From 9166dcb3a0e8784bea83d76ae01aa338c049ae05 Mon Sep 17 00:00:00 2001 From: "caryclark@google.com" Date: Mon, 8 Apr 2013 11:50:00 +0000 Subject: Add intersections for path ops This CL depends on https://codereview.chromium.org/12827020/ "Add base types for path ops" The intersection of a line, quadratic, or cubic with another curve (or with itself) is found by solving the implicit equation for the curve pair. The curves are first reduced to find the simplest form that will describe the original, and to detect degenerate or special-case data like horizontal and vertical lines. For cubic self-intersection, and for a pair of cubics, the intersection is found by recursively approximating the cubic with a series of quadratics. The implicit solutions depend on the root finding contained in the DCubic and DQuad structs, and the quartic root finder included here. Review URL: https://codereview.chromium.org/12880016 git-svn-id: http://skia.googlecode.com/svn/trunk@8552 2bbb7eff-a529-9590-31e7-b0007b416f81 --- tests/PathOpsQuadLineIntersectionTest.cpp | 132 ++++++++++++++++++++++++++++++ 1 file changed, 132 insertions(+) create mode 100644 tests/PathOpsQuadLineIntersectionTest.cpp (limited to 'tests/PathOpsQuadLineIntersectionTest.cpp') diff --git a/tests/PathOpsQuadLineIntersectionTest.cpp b/tests/PathOpsQuadLineIntersectionTest.cpp new file mode 100644 index 0000000000..09c28c1cea --- /dev/null +++ b/tests/PathOpsQuadLineIntersectionTest.cpp @@ -0,0 +1,132 @@ +/* + * Copyright 2012 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ +#include "PathOpsExtendedTest.h" +#include "SkIntersections.h" +#include "SkPathOpsLine.h" +#include "SkPathOpsQuad.h" +#include "SkReduceOrder.h" +#include "Test.h" + +static struct lineQuad { + SkDQuad quad; + SkDLine line; + int result; + SkDPoint expected[2]; +} lineQuadTests[] = { + // quad line results + {{{{1, 1}, {2, 1}, {0, 2}}}, {{{0, 0}, {1, 1}}}, 1, {{1, 1}, {0, 0}} }, + {{{{0, 0}, {1, 1}, {3, 1}}}, {{{0, 0}, {3, 1}}}, 2, {{0, 0}, {3, 1}} }, + {{{{2, 0}, {1, 1}, {2, 2}}}, {{{0, 0}, {0, 2}}}, 0, {{0, 0}, {0, 0}} }, + {{{{4, 0}, {0, 1}, {4, 2}}}, {{{3, 1}, {4, 1}}}, 0, {{0, 0}, {0, 0}} }, + {{{{0, 0}, {0, 1}, {1, 1}}}, {{{0, 1}, {1, 0}}}, 1, {{.25, .75}, {0, 0}} }, +}; + +static size_t lineQuadTests_count = sizeof(lineQuadTests) / sizeof(lineQuadTests[0]); + +static int doIntersect(SkIntersections& intersections, const SkDQuad& quad, const SkDLine& line, + bool& flipped) { + int result; + flipped = false; + if (line[0].fX == line[1].fX) { + double top = line[0].fY; + double bottom = line[1].fY; + flipped = top > bottom; + if (flipped) { + SkTSwap(top, bottom); + } + result = intersections.vertical(quad, top, bottom, line[0].fX, flipped); + } else if (line[0].fY == line[1].fY) { + double left = line[0].fX; + double right = line[1].fX; + flipped = left > right; + if (flipped) { + SkTSwap(left, right); + } + result = intersections.horizontal(quad, left, right, line[0].fY, flipped); + } else { + intersections.intersect(quad, line); + result = intersections.used(); + } + return result; +} + +static struct oneLineQuad { + SkDQuad quad; + SkDLine line; +} oneOffs[] = { + {{{{369.848602, 145.680267}, {382.360413, 121.298294}, {406.207703, 121.298294}}}, + {{{406.207703, 121.298294}, {348.781738, 123.864815}}}} + }; + +static size_t oneOffs_count = sizeof(oneOffs) / sizeof(oneOffs[0]); + +static void testOneOffs(skiatest::Reporter* reporter) { + SkIntersections intersections; + bool flipped = false; + for (size_t index = 0; index < oneOffs_count; ++index) { + const SkDQuad& quad = oneOffs[index].quad; + const SkDLine& line = oneOffs[index].line; + int result = doIntersect(intersections, quad, line, flipped); + for (int inner = 0; inner < result; ++inner) { + double quadT = intersections[0][inner]; + SkDPoint quadXY = quad.xyAtT(quadT); + double lineT = intersections[1][inner]; + SkDPoint lineXY = line.xyAtT(lineT); + REPORTER_ASSERT(reporter, quadXY.approximatelyEqual(lineXY)); + } + } +} + +static void TestQuadLineIntersection(skiatest::Reporter* reporter) { + testOneOffs(reporter); + for (size_t index = 0; index < lineQuadTests_count; ++index) { + int iIndex = static_cast(index); + const SkDQuad& quad = lineQuadTests[index].quad; + const SkDLine& line = lineQuadTests[index].line; + SkReduceOrder reducer1, reducer2; + int order1 = reducer1.reduce(quad, SkReduceOrder::kFill_Style); + int order2 = reducer2.reduce(line); + if (order1 < 3) { + SkDebugf("%s [%d] quad order=%d\n", __FUNCTION__, iIndex, order1); + REPORTER_ASSERT(reporter, 0); + } + if (order2 < 2) { + SkDebugf("%s [%d] line order=%d\n", __FUNCTION__, iIndex, order2); + REPORTER_ASSERT(reporter, 0); + } + SkIntersections intersections; + bool flipped = false; + int result = doIntersect(intersections, quad, line, flipped); + REPORTER_ASSERT(reporter, result == lineQuadTests[index].result); + if (intersections.used() <= 0) { + continue; + } + for (int pt = 0; pt < result; ++pt) { + double tt1 = intersections[0][pt]; + REPORTER_ASSERT(reporter, tt1 >= 0 && tt1 <= 1); + SkDPoint t1 = quad.xyAtT(tt1); + double tt2 = intersections[1][pt]; + REPORTER_ASSERT(reporter, tt2 >= 0 && tt2 <= 1); + SkDPoint t2 = line.xyAtT(tt2); + if (!t1.approximatelyEqual(t2)) { + SkDebugf("%s [%d,%d] x!= t1=%1.9g (%1.9g,%1.9g) t2=%1.9g (%1.9g,%1.9g)\n", + __FUNCTION__, iIndex, pt, tt1, t1.fX, t1.fY, tt2, t2.fX, t2.fY); + REPORTER_ASSERT(reporter, 0); + } + if (!t1.approximatelyEqual(lineQuadTests[index].expected[0]) + && (lineQuadTests[index].result == 1 + || !t1.approximatelyEqual(lineQuadTests[index].expected[1]))) { + SkDebugf("%s t1=(%1.9g,%1.9g)\n", __FUNCTION__, t1.fX, t1.fY); + REPORTER_ASSERT(reporter, 0); + } + } + } +} + +#include "TestClassDef.h" +DEFINE_TESTCLASS("PathOpsQuadLineIntersection", QuadLineIntersectionTestClass, \ + TestQuadLineIntersection) -- cgit v1.2.3