Module: PngStitcher
- Extended by:
- Ext
- Defined in:
- lib/png_stitcher.rb,
lib/png_stitcher/version.rb,
ext/png_stitcher/png_stitcher.c
Defined Under Namespace
Modules: Ext
Constant Summary collapse
- VERSION =
"0.1.1"
Class Method Summary collapse
Methods included from Ext
Class Method Details
.stitch(blobs) ⇒ Object
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# File 'lib/png_stitcher.rb', line 10 def stitch(blobs) streams = [] height = 0 width = nil palette = nil physical_chunk = nil blobs.each do |blob| stream = ChunkyPNG::Datastream.from_blob(blob) physical_chunk ||= stream.physical_chunk palette ||= ChunkyPNG::Palette.from_chunks(stream.palette_chunk, stream.transparency_chunk) header = stream.header_chunk width ||= header.width height += header.height raise ArgumentError, "Color Mode must be Indexed" unless header.color == ChunkyPNG::COLOR_INDEXED raise ArgumentError, "Pixel Depth must be 1 bit per pixel" unless header.depth == 1 raise ArgumentError, "Interlacing must be disabled" unless header.interlace == ChunkyPNG::INTERLACING_NONE raise ArgumentError, "All of the images must be the same width" unless header.width == width raise ArgumentError, "All of the images must have the same palette" unless palette == ChunkyPNG::Palette.from_chunks(stream.palette_chunk, stream.transparency_chunk) streams << stream end data = _stitch(streams, width, height) stream = ChunkyPNG::Datastream.new stream.header_chunk = ChunkyPNG::Chunk::Header.new( width: width, height: height, color: ChunkyPNG::COLOR_INDEXED, depth: 1, interlace: 0) stream.palette_chunk = palette.to_plte_chunk stream.transparency_chunk = palette.to_trns_chunk unless palette.opaque? stream.physical_chunk = physical_chunk stream.data_chunks = ChunkyPNG::Chunk::ImageData.split_in_chunks(data) stream.end_chunk = ChunkyPNG::Chunk::End.new stream.to_blob end |