Add base types for path ops

Paths contain lines, quads, and cubics, which are
collectively curves.

To work with path intersections, intermediary curves
are constructed. For now, those intermediates use
doubles to guarantee sufficient precision.

The DVector, DPoint, DLine, DQuad, and DCubic
structs encapsulate these intermediate curves.

The DRect and DTriangle structs are created to
describe intersectable areas of interest.

The Bounds struct inherits from SkRect to create
a SkScalar-based rectangle that intersects shared
edges.

This also includes common math equalities and
debugging that the remainder of path ops builds on,
as well as a temporary top-level interface in
include/pathops/SkPathOps.h.
Review URL: https://codereview.chromium.org/12827020

git-svn-id: http://skia.googlecode.com/svn/trunk@8551 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 106 insertions, 0 deletions

diff --git a/tests/PathOpsBoundsTest.cpp b/tests/PathOpsBoundsTest.cpp
new file mode 100644
index 0000000000..0ed19540ed
--- /dev/null
+++ b/tests/PathOpsBoundsTest.cpp
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SkPathOpsBounds.h"
+#include "Test.h"
+
+static const SkRect sectTests[][2] = {
+    {{2, 0, 4, 1}, {4, 0, 6, 1}},
+    {{2, 0, 4, 1}, {3, 0, 5, 1}},
+    {{2, 0, 4, 1}, {3, 0, 5, 0}},
+    {{2, 0, 4, 1}, {3, 1, 5, 2}},
+    {{2, 1, 4, 2}, {1, 0, 5, 3}},
+    {{2, 1, 5, 3}, {3, 1, 4, 2}},
+    {{2, 0, 4, 1}, {3, 0, 3, 0}},  // intersecting an empty bounds is OK
+    {{2, 0, 4, 1}, {4, 1, 5, 2}},  // touching just on a corner is OK
+};
+
+static const size_t sectTestsCount = sizeof(sectTests) / sizeof(sectTests[0]);
+
+static const SkRect noSectTests[][2] = {
+    {{2, 0, 4, 1}, {5, 0, 6, 1}},
+    {{2, 0, 4, 1}, {3, 2, 5, 2}},
+};
+
+static const size_t noSectTestsCount = sizeof(noSectTests) / sizeof(noSectTests[0]);
+
+static const SkRect reallyEmpty[] = {
+    {0, 0, 0, 0},
+    {1, 1, 1, 0},
+    {1, 1, 0, 1},
+    {1, 1, 0, 0},
+    {1, 2, 3, SK_ScalarNaN},
+};
+
+static const size_t emptyTestsCount = sizeof(reallyEmpty) / sizeof(reallyEmpty[0]);
+
+static const SkRect notReallyEmpty[] = {
+    {0, 0, 1, 0},
+    {0, 0, 0, 1},
+    {0, 0, 1, 1},
+};
+
+static const size_t notEmptyTestsCount = sizeof(notReallyEmpty) / sizeof(notReallyEmpty[0]);
+
+static void OpBoundsTest(skiatest::Reporter* reporter) {
+    for (size_t index = 0; index < sectTestsCount; ++index) {
+        const SkPathOpsBounds& bounds1 = static_cast<const SkPathOpsBounds&>(sectTests[index][0]);
+        const SkPathOpsBounds& bounds2 = static_cast<const SkPathOpsBounds&>(sectTests[index][1]);
+        bool touches = SkPathOpsBounds::Intersects(bounds1, bounds2);
+        REPORTER_ASSERT(reporter, touches);
+    }
+    for (size_t index = 0; index < noSectTestsCount; ++index) {
+        const SkPathOpsBounds& bounds1 = static_cast<const SkPathOpsBounds&>(noSectTests[index][0]);
+        const SkPathOpsBounds& bounds2 = static_cast<const SkPathOpsBounds&>(noSectTests[index][1]);
+        bool touches = SkPathOpsBounds::Intersects(bounds1, bounds2);
+        REPORTER_ASSERT(reporter, !touches);
+    }
+    SkPathOpsBounds bounds;
+    bounds.setEmpty();
+    bounds.add(1, 2, 3, 4);
+    SkPathOpsBounds expected;
+    expected.set(0, 0, 3, 4);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    bounds.setEmpty();
+    SkPathOpsBounds ordinal;
+    ordinal.set(1, 2, 3, 4);
+    bounds.add(ordinal);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    SkPoint topLeft = {0, 0};
+    bounds.setPointBounds(topLeft);
+    SkPoint botRight = {3, 4};
+    bounds.add(botRight);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    for (size_t index = 0; index < emptyTestsCount; ++index) {
+        const SkPathOpsBounds& bounds = static_cast<const SkPathOpsBounds&>(reallyEmpty[index]);
+        bool empty = bounds.isReallyEmpty();
+        REPORTER_ASSERT(reporter, empty);
+    }
+    for (size_t index = 0; index < notEmptyTestsCount; ++index) {
+        const SkPathOpsBounds& bounds = static_cast<const SkPathOpsBounds&>(notReallyEmpty[index]);
+        bool empty = bounds.isReallyEmpty();
+        REPORTER_ASSERT(reporter, !empty);
+    }
+    const SkPoint curvePts[] = {{0, 0}, {1, 2}, {3, 4}, {5, 6}};
+    bounds.setLineBounds(curvePts);
+    expected.set(0, 0, 1, 2);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    (bounds.*SetCurveBounds[1])(curvePts);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    bounds.setQuadBounds(curvePts);
+    expected.set(0, 0, 3, 4);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    (bounds.*SetCurveBounds[2])(curvePts);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    bounds.setCubicBounds(curvePts);
+    expected.set(0, 0, 5, 6);
+    REPORTER_ASSERT(reporter, bounds == expected);
+    (bounds.*SetCurveBounds[3])(curvePts);
+    REPORTER_ASSERT(reporter, bounds == expected);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("PathOpsBounds", PathOpsBoundsClass, OpBoundsTest)