shithub: rgbds

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Fix `ProtoPalette::compare`

Some disjoint sets were mistakenly reported not as such
For example, {0} was considered to include {1}.

--- a/include/gfx/proto_palette.hpp

+++ b/include/gfx/proto_palette.hpp

@@ -17,6 +17,7 @@

 class ProtoPalette {

 	// Up to 4 colors, sorted, and where SIZE_MAX means the slot is empty

 	// (OK because it's not a valid color index)

+	// Sorting is done on the raw numerical values to lessen `compare`'s complexity

 	std::array<uint16_t, 4> _colorIndices{UINT16_MAX, UINT16_MAX, UINT16_MAX, UINT16_MAX};

 public:

--- a/src/gfx/proto_palette.cpp

+++ b/src/gfx/proto_palette.cpp

@@ -10,6 +10,7 @@

 #include <algorithm>

 #include <array>

+#include <cassert>

 #include <stddef.h>

 #include <stdint.h>

@@ -41,6 +42,10 @@

 }

 ProtoPalette::ComparisonResult ProtoPalette::compare(ProtoPalette const &other) const {

+	// This works because the sets are sorted numerically

+	assert(std::is_sorted(_colorIndices.begin(), _colorIndices.end()));

+	assert(std::is_sorted(other._colorIndices.begin(), other._colorIndices.end()));

+

 	auto ours = _colorIndices.begin(), theirs = other._colorIndices.begin();

 	bool weBigger = true, theyBigger = true;

@@ -56,8 +61,8 @@

 			weBigger = false;

 		}

 	}

-	weBigger &= ours == _colorIndices.end();

-	theyBigger &= theirs == other._colorIndices.end();

+	weBigger &= theirs == other._colorIndices.end();

+	theyBigger &= ours == _colorIndices.end();

 	return theyBigger ? THEY_BIGGER : (weBigger ? WE_BIGGER : NEITHER);

 }