mirror of
https://github.com/zellyn/go6502.git
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33 lines
574 B
Go
33 lines
574 B
Go
package visual
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type bitmap []uint64
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const BITMAP_SHIFT = 6
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const BITMAP_MASK = 63
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func wordsForBits(bits uint) uint {
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return bits/64 + 1
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}
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func newBitmap(bits uint) bitmap {
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return make([]uint64, wordsForBits(bits))
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}
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func (b bitmap) clear() {
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for i := range b {
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b[i] = 0
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}
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}
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func (b bitmap) set(index uint, state bool) {
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if state {
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b[index>>BITMAP_SHIFT] |= 1 << (index & BITMAP_MASK)
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} else {
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b[index>>BITMAP_SHIFT] &^= 1 << (index & BITMAP_MASK)
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}
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}
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func (b bitmap) get(index uint) bool {
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return (b[index>>BITMAP_SHIFT]>>(index&BITMAP_MASK))&1 > 0
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}
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