Add a crop_image boolean parameter to Palette.convert_to_image()

Fixes some issues with the Palettize effect where the output would be different if the palette size changed and empty swatches were added, even if the colors themselves stayed the same.

src/Classes/ImageExtended.gd

@@ -84,7 +84,7 @@ func update_palette() -> void:
 func convert_indexed_to_rgb() -> void:
 	if not is_indexed:
 		return
-	var palette_image := Palettes.current_palette.convert_to_image()
+	var palette_image := Palettes.current_palette.convert_to_image(false)
 	var palette_texture := ImageTexture.create_from_image(palette_image)
 	var shader_image_effect := ShaderImageEffect.new()
 	var indices_texture := ImageTexture.create_from_image(indices_image)
@@ -98,7 +98,7 @@ func convert_indexed_to_rgb() -> void:
 func convert_rgb_to_indexed() -> void:
 	if not is_indexed:
 		return
-	var palette_image := Palettes.current_palette.convert_to_image()
+	var palette_image := Palettes.current_palette.convert_to_image(false)
 	var palette_texture := ImageTexture.create_from_image(palette_image)
 	var params := {
 		"palette_texture": palette_texture, "rgb_texture": ImageTexture.create_from_image(self)

src/Palette/Palette.gd

@@ -25,7 +25,7 @@ var colors_max := 0
 
 
 class PaletteColor:
-	var color := Color.TRANSPARENT
+	var color := Color(0, 0, 0, 0)
 	var index := -1
 
 	func _init(init_color := Color.BLACK, init_index := -1) -> void:
@@ -358,9 +358,11 @@ static func strip_unvalid_characters(string_to_strip: String) -> String:
 	return regex.sub(string_to_strip, "", true)
 
 
-func convert_to_image() -> Image:
+func convert_to_image(crop_image := true) -> Image:
 	var image := Image.create(colors_max, 1, false, Image.FORMAT_RGBA8)
 	for i in colors_max:
 		if colors.has(i):
 			image.set_pixel(i, 0, Color(colors[i].color.to_html()))
+	if crop_image:
+		image.copy_from(image.get_region(image.get_used_rect()))
 	return image