static bool drawPolygonEdge(const PolylineAux& aux, int count, const PolygonClip& clip, int ienter) { bool ret = false; vector<Point2d> pxpoints; Point2d pt1, pt2; int si, ei, n, i; for (ei = ienter + 1; (ei - ienter) % count != 0; ) { si = findVisibleEdge(clip, ei, ienter); ei = findInvisibleEdge(clip, si, ienter); n = ei - si + 1; if (n > 1) { pxpoints.resize(n); Point2d *pxs = &pxpoints.front(); n = 0; for (i = si; i <= ei; i++) { pt2 = clip.getPoint(i); if (i == si || fabsf(pt1.x - pt2.x) > 2 || fabsf(pt1.y - pt2.y) > 2) { pt1 = pt2; pxs[n++] = pt1; } } ret = aux.draw(pxs, n) || ret; } } return ret; }
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; }