mirror of https://github.com/status-im/nimPNG.git
51 lines
1.1 KiB
Nim
51 lines
1.1 KiB
Nim
import streams
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type
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BMP* = ref object
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width*, height*: int
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data*: string
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proc writeWORD(s: Stream, val: int) =
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let word = val.int16
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s.write(word)
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proc writeDWORD(s: Stream, val: int) =
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let dword = val.int32
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s.write(dword)
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proc newBMP*(w, h: int): BMP =
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new(result)
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result.width = w
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result.height = h
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result.data = newString(w * h * 3)
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proc writeBMP*(s: Stream, bmp: BMP) =
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let stride = 4 * ((bmp.width * 24 + 31) div 32)
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let imageData = stride * bmp.height
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let offset = 54
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var fileSize = imageData + offset
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s.writeWORD(19778)
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s.writeDWORD(fileSize)
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s.writeWORD(0)
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s.writeWORD(0)
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s.writeDWORD(offset)
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s.writeDWORD(40)
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s.writeDWORD(bmp.width)
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s.writeDWORD(bmp.height)
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s.writeWORD(1)
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s.writeWORD(24)
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s.writeDWORD(0)
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s.writeDWORD(imageData)
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s.writeDWORD(3780)
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s.writeDWORD(3780)
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s.writeDWORD(0)
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s.writeDWORD(0)
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let bytesPerRow = bmp.width * 3
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let paddingLen = stride - bytesPerRow
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let padding = if paddingLen > 0: newString(paddingLen) else: ""
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for i in 0..bmp.height-1:
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s.writeData(addr(bmp.data[i * bytesPerRow]), bytesPerRow)
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if paddingLen > 0: s.write(padding)
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