Add some new PolyUtils tests.
Also:
* clean up PolyUtils checks to be correct and consistent.
* fix some bugs discovered by the unit tests.
Bug: skia:
Change-Id: I1a8e07d13cb44fecc67344154dc1002f3f910f5d
Reviewed-on: https://skia-review.googlesource.com/138592
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
diff --git a/gn/tests.gni b/gn/tests.gni
index 2068ae5..7ffbb0b 100644
--- a/gn/tests.gni
+++ b/gn/tests.gni
@@ -173,6 +173,7 @@
"$_tests/PixelRefTest.cpp",
"$_tests/Point3Test.cpp",
"$_tests/PointTest.cpp",
+ "$_tests/PolyUtilsTest.cpp",
"$_tests/PremulAlphaRoundTripTest.cpp",
"$_tests/PrimitiveProcessorTest.cpp",
"$_tests/ProcessorTest.cpp",
diff --git a/src/utils/SkPolyUtils.cpp b/src/utils/SkPolyUtils.cpp
index ea9d649..e323f21 100755
--- a/src/utils/SkPolyUtils.cpp
+++ b/src/utils/SkPolyUtils.cpp
@@ -35,13 +35,20 @@
return 0;
}
-// returns 1 for ccw, -1 for cw and 0 if degenerate
-static int get_winding(const SkPoint* polygonVerts, int polygonSize) {
+// Returns 1 for cw, -1 for ccw and 0 if zero signed area (either degenerate or self-intersecting)
+int SkGetPolygonWinding(const SkPoint* polygonVerts, int polygonSize) {
+ if (polygonSize < 3) {
+ return 0;
+ }
+
// compute area and use sign to determine winding
SkScalar quadArea = 0;
- for (int curr = 0; curr < polygonSize; ++curr) {
+ SkVector v0 = polygonVerts[1] - polygonVerts[0];
+ for (int curr = 1; curr < polygonSize - 1; ++curr) {
int next = (curr + 1) % polygonSize;
- quadArea += polygonVerts[curr].cross(polygonVerts[next]);
+ SkVector v1 = polygonVerts[next] - polygonVerts[0];
+ quadArea += v0.cross(v1);
+ v0 = v1;
}
if (SkScalarNearlyZero(quadArea)) {
return 0;
@@ -111,6 +118,15 @@
return true;
}
+// compute fraction of d along v
+static inline SkScalar compute_param(const SkVector& v, const SkVector& d) {
+ if (SkScalarNearlyZero(v.fX)) {
+ return d.fY / v.fY;
+ } else {
+ return d.fX / v.fX;
+ }
+}
+
// Compute the intersection 'p' between segments s0 and s1, if any.
// 's' is the parametric value for the intersection along 's0' & 't' is the same for 's1'.
// Returns false if there is no intersection.
@@ -132,36 +148,60 @@
SkVector v0 = s0.fP1 - s0.fP0;
SkVector v1 = s1.fP1 - s1.fP0;
- // We should have culled coincident points before this
- SkASSERT(!SkPointPriv::EqualsWithinTolerance(s0.fP0, s0.fP1));
- SkASSERT(!SkPointPriv::EqualsWithinTolerance(s1.fP0, s1.fP1));
-
SkVector d = s1.fP0 - s0.fP0;
SkScalar perpDot = v0.cross(v1);
SkScalar localS, localT;
if (SkScalarNearlyZero(perpDot)) {
// segments are parallel, but not collinear
- if (!SkScalarNearlyZero(d.dot(d), SK_ScalarNearlyZero*SK_ScalarNearlyZero)) {
+ if (!SkScalarNearlyZero(d.cross(v0)) || !SkScalarNearlyZero(d.cross(v1))) {
return false;
}
- // project segment1's endpoints onto segment0
- localS = d.fX / v0.fX;
- localT = 0;
- if (localS < 0 || localS > SK_Scalar1) {
- // the first endpoint doesn't lie on segment0, try the other one
- SkScalar oldLocalS = localS;
- localS = (s1.fP1.fX - s0.fP0.fX) / v0.fX;
- localT = SK_Scalar1;
- if (localS < 0 || localS > SK_Scalar1) {
- // it's possible that segment1's interval surrounds segment0
- // this is false if the params have the same signs, and in that case no collision
- if (localS*oldLocalS > 0) {
+ // Check for degenerate segments
+ if (!SkPointPriv::CanNormalize(v0.fX, v0.fY)) {
+ // Both are degenerate
+ if (!SkPointPriv::CanNormalize(v1.fX, v1.fY)) {
+ // Check if they're the same point
+ if (!SkPointPriv::CanNormalize(d.fX, d.fY)) {
+ *p = s0.fP0;
+ *s = 0;
+ *t = 0;
+ return true;
+ } else {
return false;
}
- // otherwise project segment0's endpoint onto segment1 instead
- localS = 0;
- localT = -d.fX / v1.fX;
+ }
+ // Otherwise project onto segment1
+ localT = compute_param(v1, -d);
+ if (localT < 0 || localT > SK_Scalar1) {
