c682590538
git-svn-id: http://skia.googlecode.com/svn/trunk@3141 2bbb7eff-a529-9590-31e7-b0007b416f81
59 lines
2.1 KiB
C++
59 lines
2.1 KiB
C++
#include "CurveIntersection.h"
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#include "TestUtilities.h"
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void quad_to_cubic(const Quadratic& quad, Cubic& cubic) {
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cubic[0] = quad[0];
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cubic[1].x = quad[0].x / 3 + quad[1].x * 2 / 3;
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cubic[1].y = quad[0].y / 3 + quad[1].y * 2 / 3;
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cubic[2].x = quad[2].x / 3 + quad[1].x * 2 / 3;
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cubic[2].y = quad[2].y / 3 + quad[1].y * 2 / 3;
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cubic[3] = quad[2];
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}
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static bool tiny(const Cubic& cubic) {
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int index, minX, maxX, minY, maxY;
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minX = maxX = minY = maxY = 0;
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for (index = 1; index < 4; ++index) {
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if (cubic[minX].x > cubic[index].x) {
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minX = index;
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}
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if (cubic[minY].y > cubic[index].y) {
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minY = index;
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}
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if (cubic[maxX].x < cubic[index].x) {
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maxX = index;
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}
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if (cubic[maxY].y < cubic[index].y) {
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maxY = index;
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}
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}
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return approximately_equal(cubic[maxX].x, cubic[minX].x)
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&& approximately_equal(cubic[maxY].y, cubic[minY].y);
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}
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void find_tight_bounds(const Cubic& cubic, _Rect& bounds) {
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CubicPair cubicPair;
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chop_at(cubic, cubicPair, 0.5);
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if (!tiny(cubicPair.first()) && !controls_inside(cubicPair.first())) {
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find_tight_bounds(cubicPair.first(), bounds);
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} else {
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bounds.add(cubicPair.first()[0]);
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bounds.add(cubicPair.first()[3]);
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}
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if (!tiny(cubicPair.second()) && !controls_inside(cubicPair.second())) {
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find_tight_bounds(cubicPair.second(), bounds);
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} else {
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bounds.add(cubicPair.second()[0]);
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bounds.add(cubicPair.second()[3]);
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}
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}
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bool controls_inside(const Cubic& cubic) {
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return
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((cubic[0].x <= cubic[1].x && cubic[0].x <= cubic[2].x && cubic[1].x <= cubic[3].x && cubic[2].x <= cubic[3].x)
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|| (cubic[0].x >= cubic[1].x && cubic[0].x >= cubic[2].x && cubic[1].x >= cubic[3].x && cubic[2].x >= cubic[3].x))
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&& ((cubic[0].y <= cubic[1].y && cubic[0].y <= cubic[2].y && cubic[1].y <= cubic[3].y && cubic[2].y <= cubic[3].y)
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|| (cubic[0].y >= cubic[1].y && cubic[0].y >= cubic[2].y && cubic[1].y >= cubic[3].y && cubic[2].x >= cubic[3].y));
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}
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