1 /* libs/android_runtime/android/graphics/Path.cpp
2 **
3 ** Copyright 2006, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 **     http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17 
18 // This file was generated from the C++ include file: SkPath.h
19 // Any changes made to this file will be discarded by the build.
20 // To change this file, either edit the include, or device/tools/gluemaker/main.cpp,
21 // or one of the auxilary file specifications in device/tools/gluemaker.
22 
23 #include "jni.h"
24 #include "GraphicsJNI.h"
25 #include "core_jni_helpers.h"
26 
27 #include "SkPath.h"
28 #include "SkPathOps.h"
29 #include "SkGeometry.h" // WARNING: Internal Skia Header
30 
31 #include <vector>
32 #include <map>
33 
34 namespace android {
35 
36 class SkPathGlue {
37 public:
38 
finalizer(SkPath * obj)39     static void finalizer(SkPath* obj) {
40         delete obj;
41     }
42 
43     // ---------------- Regular JNI -----------------------------
44 
init(JNIEnv * env,jclass clazz)45     static jlong init(JNIEnv* env, jclass clazz) {
46         return reinterpret_cast<jlong>(new SkPath());
47     }
48 
init_Path(JNIEnv * env,jclass clazz,jlong valHandle)49     static jlong init_Path(JNIEnv* env, jclass clazz, jlong valHandle) {
50         SkPath* val = reinterpret_cast<SkPath*>(valHandle);
51         return reinterpret_cast<jlong>(new SkPath(*val));
52     }
53 
getFinalizer(JNIEnv * env,jclass clazz)54     static jlong getFinalizer(JNIEnv* env, jclass clazz) {
55         return static_cast<jlong>(reinterpret_cast<uintptr_t>(&finalizer));
56     }
57 
set(JNIEnv * env,jclass clazz,jlong dstHandle,jlong srcHandle)58     static void set(JNIEnv* env, jclass clazz, jlong dstHandle, jlong srcHandle) {
59         SkPath* dst = reinterpret_cast<SkPath*>(dstHandle);
60         const SkPath* src = reinterpret_cast<SkPath*>(srcHandle);
61         *dst = *src;
62     }
63 
computeBounds(JNIEnv * env,jclass clazz,jlong objHandle,jobject jbounds)64     static void computeBounds(JNIEnv* env, jclass clazz, jlong objHandle, jobject jbounds) {
65         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
66         const SkRect& bounds = obj->getBounds();
67         GraphicsJNI::rect_to_jrectf(bounds, env, jbounds);
68     }
69 
incReserve(JNIEnv * env,jclass clazz,jlong objHandle,jint extraPtCount)70     static void incReserve(JNIEnv* env, jclass clazz, jlong objHandle, jint extraPtCount) {
71         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
72         obj->incReserve(extraPtCount);
73     }
74 
moveTo__FF(JNIEnv * env,jclass clazz,jlong objHandle,jfloat x,jfloat y)75     static void moveTo__FF(JNIEnv* env, jclass clazz, jlong objHandle, jfloat x, jfloat y) {
76         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
77         obj->moveTo(x, y);
78     }
79 
rMoveTo(JNIEnv * env,jclass clazz,jlong objHandle,jfloat dx,jfloat dy)80     static void rMoveTo(JNIEnv* env, jclass clazz, jlong objHandle, jfloat dx, jfloat dy) {
81         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
82         obj->rMoveTo(dx, dy);
83     }
84 
lineTo__FF(JNIEnv * env,jclass clazz,jlong objHandle,jfloat x,jfloat y)85     static void lineTo__FF(JNIEnv* env, jclass clazz, jlong objHandle, jfloat x, jfloat y) {
86         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
87         obj->lineTo(x, y);
88     }
89 
rLineTo(JNIEnv * env,jclass clazz,jlong objHandle,jfloat dx,jfloat dy)90     static void rLineTo(JNIEnv* env, jclass clazz, jlong objHandle, jfloat dx, jfloat dy) {
91         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
92         obj->rLineTo(dx, dy);
93     }
94 
quadTo__FFFF(JNIEnv * env,jclass clazz,jlong objHandle,jfloat x1,jfloat y1,jfloat x2,jfloat y2)95     static void quadTo__FFFF(JNIEnv* env, jclass clazz, jlong objHandle, jfloat x1, jfloat y1,
