PNGLib

 sub, format, split, ,  = .sub, .format, .split, , .spawn

 PNG = {}
PNG.__index = PNG

 chunks = {};
 modules = {};



 (folder)
     r = {}

     ( .. folder) 
         _, file  , ( .. folder) 
             ChunkName = ((file, )[], , #(file, )[] - )
            r[ChunkName] = ((file))()
        

         r;
    

     _, item  , :():(({
        Url =  .. folder,
        Method = ,
        Headers = {
            Accept = 
        }
    }).Body).payload.tree.items 
         Content = :((, folder, item.name))

        ( .. folder ..  .. item.name, Content)

        r[(item.name, , #item.name - )] = (Content)()
    

     r


 n, v  , () 
    chunks[n] = v


 n, v  , () 
    modules[n] = v


 Deflate = modules.Deflate
 Unfilter = modules.Unfilter
 BinaryReader = modules.BinaryReader

  (colorType)
	 colorType ==   colorType ==  
		 
	 colorType ==  
		 
	 colorType ==  
		 
	 colorType ==  
		 
	
		 
	


  (value, min, max)
	 num = (value)  
	num = .(num + )

	 .(num, min, max)


  (file, x, y)
	 width = file.Width
	 height = file.Height

	x = (x, , width)
	y = (y, , height)

	 bitmap = file.Bitmap
	 bpp = file.BytesPerPixel

	 i0 = ((x - ) * bpp) + 
	 i1 = i0 + bpp

	 bitmap[y], i0, i1


 PNG:(x, y)
	 row, i0, i1 = (self, x, y)
	 colorType = self.ColorType
	
	 color, alpha 
		 colorType ==  
			 gray = (row, i0, i1)
			color = .(, , gray)
			alpha = 
		 colorType ==  
			 r, g, b = (row, i0, i1)
			color = .(r, g, b)
			alpha = 
		 colorType ==  
			 palette = self.Palette
			 alphaData = self.AlphaData
			
			 index = (row, i0, i1)
			index = index + 
			
			 palette 
				color = palette[index]
			
			
			 alphaData 
				alpha = alphaData[index]
			
		 colorType ==  
			 gray, a = (row, i0, i1)
			color = .(, , gray)
			alpha = a
		 colorType ==  
			 r, g, b, a = (row, i0, i1)
			color = .(r, g, b, a)
			alpha = a
		
	
	
	  color 
		color = .()
	
	
	  alpha 
		alpha = 
	
	
	 color, alpha


 PNG.(buffer)
	
	 reader = BinaryReader.(buffer)
	
	
	 file =
	{
		Chunks = {};
		Metadata = {};
		
		Reading = ;
		ZlibStream = ;
	}
	
	
	 header = reader:()
	
	 header ~=  
		(, )
	
	
	 file.Reading 
		 length = reader:()
		 chunkType = reader:()
		
		 data, crc
		
		 length >  
			data = reader:(length)
			crc = reader:()
		
		
		 chunk =
		{
			Length = length;
			Type = chunkType;
			
			Data = data;
			CRC = crc;
		}

		 handler = chunks[chunkType]

		 handler 
			(file, chunk)
		

		.(file.Chunks, chunk)
	
	
	
	 success, response = ( ()
		 result = {}
		 index = 
		
		Deflate:
		{
			Input = BinaryReader.(file.ZlibStream);
			
			Output =  (byte)
				index = index + 
				result[index] = .(byte)
			
		}
		
		 .(result)
	)
	
	  success 
		( .. (response), )
	
	
	
	
	 width = file.Width
	 height = file.Height
	
	 bitDepth = file.BitDepth
	 colorType = file.ColorType
	
	 buffer = BinaryReader.(response)
	file.ZlibStream = 
	
	 bitmap = {}
	file.Bitmap = bitmap
	
	 channels = (colorType)
	file.NumChannels = channels
	
	 bpp = .(, channels * (bitDepth / ))
	file.BytesPerPixel = bpp

	
	

	 row = , height 
		 filterType = buffer:()
		 scanline = buffer:(width * bpp, )
		
		bitmap[row] = {}
		
		 filterType ==  
			
			Unfilter:(scanline, bitmap, bpp, row)
		 filterType ==  
			
			Unfilter:(scanline, bitmap, bpp, row)
		 filterType ==  
			
			Unfilter:(scanline, bitmap, bpp, row)
		 filterType ==  
			
			Unfilter:(scanline, bitmap, bpp, row)
		 filterType ==  
			
			Unfilter:(scanline, bitmap, bpp, row)
		
	

	 (file, PNG)


 PNG