+ return false;
+ }
+ localS = 0;
+ } else {
+ // Project segment1's endpoints onto segment0
+ localS = compute_param(v0, d);
+ localT = 0;
+ if (localS < 0 || localS > SK_Scalar1) {
+ // The first endpoint doesn't lie on segment0
+ // If segment1 is degenerate, then there's no collision
+ if (!SkPointPriv::CanNormalize(v1.fX, v1.fY)) {
+ return false;
+ }
+
+ // Otherwise try the other one
+ SkScalar oldLocalS = localS;
+ localS = compute_param(v0, s1.fP1 - s0.fP0);
+ localT = SK_Scalar1;
+ if (localS < 0 || localS > SK_Scalar1) {
+ // it's possible that segment1's interval surrounds segment0
+ // this is false if params have the same signs, and in that case no collision
+ if (localS*oldLocalS > 0) {
+ return false;
+ }
+ // otherwise project segment0's endpoint onto segment1 instead
+ localS = 0;
+ localT = compute_param(v1, -d);
+ }
}
}
} else {
@@ -175,8 +215,7 @@
}
}
- v0 *= localS;
- *p = s0.fP0 + v0;
+ *p = s0.fP0 + v0*localS;
*s = localS;
*t = localT;
@@ -207,25 +246,49 @@
return localS;
}
-static bool is_convex(const SkTDArray<SkPoint>& poly) {
- if (poly.count() <= 3) {
- return true;
+bool SkIsConvexPolygon(const SkPoint* polygonVerts, int polygonSize) {
+ if (polygonSize < 3) {
+ return false;
}
- SkVector v0 = poly[0] - poly[poly.count() - 1];
- SkVector v1 = poly[1] - poly[poly.count() - 1];
- SkScalar winding = v0.cross(v1);
+ SkScalar lastArea = 0;
+ SkScalar lastPerpDot = 0;
- for (int i = 0; i < poly.count() - 1; ++i) {
- int j = i + 1;
- int k = (i + 2) % poly.count();
-
- SkVector v0 = poly[j] - poly[i];
- SkVector v1 = poly[k] - poly[i];
+ int prevIndex = polygonSize - 1;
+ int currIndex = 0;
+ int nextIndex = 1;
+ SkPoint origin = polygonVerts[0];
+ SkVector v0 = polygonVerts[currIndex] - polygonVerts[prevIndex];
+ SkVector v1 = polygonVerts[nextIndex] - polygonVerts[currIndex];
+ SkVector w0 = polygonVerts[currIndex] - origin;
+ SkVector w1 = polygonVerts[nextIndex] - origin;
+ for (int i = 0; i < polygonSize; ++i) {
+ // Check that winding direction is always the same (otherwise we have a reflex vertex)
SkScalar perpDot = v0.cross(v1);
- if (winding*perpDot < 0) {
+ if (lastPerpDot*perpDot < 0) {
return false;
}
+ if (0 != perpDot) {
+ lastPerpDot = perpDot;
+ }
+
+ // If the signed area ever flips it's concave
+ // TODO: see if we can verify convexity only with signed area
+ SkScalar quadArea = w0.cross(w1);
+ if (quadArea*lastArea < 0) {
+ return false;
+ }
+ if (0 != quadArea) {
+ lastArea = quadArea;
+ }
+
+ prevIndex = currIndex;
+ currIndex = nextIndex;
+ nextIndex = (currIndex + 1) % polygonSize;
+ v0 = v1;
+ v1 = polygonVerts[nextIndex] - polygonVerts[currIndex];
+ w0 = w1;
+ w1 = polygonVerts[nextIndex] - origin;
}
return true;
@@ -281,7 +344,7 @@
}
// get winding direction
- int winding = get_winding(inputPolygonVerts, inputPolygonSize);
+ int winding = SkGetPolygonWinding(inputPolygonVerts, inputPolygonSize);
if (0 == winding) {
return false;
}
@@ -395,7 +458,7 @@
insetPolygon->pop();
}
- return (insetPolygon->count() >= 3 && is_convex(*insetPolygon));
+ return SkIsConvexPolygon(insetPolygon->begin(), insetPolygon->count());
}
///////////////////////////////////////////////////////////////////////////////////////////
@@ -416,6 +479,8 @@
*n = steps;
}
+///////////////////////////////////////////////////////////////////////////////////////////
+
// tolerant less-than comparison
static inline bool nearly_lt(SkScalar a, SkScalar b, SkScalar tolerance = SK_ScalarNearlyZero) {
return a < b - tolerance;
@@ -626,7 +691,7 @@
}
// get winding direction
- int winding = get_winding(inputPolygonVerts, inputPolygonSize);
+ int winding = SkGetPolygonWinding(inputPolygonVerts, inputPolygonSize);
if (0 == winding) {
return false;
}
@@ -787,7 +852,7 @@
}
// check winding of offset polygon (it should be same as the original polygon)
