Cocos 2d draw line doesn't work - ios

Question

I want to draw line on finger touch in cocos 2d.
-(void) ccTouchesMoved:(NSSet *)inappropriateTouches withEvent:(UIEvent *)event
{
UITouch *touch = [inappropriateTouches anyObject];
CGPoint currentTouchArea = [touch locationInView:[touch view] ];
CGPoint lastTouchArea = [touch previousLocationInView:[touch view]];
currentTouchArea = [[CCDirector sharedDirector] convertToGL:currentTouchArea];
lastTouchArea = [[CCDirector sharedDirector] convertToGL:lastTouchArea];
// throw to console my inappropriate touches
NSLog(#"current x=%2f,y=%2f",currentTouchArea.x, currentTouchArea.y);
NSLog(#"last x=%2f,y=%2f",lastTouchArea.x, lastTouchArea.y);
glColor4f(0.8, 1.0, 0.76, 1.0);
glLineWidth(6.0f);
ccDrawLine(currentTouchArea, lastTouchArea);
}
I use this code but nothing is drawn on the screen. What is wrong in my code?

Answer 1

All OpenGL drawing you want to do in the draw method. Like this:
-(void)draw
{
if(lastTouchArea != 0)
{
glColor4f(0.8, 1.0, 0.76, 1.0);
glLineWidth(6.0f);
ccDrawLine(currentTouchArea, lastTouchArea);
lastTouchArea = 0;
}
}

Answer 2

Try this : to save a line in a NSMutableArray
-(void) ccTouchesMoved:(NSSet *)inappropriateTouches withEvent:(UIEvent *)event
{
UITouch *touchMyMinge = [inappropriateTouches anyObject];
CGPoint currentTouchArea = [touchMyMinge locationInView:[touchMyminge view] ];
CGPoint lastTouchArea = [touchMyMinge previousLocationInView:[touchMyMinge view]];
// flip belly up. no one likes being entered from behind.
currentTouchArea = [[CCDirector sharedDirector] convertToGL:currentTouchArea];
lastTouchArea = [[CCDirector sharedDirector] convertToGL:lastTouchArea];
// throw to console my inappropriate touches
NSLog(#"current x=%2f,y=%2f",currentTouchArea.x, currentTouchArea.y);
NSLog(#"last x=%2f,y=%2f",lastTouchArea.x, lastTouchArea.y);
// add my touches to the naughty touch array
naughtyTouchArray addObject:NSStringFromCGPoint(currentTouchArea)];
naughtyTouchArray addObject:NSStringFromCGPoint(lastTouchArea)];
}
#implementation DrawMyTouch
-(id) init
{
if( (self=[super init]))
{ }
return self;
}
-(void)draw
{
glEnable(GL_LINE_SMOOTH);
for(int i = 0; i < [naughtyTouchArray count]; i+=2)
{
start = CGPointFromString([naughtyTouchArray objectAtIndex:i]);
end = CGPointFromString([naughtyTouchArray objectAtIndex:i+1]);
ccDrawLine(start, end);
}
}
-(void) ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
DrawMyTouch *line = [DrawMyTouch node];
[self addChild: line];
}
Hope this help