shape ops work in progress
git-svn-id: http://skia.googlecode.com/svn/trunk@3566 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/Intersection/LineQuadraticIntersection.cpp b/experimental/Intersection/LineQuadraticIntersection.cpp
index 0d6477b..737b767 100644
--- a/experimental/Intersection/LineQuadraticIntersection.cpp
+++ b/experimental/Intersection/LineQuadraticIntersection.cpp
@@ -131,6 +131,16 @@
return roots > 0;
}
+int horizontalIntersect(double axisIntercept) {
+ double D = quad[2].y; // f
+ double E = quad[1].y; // e
+ double F = quad[0].y; // d
+ D += F - 2 * E; // D = d - 2*e + f
+ E -= F; // E = -(d - e)
+ F -= axisIntercept;
+ return quadraticRoots(D, E, F, intersections.fT[0]);
+}
+
protected:
double findLineT(double t) {
@@ -156,7 +166,24 @@
bool moreHorizontal;
};
-
+
+int horizontalIntersect(const Quadratic& quad, double left, double right,
+ double y, double tRange[2]) {
+ Intersections i;
+ LineQuadraticIntersections q(quad, *((_Line*) 0), i);
+ int result = q.horizontalIntersect(y);
+ int tCount = 0;
+ for (int index = 0; index < result; ++index) {
+ double x, y;
+ xy_at_t(quad, i.fT[0][index], x, y);
+ if (x < left || x > right) {
+ continue;
+ }
+ tRange[tCount++] = i.fT[0][index];
+ }
+ return tCount;
+}
+
bool intersect(const Quadratic& quad, const _Line& line, Intersections& i) {
LineQuadraticIntersections q(quad, line, i);
return q.intersect();