- SkScalar offsetWinding = get_winding(offsetPolygon->begin(), offsetPolygon->count());
+ SkScalar offsetWinding = SkGetPolygonWinding(offsetPolygon->begin(), offsetPolygon->count());
return (winding*offsetWinding > 0 &&
SkIsSimplePolygon(offsetPolygon->begin(), offsetPolygon->count()));
@@ -891,7 +956,7 @@
// get winding direction
// TODO: we do this for all the polygon routines -- might be better to have the client
// compute it and pass it in
- int winding = get_winding(polygonVerts, polygonSize);
+ int winding = SkGetPolygonWinding(polygonVerts, polygonSize);
if (0 == winding) {
return false;
}
diff --git a/src/utils/SkPolyUtils.h b/src/utils/SkPolyUtils.h
index ab5ebb8..9c25a07 100755
--- a/src/utils/SkPolyUtils.h
+++ b/src/utils/SkPolyUtils.h
@@ -118,7 +118,28 @@
SkScalar* rotSin, SkScalar* rotCos, int* n);
/**
+ * Determine winding direction for a polygon.
+ * The input polygon must be simple or the result will be meaningless.
+ *
+ * @param polygonVerts Array of points representing the vertices of the polygon.
+ * @param polygonSize Number of vertices in the polygon.
+ * @return 1 for cw, -1 for ccw, and 0 if zero signed area (either degenerate or self-intersecting).
+ * The y-axis is assumed to be pointing down.
+ */
+int SkGetPolygonWinding(const SkPoint* polygonVerts, int polygonSize);
+
+/**
+ * Determine whether a polygon is convex or not.
+ *
+ * @param polygonVerts Array of points representing the vertices of the polygon.
+ * @param polygonSize Number of vertices in the polygon.
+ * @return true if the polygon is convex, false otherwise.
+ */
+bool SkIsConvexPolygon(const SkPoint* polygonVerts, int polygonSize);
+
+/**
* Determine whether a polygon is simple (i.e., not self-intersecting) or not.
+ * The input polygon must have no coincident vertices or the test will fail.
*
* @param polygonVerts Array of points representing the vertices of the polygon.
* @param polygonSize Number of vertices in the polygon.
diff --git a/src/utils/SkShadowTessellator.cpp b/src/utils/SkShadowTessellator.cpp
index 3d84e8f..873e6d2 100755
--- a/src/utils/SkShadowTessellator.cpp
+++ b/src/utils/SkShadowTessellator.cpp
@@ -92,7 +92,6 @@
SkPoint fCentroid;
SkScalar fArea;
SkScalar fLastArea;
- int fAreaSignFlips;
SkScalar fLastCross;
int fFirstVertexIndex;
@@ -137,18 +136,16 @@
static SkScalar perp_dot(const SkPoint& p0, const SkPoint& p1, const SkPoint& p2) {
SkVector v0 = p1 - p0;
- SkVector v1 = p2 - p0;
+ SkVector v1 = p2 - p1;
return v0.cross(v1);
}
-
SkBaseShadowTessellator::SkBaseShadowTessellator(const SkPoint3& zPlaneParams, bool transparent)
: fZPlaneParams(zPlaneParams)
, fZOffset(0)
, fCentroid({0, 0})
, fArea(0)
, fLastArea(0)
- , fAreaSignFlips(0)
, fLastCross(0)
, fFirstVertexIndex(-1)
, fSucceeded(false)
@@ -189,15 +186,20 @@
return false;
}
- SkScalar quadArea = curr.cross(next);
- fCentroid.fX += (curr.fX + next.fX) * quadArea;
- fCentroid.fY += (curr.fY + next.fY) * quadArea;
+ SkASSERT(fPathPolygon.count() > 0);
+ SkVector v0 = curr - fPathPolygon[0];
+ SkVector v1 = next - fPathPolygon[0];
+ SkScalar quadArea = v0.cross(v1);
+ fCentroid.fX += (v0.fX + v1.fX) * quadArea;
+ fCentroid.fY += (v0.fY + v1.fY) * quadArea;
fArea += quadArea;
// convexity check
if (quadArea*fLastArea < 0) {
- ++fAreaSignFlips;
+ fIsConvex = false;
}
- fLastArea = quadArea;
+ if (0 != quadArea) {
+ fLastArea = quadArea;
+ }
return true;
}
@@ -215,7 +217,9 @@
if (fLastCross*cross < 0) {
fIsConvex = false;
}
- fLastCross = cross;
+ if (0 != cross) {
+ fLastCross = cross;
+ }
return true;
}
@@ -229,6 +233,9 @@
}
if (fPathPolygon.count() > 2) {
+ // do this before the final convexity check, so we use the correct fPathPolygon[0]
+ fCentroid *= sk_ieee_float_divide(1, 3 * fArea);
+ fCentroid += fPathPolygon[0];
