diff options
| -rw-r--r-- | gfx/2d/Matrix.h | 18 | ||||
| -rw-r--r-- | gfx/tests/gtest/TestMatrix.cpp | 61 | ||||
| -rw-r--r-- | gfx/tests/gtest/moz.build | 1 |
3 files changed, 77 insertions, 3 deletions
diff --git a/gfx/2d/Matrix.h b/gfx/2d/Matrix.h index 84c9a5280..d6835c8e6 100644 --- a/gfx/2d/Matrix.h +++ b/gfx/2d/Matrix.h @@ -723,7 +723,7 @@ public: * The resulting vertices are populated in aVerts. aVerts must be * pre-allocated to hold at least kTransformAndClipRectMaxVerts Points. * The vertex count is returned by TransformAndClipRect. It is possible to - * emit fewer that 3 vertices, indicating that aRect will not be visible + * emit fewer than 3 vertices, indicating that aRect will not be visible * within aClip. */ template<class F> @@ -751,8 +751,10 @@ public: planeNormals[3] = Point4DTyped<UnknownUnits, F>(0.0, -1.0, 0.0, aClip.YMost()); // Iterate through each clipping plane and clip the polygon. - // In each pass, we double buffer, alternating between points[0] and - // points[1]. + // For each clipping plane, we intersect the plane with all polygon edges. + // Each pass can increase or decrease the number of points that make up the + // current clipped polygon. We double buffer that set of points, alternating + // between points[0] and points[1]. for (int plane=0; plane < 4; plane++) { planeNormals[plane].Normalize(); Point4DTyped<UnknownUnits, F>* srcPoint = dstPointStart; @@ -761,6 +763,14 @@ public: dstPointStart = points[~plane & 1]; dstPoint = dstPointStart; + // Iterate over the polygon edges. In each iteration the current edge is + // the edge from prevPoint to srcPoint. If the two end points lie on + // different sides of the plane, we have an intersection. Otherwise, the + // edge is either completely "inside" the half-space created by the + // clipping plane, and we add srcPoint, or it is completely "outside", and + // we discard srcPoint. + // We may create duplicated points in the polygon. We keep those around + // until all clipping is done and then filter out duplicates at the end. Point4DTyped<UnknownUnits, F>* prevPoint = srcPointEnd - 1; F prevDot = planeNormals[plane].DotProduct(*prevPoint); while (srcPoint < srcPointEnd && ((dstPoint - dstPointStart) < kTransformAndClipRectMaxVerts)) { @@ -784,6 +794,8 @@ public: } if (dstPoint == dstPointStart) { + // No polygon points were produced, so the polygon has been + // completely clipped away by the current clipping plane. Exit. break; } } diff --git a/gfx/tests/gtest/TestMatrix.cpp b/gfx/tests/gtest/TestMatrix.cpp new file mode 100644 index 000000000..bc2f9e63c --- /dev/null +++ b/gfx/tests/gtest/TestMatrix.cpp @@ -0,0 +1,61 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "gtest/gtest.h" +#include "mozilla/gfx/Matrix.h" + +using namespace mozilla; +using namespace mozilla::gfx; + +static Rect NudgedToInt(const Rect& aRect) { + Rect r(aRect); + r.NudgeToIntegers(); + return r; +} + +TEST(Matrix, TransformAndClipRect) +{ + Rect c(100, 100, 100, 100); + Matrix4x4 m; + EXPECT_TRUE(m.TransformAndClipBounds(Rect(50, 50, 20, 20), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(250, 50, 20, 20), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(250, 250, 20, 20), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(50, 250, 20, 20), c).IsEmpty()); + + EXPECT_TRUE(m.TransformAndClipBounds(Rect(50, 50, 100, 20), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(150, 50, 100, 20), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(50, 250, 100, 20), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(150, 250, 100, 20), c).IsEmpty()); + + EXPECT_TRUE(m.TransformAndClipBounds(Rect(50, 50, 20, 100), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(50, 150, 20, 100), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(250, 50, 20, 100), c).IsEmpty()); + EXPECT_TRUE(m.TransformAndClipBounds(Rect(250, 150, 20, 100), c).IsEmpty()); + + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(50, 50, 100, 100), c)) + .IsEqualInterior(Rect(100, 100, 50, 50))); + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(150, 50, 100, 100), c)) + .IsEqualInterior(Rect(150, 100, 50, 50))); + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(150, 150, 100, 100), c)) + .IsEqualInterior(Rect(150, 150, 50, 50))); + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(50, 150, 100, 100), c)) + .IsEqualInterior(Rect(100, 150, 50, 50))); + + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(110, 110, 80, 80), c)) + .IsEqualInterior(Rect(110, 110, 80, 80))); + + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(50, 50, 200, 200), c)) + .IsEqualInterior(Rect(100, 100, 100, 100))); + + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(50, 50, 200, 100), c)) + .IsEqualInterior(Rect(100, 100, 100, 50))); + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(50, 150, 200, 100), c)) + .IsEqualInterior(Rect(100, 150, 100, 50))); + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(50, 50, 100, 200), c)) + .IsEqualInterior(Rect(100, 100, 50, 100))); + EXPECT_TRUE(NudgedToInt(m.TransformAndClipBounds(Rect(150, 50, 100, 200), c)) + .IsEqualInterior(Rect(150, 100, 50, 100))); +} diff --git a/gfx/tests/gtest/moz.build b/gfx/tests/gtest/moz.build index 23b019d1b..ea18c1e3b 100644 --- a/gfx/tests/gtest/moz.build +++ b/gfx/tests/gtest/moz.build @@ -17,6 +17,7 @@ UNIFIED_SOURCES += [ 'TestGfxWidgets.cpp', 'TestJobScheduler.cpp', 'TestLayers.cpp', + 'TestMatrix.cpp', 'TestMoz2D.cpp', 'TestPolygon.cpp', 'TestQcms.cpp', |