bool GiGraphics::drawPolygon(const GiContext* ctx, int count,
const Point2d* points, bool modelUnit)
{
if (m_impl->drawRefcnt == 0 || count < 2 || points == NULL)
return false;
GiLock lock (&m_impl->drawRefcnt);
if (count > 0x2000)
count = 0x2000;
bool ret = false;
const Box2d extent (count, points); // 模型坐标范围
if (!DRAW_RECT(m_impl, modelUnit).isIntersect(extent)) // 全部在显示区域外
return false;
if (DRAW_MAXR(m_impl, modelUnit).contains(extent)) // 全部在显示区域内
{
ret = _DrawPolygon(m_impl->canvas, ctx,
count, points, true, true, true, modelUnit);
}
else // 部分在显示区域内
{
PolygonClip clip (m_impl->rectDraw);
if (!clip.clip(count, points, &S2D(xf(), modelUnit))) // 多边形剪裁
return false;
count = clip.getCount();
points = clip.getPoints();
ret = _DrawPolygon(m_impl->canvas, ctx,
count, points, false, true, false, modelUnit);
int ienter = findInvisibleEdge(clip);
if (ienter == count)
{
ret = _DrawPolygon(m_impl->canvas, ctx, count, points,
false, false, true, modelUnit) || ret;
}
else
{
ret = drawPolygonEdge(PolylineAux(this, ctx), count, clip, ienter) || ret;
}
}
return ret;
}
bool GiGraphics::drawPolygon(const GiContext* ctx, int count,
const Point2d* points, bool modelUnit)
{
if (count < 2 || !points || isStopping())
return false;
count = count > 0x2000 ? 0x2000 : count;
ctx = ctx ? ctx : &(m_impl->ctx);
bool ret = false;
const Box2d extent (count, points); // 模型坐标范围
if (!DRAW_RECT(m_impl, modelUnit).isIntersect(extent)) // 全部在显示区域外
return false;
if (DRAW_MAXR(m_impl, modelUnit).contains(extent)) { // 全部在显示区域内
ret = _drawPolygon(ctx, count, points, true, true, true, modelUnit);
} else { // 部分在显示区域内
PolygonClip clip (m_impl->rectDraw);
if (!clip.clip(count, points, &S2D(xf(), modelUnit))) // 多边形剪裁
return false;
count = clip.getCount();
points = clip.getPoints();
ret = _drawPolygon(ctx, count, points, false, true, false, modelUnit);
int ienter = findInvisibleEdge(clip);
if (ienter == count) {
ret = _drawPolygon(ctx, count, points, false, false, true, modelUnit) || ret;
} else {
ret = drawPolygonEdge(PolylineAux(this, ctx), count, clip, ienter) || ret;
}
}
return ret;
}
static inline int findInvisibleEdge(const PolygonClip& clip, int i, int end)
{
for (; (i - end) % clip.getCount() != 0 && clip.isLinked(i); i++) ;
return i;
}
static inline int findInvisibleEdge(const PolygonClip& clip)
{
int i = 0;
for (; i < clip.getCount() && clip.isLinked(i); i++) ;
return i;
}