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Diffstat (limited to 'experimental/Intersection/BezierClip.cpp')
-rw-r--r-- | experimental/Intersection/BezierClip.cpp | 83 |
1 files changed, 0 insertions, 83 deletions
diff --git a/experimental/Intersection/BezierClip.cpp b/experimental/Intersection/BezierClip.cpp deleted file mode 100644 index 1b5c60c182..0000000000 --- a/experimental/Intersection/BezierClip.cpp +++ /dev/null @@ -1,83 +0,0 @@ -#include "CubicIntersection.h" -#include "LineParameters.h" -#include <algorithm> // used for std::swap - -// return false if unable to clip (e.g., unable to create implicit line) -// caller should subdivide, or create degenerate if the values are too small -bool bezier_clip(const Cubic& cubic1, const Cubic& cubic2, double& minT, double& maxT) { - minT = 1; - maxT = 0; - // determine normalized implicit line equation for pt[0] to pt[3] - // of the form ax + by + c = 0, where a*a + b*b == 1 - - // find the implicit line equation parameters - LineParameters endLine; - endLine.cubicEndPoints(cubic1); - if (!endLine.normalize()) { - printf("line cannot be normalized: need more code here\n"); - return false; - } - - double distance[2]; - endLine.controlPtDistance(cubic1, distance); - - // find fat line - double top = distance[0]; - double bottom = distance[1]; - if (top > bottom) { - std::swap(top, bottom); - } - if (top * bottom >= 0) { - const double scale = 3/4.0; // http://cagd.cs.byu.edu/~tom/papers/bezclip.pdf (13) - if (top < 0) { - top *= scale; - bottom = 0; - } else { - top = 0; - bottom *= scale; - } - } else { - const double scale = 4/9.0; // http://cagd.cs.byu.edu/~tom/papers/bezclip.pdf (15) - top *= scale; - bottom *= scale; - } - - // compute intersecting candidate distance - Cubic distance2y; // points with X of (0, 1/3, 2/3, 1) - endLine.cubicDistanceY(cubic2, distance2y); - - int flags = 0; - if (approximately_lesser(distance2y[0].y, top)) { - flags |= kFindTopMin; - } else if (approximately_greater(distance2y[0].y, bottom)) { - flags |= kFindBottomMin; - } else { - minT = 0; - } - - if (approximately_lesser(distance2y[3].y, top)) { - flags |= kFindTopMax; - } else if (approximately_greater(distance2y[3].y, bottom)) { - flags |= kFindBottomMax; - } else { - maxT = 1; - } - // Find the intersection of distance convex hull and fat line. - char to_0[2]; - char to_3[2]; - bool do_1_2_edge = convex_x_hull(distance2y, to_0, to_3); - x_at(distance2y[0], distance2y[to_0[0]], top, bottom, flags, minT, maxT); - if (to_0[0] != to_0[1]) { - x_at(distance2y[0], distance2y[to_0[1]], top, bottom, flags, minT, maxT); - } - x_at(distance2y[to_3[0]], distance2y[3], top, bottom, flags, minT, maxT); - if (to_3[0] != to_3[1]) { - x_at(distance2y[to_3[1]], distance2y[3], top, bottom, flags, minT, maxT); - } - if (do_1_2_edge) { - x_at(distance2y[1], distance2y[2], top, bottom, flags, minT, maxT); - } - - return minT < maxT; // returns false if distance shows no intersection -} - |