Example #1
0
// A generic function for finding the target node with the lowest distance metric. A distance metric here is the result
// of a distance-like function, that computes how well the touch hits the node.
// Distance functions could for instance be distance squared or area of intersection.
bool findNodeWithLowestDistanceMetric(Node*& targetNode, IntPoint& targetPoint, IntRect& targetArea, const IntPoint& touchHotspot, const IntRect& touchArea, SubtargetGeometryList& subtargets, DistanceFunction distanceFunction)
{
    targetNode = 0;
    float bestDistanceMetric = std::numeric_limits<float>::infinity();
    SubtargetGeometryList::const_iterator it = subtargets.begin();
    const SubtargetGeometryList::const_iterator end = subtargets.end();
    IntPoint adjustedPoint;

    for (; it != end; ++it) {
        Node* node = it->node();
        float distanceMetric = distanceFunction(touchHotspot, touchArea, *it);
        if (distanceMetric < bestDistanceMetric) {
            if (snapTo(*it, touchHotspot, touchArea, adjustedPoint)) {
                targetPoint = adjustedPoint;
                targetArea = it->boundingBox();
                targetNode = node;
                bestDistanceMetric = distanceMetric;
            }
        } else if (distanceMetric - bestDistanceMetric < zeroTolerance) {
            if (snapTo(*it, touchHotspot, touchArea, adjustedPoint)) {
                if (node->isDescendantOf(targetNode)) {
                    // Try to always return the inner-most element.
                    targetPoint = adjustedPoint;
                    targetNode = node;
                    targetArea = it->boundingBox();
                }
            }
        }
    }
    if (targetNode) {
        targetArea = targetNode->document()->view()->contentsToWindow(targetArea);
    }
    return (targetNode);
}
Example #2
0
// A generic function for finding the target node with the lowest distance metric. A distance metric here is the result
// of a distance-like function, that computes how well the touch hits the node.
// Distance functions could for instance be distance squared or area of intersection.
bool findNodeWithLowestDistanceMetric(Node*& targetNode, IntPoint& targetPoint, const IntPoint& touchHotspot, const IntRect& touchArea, SubtargetGeometryList& subtargets, DistanceFunction distanceFunction)
{
    targetNode = 0;
    float bestDistanceMetric = INFINITY;
    SubtargetGeometryList::const_iterator it = subtargets.begin();
    const SubtargetGeometryList::const_iterator end = subtargets.end();
    for (; it != end; ++it) {
        Node* node = it->node();
        float distanceMetric = distanceFunction(touchHotspot, touchArea, *it);
        if (distanceMetric < bestDistanceMetric) {
            targetPoint = roundedIntPoint(it->quad().center());
            targetNode = node;
            bestDistanceMetric = distanceMetric;
        } else if (distanceMetric == bestDistanceMetric) {
            // Try to always return the inner-most element.
            if (node->isDescendantOf(targetNode))
                targetNode = node;
        }
    }

    return (targetNode);
}