Line Drawn Using CCSprite is Close or Open

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Line Drawn Using CCSprite is Close or Open

(4 posts) (3 voices)

Started 3 months ago by anandgupadhyay
Latest reply from anandgupadhyay

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anandgupadhyay
Member

User can draw any shape on screen,

Drawing Line Using CCSprite

-(void) ccTouchesMoved:(NSSet *)touchess withEvent:(UIEvent *)event
        {
            UITouch *touchMyMinge = [touchess anyObject];
            CGPoint start = [self convertTouchToNodeSpace:touchMyMinge];
            CGPoint end = [touchMyMinge previousLocationInView:touchMyMinge.view];
            end = [[CCDirector sharedDirector]convertToGL:end];
            end = [self convertToNodeSpace:end];

            NSValue *value= [NSValue valueWithCGPoint:start];
            [linePoints addObject:value ];

            float distance = ccpDistance(start, end);
            for (int i = 0; i < distance; i++)
            {
                float difx = end.x - start.x;
                float dify = end.y - start.y;
                float delta = (float)i / distance;
                brush = [[CCSprite spriteWithFile:[NSString stringWithFormat:@"Circle%d.png",1]] retain];
                brush.scale = 2.0f;
                [brush setPosition:ccp(start.x + (difx * delta), start.y + (dify * delta))];
                [self add![enter image description here][1]Child:brush];
                [lineSprites addObject:brush];
            }
        }

--> How to Check whether User drawn path is complete shape(I call it Close) or just an open line (I call it open).

Hope,I am able to explain what is the required,
Hopping for quick reply,

Thanks in advance.

Posted 3 months ago #

Krithik B
Member

Check out A Star Pathfinding algorithm , i guess it will be useful .

Posted 3 months ago #

tbone28
Member

In my game Star Catch this is how I find out if I have closed the loop

- (BOOL) lineIntersectOccured:(CGPoint)t1 pointEnd:(CGPoint)t2 {
	BOOL result = NO;
	int pointsCount = [points count];

	CGPoint cp1;
	CGPoint cp2;

	for(int i = 0, j = 1; j < pointsCount; i++,j++) {
		[[points objectAtIndex:i] getValue:&cp1];
		[[points objectAtIndex:j] getValue:&cp2];

		// lines connected do not need to be included.
		if((cp2.x == t1.x && cp2.y == t1.y) || (cp1.x == t2.x && cp1.y == t2.y)) {
			continue;
		}

		CGPoint diffLA = CGPointMake(cp2.x - cp1.x,cp2.y - cp1.y);
		CGPoint diffLB = CGPointMake(t2.x - t1.x, t2.y - t1.y);

		float compA = diffLA.x*cp1.y - diffLA.y * cp1.x;
		float compB = diffLB.x*t1.y - diffLB.y*t1.x;

		BOOL compA1 = (diffLA.x*t1.y - diffLA.y*t1.x) < compA;
		BOOL compA2 = (diffLA.x*t2.y - diffLA.y*t2.x) < compA;
		BOOL compB1 = (diffLB.x*cp1.y - diffLB.y*cp1.x) < compB;
		BOOL compB2 = (diffLB.x*cp2.y - diffLB.y*cp2.x) < compB;

		if(((!compA1 && compA2) || (compA1 && !compA2)) && ((!compB1 && compB2) || (compB1 && !compB2))) {
			result = YES;
			pointArrayIntersectPos = j;

			if((cp2.x - cp1.x) == 0) {
				intersect.x = cp2.x;
				intersect.y = cp1.y;
			}
			else if((t2.x - t1.x) == 0) {
				intersect.x = t2.x;
				intersect.y = t1.y;
			}
			else {
				float p1slope = (cp2.y - cp1.y) / (cp2.x - cp1.x);
				float p2slope = (t2.y - t1.y) / (t2.x - t1.x);
				intersect.x = (p1slope * cp1.x - p2slope * t1.x + t1.y - cp1.y) / (p1slope - p2slope);
				intersect.y = p1slope * (intersect.x - cp1.x) + cp1.y;
			}
		}
	}

	return result;
}

Line Drawn Using CCSprite is Close or Open

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