96             jfloat x2, jfloat y2) {
97         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
98         obj->quadTo(x1, y1, x2, y2);
99     }
100 
rQuadTo(JNIEnv * env,jclass clazz,jlong objHandle,jfloat dx1,jfloat dy1,jfloat dx2,jfloat dy2)101     static void rQuadTo(JNIEnv* env, jclass clazz, jlong objHandle, jfloat dx1, jfloat dy1,
102             jfloat dx2, jfloat dy2) {
103         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
104         obj->rQuadTo(dx1, dy1, dx2, dy2);
105     }
106 
cubicTo__FFFFFF(JNIEnv * env,jclass clazz,jlong objHandle,jfloat x1,jfloat y1,jfloat x2,jfloat y2,jfloat x3,jfloat y3)107     static void cubicTo__FFFFFF(JNIEnv* env, jclass clazz, jlong objHandle, jfloat x1, jfloat y1,
108             jfloat x2, jfloat y2, jfloat x3, jfloat y3) {
109         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
110         obj->cubicTo(x1, y1, x2, y2, x3, y3);
111     }
112 
rCubicTo(JNIEnv * env,jclass clazz,jlong objHandle,jfloat x1,jfloat y1,jfloat x2,jfloat y2,jfloat x3,jfloat y3)113     static void rCubicTo(JNIEnv* env, jclass clazz, jlong objHandle, jfloat x1, jfloat y1,
114             jfloat x2, jfloat y2, jfloat x3, jfloat y3) {
115         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
116         obj->rCubicTo(x1, y1, x2, y2, x3, y3);
117     }
118 
arcTo(JNIEnv * env,jclass clazz,jlong objHandle,jfloat left,jfloat top,jfloat right,jfloat bottom,jfloat startAngle,jfloat sweepAngle,jboolean forceMoveTo)119     static void arcTo(JNIEnv* env, jclass clazz, jlong objHandle, jfloat left, jfloat top,
120             jfloat right, jfloat bottom, jfloat startAngle, jfloat sweepAngle,
121             jboolean forceMoveTo) {
122         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
123         SkRect oval = SkRect::MakeLTRB(left, top, right, bottom);
124         obj->arcTo(oval, startAngle, sweepAngle, forceMoveTo);
125     }
126 
close(JNIEnv * env,jclass clazz,jlong objHandle)127     static void close(JNIEnv* env, jclass clazz, jlong objHandle) {
128         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
129         obj->close();
130     }
131 
addRect(JNIEnv * env,jclass clazz,jlong objHandle,jfloat left,jfloat top,jfloat right,jfloat bottom,jint dirHandle)132     static void addRect(JNIEnv* env, jclass clazz, jlong objHandle,
133             jfloat left, jfloat top, jfloat right, jfloat bottom, jint dirHandle) {
134         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
135         SkPath::Direction dir = static_cast<SkPath::Direction>(dirHandle);
136         obj->addRect(left, top, right, bottom, dir);
137     }
138 
addOval(JNIEnv * env,jclass clazz,jlong objHandle,jfloat left,jfloat top,jfloat right,jfloat bottom,jint dirHandle)139     static void addOval(JNIEnv* env, jclass clazz, jlong objHandle,
140             jfloat left, jfloat top, jfloat right, jfloat bottom, jint dirHandle) {
141         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
142         SkPath::Direction dir = static_cast<SkPath::Direction>(dirHandle);
143         SkRect oval = SkRect::MakeLTRB(left, top, right, bottom);
144         obj->addOval(oval, dir);
145     }
146 
addCircle(JNIEnv * env,jclass clazz,jlong objHandle,jfloat x,jfloat y,jfloat radius,jint dirHandle)147     static void addCircle(JNIEnv* env, jclass clazz, jlong objHandle, jfloat x, jfloat y,
148             jfloat radius, jint dirHandle) {
149         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
150         SkPath::Direction dir = static_cast<SkPath::Direction>(dirHandle);
151         obj->addCircle(x, y, radius, dir);
152     }
153 
