calcPositions for WordCloudView

calcPositions.swift

func checkIntersects(rect: CGRect, rects: [CGRect]) -> Bool {
    for r in rects {
        if rect.intersects(r) {
            return true
        }
    }
    return false
}

func checkOutsideBoundry(canvasSize: CGSize, rect: CGRect) -> Bool {
    if rect.maxY > canvasRect.height/2 {
        return true
    }
    if rect.minY < -canvasRect.height/2 {
        return true
    }
    return false
}

func calcPositions(canvasSize: CGSize, itemSizes: [CGSize]) -> [CGPoint] {
    var pos = [CGPoint](repeating: CGPoint.zero, count: itemSizes.count)
    if canvasSize.height == 0 {
        return pos
    }

    var rects = [CGRect]()
    
    var step : CGFloat = 0
    let ratio = canvasSize.width * 1.5 / canvasSize.height
    
    let startPos = CGPoint(x: CGFloat.random(in: 0...1) * canvasSize.width * 0.1,
                           y: CGFloat.random(in: 0...1) * canvasSize.height * 0.1)
    
    for (index, itemSize) in itemSizes.enumerated() {
        var nextRect = CGRect(origin: CGPoint(x: startPos.x - itemSize.width/2,
                                              y: startPos.y - itemSize.height/2),
                              size: itemSize)
        if index > 0 {
            while checkOutsideBoundry(canvasSize: canvasSize,
                                      rect: nextRect)
                    || checkIntersects(rect: nextRect, rects: rects) {
                nextRect.origin.x = startPos.x + ratio * step * cos(step) + startPos.x - itemSize.width/2
                nextRect.origin.y = startPos.y + step * sin(step) + startPos.y - itemSize.height/2
                step = step + 0.01
            }
        }
        pos[index] = nextRect.center
        rects.append(nextRect)
    }
    return pos
}