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+# Font character oversampling for rendering from atlas textures
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+
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+TL,DR: Run oversample.exe on a windows machine to see the
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+benefits of oversampling. Type the name of a .ttf file on
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+the command-line, or it will look for Arial in the Windows
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+font directory.
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+
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+## About oversampling
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+
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+A common strategy for rendering text is to cache character bitmaps
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+and reuse them. For hinted characters, every instance of a given
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+character is always identical, so this works fine. However, stb_truetype
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+doesn't do hinting.
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+
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+For anti-aliased characters, you can actually position the characters
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+with subpixel precision, and get different bitmaps based on that positioning
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+if you re-render the vector data.
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+
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+However, if you simply cache a single version of the bitmap and
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+draw it at different subpixel positions with a GPU, you will get
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+either the exact same result (if you use point-sampling on the
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+texture) or linear filtering. Linear filtering will cause a sub-pixel
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+positioned bitmap to blur further, causing a visible desharpening
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+of the character. (And, since the character wasn't hinted, it was
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+already blurrier than a hinted one would be, and not it gets even
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+more blurry.)
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+
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+You can avoid this by caching multiple variants of a character which
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+were rendered independently from the vector data. For example, you
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+might cache 3 versions of a char, at 0, 1/3, and 2/3rds of a pixel
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+horizontal offset, and always require characters to fall on integer
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+positions vertically.
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+
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+When creating a texture atlas for use on GPUs, which support bilinear
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+filtering, there is a better approach than caching several indepdent
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+positions, which is to allow lerping between the versions to allow
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+finer subpixel positioning. You can achieve these by interleaving
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+each of the cached bitmaps, but this turns out to be mathematically
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+equivalent to a simpler operation: oversampling and prefiltering the
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+characters.
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+
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+So, setting oversampling of 2x2 in stb_truetype is equivalent to caching
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+each character in 4 different variations, 1 for each subpixel position
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+in a 2x2 set.
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nothings