class.new(
decoded_bytes.getbyte(t),
decoded_bytes.getbyte(t+1),
decoded_bytes.getbyte(t+2)
)
end
end
# if image has tRNS chunk - 10% slower than RGB24
module RGB24_TRNS
def [] x
t = x*3
# color_class is for (limited) BMP support
color = image.color_class.new(
decoded_bytes.getbyte(t),
decoded_bytes.getbyte(t+1),
decoded_bytes.getbyte(t+2)
)
color.alpha = image._alpha_color(color)
color
end
end
# RGBA 8 bits per sample = 32bpp
module RGBA32
def [] x
# substring => 1.50s on 270_000 pixels
# getbyte(s) => 1.25s on 270_000 pixels
t = x*4
image.color_class.new(
decoded_bytes.getbyte(t),
decoded_bytes.getbyte(t+1),
decoded_bytes.getbyte(t+2),
decoded_bytes.getbyte(t+3)
)
end
end
end # Mixins
end # ScanLine
end # ZPNG
Version data entries
15 entries across 15 versions & 1 rubygems