addArc(JNIEnv * env,jclass clazz,jlong objHandle,jfloat left,jfloat top,jfloat right,jfloat bottom,jfloat startAngle,jfloat sweepAngle)154     static void addArc(JNIEnv* env, jclass clazz, jlong objHandle, jfloat left, jfloat top,
155             jfloat right, jfloat bottom, jfloat startAngle, jfloat sweepAngle) {
156         SkRect oval = SkRect::MakeLTRB(left, top, right, bottom);
157         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
158         obj->addArc(oval, startAngle, sweepAngle);
159     }
160 
addRoundRectXY(JNIEnv * env,jclass clazz,jlong objHandle,jfloat left,jfloat top,jfloat right,jfloat bottom,jfloat rx,jfloat ry,jint dirHandle)161     static void addRoundRectXY(JNIEnv* env, jclass clazz, jlong objHandle, jfloat left, jfloat top,
162             jfloat right, jfloat bottom, jfloat rx, jfloat ry, jint dirHandle) {
163         SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
164         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
165         SkPath::Direction dir = static_cast<SkPath::Direction>(dirHandle);
166         obj->addRoundRect(rect, rx, ry, dir);
167     }
168 
addRoundRect8(JNIEnv * env,jclass clazz,jlong objHandle,jfloat left,jfloat top,jfloat right,jfloat bottom,jfloatArray array,jint dirHandle)169     static void addRoundRect8(JNIEnv* env, jclass clazz, jlong objHandle, jfloat left, jfloat top,
170                 jfloat right, jfloat bottom, jfloatArray array, jint dirHandle) {
171         SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
172         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
173         SkPath::Direction dir = static_cast<SkPath::Direction>(dirHandle);
174         AutoJavaFloatArray  afa(env, array, 8);
175 #ifdef SK_SCALAR_IS_FLOAT
176         const float* src = afa.ptr();
177 #else
178         #error Need to convert float array to SkScalar array before calling the following function.
179 #endif
180         obj->addRoundRect(rect, src, dir);
181     }
182 
addPath__PathFF(JNIEnv * env,jclass clazz,jlong objHandle,jlong srcHandle,jfloat dx,jfloat dy)183     static void addPath__PathFF(JNIEnv* env, jclass clazz, jlong objHandle, jlong srcHandle,
184             jfloat dx, jfloat dy) {
185         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
186         SkPath* src = reinterpret_cast<SkPath*>(srcHandle);
187         obj->addPath(*src, dx, dy);
188     }
189 
addPath__Path(JNIEnv * env,jclass clazz,jlong objHandle,jlong srcHandle)190     static void addPath__Path(JNIEnv* env, jclass clazz, jlong objHandle, jlong srcHandle) {
191         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
192         SkPath* src = reinterpret_cast<SkPath*>(srcHandle);
193         obj->addPath(*src);
194     }
195 
addPath__PathMatrix(JNIEnv * env,jclass clazz,jlong objHandle,jlong srcHandle,jlong matrixHandle)196     static void addPath__PathMatrix(JNIEnv* env, jclass clazz, jlong objHandle, jlong srcHandle,
197             jlong matrixHandle) {
198         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
199         SkPath* src = reinterpret_cast<SkPath*>(srcHandle);
200         SkMatrix* matrix = reinterpret_cast<SkMatrix*>(matrixHandle);
201         obj->addPath(*src, *matrix);
202     }
203 
offset__FF(JNIEnv * env,jclass clazz,jlong objHandle,jfloat dx,jfloat dy)204     static void offset__FF(JNIEnv* env, jclass clazz, jlong objHandle, jfloat dx, jfloat dy) {
205         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
206         obj->offset(dx, dy);
207     }
208 
setLastPoint(JNIEnv * env,jclass clazz,jlong objHandle,jfloat dx,jfloat dy)209     static void setLastPoint(JNIEnv* env, jclass clazz, jlong objHandle, jfloat dx, jfloat dy) {
210         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
211         obj->setLastPt(dx, dy);
212     }
213 
