add rotation and aspect ration functions for rotation test

lua_examples/u8g_rotation.lua

@@ -0,0 +1,64 @@
+
+-- setup I2c and connect display
+function init_i2c_display()
+     sda = 5
+     scl = 6
+     sla = 0x3c
+     i2c.setup(0, sda, scl, i2c.SLOW)
+     disp = u8g.ssd1306_128x64_i2c(sla)
+end
+
+-- the draw() routine
+function draw()
+     disp:setFont(u8g.font_6x10)
+     disp:drawStr( 0+0, 20+0, "Hello!")
+     disp:drawStr( 0+2, 20+16, "Hello!")
+
+     disp:drawBox(0, 0, 3, 3)
+     disp:drawBox(disp:getWidth()-6, 0, 6, 6)
+     disp:drawBox(disp:getWidth()-9, disp:getHeight()-9, 9, 9)
+     disp:drawBox(0, disp:getHeight()-12, 12, 12)
+end
+
+
+function rotate()
+     if (next_rotation < tmr.now() / 1000) then
+          if (dir == 0) then
+               disp:undoRotation()
+          elseif (dir == 1) then
+               disp:setRot90()
+          elseif (dir == 2) then
+               disp:setRot180()
+          elseif (dir == 3) then
+               disp:setRot270()
+          end
+
+          dir = dir + 1
+          dir = bit.band(dir, 3)
+          next_rotation = tmr.now() / 1000 + 1000
+     end
+end
+
+function rotation_test()
+     init_i2c_display()
+
+     print("--- Starting Rotation Test ---")
+     dir = 0
+     next_rotation = 0
+
+     local loopcnt
+     for loopcnt = 1, 100, 1 do
+          rotate()
+
+          disp:firstPage()
+          repeat
+               draw(draw_state)
+          until disp:nextPage() == false
+
+          tmr.wdclr()
+     end
+
+     print("--- Rotation Test done ---")
+end
+
+rotation_test()