skia2/experimental/Intersection/CubicBounds.cpp
caryclark@google.com 8dcf114db9 shape ops work in progress
M    Intersection/DataTypes.cpp
M    Intersection/QuadraticIntersection_Test.cpp
M    Intersection/EdgeWalker.cpp
M    Intersection/LineQuadraticIntersection_Test.cpp
M    Intersection/LineIntersection_Test.cpp
M    Intersection/LineIntersection.cpp
D    Intersection/edge.xcodeproj
M    Intersection/SimplifyFindTop_Test.cpp
M    Intersection/DataTypes.h
A    Intersection/SimplifyRect4x4_Test.cpp
M    Intersection/CubicIntersection_Test.cpp
M    Intersection/QuadraticUtilities.h
M    Intersection/LineCubicIntersection_Test.cpp
A    Intersection/CurveUtilities.h
M    Intersection/QuadraticBezierClip.cpp
M    Intersection/QuadraticBounds.cpp
M    Intersection/LineUtilities.h
M    Intersection/Intersection_Tests.cpp
M    Intersection/Simplify.cpp
M    Intersection/EdgeWalker_TestUtility.cpp
M    Intersection/QuadraticUtilities.cpp
M    Intersection/thingsToDo.txt
M    Intersection/LineUtilities.cpp
M    Intersection/CubicUtilities.h
M    Intersection/SimplifyFindNext_Test.cpp
M    Intersection/Intersection_Tests.h
M    Intersection/CubicBezierClip.cpp
M    Intersection/ActiveEdge_Test.cpp
M    Intersection/CubicBounds.cpp
M    Intersection/Simplify.h
M    Intersection/SimplifyNew_Test.cpp
M    Intersection/EdgeWalker_Test.h
M    Intersection/CubicUtilities.cpp
M    Intersection/op.htm
M    Intersection/ConvexHull.cpp
D    Intersection/RectUtilities.cpp
M    Intersection/SimplifyAddIntersectingTs_Test.cpp



git-svn-id: http://skia.googlecode.com/svn/trunk@4429 2bbb7eff-a529-9590-31e7-b0007b416f81
2012-07-02 20:27:02 +00:00

65 lines
1.8 KiB
C++

#include "CurveIntersection.h"
#include "CurveUtilities.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]);
}
}