Implement -c embedded:multiple (#2194)

include/gfx/main.hpp

@@ -28,6 +28,7 @@ struct Options {
 		INLINE,
 		EXTERNAL,
 		EMBEDDED,
+		EMBEDDED_MULTIPLE,
 		DMG,
 	} palSpecType = NO_SPEC; // -c
 	std::vector<std::array<std::optional<Rgba>, 4>> palSpec{};
@@ -61,6 +62,9 @@ struct Options {
 	uint16_t maxNbColors() const { return nbColorsPerPal * nbPalettes; }
 
 	bool hasExplicitPalSpec() const { return palSpecType == INLINE || palSpecType == EXTERNAL; }
+	bool hasEmbeddedPalSpec() const {
+		return palSpecType == EMBEDDED || palSpecType == EMBEDDED_MULTIPLE;
+	}
 
 	uint8_t dmgColors[4] = {};
 	uint8_t dmgValue(uint8_t i) const {

include/gfx/pal_spec.hpp

@@ -10,6 +10,7 @@
 
 void parseInlinePalSpec(char const * const rawArg);
 void parseEmbeddedPalSpec(Png const &png);
+void parseEmbeddedMultiplePalSpec(Png const &png);
 void parseExternalPalSpec(char const *arg);
 void parseDmgPalSpec(char const * const rawArg);
 void parseBackgroundPalSpec(char const *arg);