if (!checkConvexity(fPathPolygon[fPathPolygon.count() - 2],
fPathPolygon[fPathPolygon.count() - 1],
fPathPolygon[0])) {
@@ -238,14 +245,6 @@
}
}
- fCentroid *= sk_ieee_float_divide(1, 3 * fArea);
- // It's possible to have a concave path that self-intersects but also passes the
- // cross-product check (e.g., a star). In that case, the signed area will change signs more
- // than twice, so we check for that here.
- if (fAreaSignFlips > 2) {
- fIsConvex = false;
- }
-
// if area is positive, winding is ccw
fDirection = fArea > 0 ? -1 : 1;
}
diff --git a/tests/InsetConvexPolyTest.cpp b/tests/InsetConvexPolyTest.cpp
index 022060c..facabb7 100644
--- a/tests/InsetConvexPolyTest.cpp
+++ b/tests/InsetConvexPolyTest.cpp
@@ -7,30 +7,6 @@
#include "Test.h"
#include "SkPolyUtils.h"
-static bool is_convex(const SkTDArray<SkPoint>& poly) {
- if (poly.count() < 3) {
- return false;
- }
-
- SkVector v0 = poly[0] - poly[poly.count() - 1];
- SkVector v1 = poly[1] - poly[poly.count() - 1];
- SkScalar winding = v0.cross(v1);
-
- for (int i = 0; i < poly.count()-1; ++i) {
- int j = i + 1;
- int k = (i + 2) % poly.count();
-
- SkVector v0 = poly[j] - poly[i];
- SkVector v1 = poly[k] - poly[i];
- SkScalar perpDot = v0.cross(v1);
- if (winding*perpDot < 0) {
- return false;
- }
- }
-
- return true;
-}
-
DEF_TEST(InsetConvexPoly, reporter) {
SkTDArray<SkPoint> rrectPoly;
@@ -55,18 +31,18 @@
*rrectPoly.push() = SkPoint::Make(-100 - 4.330127f, 50 + 2.5f);
*rrectPoly.push() = SkPoint::Make(-100 - 3.535534f, 50 + 3.535534f);
*rrectPoly.push() = SkPoint::Make(-100 - 2.5f, 50 + 4.330127f);
- REPORTER_ASSERT(reporter, is_convex(rrectPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(rrectPoly.begin(), rrectPoly.count()));
// inset a little
SkTDArray<SkPoint> insetPoly;
- bool result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 3, &insetPoly);
+ bool result = SkInsetConvexPolygon(rrectPoly.begin(), rrectPoly.count(), 3, &insetPoly);
REPORTER_ASSERT(reporter, result);
- REPORTER_ASSERT(reporter, is_convex(insetPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(insetPoly.begin(), insetPoly.count()));
// inset to rect
- result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 10, &insetPoly);
+ result = SkInsetConvexPolygon(rrectPoly.begin(), rrectPoly.count(), 10, &insetPoly);
REPORTER_ASSERT(reporter, result);
- REPORTER_ASSERT(reporter, is_convex(insetPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(insetPoly.begin(), insetPoly.count()));
REPORTER_ASSERT(reporter, insetPoly.count() == 4);
if (insetPoly.count() == 4) {
REPORTER_ASSERT(reporter, insetPoly[0].equals(-95, 45));
@@ -77,9 +53,9 @@
// just to full inset
// fails, but outputs a line segment
- result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 55, &insetPoly);
+ result = SkInsetConvexPolygon(rrectPoly.begin(), rrectPoly.count(), 55, &insetPoly);
REPORTER_ASSERT(reporter, !result);
- REPORTER_ASSERT(reporter, !is_convex(insetPoly));
+ REPORTER_ASSERT(reporter, !SkIsConvexPolygon(insetPoly.begin(), insetPoly.count()));
REPORTER_ASSERT(reporter, insetPoly.count() == 2);
if (insetPoly.count() == 2) {
REPORTER_ASSERT(reporter, insetPoly[0].equals(-50, 0));
@@ -87,7 +63,7 @@
}
// past full inset
- result = SkInsetConvexPolygon(&rrectPoly[0], rrectPoly.count(), 75, &insetPoly);
+ result = SkInsetConvexPolygon(rrectPoly.begin(), rrectPoly.count(), 75, &insetPoly);
REPORTER_ASSERT(reporter, !result);
REPORTER_ASSERT(reporter, insetPoly.count() == 0);
@@ -120,10 +96,11 @@
*clippedRRectPoly.push() = SkPoint::Make(381.195313f, 432.207275f);
*clippedRRectPoly.push() = SkPoint::Make(377.312134f, 432.947998f);
*clippedRRectPoly.push() = SkPoint::Make(342.289948f, 432.947998f);
- REPORTER_ASSERT(reporter, is_convex(clippedRRectPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(clippedRRectPoly.begin(),
