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Two glyph sizes are available: 16x16 glyphs are stored in the first half of xf_font.dat, and 12x12 glyphs in the second half. Each 12x12 glyph is stored in the top left corner of a 16x16 bitmap, so the row/glyph alignment is the same in both cases: 2 bytes per pixel row and 32 bytes per glyph. The pixel packing is 1-bit black-and-white (i.e., without antialiasing), much more space-efficient than the 8-bit grayscale storage used in Oni's [[TSFT]]. Another gain comes from not having any glyph descriptors ([[TSGA]]s), and from having only two fonts instead of Oni's typical 15. | Two glyph sizes are available: 16x16 glyphs are stored in the first half of xf_font.dat, and 12x12 glyphs in the second half. Each 12x12 glyph is stored in the top left corner of a 16x16 bitmap, so the row/glyph alignment is the same in both cases: 2 bytes per pixel row and 32 bytes per glyph. The pixel packing is 1-bit black-and-white (i.e., without antialiasing), much more space-efficient than the 8-bit grayscale storage used in Oni's [[TSFT]]. Another gain comes from not having any glyph descriptors ([[TSGA]]s), and from having only two fonts instead of Oni's typical 15. | ||
All the GB 2312 glyphs listed [[wp:GB_2312#Non-Hanzi_rows|HERE]] and [[wikt:Appendix:Chinese_hanzi_by_GB_2312_quwei_code|HERE]] are implemented, except for the euro sign (row 2) and the ten glyphs from [[wp:Vertical_Forms|Vertical Forms]] (row 6). Thus of the 8,836 available code points only 7,668 (including the ideographic space A1,A1) correspond to actual glyphs, whereas the other 1,168 correspond to blank pixel data (indistinguishable from a space). | All the GB 2312 glyphs listed [[wp:GB_2312#Non-Hanzi_rows|HERE]] and [[wikt:Appendix:Chinese_hanzi_by_GB_2312_quwei_code|HERE]] are implemented, except for the euro sign (row 2) and the ten glyphs from [[wp:Vertical_Forms|Vertical Forms]] (row 6). Thus of the 8,836 available code points only 7,668 (including the ideographic space A1,A1) correspond to actual glyphs, whereas the other 1,168 correspond to blank pixel data (indistinguishable from a space). In terms of space efficiency, only 74,752 bytes are thus wasted on blank pixel data (2 x 1,168 x 32), whereas trimmed-down pixel data would require at least 2x7,668 + 2 = 15,338 bytes for an indexation of the available glyphs, as well as additional lookup logic. | ||
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