Add BitMap methods for bitwise boolean operations

Created methods for BitMap for boolean operators AND, OR, XOR, and NOT.  Binary operations only work when two BitMaps are the same size.  Docs included.

Co-Authored-By: Micky <[email protected]>
Co-Authored-By: A Thousand Ships <[email protected]>

doc/classes/BitMap.xml

@@ -9,6 +9,36 @@
 	<tutorials>
 	</tutorials>
 	<methods>
+		<method name="bitwise_and" qualifiers="const">
+			<return type="BitMap" />
+			<param index="0" name="other" type="BitMap" />
+			<description>
+				Creates a new [BitMap] from the boolean AND operation between this bitmap and [param other].
+				This method fails and returns an empty [BitMap] if the two bitmaps are not exactly the same size.
+			</description>
+		</method>
+		<method name="bitwise_not" qualifiers="const">
+			<return type="BitMap" />
+			<description>
+				Creates a new [BitMap] from the boolean NOT operation on this bitmap. This causes every bit to flip from [code]true[/code] to [code]false[/code], and from [code]false[/code] to [code]true[/code].
+			</description>
+		</method>
+		<method name="bitwise_or" qualifiers="const">
+			<return type="BitMap" />
+			<param index="0" name="other" type="BitMap" />
+			<description>
+				Creates a new [BitMap] from the boolean OR operation between this bitmap and [param other].
+				This method fails and returns an empty [BitMap] if the two bitmaps are not exactly the same size.
+			</description>
+		</method>
+		<method name="bitwise_xor" qualifiers="const">
+			<return type="BitMap" />
+			<param index="0" name="other" type="BitMap" />
+			<description>
+				Creates a new [BitMap] from the boolean XOR operation between this bitmap and [param other].
+				This method fails and returns an empty [BitMap] if the two bitmaps are not exactly the same size.
+			</description>
+		</method>
 		<method name="convert_to_image" qualifiers="const">
 			<return type="Image" />
 			<description>

scene/resources/bit_map.cpp

@@ -704,6 +704,125 @@ void BitMap::blit(const Vector2i &p_pos, const Ref<BitMap> &p_bitmap) {
 	}
 }
 
