52 lines
1.3 KiB
Go
52 lines
1.3 KiB
Go
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package world
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// `SectionPalette` is a "palette", which is a sort of look-up-table (LUT) between
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// an index into the LUT, and the resulting `BlockID`
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//
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// This palette is unique to each section, and allows ranges of blocks to be
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// changed in constant time, with the downside of having to "compact" the palette
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type SectionPalette []BlockID
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// `Compact` removes all duplicate states from a palette and returns a new palette
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func (p SectionPalette) Compact() SectionPalette {
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ids := make(map[BlockID]bool)
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// Filter out the duplicate block ids
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for _, blockId := range p {
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ids[blockId] = true
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}
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var np SectionPalette
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for blockId := range ids {
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np = append(np, blockId)
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}
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return np
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}
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// `IndexFor` returns the palette index for a specified block id
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//
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// If the block id does not exist, it is placed in the palette and the index
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// is returned
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func (p SectionPalette) IndexFor(state BlockID) PaletteIndex {
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// If the state is already in the palette, return it
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for index, blockId := range p {
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if state == blockId {
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return PaletteIndex(index)
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}
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}
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// Otherwise, insert it into the palette and return the index
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p = append(p, state)
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return PaletteIndex(len(p) - 1)
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}
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// `State` returns the state for a palette's index
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func (p SectionPalette) State(index PaletteIndex) BlockID {
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return p[index]
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}
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type PaletteIndex byte
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