Index: experimental/Intersection/ConvexHull.cpp |
diff --git a/experimental/Intersection/ConvexHull.cpp b/experimental/Intersection/ConvexHull.cpp |
deleted file mode 100644 |
index 86cb2dc6f5d2df16246625f08b24f07aa7903f18..0000000000000000000000000000000000000000 |
--- a/experimental/Intersection/ConvexHull.cpp |
+++ /dev/null |
@@ -1,143 +0,0 @@ |
-/* |
- * Copyright 2012 Google Inc. |
- * |
- * Use of this source code is governed by a BSD-style license that can be |
- * found in the LICENSE file. |
- */ |
-#include "CurveIntersection.h" |
-#include "CurveUtilities.h" |
-#include "IntersectionUtilities.h" |
- |
-/* Given a cubic, find the convex hull described by the end and control points. |
- The hull may have 3 or 4 points. Cubics that degenerate into a point or line |
- are not considered. |
- |
- The hull is computed by assuming that three points, if unique and non-linear, |
- form a triangle. The fourth point may replace one of the first three, may be |
- discarded if in the triangle or on an edge, or may be inserted between any of |
- the three to form a convex quadralateral. |
- |
- The indices returned in order describe the convex hull. |
-*/ |
-int convex_hull(const Cubic& cubic, char order[4]) { |
- size_t index; |
- // find top point |
- size_t yMin = 0; |
- for (index = 1; index < 4; ++index) { |
- if (cubic[yMin].y > cubic[index].y || (cubic[yMin].y == cubic[index].y |
- && cubic[yMin].x > cubic[index].x)) { |
- yMin = index; |
- } |
- } |
- order[0] = yMin; |
- int midX = -1; |
- int backupYMin = -1; |
- for (int pass = 0; pass < 2; ++pass) { |
- for (index = 0; index < 4; ++index) { |
- if (index == yMin) { |
- continue; |
- } |
- // rotate line from (yMin, index) to axis |
- // see if remaining two points are both above or below |
- // use this to find mid |
- int mask = other_two(yMin, index); |
- int side1 = yMin ^ mask; |
- int side2 = index ^ mask; |
- Cubic rotPath; |
- if (!rotate(cubic, yMin, index, rotPath)) { // ! if cbc[yMin]==cbc[idx] |
- order[1] = side1; |
- order[2] = side2; |
- return 3; |
- } |
- int sides = side(rotPath[side1].y - rotPath[yMin].y); |
- sides ^= side(rotPath[side2].y - rotPath[yMin].y); |
- if (sides == 2) { // '2' means one remaining point <0, one >0 |
- if (midX >= 0) { |
- printf("%s unexpected mid\n", __FUNCTION__); // there can be only one mid |
- } |
- midX = index; |
- } else if (sides == 0) { // '0' means both to one side or the other |
- backupYMin = index; |
- } |
- } |
- if (midX >= 0) { |
- break; |
- } |
- if (backupYMin < 0) { |
- break; |
- } |
- yMin = backupYMin; |
- backupYMin = -1; |
- } |
- if (midX < 0) { |
- midX = yMin ^ 3; // choose any other point |
- } |
- int mask = other_two(yMin, midX); |
- int least = yMin ^ mask; |
- int most = midX ^ mask; |
- order[0] = yMin; |
- order[1] = least; |
- |
- // see if mid value is on same side of line (least, most) as yMin |
- Cubic midPath; |
- if (!rotate(cubic, least, most, midPath)) { // ! if cbc[least]==cbc[most] |
- order[2] = midX; |
- return 3; |
- } |
- int midSides = side(midPath[yMin].y - midPath[least].y); |
- midSides ^= side(midPath[midX].y - midPath[least].y); |
- if (midSides != 2) { // if mid point is not between |
- order[2] = most; |
- return 3; // result is a triangle |
- } |
- order[2] = midX; |
- order[3] = most; |
- return 4; // result is a quadralateral |
-} |
- |
-/* Find the convex hull for cubics with the x-axis interval regularly spaced. |
- Cubics computed as distance functions are formed this way. |
- |
- connectTo0[0], connectTo0[1] are the point indices that cubic[0] connects to. |
- connectTo3[0], connectTo3[1] are the point indices that cubic[3] connects to. |
- |
- Returns true if cubic[1] to cubic[2] also forms part of the hull. |
-*/ |
-bool convex_x_hull(const Cubic& cubic, char connectTo0[2], char connectTo3[2]) { |
- double projectedY[4]; |
- projectedY[0] = 0; |
- int index; |
- for (index = 1; index < 4; ++index) { |
- projectedY[index] = (cubic[index].y - cubic[0].y) * (3.0 / index); |
- } |
- int lower0Index = 1; |
- int upper0Index = 1; |
- for (index = 2; index < 4; ++index) { |
- if (approximately_greater_or_equal(projectedY[lower0Index], projectedY[index])) { |
- lower0Index = index; |
- } |
- if (approximately_lesser_or_equal(projectedY[upper0Index], projectedY[index])) { |
- upper0Index = index; |
- } |
- } |
- connectTo0[0] = lower0Index; |
- connectTo0[1] = upper0Index; |
- for (index = 0; index < 3; ++index) { |
- projectedY[index] = (cubic[3].y - cubic[index].y) * (3.0 / (3 - index)); |
- } |
- projectedY[3] = 0; |
- int lower3Index = 2; |
- int upper3Index = 2; |
- for (index = 1; index > -1; --index) { |
- if (approximately_greater_or_equal(projectedY[lower3Index], projectedY[index])) { |
- lower3Index = index; |
- } |
- if (approximately_lesser_or_equal(projectedY[upper3Index], projectedY[index])) { |
- upper3Index = index; |
- } |
- } |
- connectTo3[0] = lower3Index; |
- connectTo3[1] = upper3Index; |
- return (1 << lower0Index | 1 << upper0Index |
- | 1 << lower3Index | 1 << upper3Index) == 0x0F; |
-} |