Add pixel getter #34
Add pixel getter #34
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| match self.header.bpp { | ||
| Bpp::Bits1 => RawDataSlice::<RawU1, LittleEndian>::new(row) | ||
| .into_iter() | ||
| .nth(p.x as usize) |
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Using nth() seems to be rather expensive for random pixel lookup.
In Bmp format it should be possible to lookup pixels in the raw data block in O(1) time.
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There is a specialized implementation of nth which is O(1).
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RawDataSlice and the iterators are included in embedded-graphics: https://github.com/embedded-graphics/embedded-graphics/blob/master/src/iterator/raw.rs
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Cool. Does that also count for the nth in line 100?
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Yes, Chunks does also implements nth: https://doc.rust-lang.org/src/core/slice/iter.rs.html#1501
There might be some performance gain by not using Chunks, but that could be explored later. My focus for this PR was getting a working implementation not necessarily the fastest.
This PR adds pixel getters to
BmpandRawBmp. It doesn't yet implement the newImagePixelGettertrait (embedded-graphics/embedded-graphics#612) to stay compatible with e-g0.7.