9e49fb63d3
add copyrights everywhere start working on quadratic line segments (for quad intersection) git-svn-id: http://skia.googlecode.com/svn/trunk@5286 2bbb7eff-a529-9590-31e7-b0007b416f81
54 lines
1.4 KiB
C++
54 lines
1.4 KiB
C++
/*
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* Copyright 2012 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "CurveIntersection.h"
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#include "CurveUtilities.h"
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#include "Extrema.h"
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static int isBoundedByEndPoints(double a, double b, double c)
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{
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return (a <= b && b <= c) || (a >= b && b >= c);
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}
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double leftMostT(const Quadratic& quad, double startT, double endT) {
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double leftT;
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if (findExtrema(quad[0].x, quad[1].x, quad[2].x, &leftT)
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&& startT <= leftT && leftT <= endT) {
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return leftT;
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}
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_Point startPt;
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xy_at_t(quad, startT, startPt.x, startPt.y);
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_Point endPt;
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xy_at_t(quad, endT, endPt.x, endPt.y);
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return startPt.x <= endPt.x ? startT : endT;
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}
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void _Rect::setBounds(const Quadratic& quad) {
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set(quad[0]);
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add(quad[2]);
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double tValues[2];
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int roots = 0;
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if (!isBoundedByEndPoints(quad[0].x, quad[1].x, quad[2].x)) {
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roots = findExtrema(quad[0].x, quad[1].x, quad[2].x, tValues);
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}
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if (!isBoundedByEndPoints(quad[0].y, quad[1].y, quad[2].y)) {
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roots += findExtrema(quad[0].y, quad[1].y, quad[2].y,
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&tValues[roots]);
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}
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for (int x = 0; x < roots; ++x) {
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_Point result;
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xy_at_t(quad, tValues[x], result.x, result.y);
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add(result);
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}
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}
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void _Rect::setRawBounds(const Quadratic& quad) {
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set(quad[0]);
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for (int x = 1; x < 3; ++x) {
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add(quad[x]);
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}
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}
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