Adding modding folder with a hacked build.

modding/hacked/ss1/content/movie/internal/compression/TilePaletteKey.go

@@ -0,0 +1,70 @@
+package compression
+
+import "math/bits"
+
+// TilePaletteKey marks use of colors of a 256 palette.
+type TilePaletteKey struct {
+	usedColors [4]uint64
+	size       int
+}
+
+// TilePaletteKeyFrom returns a key for the given slice of colors.
+func TilePaletteKeyFrom(colors []byte) TilePaletteKey {
+	var key TilePaletteKey
+	for _, c := range colors {
+		key.UseColor(c)
+	}
+	return key
+}
+
+// Buffer returns the color indices marked in use by this key.
+func (key *TilePaletteKey) Buffer() []byte {
+	result := make([]byte, 0, key.size)
+	for i := 0; i < 256; i++ {
+		if key.HasColor(byte(i)) {
+			result = append(result, byte(i))
+		}
+	}
+	return result
+}
+
+// UseColor marks the given color index in use.
+func (key *TilePaletteKey) UseColor(index byte) {
+	if !key.HasColor(index) {
+		key.usedColors[index/64] |= 1 << uint(index%64)
+		key.size++
+	}
+}
+
+// HasColor returns true if the given color index is in use by this key.
+func (key *TilePaletteKey) HasColor(index byte) bool {
+	return (key.usedColors[index/64] & (1 << uint(index%64))) != 0
+}
+
+// Contains returns true if this key is equal to, or a superset of, the given key.
+func (key *TilePaletteKey) Contains(other *TilePaletteKey) bool {
+	return ((^key.usedColors[0] & other.usedColors[0]) == 0) &&
+		((^key.usedColors[1] & other.usedColors[1]) == 0) &&
+		((^key.usedColors[2] & other.usedColors[2]) == 0) &&
+		((^key.usedColors[3] & other.usedColors[3]) == 0)
+}
+
+// Without returns a new key instance that has all remaining colors marked in use.
+func (key *TilePaletteKey) Without(other *TilePaletteKey) TilePaletteKey {
+	var result TilePaletteKey
+	for i := 0; i < 4; i++ {
+		result.usedColors[i] = key.usedColors[i] & ^other.usedColors[i]
+		result.size += bits.OnesCount64(result.usedColors[i])
+	}
+	return result
+}
+
+// LessThan is a sorting function to order keys.
+func (key *TilePaletteKey) LessThan(other *TilePaletteKey) bool {
+	for i := 0; i < 4; i++ {
+		if key.usedColors[i] < other.usedColors[i] {
+			return true
+		}
+	}
+	return false
+}