Ahhhh...After trying long hours ...found an solution..
Just one line on CanvasView.swift
override func draw(_ rect: CGRect) {
let context = UIGraphicsGetCurrentContext()!
context.setLineCap(.round)
needsFullRedraw = false //Added this line
if (needsFullRedraw) {
setFrozenImageNeedsUpdate()
frozenContext.clear(bounds)
for array in [finishedLines,lines] {
for line in array {
line.drawCommitedPointsInContext(frozenContext, isDebuggingEnabled: isDebuggingEnabled, usePreciseLocation: usePreciseLocations)
}
}
needsFullRedraw = false
}
frozenImage = frozenImage ?? frozenContext.makeImage()
if let frozenImage = frozenImage {
context.draw(frozenImage, in: bounds)
}
for line in lines {
line.drawInContext(context, isDebuggingEnabled: isDebuggingEnabled, usePreciseLocation: usePreciseLocations)
}
}
or just commented the following line
/*if (needsFullRedraw) {
setFrozenImageNeedsUpdate()
frozenContext.clear(bounds)
for array in [finishedLines,lines] {
for line in array {
line.drawCommitedPointsInContext(frozenContext, isDebuggingEnabled: isDebuggingEnabled, usePreciseLocation: usePreciseLocations)
}
}
needsFullRedraw = false
}*/