transform__MatrixPath(JNIEnv * env,jclass clazz,jlong objHandle,jlong matrixHandle,jlong dstHandle)214     static void transform__MatrixPath(JNIEnv* env, jclass clazz, jlong objHandle, jlong matrixHandle,
215             jlong dstHandle) {
216         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
217         SkMatrix* matrix = reinterpret_cast<SkMatrix*>(matrixHandle);
218         SkPath* dst = reinterpret_cast<SkPath*>(dstHandle);
219         obj->transform(*matrix, dst);
220     }
221 
transform__Matrix(JNIEnv * env,jclass clazz,jlong objHandle,jlong matrixHandle)222     static void transform__Matrix(JNIEnv* env, jclass clazz, jlong objHandle, jlong matrixHandle) {
223         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
224         SkMatrix* matrix = reinterpret_cast<SkMatrix*>(matrixHandle);
225         obj->transform(*matrix);
226     }
227 
op(JNIEnv * env,jclass clazz,jlong p1Handle,jlong p2Handle,jint opHandle,jlong rHandle)228     static jboolean op(JNIEnv* env, jclass clazz, jlong p1Handle, jlong p2Handle, jint opHandle,
229             jlong rHandle) {
230         SkPath* p1  = reinterpret_cast<SkPath*>(p1Handle);
231         SkPath* p2  = reinterpret_cast<SkPath*>(p2Handle);
232         SkPathOp op = static_cast<SkPathOp>(opHandle);
233         SkPath* r   = reinterpret_cast<SkPath*>(rHandle);
234         return Op(*p1, *p2, op, r);
235      }
236 
237     typedef SkPoint (*bezierCalculation)(float t, const SkPoint* points);
238 
addMove(std::vector<SkPoint> & segmentPoints,std::vector<float> & lengths,const SkPoint & point)239     static void addMove(std::vector<SkPoint>& segmentPoints, std::vector<float>& lengths,
240             const SkPoint& point) {
241         float length = 0;
242         if (!lengths.empty()) {
243             length = lengths.back();
244         }
245         segmentPoints.push_back(point);
246         lengths.push_back(length);
247     }
248 
addLine(std::vector<SkPoint> & segmentPoints,std::vector<float> & lengths,const SkPoint & toPoint)249     static void addLine(std::vector<SkPoint>& segmentPoints, std::vector<float>& lengths,
250             const SkPoint& toPoint) {
251         if (segmentPoints.empty()) {
252             segmentPoints.push_back(SkPoint::Make(0, 0));
253             lengths.push_back(0);
254         } else if (segmentPoints.back() == toPoint) {
255             return; // Empty line
256         }
257         float length = lengths.back() + SkPoint::Distance(segmentPoints.back(), toPoint);
258         segmentPoints.push_back(toPoint);
259         lengths.push_back(length);
260     }
261 
cubicCoordinateCalculation(float t,float p0,float p1,float p2,float p3)262     static float cubicCoordinateCalculation(float t, float p0, float p1, float p2, float p3) {
263         float oneMinusT = 1 - t;
264         float oneMinusTSquared = oneMinusT * oneMinusT;
265         float oneMinusTCubed = oneMinusTSquared * oneMinusT;
266         float tSquared = t * t;
267         float tCubed = tSquared * t;
268         return (oneMinusTCubed * p0) + (3 * oneMinusTSquared * t * p1)
269                 + (3 * oneMinusT * tSquared * p2) + (tCubed * p3);
270     }
271 
cubicBezierCalculation(float t,const SkPoint * points)272     static SkPoint cubicBezierCalculation(float t, const SkPoint* points) {
273         float x = cubicCoordinateCalculation(t, points[0].x(), points[1].x(),
274             points[2].x(), points[3].x());
275         float y = cubicCoordinateCalculation(t, points[0].y(), points[1].y(),
276             points[2].y(), points[3].y());
277         return SkPoint::Make(x, y);
278     }
279 
quadraticCoordinateCalculation(float t,float p0,float p1,float p2)280     static float quadraticCoordinateCalculation(float t, float p0, float p1, float p2) {
