本文整理汇总了C++中Vertices::prevPos方法的典型用法代码示例。如果您正苦于以下问题：C++ Vertices::prevPos方法的具体用法？C++ Vertices::prevPos怎么用？C++ Vertices::prevPos使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Vertices的用法示例。
在下文中一共展示了Vertices::prevPos方法的3个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: removeEdges
void QTessellatorPrivate::removeEdges()
{
int cv = currentVertex;
while (cv < vertices.nPoints) {
const Vertex *v = vertices.sorted[cv];
if (v->y > y)
break;
if (v->flags & LineBeforeEnds) {
QDEBUG() << " removing edge" << vertices.prevPos(v);
int pos = scanline.findEdge(vertices.prevPos(v));
if (pos == -1)
continue;
scanline.edges[pos]->mark = true;
if (pos > 0)
scanline.edges[pos - 1]->intersect_right = true;
if (pos < scanline.size - 1)
scanline.edges[pos + 1]->intersect_left = true;
scanline.removeAt(pos);
}
if (v->flags & LineAfterEnds) {
QDEBUG() << " removing edge" << vertices.position(v);
int pos = scanline.findEdge(vertices.position(v));
if (pos == -1)
continue;
scanline.edges[pos]->mark = true;
if (pos > 0)
scanline.edges[pos - 1]->intersect_right = true;
if (pos < scanline.size - 1)
scanline.edges[pos + 1]->intersect_left = true;
scanline.removeAt(pos);
}
++cv;
}
}示例2: addEdges
void QTessellatorPrivate::addEdges()
{
while (currentVertex < vertices.nPoints) {
const Vertex *v = vertices.sorted[currentVertex];
if (v->y > y)
break;
if (v->flags & LineBeforeStarts) {
// add new edge
int start = vertices.prevPos(v);
Edge e(vertices, start);
int pos = scanline.findEdgePosition(e);
QDEBUG() << " adding edge" << start << "at position" << pos;
scanline.insert(pos, e);
if (!mark_clever || !(v->flags & LineAfterEnds)) {
if (pos > 0)
scanline.edges[pos - 1]->mark = true;
if (pos < scanline.size - 1)
scanline.edges[pos + 1]->mark = true;
}
}
if (v->flags & LineAfterStarts) {
Edge e(vertices, vertices.position(v));
int pos = scanline.findEdgePosition(e);
QDEBUG() << " adding edge" << vertices.position(v) << "at position" << pos;
scanline.insert(pos, e);
if (!mark_clever || !(v->flags & LineBeforeEnds)) {
if (pos > 0)
scanline.edges[pos - 1]->mark = true;
if (pos < scanline.size - 1)
scanline.edges[pos + 1]->mark = true;
}
}
if (v->flags & LineAfterHorizontal) {
int pos1 = scanline.findEdgePosition(v->x, v->y);
const Vertex *next = vertices.next(v);
Q_ASSERT(v->y == next->y);
int pos2 = scanline.findEdgePosition(next->x, next->y);
if (pos2 < pos1)
qSwap(pos1, pos2);
if (pos1 > 0)
--pos1;
if (pos2 == scanline.size)
--pos2;
//QDEBUG() << "marking horizontal edge from " << pos1 << "to" << pos2;
scanline.markEdges(pos1, pos2);
}
++currentVertex;
}
}示例3: addIntersection
void QTessellatorPrivate::addIntersection(const Edge *e1, const Edge *e2)
{
const IntersectionLink emptyLink = {-1, -1};
int next = vertices.nextPos(vertices[e1->edge]);
if (e2->edge == next)
return;
int prev = vertices.prevPos(vertices[e1->edge]);
if (e2->edge == prev)
return;
Q27Dot5 yi;
bool det_positive;
bool isect = e1->intersect(*e2, &yi, &det_positive);
QDEBUG("checking edges %d and %d", e1->edge, e2->edge);
if (!isect) {
QDEBUG() << " no intersection";
return;
}
// don't emit an intersection if it's at the start of a line segment or above us
if (yi <= y) {
if (!det_positive)
return;
QDEBUG() << " ----->>>>>> WRONG ORDER!";
yi = y;
}
QDEBUG() << " between edges " << e1->edge << "and" << e2->edge << "at point ("
<< Q27Dot5ToDouble(yi) << ')';
Intersection i1;
i1.y = yi;
i1.edge = e1->edge;
IntersectionLink link1 = intersections.value(i1, emptyLink);
Intersection i2;
i2.y = yi;
i2.edge = e2->edge;
IntersectionLink link2 = intersections.value(i2, emptyLink);
// new pair of edges
if (link1.next == -1 && link2.next == -1) {
link1.next = link1.prev = i2.edge;
link2.next = link2.prev = i1.edge;
} else if (link1.next == i2.edge || link1.prev == i2.edge
|| link2.next == i1.edge || link2.prev == i1.edge) {
#ifdef DEBUG
checkLinkChain(intersections, i1);
checkLinkChain(intersections, i2);
Q_ASSERT(edgeInChain(i1, i2.edge));
#endif
return;
} else if (link1.next == -1 || link2.next == -1) {
if (link2.next == -1) {
qSwap(i1, i2);
qSwap(link1, link2);
}
Q_ASSERT(link1.next == -1);
#ifdef DEBUG
checkLinkChain(intersections, i2);
#endif
// only i2 in list
link1.next = i2.edge;
link1.prev = link2.prev;
link2.prev = i1.edge;
Intersection other;
other.y = yi;
other.edge = link1.prev;
IntersectionLink link = intersections.value(other, emptyLink);
Q_ASSERT(link.next == i2.edge);
Q_ASSERT(link.prev != -1);
link.next = i1.edge;
intersections.insert(other, link);
} else {
bool connected = edgeInChain(i1, i2.edge);
if (connected)
return;
#ifdef DEBUG
checkLinkChain(intersections, i1);
checkLinkChain(intersections, i2);
#endif
// both already in some list. Have to make sure they are connected
// this can be done by cutting open the ring(s) after the two eges and
// connecting them again
Intersection other1;
other1.y = yi;
other1.edge = link1.next;
IntersectionLink linko1 = intersections.value(other1, emptyLink);
Intersection other2;
other2.y = yi;
other2.edge = link2.next;
IntersectionLink linko2 = intersections.value(other2, emptyLink);
linko1.prev = i2.edge;
link2.next = other1.edge;
linko2.prev = i1.edge;
link1.next = other2.edge;
intersections.insert(other1, linko1);
intersections.insert(other2, linko2);
}
//.........这里部分代码省略.........