+ clippedRRectPoly.count()));
- result = SkInsetConvexPolygon(&clippedRRectPoly[0], clippedRRectPoly.count(), 32.3699417f,
+ result = SkInsetConvexPolygon(clippedRRectPoly.begin(), clippedRRectPoly.count(), 32.3699417f,
&insetPoly);
REPORTER_ASSERT(reporter, result);
- REPORTER_ASSERT(reporter, is_convex(insetPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(insetPoly.begin(), insetPoly.count()));
}
diff --git a/tests/OffsetSimplePolyTest.cpp b/tests/OffsetSimplePolyTest.cpp
index 547dc9e..0f4f18f 100644
--- a/tests/OffsetSimplePolyTest.cpp
+++ b/tests/OffsetSimplePolyTest.cpp
@@ -7,30 +7,6 @@
#include "Test.h"
#include "SkPolyUtils.h"
-static bool is_convex(const SkTDArray<SkPoint>& poly) {
- if (poly.count() < 3) {
- return false;
- }
-
- SkVector v0 = poly[0] - poly[poly.count() - 1];
- SkVector v1 = poly[1] - poly[poly.count() - 1];
- SkScalar winding = v0.cross(v1);
-
- for (int i = 0; i < poly.count()-1; ++i) {
- int j = i + 1;
- int k = (i + 2) % poly.count();
-
- SkVector v0 = poly[j] - poly[i];
- SkVector v1 = poly[k] - poly[i];
- SkScalar perpDot = v0.cross(v1);
- if (winding*perpDot < 0) {
- return false;
- }
- }
-
- return true;
-}
-
DEF_TEST(OffsetSimplePoly, reporter) {
SkTDArray<SkPoint> rrectPoly;
@@ -58,18 +34,18 @@
*rrectPoly.push() = SkPoint::Make(-100 - 4.330127f, 50 + 2.5f);
*rrectPoly.push() = SkPoint::Make(-100 - 3.535534f, 50 + 3.535534f);
*rrectPoly.push() = SkPoint::Make(-100 - 2.5f, 50 + 4.330127f);
- REPORTER_ASSERT(reporter, is_convex(rrectPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(rrectPoly.begin(), rrectPoly.count()));
// inset a little
SkTDArray<SkPoint> offsetPoly;
- bool result = SkOffsetSimplePolygon(&rrectPoly[0], rrectPoly.count(), 3, &offsetPoly);
+ bool result = SkOffsetSimplePolygon(rrectPoly.begin(), rrectPoly.count(), 3, &offsetPoly);
REPORTER_ASSERT(reporter, result);
- REPORTER_ASSERT(reporter, is_convex(offsetPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(offsetPoly.begin(), offsetPoly.count()));
// inset to rect
- result = SkOffsetSimplePolygon(&rrectPoly[0], rrectPoly.count(), 10, &offsetPoly);
+ result = SkOffsetSimplePolygon(rrectPoly.begin(), rrectPoly.count(), 10, &offsetPoly);
REPORTER_ASSERT(reporter, result);
- REPORTER_ASSERT(reporter, is_convex(offsetPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(offsetPoly.begin(), offsetPoly.count()));
REPORTER_ASSERT(reporter, offsetPoly.count() == 4);
if (offsetPoly.count() == 4) {
REPORTER_ASSERT(reporter, offsetPoly[0].equals(-95, 45));
@@ -80,9 +56,9 @@
// just to full inset
// fails, but outputs a line segment
- result = SkOffsetSimplePolygon(&rrectPoly[0], rrectPoly.count(), 55, &offsetPoly);
+ result = SkOffsetSimplePolygon(rrectPoly.begin(), rrectPoly.count(), 55, &offsetPoly);
REPORTER_ASSERT(reporter, !result);
- REPORTER_ASSERT(reporter, !is_convex(offsetPoly));
+ REPORTER_ASSERT(reporter, !SkIsConvexPolygon(offsetPoly.begin(), offsetPoly.count()));
REPORTER_ASSERT(reporter, offsetPoly.count() == 2);
if (offsetPoly.count() == 2) {
REPORTER_ASSERT(reporter, offsetPoly[0].equals(-50, 0));
@@ -90,7 +66,7 @@
}
// past full inset
- result = SkOffsetSimplePolygon(&rrectPoly[0], rrectPoly.count(), 75, &offsetPoly);
+ result = SkOffsetSimplePolygon(rrectPoly.begin(), rrectPoly.count(), 75, &offsetPoly);
REPORTER_ASSERT(reporter, !result);
// troublesome case
@@ -122,12 +98,13 @@
*clippedRRectPoly.push() = SkPoint::Make(381.195313f, 432.207275f);
*clippedRRectPoly.push() = SkPoint::Make(377.312134f, 432.947998f);
*clippedRRectPoly.push() = SkPoint::Make(342.289948f, 432.947998f);
- REPORTER_ASSERT(reporter, is_convex(clippedRRectPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(clippedRRectPoly.begin(),
+ clippedRRectPoly.count()));
