rpgedit/dist/resources/entity/red_circle.json

{
	"sprite": "red_circle",
	"collision": [
		{
			"type": "polygon",
			"vertices": [
				[-0.5, -0.5],
				[-0.5, 0.5],
				[0.5, 0.5],
				[0.5, -0.5]
			]
		}
	]
}