281         float oneMinusT = 1 - t;
282         return oneMinusT * ((oneMinusT * p0) + (t * p1)) + t * ((oneMinusT * p1) + (t * p2));
283     }
284 
quadraticBezierCalculation(float t,const SkPoint * points)285     static SkPoint quadraticBezierCalculation(float t, const SkPoint* points) {
286         float x = quadraticCoordinateCalculation(t, points[0].x(), points[1].x(), points[2].x());
287         float y = quadraticCoordinateCalculation(t, points[0].y(), points[1].y(), points[2].y());
288         return SkPoint::Make(x, y);
289     }
290 
291     // Subdivide a section of the Bezier curve, set the mid-point and the mid-t value.
292     // Returns true if further subdivision is necessary as defined by errorSquared.
subdividePoints(const SkPoint * points,bezierCalculation bezierFunction,float t0,const SkPoint & p0,float t1,const SkPoint & p1,float & midT,SkPoint & midPoint,float errorSquared)293     static bool subdividePoints(const SkPoint* points, bezierCalculation bezierFunction,
294             float t0, const SkPoint &p0, float t1, const SkPoint &p1,
295             float& midT, SkPoint &midPoint, float errorSquared) {
296         midT = (t1 + t0) / 2;
297         float midX = (p1.x() + p0.x()) / 2;
298         float midY = (p1.y() + p0.y()) / 2;
299 
300         midPoint = (*bezierFunction)(midT, points);
301         float xError = midPoint.x() - midX;
302         float yError = midPoint.y() - midY;
303         float midErrorSquared = (xError * xError) + (yError * yError);
304         return midErrorSquared > errorSquared;
305     }
306 
307     // Divides Bezier curves until linear interpolation is very close to accurate, using
308     // errorSquared as a metric. Cubic Bezier curves can have an inflection point that improperly
309     // short-circuit subdivision. If you imagine an S shape, the top and bottom points being the
310     // starting and end points, linear interpolation would mark the center where the curve places
311     // the point. It is clearly not the case that we can linearly interpolate at that point.
312     // doubleCheckDivision forces a second examination between subdivisions to ensure that linear
313     // interpolation works.
addBezier(const SkPoint * points,bezierCalculation bezierFunction,std::vector<SkPoint> & segmentPoints,std::vector<float> & lengths,float errorSquared,bool doubleCheckDivision)314     static void addBezier(const SkPoint* points,
315             bezierCalculation bezierFunction, std::vector<SkPoint>& segmentPoints,
316             std::vector<float>& lengths, float errorSquared, bool doubleCheckDivision) {
317         typedef std::map<float, SkPoint> PointMap;
318         PointMap tToPoint;
319 
320         tToPoint[0] = (*bezierFunction)(0, points);
321         tToPoint[1] = (*bezierFunction)(1, points);
322 
323         PointMap::iterator iter = tToPoint.begin();
324         PointMap::iterator next = iter;
325         ++next;
326         while (next != tToPoint.end()) {
327             bool needsSubdivision = true;
328             SkPoint midPoint;
329             do {
330                 float midT;
331                 needsSubdivision = subdividePoints(points, bezierFunction, iter->first,
332                     iter->second, next->first, next->second, midT, midPoint, errorSquared);
333                 if (!needsSubdivision && doubleCheckDivision) {
334                     SkPoint quarterPoint;
335                     float quarterT;
336                     needsSubdivision = subdividePoints(points, bezierFunction, iter->first,
337                         iter->second, midT, midPoint, quarterT, quarterPoint, errorSquared);
338                     if (needsSubdivision) {
339                         // Found an inflection point. No need to double-check.