- result = SkOffsetSimplePolygon(&clippedRRectPoly[0], clippedRRectPoly.count(), 32.3699417f,
+ result = SkOffsetSimplePolygon(clippedRRectPoly.begin(), clippedRRectPoly.count(), 32.3699417f,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
- REPORTER_ASSERT(reporter, is_convex(offsetPoly));
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(offsetPoly.begin(), offsetPoly.count()));
////////////////////////////////////////////////////////////////////////////////
// Concave tests
@@ -145,46 +122,54 @@
*starPoly.push() = SkPoint::Make(-28.86f, 0.0f);
*starPoly.push() = SkPoint::Make(-43.30f, -25.0f);
*starPoly.push() = SkPoint::Make(-14.43f, -25.0f);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(starPoly.begin(), starPoly.count()));
// try a variety of distances
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), 0.1f,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), 0.1f,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), 5.665f,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), 5.665f,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), 28,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), 28,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
// down to a point
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), 28.866f,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), 28.866f,
&offsetPoly);
REPORTER_ASSERT(reporter, !result);
// and past
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), 50.5f,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), 50.5f,
&offsetPoly);
REPORTER_ASSERT(reporter, !result);
// and now out
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), -0.1f,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), -0.1f,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), -5.6665f,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), -5.6665f,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), -50,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), -50,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
- result = SkOffsetSimplePolygon(&starPoly[0], starPoly.count(), -100,
+ result = SkOffsetSimplePolygon(starPoly.begin(), starPoly.count(), -100,
&offsetPoly);
REPORTER_ASSERT(reporter, result);
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(offsetPoly.begin(), offsetPoly.count()));
SkTDArray<SkPoint> intersectingPoly;
*intersectingPoly.push() = SkPoint::Make(0.0f, -50.0f);
@@ -201,6 +186,6 @@
*intersectingPoly.push() = SkPoint::Make(-14.43f, -25.0f);
// SkOffsetSimplePolygon now assumes that the input is simple, so we'll just check for that
- result = SkIsSimplePolygon(&intersectingPoly[0], intersectingPoly.count());
+ result = SkIsSimplePolygon(intersectingPoly.begin(), intersectingPoly.count());
REPORTER_ASSERT(reporter, !result);
}
diff --git a/tests/PolyUtilsTest.cpp b/tests/PolyUtilsTest.cpp
new file mode 100644
index 0000000..bc5a1a4
--- /dev/null
+++ b/tests/PolyUtilsTest.cpp
@@ -0,0 +1,232 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "Test.h"
+#include "SkPolyUtils.h"
+
+DEF_TEST(PolyUtils, reporter) {
+
+ SkTDArray<SkPoint> poly;
+ // init simple index map
+ uint16_t indexMap[256];
+ for (int i = 0; i < 256; ++i) {
+ indexMap[i] = i;
+ }
+ SkTDArray<uint16_t> triangleIndices;
+
+ // skinny triangle
+ *poly.push() = SkPoint::Make(-100, 55);
+ *poly.push() = SkPoint::Make(100, 55);
+ *poly.push() = SkPoint::Make(102.5f, 54.330127f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) < 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // switch winding
+ poly[2].set(102.5f, 55.330127f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) > 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // make degenerate
+ poly[2].set(100 + 2.5f, 55);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) == 0);
+ // TODO: should these fail?
