# Source code for fontTools.ttLib.tables.C_B_D_T_

    # Copyright 2013 Google, Inc. All Rights Reserved.
    #
    # Google Author(s): Matt Fontaine

    from fontTools.misc.textTools import bytesjoin
    from fontTools.misc import sstruct
    from . import E_B_D_T_
    from .BitmapGlyphMetrics import (
        BigGlyphMetrics,
        bigGlyphMetricsFormat,
        SmallGlyphMetrics,
        smallGlyphMetricsFormat,
    )
    from .E_B_D_T_ import (
        BitmapGlyph,
        BitmapPlusSmallMetricsMixin,
        BitmapPlusBigMetricsMixin,
    )
    import struct

    class table_C_B_D_T_(E_B_D_T_.table_E_B_D_T_):
        """Color Bitmap Data table

        The ``CBDT`` table contains color bitmap data for glyphs. It must
        be used in concert with the ``CBLC`` table.

        It is backwards-compatible with the monochrome/grayscale ``EBDT`` table.

        See also https://learn.microsoft.com/en-us/typography/opentype/spec/cbdt
        """

        # Change the data locator table being referenced.
        locatorName = "CBLC"

        # Modify the format class accessor for color bitmap use.

        def getImageFormatClass(self, imageFormat):
            try:
                return E_B_D_T_.table_E_B_D_T_.getImageFormatClass(self, imageFormat)
            except KeyError:
                return cbdt_bitmap_classes[imageFormat]

    # Helper method for removing export features not supported by color bitmaps.
    # Write data in the parent class will default to raw if an option is unsupported.
    def _removeUnsupportedForColor(dataFunctions):
        dataFunctions = dict(dataFunctions)
        del dataFunctions["row"]
        return dataFunctions

    class ColorBitmapGlyph(BitmapGlyph):
        fileExtension = ".png"
        xmlDataFunctions = _removeUnsupportedForColor(BitmapGlyph.xmlDataFunctions)

    class cbdt_bitmap_format_17(BitmapPlusSmallMetricsMixin, ColorBitmapGlyph):

        def decompile(self):
            self.metrics = SmallGlyphMetrics()
            dummy, data = sstruct.unpack2(smallGlyphMetricsFormat, self.data, self.metrics)
            (dataLen,) = struct.unpack(">L", data[:4])
            data = data[4:]

            # For the image data cut it to the size specified by dataLen.
            assert dataLen <= len(data), "Data overun in format 17"
            self.imageData = data[:dataLen]

        def compile(self, ttFont):
            dataList = []
            dataList.append(sstruct.pack(smallGlyphMetricsFormat, self.metrics))
            dataList.append(struct.pack(">L", len(self.imageData)))
            dataList.append(self.imageData)
            return bytesjoin(dataList)

    class cbdt_bitmap_format_18(BitmapPlusBigMetricsMixin, ColorBitmapGlyph):

        def decompile(self):
            self.metrics = BigGlyphMetrics()
            dummy, data = sstruct.unpack2(bigGlyphMetricsFormat, self.data, self.metrics)
            (dataLen,) = struct.unpack(">L", data[:4])
            data = data[4:]

            # For the image data cut it to the size specified by dataLen.
            assert dataLen <= len(data), "Data overun in format 18"
            self.imageData = data[:dataLen]

        def compile(self, ttFont):
            dataList = []
            dataList.append(sstruct.pack(bigGlyphMetricsFormat, self.metrics))
            dataList.append(struct.pack(">L", len(self.imageData)))
            dataList.append(self.imageData)
            return bytesjoin(dataList)

    class cbdt_bitmap_format_19(ColorBitmapGlyph):

        def decompile(self):
            (dataLen,) = struct.unpack(">L", self.data[:4])
            data = self.data[4:]

            assert dataLen <= len(data), "Data overun in format 19"
            self.imageData = data[:dataLen]

        def compile(self, ttFont):
            return struct.pack(">L", len(self.imageData)) + self.imageData

    # Dict for CBDT extended formats.
    cbdt_bitmap_classes = {
        17: cbdt_bitmap_format_17,
        18: cbdt_bitmap_format_18,
        19: cbdt_bitmap_format_19,
    }