340                         doubleCheckDivision = false;
341                     }
342                 }
343                 if (needsSubdivision) {
344                     next = tToPoint.insert(iter, PointMap::value_type(midT, midPoint));
345                 }
346             } while (needsSubdivision);
347             iter = next;
348             next++;
349         }
350 
351         // Now that each division can use linear interpolation with less than the allowed error
352         for (iter = tToPoint.begin(); iter != tToPoint.end(); ++iter) {
353             addLine(segmentPoints, lengths, iter->second);
354         }
355     }
356 
createVerbSegments(const SkPath::Iter & pathIter,SkPath::Verb verb,const SkPoint * points,std::vector<SkPoint> & segmentPoints,std::vector<float> & lengths,float errorSquared,float errorConic)357     static void createVerbSegments(const SkPath::Iter& pathIter, SkPath::Verb verb,
358             const SkPoint* points, std::vector<SkPoint>& segmentPoints,
359             std::vector<float>& lengths, float errorSquared, float errorConic) {
360         switch (verb) {
361             case SkPath::kMove_Verb:
362                 addMove(segmentPoints, lengths, points[0]);
363                 break;
364             case SkPath::kClose_Verb:
365                 addLine(segmentPoints, lengths, points[0]);
366                 break;
367             case SkPath::kLine_Verb:
368                 addLine(segmentPoints, lengths, points[1]);
369                 break;
370             case SkPath::kQuad_Verb:
371                 addBezier(points, quadraticBezierCalculation, segmentPoints, lengths,
372                     errorSquared, false);
373                 break;
374             case SkPath::kCubic_Verb:
375                 addBezier(points, cubicBezierCalculation, segmentPoints, lengths,
376                     errorSquared, true);
377                 break;
378             case SkPath::kConic_Verb: {
379                 SkAutoConicToQuads converter;
380                 const SkPoint* quads = converter.computeQuads(
381                         points, pathIter.conicWeight(), errorConic);
382                 for (int i = 0; i < converter.countQuads(); i++) {
383                     // Note: offset each subsequent quad by 2, since end points are shared
384                     const SkPoint* quad = quads + i * 2;
385                     addBezier(quad, quadraticBezierCalculation, segmentPoints, lengths,
386                         errorConic, false);
387                 }
388                 break;
389             }
390             default:
391                 static_assert(SkPath::kMove_Verb == 0
392                                 && SkPath::kLine_Verb == 1
393                                 && SkPath::kQuad_Verb == 2
394                                 && SkPath::kConic_Verb == 3
395                                 && SkPath::kCubic_Verb == 4
396                                 && SkPath::kClose_Verb == 5
397                                 && SkPath::kDone_Verb == 6,
398                         "Path enum changed, new types may have been added.");
399                 break;
400         }
401     }
402 
403     // Returns a float[] with each point along the path represented by 3 floats
404     // * fractional length along the path that the point resides
405     // * x coordinate
406     // * y coordinate
407     // Note that more than one point may have the same length along the path in
408     // the case of a move.