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, !SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // giant triangle
+ poly[0].set(-1.0e+37f, 1.0e+37f);
+ poly[1].set(1.0e+37f, 1.0e+37f);
+ poly[2].set(-1.0e+37f, -1.0e+37f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) < 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // teeny triangle
+ poly[0].set(-1.0e-38f, 1.0e-38f);
+ poly[1].set(-1.0e-38f, -1.0e-38f);
+ poly[2].set(1.0e-38f, 1.0e-38f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) == 0);
+ // TODO: should these fail?
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, !SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // triangle way off in space (relative to size so we don't completely obliterate values)
+ poly[0].set(-100 + 1.0e+9f, 55 - 1.0e+9f);
+ poly[1].set(100 + 1.0e+9f, 55 - 1.0e+9f);
+ poly[2].set(150 + 1.0e+9f, 100 - 1.0e+9f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) > 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ ///////////////////////////////////////////////////////////////////////
+ // round rect
+ poly.reset();
+ *poly.push() = SkPoint::Make(-100, 55);
+ *poly.push() = SkPoint::Make(100, 55);
+ *poly.push() = SkPoint::Make(100 + 2.5f, 50 + 4.330127f);
+ *poly.push() = SkPoint::Make(100 + 3.535534f, 50 + 3.535534f);
+ *poly.push() = SkPoint::Make(100 + 4.330127f, 50 + 2.5f);
+ *poly.push() = SkPoint::Make(105, 50);
+ *poly.push() = SkPoint::Make(105, -50);
+ *poly.push() = SkPoint::Make(100 + 4.330127f, -50 - 2.5f);
+ *poly.push() = SkPoint::Make(100 + 3.535534f, -50 - 3.535534f);
+ *poly.push() = SkPoint::Make(100 + 2.5f, -50 - 4.330127f);
+ *poly.push() = SkPoint::Make(100, -55);
+ *poly.push() = SkPoint::Make(-100, -55);
+ *poly.push() = SkPoint::Make(-100 - 2.5f, -50 - 4.330127f);
+ *poly.push() = SkPoint::Make(-100 - 3.535534f, -50 - 3.535534f);
+ *poly.push() = SkPoint::Make(-100 - 4.330127f, -50 - 2.5f);
+ *poly.push() = SkPoint::Make(-105, -50);
+ *poly.push() = SkPoint::Make(-105, 50);
+ *poly.push() = SkPoint::Make(-100 - 4.330127f, 50 + 2.5f);
+ *poly.push() = SkPoint::Make(-100 - 3.535534f, 50 + 3.535534f);
+ *poly.push() = SkPoint::Make(-100 - 2.5f, 50 + 4.330127f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) < 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // translate far enough to obliterate some low bits
+ for (int i = 0; i < poly.count(); ++i) {
+ poly[i].offset(1.0e+7f, 1.0e+7f);
+ }
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) < 0);
+ // Due to floating point error it's no longer convex
+ REPORTER_ASSERT(reporter, !SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // translate a little farther to create some coincident vertices
+ for (int i = 0; i < poly.count(); ++i) {
+ poly[i].offset(4.0e+7f, 4.0e+7f);
+ }
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) < 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ // These can't handle coincident vertices
+ REPORTER_ASSERT(reporter, !SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, !SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // troublesome case -- clipped roundrect
+ poly.reset();
+ *poly.push() = SkPoint::Make(335.928101f, 428.219055f);
+ *poly.push() = SkPoint::Make(330.414459f, 423.034912f);
+ *poly.push() = SkPoint::Make(325.749084f, 417.395508f);
+ *poly.push() = SkPoint::Make(321.931946f, 411.300842f);
+ *poly.push() = SkPoint::Make(318.963074f, 404.750977f);
+ *poly.push() = SkPoint::Make(316.842468f, 397.745850f);
+ *poly.push() = SkPoint::Make(315.570068f, 390.285522f);
+ *poly.push() = SkPoint::Make(315.145966f, 382.369965f);
+ *poly.push() = SkPoint::Make(315.570068f, 374.454346f);
+ *poly.push() = SkPoint::Make(316.842468f, 366.994019f);
