## 8dots3Dtiltspin2.py >>> double buffer added

## 8dots3Dtiltspin2.py >>> double buffer added

import math,e32,appuifw,graphics,key_codes,time,sensor

def draw(rect):
    try: c.blit(img)
    except: pass

xm,ym,x2,y2 = 0,0,0,0
def redraw():
    global xm,ym
    try: ym,xm,zm=(sens.x/10.0,sens.y/10.0,sens.z/10.0) ### Z axis is not needed
    except: pass

def exit(pos):
    global run
    run=0

run = 1
img=graphics.Image.new((640,360))
appuifw.app.directional_pad=False
c=appuifw.Canvas(redraw_callback=draw)
appuifw.app.body=c
c.bind(key_codes.EButton1Down,exit)
sens=sensor.AccelerometerXYZAxisData(data_filter=sensor.LowPassFilter())
sens.set_callback(data_callback=redraw)
sens.start_listening()
appuifw.app.orientation='landscape'
appuifw.app.screen='full'

halfResX = c.size[0]/2
halfResY = c.size[1]/2
distance = 180

PX = 0
PY = 0
PZ = 200
Size = 10
xyz=80
VX = [-xyz, xyz, -xyz, xyz, -xyz, xyz, -xyz, xyz]
VY = [-xyz, -xyz, xyz, xyz, -xyz, -xyz, xyz, xyz]
VZ = [-xyz, -xyz, -xyz, -xyz, xyz, xyz, xyz, xyz]
ANGLEX = 0
ANGLEY = 0
ANGLEZ = 0

while run:
    rax = ANGLEX*math.pi/180
    ray = ANGLEY*math.pi/180
    raz = ANGLEZ*math.pi/180

    sinx = math.sin(rax)
    cosx = math.cos(rax)
    siny = math.sin(ray)
    cosy = math.cos(ray)
    sinz = math.sin(raz)
    cosz = math.cos(raz)

    buf=graphics.Image.new((640,360)) ### not sure if this is the pythonic double buffer, but it works like a charm
    img=graphics.Image.new((640,360))
    try:
        for n in record:
            x,y,z = n
            buf.point((x,y),0xffffff,width=z)
    except:pass

    buf.text((20,40),'X:'+unicode(x2),0xffffff)
    buf.text((20,80),'Y:'+unicode(y2),0xffffff)
    record=[]

    for n in range(8):
        ZX = VX[n]*cosz - VY[n]*sinz - VX[n]
        ZY = VX[n]*sinz + VY[n]*cosz - VY[n]
        YX = (VX[n]+ZX)*cosy - VZ[n]*siny - (VX[n]+ZX)
        YZ = (VX[n]+ZX)*siny + VZ[n]*cosy - VZ[n]
        XY = (VY[n]+ZY)*cosx - (VZ[n]+YZ)*sinx - (VY[n]+ZY)
        XZ = (VY[n]+ZY)*sinx + (VZ[n]+YZ)*cosx - (VZ[n]+YZ)
        XR = YX+ZX
        YR = ZY+XY
        ZR = XZ+YZ
        z = (VZ[n]+PZ+ZR)/distance
        x = ((VX[n]+PX+XR)/z)+halfResX
        y = ((VY[n]+PY+YR)/z)+halfResY
        z = int(Size/z)
        buf.point((int(x),int(y)),0x0000ff,width=z)
        record.append((x,y,z))
    buf.point((PX+halfResX,PY+halfResY),0xff0000,width=Size*3)
    buf.text((20,40),'X:'+unicode(xm),0x000000)
    buf.text((20,80),'Y:'+unicode(ym),0x000000)
    x2,y2=xm,ym

    ANGLEX+=ym
    ANGLEY+=xm
    img=buf
    draw(())

    wait=time.time()+0.005 ### ZZZ might flicker with a less wait
    while time.time() < wait:
        pass
    e32.ao_yield()