Add variable offset support
Bug: skia:7970
Change-Id: I9dadf75f21e19ebe26f82643bcc47dd5794d8970
Reviewed-on: https://skia-review.googlesource.com/134421
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/gm/polygonoffset.cpp b/gm/polygonoffset.cpp
index cbf0849..48b6d1a 100644
--- a/gm/polygonoffset.cpp
+++ b/gm/polygonoffset.cpp
@@ -406,18 +406,30 @@
namespace skiagm {
// This GM is intended to exercise the offsetting of polygons
+// When fVariableOffset is true it will skew the offset by x,
+// to test perspective and other variable offset functions
class PolygonOffsetGM : public GM {
public:
- PolygonOffsetGM(bool convexOnly) : fConvexOnly(convexOnly) {
+ PolygonOffsetGM(bool convexOnly, bool variableOffset)
+ : fConvexOnly(convexOnly)
+ , fVariableOffset(variableOffset) {
this->setBGColor(0xFFFFFFFF);
}
protected:
SkString onShortName() override {
if (fConvexOnly) {
- return SkString("convex-polygon-inset");
+ if (fVariableOffset) {
+ return SkString("convex-polygon-inset-v");
+ } else {
+ return SkString("convex-polygon-inset");
+ }
} else {
- return SkString("simple-polygon-offset");
+ if (fVariableOffset) {
+ return SkString("simple-polygon-offset-v");
+ } else {
+ return SkString("simple-polygon-offset");
+ }
}
}
SkISize onISize() override { return SkISize::Make(kGMWidth, kGMHeight); }
@@ -495,6 +507,7 @@
void drawPolygon(SkCanvas* canvas, int index, SkPoint* offset) {
SkPoint center;
+ SkRect bounds;
{
std::unique_ptr<SkPoint[]> data(nullptr);
int numPts;
@@ -503,7 +516,6 @@
} else {
GetSimplePolygon(index, SkPath::kCW_Direction, &data, &numPts);
}
- SkRect bounds;
bounds.set(data.get(), numPts);
if (!fConvexOnly) {
bounds.outset(kMaxOutset, kMaxOutset);
@@ -551,12 +563,25 @@
SkTDArray<SkPoint> offsetPoly;
size_t count = fConvexOnly ? SK_ARRAY_COUNT(insets) : SK_ARRAY_COUNT(offsets);
+ SkScalar localCenterX = bounds.centerX();
for (size_t i = 0; i < count; ++i) {
+ SkScalar offset = fConvexOnly ? insets[i] : offsets[i];
+ std::function<SkScalar(const SkPoint&)> offsetFunc;
+ if (fVariableOffset) {
+ offsetFunc = [offset, localCenterX](const SkPoint& p) {
+ return offset + 0.04f*(p.fX - localCenterX);
+ };
+ } else {
+ offsetFunc = [offset](const SkPoint& p) {
+ return offset;
+ };
+ }
+
bool result;
if (fConvexOnly) {
- result = SkInsetConvexPolygon(data.get(), numPts, insets[i], &offsetPoly);
+ result = SkInsetConvexPolygon(data.get(), numPts, offsetFunc, &offsetPoly);
} else {
- result = SkOffsetSimplePolygon(data.get(), numPts, offsets[i], &offsetPoly);
+ result = SkOffsetSimplePolygon(data.get(), numPts, offsetFunc, &offsetPoly);
}
if (result) {
SkPath path;
@@ -595,12 +620,15 @@
static constexpr int kGMHeight = 512;
bool fConvexOnly;
+ bool fVariableOffset;
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
-DEF_GM(return new PolygonOffsetGM(true);)
-DEF_GM(return new PolygonOffsetGM(false);)
+DEF_GM(return new PolygonOffsetGM(true, false);)
+DEF_GM(return new PolygonOffsetGM(true, true);)
+DEF_GM(return new PolygonOffsetGM(false, false);)
+DEF_GM(return new PolygonOffsetGM(false, true);)
}