+ *poly.push() = SkPoint::Make(318.963074f, 359.988892f);
+ *poly.push() = SkPoint::Make(321.931946f, 353.439056f);
+ *poly.push() = SkPoint::Make(325.749084f, 347.344421f);
+ *poly.push() = SkPoint::Make(330.414459f, 341.705017f);
+ *poly.push() = SkPoint::Make(335.928101f, 336.520813f);
+ *poly.push() = SkPoint::Make(342.289948f, 331.791901f);
+ *poly.push() = SkPoint::Make(377.312134f, 331.791901f);
+ *poly.push() = SkPoint::Make(381.195313f, 332.532593f);
+ *poly.push() = SkPoint::Make(384.464935f, 334.754700f);
+ *poly.push() = SkPoint::Make(386.687042f, 338.024292f);
+ *poly.push() = SkPoint::Make(387.427765f, 341.907532f);
+ *poly.push() = SkPoint::Make(387.427765f, 422.832367f);
+ *poly.push() = SkPoint::Make(386.687042f, 426.715576f);
+ *poly.push() = SkPoint::Make(384.464935f, 429.985168f);
+ *poly.push() = SkPoint::Make(381.195313f, 432.207275f);
+ *poly.push() = SkPoint::Make(377.312134f, 432.947998f);
+ *poly.push() = SkPoint::Make(342.289948f, 432.947998f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) > 0);
+ REPORTER_ASSERT(reporter, SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // a star is born
+ poly.reset();
+ *poly.push() = SkPoint::Make(0.0f, -50.0f);
+ *poly.push() = SkPoint::Make(14.43f, -25.0f);
+ *poly.push() = SkPoint::Make(43.30f, -25.0f);
+ *poly.push() = SkPoint::Make(28.86f, 0.0f);
+ *poly.push() = SkPoint::Make(43.30f, 25.0f);
+ *poly.push() = SkPoint::Make(14.43f, 25.0f);
+ *poly.push() = SkPoint::Make(0.0f, 50.0f);
+ *poly.push() = SkPoint::Make(-14.43f, 25.0f);
+ *poly.push() = SkPoint::Make(-43.30f, 25.0f);
+ *poly.push() = SkPoint::Make(-28.86f, 0.0f);
+ *poly.push() = SkPoint::Make(-43.30f, -25.0f);
+ *poly.push() = SkPoint::Make(-14.43f, -25.0f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) > 0);
+ REPORTER_ASSERT(reporter, !SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // self-intersecting polygon
+ poly.reset();
+ *poly.push() = SkPoint::Make(0.0f, -50.0f);
+ *poly.push() = SkPoint::Make(14.43f, -25.0f);
+ *poly.push() = SkPoint::Make(43.30f, -25.0f);
+ *poly.push() = SkPoint::Make(-28.86f, 0.0f);
+ *poly.push() = SkPoint::Make(43.30f, 25.0f);
+ *poly.push() = SkPoint::Make(14.43f, 25.0f);
+ *poly.push() = SkPoint::Make(0.0f, 50.0f);
+ *poly.push() = SkPoint::Make(-14.43f, 25.0f);
+ *poly.push() = SkPoint::Make(-43.30f, 25.0f);
+ *poly.push() = SkPoint::Make(28.86f, 0.0f);
+ *poly.push() = SkPoint::Make(-43.30f, -25.0f);
+ *poly.push() = SkPoint::Make(-14.43f, -25.0f);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) > 0);
+ REPORTER_ASSERT(reporter, !SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, !SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ // running this just to make sure it doesn't crash
+ // the fact that it succeeds doesn't mean anything since the input is not simple
+ REPORTER_ASSERT(reporter, SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+
+ // self-intersecting polygon with coincident point
+ poly.reset();
+ *poly.push() = SkPoint::Make(0.0f, 0.0f);
+ *poly.push() = SkPoint::Make(-50, -50);
+ *poly.push() = SkPoint::Make(50, -50);
+ *poly.push() = SkPoint::Make(0.00000001f, -0.00000001f);
+ *poly.push() = SkPoint::Make(-50, 50);
+ *poly.push() = SkPoint::Make(50, 50);
+ REPORTER_ASSERT(reporter, SkGetPolygonWinding(poly.begin(), poly.count()) == 0);
+ REPORTER_ASSERT(reporter, !SkIsConvexPolygon(poly.begin(), poly.count()));
+ REPORTER_ASSERT(reporter, !SkIsSimplePolygon(poly.begin(), poly.count()));
+ triangleIndices.reset();
+ // running this just to make sure it doesn't crash
+ REPORTER_ASSERT(reporter, !SkTriangulateSimplePolygon(poly.begin(), indexMap, poly.count(),
+ &triangleIndices));
+}