import ui
import numpy as np
W=1024



import time
from objc_util import *
CAShapeLayer=ObjCClass('CAShapeLayer')

t=np.linspace(0,1,1024)
f=25
class plotView(ui.View):
	def update(self):

		y=self.A*np.sin(2*np.pi*f*t)*np.exp(-t/self.tau)+self.height/2
		p=ui.Path()
		p.move_to(0,y[0])
		for ti,yi in zip((t-t[0])/(t[-1]-t[0])*W,y):
			p.line_to(ti,yi)

		self.L.path=p.objc_instance.CGPath()
		self.L.setNeedsDisplay()
		self.fps.text='{}'.format(1/(time.perf_counter()-self.t))
		self.t=time.perf_counter()
	def __init__(self):
		self.bg_color='white'
		L=CAShapeLayer.alloc().init()
		L.strokeColor=UIColor.redColor().CGColor()
		L.fillColor=UIColor.clearColor().CGColor()
		L.lineWidth=2
		self.objc_instance.layer().addSublayer_(L)
		L.setNeedsDisplay()
		self.L=L
		self.tau=1
		self.A=200
		self.fps=ui.Label(0,0,100,40)
		self.fps.text='0.0'
		self.t=time.perf_counter()
		self.add_subview(self.fps)
	def touch_moved(self,touch):
		x,y=touch.location
		#up/down bumps up amplitude
		#l/r changes tau
		self.tau=x/1024
		self.A=y-self.center.y
		self.update()
		#self.L.setNeedsDisplay()


v=plotView()
#v.update_interval=1/15

v.present()