skia2/gm/pathopsinverse.cpp
caryclark 54359294a7 cumulative pathops patch
Replace the implicit curve intersection with a geometric curve intersection. The implicit intersection proved mathematically unstable and took a long time to zero in on an answer.

Use pointers instead of indices to refer to parts of curves. Indices required awkward renumbering.

Unify t and point values so that small intervals can be eliminated in one pass.

Break cubics up front to eliminate loops and cusps.

Make the Simplify and Op code more regular and eliminate arbitrary differences.

Add a builder that takes an array of paths and operators.

Delete unused code.

BUG=skia:3588
R=reed@google.com

Review URL: https://codereview.chromium.org/1037573004
2015-03-26 07:52:43 -07:00

115 lines
3.8 KiB
C++

/*
* 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 "gm.h"
#include "SkBitmap.h"
#include "SkPath.h"
#include "SkPathOps.h"
#include "SkRect.h"
namespace skiagm {
class PathOpsInverseGM : public GM {
public:
PathOpsInverseGM() {
}
protected:
void onOnceBeforeDraw() override {
const unsigned oneColor = 0xFF8080FF;
const unsigned twoColor = 0x807F1f1f;
SkColor blendColor = blend(oneColor, twoColor);
makePaint(&fOnePaint, oneColor);
makePaint(&fTwoPaint, twoColor);
makePaint(&fOpPaint[kDifference_SkPathOp], oneColor);
makePaint(&fOpPaint[kIntersect_SkPathOp], blendColor);
makePaint(&fOpPaint[kUnion_SkPathOp], 0xFFc0FFc0);
makePaint(&fOpPaint[kReverseDifference_SkPathOp], twoColor);
makePaint(&fOpPaint[kXOR_SkPathOp], 0xFFa0FFe0);
makePaint(&fOutlinePaint, 0xFF000000);
fOutlinePaint.setStyle(SkPaint::kStroke_Style);
}
SkColor blend(SkColor one, SkColor two) {
SkBitmap temp;
temp.allocN32Pixels(1, 1);
SkCanvas canvas(temp);
canvas.drawColor(one);
canvas.drawColor(two);
void* pixels = temp.getPixels();
return *(SkColor*) pixels;
}
void makePaint(SkPaint* paint, SkColor color) {
paint->setAntiAlias(true);
paint->setStyle(SkPaint::kFill_Style);
paint->setColor(color);
}
SkString onShortName() override {
return SkString("pathopsinverse");
}
SkISize onISize() override {
return SkISize::Make(1200, 900);
}
void onDraw(SkCanvas* canvas) override {
SkPath one, two;
int yPos = 0;
for (int oneFill = 0; oneFill <= 1; ++oneFill) {
SkPath::FillType oneF = oneFill ? SkPath::kInverseEvenOdd_FillType
: SkPath::kEvenOdd_FillType;
for (int twoFill = 0; twoFill <= 1; ++twoFill) {
SkPath::FillType twoF = twoFill ? SkPath::kInverseEvenOdd_FillType
: SkPath::kEvenOdd_FillType;
one.reset();
one.setFillType(oneF);
one.addRect(10, 10, 70, 70);
two.reset();
two.setFillType(twoF);
two.addRect(40, 40, 100, 100);
canvas->save();
canvas->translate(0, SkIntToScalar(yPos));
canvas->clipRect(SkRect::MakeWH(110, 110), SkRegion::kIntersect_Op, true);
canvas->drawPath(one, fOnePaint);
canvas->drawPath(one, fOutlinePaint);
canvas->drawPath(two, fTwoPaint);
canvas->drawPath(two, fOutlinePaint);
canvas->restore();
int xPos = 150;
for (int op = kDifference_SkPathOp; op <= kReverseDifference_SkPathOp; ++op) {
SkPath result;
Op(one, two, (SkPathOp) op, &result);
canvas->save();
canvas->translate(SkIntToScalar(xPos), SkIntToScalar(yPos));
canvas->clipRect(SkRect::MakeWH(110, 110), SkRegion::kIntersect_Op, true);
canvas->drawPath(result, fOpPaint[op]);
canvas->drawPath(result, fOutlinePaint);
canvas->restore();
xPos += 150;
}
yPos += 150;
}
}
}
private:
SkPaint fOnePaint;
SkPaint fTwoPaint;
SkPaint fOutlinePaint;
SkPaint fOpPaint[kReverseDifference_SkPathOp - kDifference_SkPathOp + 1];
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
static GM* MyFactory(void*) { return new PathOpsInverseGM; }
static GMRegistry reg(MyFactory);
}