// 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);
}
// 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);
}
