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/CubicBounds.cpp b/experimental/Intersection/CubicBounds.cpp
index 3534425..5d21be6 100644
--- a/experimental/Intersection/CubicBounds.cpp
+++ b/experimental/Intersection/CubicBounds.cpp
@@ -1,10 +1,63 @@
-/*
- * CubicBounds.cpp
- * edge
- *
- * Created by Cary Clark on 1/27/12.
- * Copyright 2012 __MyCompanyName__. All rights reserved.
- *
- */
+#include "DataTypes.h"
+#include "Extrema.h"
+static int isBoundedByEndPoints(double a, double b, double c, double d)
+{
+ return (a <= b && a <= c && b <= d && c <= d)
+ || (a >= b && a >= c && b >= d && c >= d);
+}
+double leftMostT(const Cubic& cubic, double startT, double endT) {
+ double leftTs[2];
+ _Point pt[2];
+ int results = findExtrema(cubic[0].x, cubic[1].x, cubic[2].x, cubic[3].x,
+ leftTs);
+ int best = -1;
+ for (int index = 0; index < results; ++index) {
+ if (startT > leftTs[index] || leftTs[index] > endT) {
+ continue;
+ }
+ if (best < 0) {
+ best = index;
+ continue;
+ }
+ xy_at_t(cubic, leftTs[0], pt[0].x, pt[0].y);
+ xy_at_t(cubic, leftTs[1], pt[1].x, pt[1].y);
+ if (pt[0].x > pt[1].x) {
+ best = 1;
+ }
+ }
+ if (best >= 0) {
+ return leftTs[best];
+ }
+ xy_at_t(cubic, startT, pt[0].x, pt[0].y);
+ xy_at_t(cubic, endT, pt[1].x, pt[1].y);
+ return pt[0].x <= pt[1].x ? startT : endT;
+}
+
+void _Rect::setBounds(const Cubic& cubic) {
+ set(cubic[0]);
+ add(cubic[3]);
+ double tValues[4];
+ int roots = 0;
+ if (!isBoundedByEndPoints(cubic[0].x, cubic[1].x, cubic[2].x, cubic[3].x)) {
+ roots = findExtrema(cubic[0].x, cubic[1].x, cubic[2].x,
+ cubic[3].x, tValues);
+ }
+ if (!isBoundedByEndPoints(cubic[0].y, cubic[1].y, cubic[2].y, cubic[3].y)) {
+ roots += findExtrema(cubic[0].y, cubic[1].y, cubic[2].y,
+ cubic[3].y, &tValues[roots]);
+ }
+ for (int x = 0; x < roots; ++x) {
+ _Point result;
+ xy_at_t(cubic, tValues[x], result.x, result.y);
+ add(result);
+ }
+}
+
+void _Rect::setRawBounds(const Cubic& cubic) {
+ set(cubic[0]);
+ for (int x = 1; x < 4; ++x) {
+ add(cubic[x]);
+ }
+}