409     // NULL can be returned if the Path is empty.
approximate(JNIEnv * env,jclass clazz,jlong pathHandle,float acceptableError)410     static jfloatArray approximate(JNIEnv* env, jclass clazz, jlong pathHandle,
411             float acceptableError) {
412         SkPath* path = reinterpret_cast<SkPath*>(pathHandle);
413         SkASSERT(path);
414         SkPath::Iter pathIter(*path, false);
415         SkPath::Verb verb;
416         SkPoint points[4];
417         std::vector<SkPoint> segmentPoints;
418         std::vector<float> lengths;
419         float errorSquared = acceptableError * acceptableError;
420         float errorConic = acceptableError / 2; // somewhat arbitrary
421 
422         while ((verb = pathIter.next(points, false)) != SkPath::kDone_Verb) {
423             createVerbSegments(pathIter, verb, points, segmentPoints, lengths,
424                     errorSquared, errorConic);
425         }
426 
427         if (segmentPoints.empty()) {
428             int numVerbs = path->countVerbs();
429             if (numVerbs == 1) {
430                 addMove(segmentPoints, lengths, path->getPoint(0));
431             } else {
432                 // Invalid or empty path. Fall back to point(0,0)
433                 addMove(segmentPoints, lengths, SkPoint());
434             }
435         }
436 
437         float totalLength = lengths.back();
438         if (totalLength == 0) {
439             // Lone Move instructions should still be able to animate at the same value.
440             segmentPoints.push_back(segmentPoints.back());
441             lengths.push_back(1);
442             totalLength = 1;
443         }
444 
445         size_t numPoints = segmentPoints.size();
446         size_t approximationArraySize = numPoints * 3;
447 
448         float* approximation = new float[approximationArraySize];
449 
450         int approximationIndex = 0;
451         for (size_t i = 0; i < numPoints; i++) {
452             const SkPoint& point = segmentPoints[i];
453             approximation[approximationIndex++] = lengths[i] / totalLength;
454             approximation[approximationIndex++] = point.x();
455             approximation[approximationIndex++] = point.y();
456         }
457 
458         jfloatArray result = env->NewFloatArray(approximationArraySize);
459         env->SetFloatArrayRegion(result, 0, approximationArraySize, approximation);
460         delete[] approximation;
461         return result;
462     }
463 
464     // ---------------- @FastNative -----------------------------
465 
isRect(JNIEnv * env,jclass clazz,jlong objHandle,jobject jrect)466     static jboolean isRect(JNIEnv* env, jclass clazz, jlong objHandle, jobject jrect) {
467         SkRect rect;
468         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
469         jboolean result = obj->isRect(&rect);
470         if (jrect) {
471             GraphicsJNI::rect_to_jrectf(rect, env, jrect);
472         }
473         return result;
474     }
475 
476     // ---------------- @CriticalNative -------------------------
477 
reset(jlong objHandle)478     static void reset(jlong objHandle) {
479         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
480         obj->reset();
481     }
482 
rewind(jlong objHandle)483     static void rewind(jlong objHandle) {
484         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
485         obj->rewind();
486     }
487 
isEmpty(jlong objHandle)488     static jboolean isEmpty(jlong objHandle) {
489         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
490         return obj->isEmpty();
491     }
492 
isConvex(jlong objHandle)493     static jboolean isConvex(jlong objHandle) {
