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Implement bit flipping with a lookup table

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Should improve performance.
This version is cooler, and also does not suffer from iteration limits
This commit is contained in:
ISSOtm
2022-05-21 12:57:46 +02:00
committed by Eldred Habert
parent b4dadd35b6
commit 7a7126f3b8
3 changed files with 19 additions and 11 deletions
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6
src/gfx/process.cpp
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@@ -652,7 +652,7 @@ public:
// Count the line itself as mirrorred; vertical mirroring is
// already taken care of because the symmetric line will be XOR'd
// the same way. (...which is a problem, but probably benign.)
_hash ^= flip(bitplanes >> 8) << 8 | flip(bitplanes & 0xFF);
_hash ^= flipTable[bitplanes >> 8] << 8 | flipTable[bitplanes & 0xFF];
}
}
}
@@ -680,7 +680,7 @@ public:
// Check if we have horizontal mirroring, which scans the array forward again
if (std::equal(_data.begin(), _data.end(), other._data.begin(),
[](uint8_t lhs, uint8_t rhs) { return lhs == flip(rhs); })) {
[](uint8_t lhs, uint8_t rhs) { return lhs == flipTable[rhs]; })) {
return MatchType::HFLIP;
}
@@ -694,7 +694,7 @@ public:
if (lhs != rhs) {
hasVFlip = false;
}
if (lhs != flip(rhs)) {
if (lhs != flipTable[rhs]) {
hasVHFlip = false;
}
if (!hasVFlip && !hasVHFlip) {