work in progress
in the middle of switching to sortless version
git-svn-id: http://skia.googlecode.com/svn/trunk@3768 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/Intersection/LineCubicIntersection.cpp b/experimental/Intersection/LineCubicIntersection.cpp
index 8517b7e..6f2cf6c 100644
--- a/experimental/Intersection/LineCubicIntersection.cpp
+++ b/experimental/Intersection/LineCubicIntersection.cpp
@@ -109,6 +109,13 @@
return cubicRoots(A, B, C, D, range);
}
+int verticalIntersect(double axisIntercept) {
+ double A, B, C, D;
+ coefficients(&cubic[0].x, A, B, C, D);
+ D -= axisIntercept;
+ return cubicRoots(A, B, C, D, range);
+}
+
double findLineT(double t) {
const double* cPtr;
const double* lPtr;
@@ -158,6 +165,56 @@
return result;
}
+int horizontalIntersect(const Cubic& cubic, double left, double right, double y,
+ bool flipped, Intersections& intersections) {
+ LineCubicIntersections c(cubic, *((_Line*) 0), intersections.fT[0]);
+ int result = c.horizontalIntersect(y);
+ for (int index = 0; index < result; ) {
+ double x, y;
+ xy_at_t(cubic, intersections.fT[0][index], x, y);
+ if (x < left || x > right) {
+ if (--result > index) {
+ intersections.fT[0][index] = intersections.fT[0][result];
+ }
+ continue;
+ }
+ intersections.fT[0][index] = (x - left) / (right - left);
+ ++index;
+ }
+ if (flipped) {
+ // OPTIMIZATION: instead of swapping, pass original line, use [1].x - [0].x
+ for (int index = 0; index < result; ++index) {
+ intersections.fT[1][index] = 1 - intersections.fT[1][index];
+ }
+ }
+ return result;
+}
+
+int verticalIntersect(const Cubic& cubic, double top, double bottom, double x,
+ bool flipped, Intersections& intersections) {
+ LineCubicIntersections c(cubic, *((_Line*) 0), intersections.fT[0]);
+ int result = c.verticalIntersect(x);
+ for (int index = 0; index < result; ) {
+ double x, y;
+ xy_at_t(cubic, intersections.fT[0][index], x, y);
+ if (y < top || y > bottom) {
+ if (--result > index) {
+ intersections.fT[0][index] = intersections.fT[0][result];
+ }
+ continue;
+ }
+ intersections.fT[0][index] = (y - top) / (bottom - top);
+ ++index;
+ }
+ if (flipped) {
+ // OPTIMIZATION: instead of swapping, pass original line, use [1].x - [0].x
+ for (int index = 0; index < result; ++index) {
+ intersections.fT[1][index] = 1 - intersections.fT[1][index];
+ }
+ }
+ return result;
+}
+
int intersect(const Cubic& cubic, const _Line& line, double cRange[3], double lRange[3]) {
LineCubicIntersections c(cubic, line, cRange);
int roots;