494         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
495         return obj->isConvex();
496     }
497 
getFillType(jlong objHandle)498     static jint getFillType(jlong objHandle) {
499         SkPath* obj = reinterpret_cast<SkPath*>(objHandle);
500         return obj->getFillType();
501     }
502 
setFillType(jlong pathHandle,jint ftHandle)503     static void setFillType(jlong pathHandle, jint ftHandle) {;
504         SkPath* path = reinterpret_cast<SkPath*>(pathHandle);
505         SkPath::FillType ft = static_cast<SkPath::FillType>(ftHandle);
506         path->setFillType(ft);
507     }
508 };
509 
510 static const JNINativeMethod methods[] = {
511     {"nInit","()J", (void*) SkPathGlue::init},
512     {"nInit","(J)J", (void*) SkPathGlue::init_Path},
513     {"nGetFinalizer", "()J", (void*) SkPathGlue::getFinalizer},
514     {"nSet","(JJ)V", (void*) SkPathGlue::set},
515     {"nComputeBounds","(JLandroid/graphics/RectF;)V", (void*) SkPathGlue::computeBounds},
516     {"nIncReserve","(JI)V", (void*) SkPathGlue::incReserve},
517     {"nMoveTo","(JFF)V", (void*) SkPathGlue::moveTo__FF},
518     {"nRMoveTo","(JFF)V", (void*) SkPathGlue::rMoveTo},
519     {"nLineTo","(JFF)V", (void*) SkPathGlue::lineTo__FF},
520     {"nRLineTo","(JFF)V", (void*) SkPathGlue::rLineTo},
521     {"nQuadTo","(JFFFF)V", (void*) SkPathGlue::quadTo__FFFF},
522     {"nRQuadTo","(JFFFF)V", (void*) SkPathGlue::rQuadTo},
523     {"nCubicTo","(JFFFFFF)V", (void*) SkPathGlue::cubicTo__FFFFFF},
524     {"nRCubicTo","(JFFFFFF)V", (void*) SkPathGlue::rCubicTo},
525     {"nArcTo","(JFFFFFFZ)V", (void*) SkPathGlue::arcTo},
526     {"nClose","(J)V", (void*) SkPathGlue::close},
527     {"nAddRect","(JFFFFI)V", (void*) SkPathGlue::addRect},
528     {"nAddOval","(JFFFFI)V", (void*) SkPathGlue::addOval},
529     {"nAddCircle","(JFFFI)V", (void*) SkPathGlue::addCircle},
530     {"nAddArc","(JFFFFFF)V", (void*) SkPathGlue::addArc},
531     {"nAddRoundRect","(JFFFFFFI)V", (void*) SkPathGlue::addRoundRectXY},
532     {"nAddRoundRect","(JFFFF[FI)V", (void*) SkPathGlue::addRoundRect8},
533     {"nAddPath","(JJFF)V", (void*) SkPathGlue::addPath__PathFF},
534     {"nAddPath","(JJ)V", (void*) SkPathGlue::addPath__Path},
535     {"nAddPath","(JJJ)V", (void*) SkPathGlue::addPath__PathMatrix},
536     {"nOffset","(JFF)V", (void*) SkPathGlue::offset__FF},
537     {"nSetLastPoint","(JFF)V", (void*) SkPathGlue::setLastPoint},
538     {"nTransform","(JJJ)V", (void*) SkPathGlue::transform__MatrixPath},
539     {"nTransform","(JJ)V", (void*) SkPathGlue::transform__Matrix},
540     {"nOp","(JJIJ)Z", (void*) SkPathGlue::op},
541     {"nApproximate", "(JF)[F", (void*) SkPathGlue::approximate},
542 
543     // ------- @FastNative below here ----------------------
544     {"nIsRect","(JLandroid/graphics/RectF;)Z", (void*) SkPathGlue::isRect},
545 
546     // ------- @CriticalNative below here ------------------
547     {"nReset","(J)V", (void*) SkPathGlue::reset},
548     {"nRewind","(J)V", (void*) SkPathGlue::rewind},
549     {"nIsEmpty","(J)Z", (void*) SkPathGlue::isEmpty},
550     {"nIsConvex","(J)Z", (void*) SkPathGlue::isConvex},
551     {"nGetFillType","(J)I", (void*) SkPathGlue::getFillType},
552     {"nSetFillType","(JI)V", (void*) SkPathGlue::setFillType},
553 };
554 
register_android_graphics_Path(JNIEnv * env)555 int register_android_graphics_Path(JNIEnv* env) {
556     return RegisterMethodsOrDie(env, "android/graphics/Path", methods, NELEM(methods));
557 
558     static_assert(0  == SkPath::kCW_Direction,  "direction_mismatch");
559     static_assert(1  == SkPath::kCCW_Direction, "direction_mismatch");
560 }
561 
562 }
563