# Resize `buffer_array` and `buffer_element` to fit all `sprites` (and more)
	fun resize
	do
		app.perf_clock_sprites.lapse

		# Allocate a bit more space
		var capacity = (sprites.capacity.to_f * resize_ratio).to_i

		var array_bytes = capacity * bytes_per_sprite
		glBindBuffer(gl_ARRAY_BUFFER, buffer_array)
		assert glIsBuffer(buffer_array)
		glBufferData(gl_ARRAY_BUFFER, array_bytes, new Pointer.nul, usage)
		assert glGetError == gl_NO_ERROR

		# GL_TRIANGLES 6 vertices * sprite
		var n_indices = capacity * indices_per_sprite
		var ius = 2 # sizeof(GL_UNSIGNED_SHORT)
		var element_bytes = n_indices * ius
		glBindBuffer(gl_ELEMENT_ARRAY_BUFFER, buffer_element)
		assert glIsBuffer(buffer_element)
		glBufferData(gl_ELEMENT_ARRAY_BUFFER, element_bytes, new Pointer.nul, usage)
		assert glGetError == gl_NO_ERROR

		buffer_capacity = capacity

		sys.perfs["gamnit flat gpu resize"].add app.perf_clock_sprites.lapse
	end