+Ref<BitMap> BitMap::bitwise_and(const Ref<BitMap> &p_other) const {
+	ERR_FAIL_COND_V_EDMSG(p_other.is_null(), Ref<BitMap>(), "Null reference to supplied BitMap other.");
+
+	Ref<BitMap> new_bitmap;
+	new_bitmap.instantiate();
+
+	ERR_FAIL_COND_V_EDMSG(get_size() != p_other->get_size(), new_bitmap, "The given bitmap is not the expected size for the specified operation.");
+
+	new_bitmap->create(get_size());
+
+	int ds = bitmask.size();
+	const uint8_t *d = bitmask.ptr();
+	const uint8_t *d2 = p_other->bitmask.ptr();
+	uint8_t *w = new_bitmap->bitmask.ptrw();
+
+	const uint64_t *d_u64 = (uint64_t*) d;
+	const uint64_t *d2_u64 = (uint64_t*) d2;
+	uint64_t *w_u64 = (uint64_t*) w;
+
+	for (int i = 0; i < (ds >> 3); i++) {
+		w_u64[i] = d_u64[i] & d2_u64[i];
+	}
+
+	for (int i = ds & ~0b111; i < ds; i++) {
+		w[i] = d[i] & d2[i];
+	}
+
+	return new_bitmap;
+}
+
+Ref<BitMap> BitMap::bitwise_not() const {
+	Ref<BitMap> new_bitmap;
+	new_bitmap.instantiate();
+	new_bitmap->create(get_size());
+
+	int ds = bitmask.size();
+	const uint8_t *d = bitmask.ptr();
+	uint8_t *w = new_bitmap->bitmask.ptrw();
+
+	const uint64_t *d_u64 = (uint64_t*) d;
+	uint64_t *w_u64 = (uint64_t*) w;
+
+	for (int i = 0; i < (ds >> 3); i++) {
+		w_u64[i] = ~d_u64[i];
+	}
+
+	for (int i = ds & ~0b111; i < ds; i++) {
+		w[i] = ~d[i];
+	}
+
+	// mask "hidden" bits for true bit count
+	int hidden_count = (ds << 3) - (width * height);
+	if (hidden_count > 0) {
+		w[ds - 1] &= 0xFF << hidden_count;
+	}
+
+	return new_bitmap;
+}
+
+Ref<BitMap> BitMap::bitwise_or(const Ref<BitMap> &p_other) const {
+	ERR_FAIL_COND_V_EDMSG(p_other.is_null(), Ref<BitMap>(), "Null reference to supplied BitMap other.");
+
+	Ref<BitMap> new_bitmap;
+	new_bitmap.instantiate();
+
+	ERR_FAIL_COND_V_EDMSG(get_size() != p_other->get_size(), new_bitmap, "The given bitmap is not the expected size for the specified operation.");
+
+	new_bitmap->create(get_size());
+
+	int ds = bitmask.size();
+	const uint8_t *d = bitmask.ptr();
+	const uint8_t *d2 = p_other->bitmask.ptr();
+	uint8_t *w = new_bitmap->bitmask.ptrw();
+
+	const uint64_t *d_u64 = (uint64_t*) d;
+	const uint64_t *d2_u64 = (uint64_t*) d2;
+	uint64_t *w_u64 = (uint64_t*) w;
+
+	for (int i = 0; i < (ds >> 3); i++) {
+		w_u64[i] = d_u64[i] | d2_u64[i];
+	}
+
+	for (int i = ds & ~0b111; i < ds; i++) {
+		w[i] = d[i] | d2[i];
+	}
+
+	return new_bitmap;
+}
+
+Ref<BitMap> BitMap::bitwise_xor(const Ref<BitMap> &p_other) const {
+	ERR_FAIL_COND_V_EDMSG(p_other.is_null(), Ref<BitMap>(), "Null reference to supplied BitMap other.");
+
+	Ref<BitMap> new_bitmap;
+	new_bitmap.instantiate();
+
+	ERR_FAIL_COND_V_EDMSG(get_size() != p_other->get_size(), new_bitmap, "The given bitmap is not the expected size for the specified operation.");
+
+	new_bitmap->create(get_size());
+
+	int ds = bitmask.size();
+	const uint8_t *d = bitmask.ptr();
+	const uint8_t *d2 = p_other->bitmask.ptr();
+	uint8_t *w = new_bitmap->bitmask.ptrw();
+
+	const uint64_t *d_u64 = (uint64_t*) d;
+	const uint64_t *d2_u64 = (uint64_t*) d2;
+	uint64_t *w_u64 = (uint64_t*) w;
+
+	for (int i = 0; i < (ds >> 3); i++) {
+		w_u64[i] = d_u64[i] ^ d2_u64[i];
+	}
+
+	for (int i = ds & ~0b111; i < ds; i++) {
+		w[i] = d[i] ^ d2[i];
+	}
+
+	return new_bitmap;
+}
+
 void BitMap::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("create", "size"), &BitMap::create);
 	ClassDB::bind_method(D_METHOD("create_from_image_alpha", "image", "threshold"), &BitMap::create_from_image_alpha, DEFVAL(0.1));
@@ -726,6 +845,11 @@ void BitMap::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("convert_to_image"), &BitMap::convert_to_image);
 	ClassDB::bind_method(D_METHOD("opaque_to_polygons", "rect", "epsilon"), &BitMap::_opaque_to_polygons_bind, DEFVAL(2.0));
 
+	ClassDB::bind_method(D_METHOD("bitwise_and", "other"), &BitMap::bitwise_and);
+	ClassDB::bind_method(D_METHOD("bitwise_not"), &BitMap::bitwise_not);
+	ClassDB::bind_method(D_METHOD("bitwise_or", "other"), &BitMap::bitwise_or);
+	ClassDB::bind_method(D_METHOD("bitwise_xor", "other"), &BitMap::bitwise_xor);
+
 	ADD_PROPERTY(PropertyInfo(Variant::DICTIONARY, "data", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR | PROPERTY_USAGE_INTERNAL), "_set_data", "_get_data");
 }
 

scene/resources/bit_map.h

@@ -79,6 +79,11 @@ class BitMap : public Resource {
 
 	Vector<Vector<Vector2>> clip_opaque_to_polygons(const Rect2i &p_rect, float p_epsilon = 2.0) const;
 
+	Ref<BitMap> bitwise_and(const Ref<BitMap> &p_other) const;
+	Ref<BitMap> bitwise_not() const;
+	Ref<BitMap> bitwise_or(const Ref<BitMap> &p_other) const;
+	Ref<BitMap> bitwise_xor(const Ref<BitMap> &p_other) const;
+
 	BitMap();
 };