VectorDrawable.cpp revision 71e806b2f464b0ac85367fe008b554b44e4c5812 
1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "VectorDrawable.h"
18
19#include "PathParser.h"
20#include "SkImageInfo.h"
21#include "SkShader.h"
22#include <utils/Log.h>
23#include "utils/Macros.h"
24#include "utils/VectorDrawableUtils.h"
25
26#include <math.h>
27#include <string.h>
28
29namespace android {
30namespace uirenderer {
31namespace VectorDrawable {
32
33const int Tree::MAX_CACHED_BITMAP_SIZE = 2048;
34
35void Path::draw(SkCanvas* outCanvas, const SkMatrix& groupStackedMatrix, float scaleX, float scaleY) {
36    float matrixScale = getMatrixScale(groupStackedMatrix);
37    if (matrixScale == 0) {
38        // When either x or y is scaled to 0, we don't need to draw anything.
39        return;
40    }
41
42    const SkPath updatedPath = getUpdatedPath();
43    SkMatrix pathMatrix(groupStackedMatrix);
44    pathMatrix.postScale(scaleX, scaleY);
45
46    //TODO: try apply the path matrix to the canvas instead of creating a new path.
47    SkPath renderPath;
48    renderPath.reset();
49    renderPath.addPath(updatedPath, pathMatrix);
50
51    float minScale = fmin(scaleX, scaleY);
52    float strokeScale = minScale * matrixScale;
53    drawPath(outCanvas, renderPath, strokeScale, pathMatrix);
54}
55
56void Path::setPathData(const Data& data) {
57    if (mData == data) {
58        return;
59    }
60    // Updates the path data. Note that we don't generate a new Skia path right away
61    // because there are cases where the animation is changing the path data, but the view
62    // that hosts the VD has gone off screen, in which case we won't even draw. So we
63    // postpone the Skia path generation to the draw time.
64    mData = data;
65    mSkPathDirty = true;
66}
67
68void Path::dump() {
69    ALOGD("Path: %s has %zu points", mName.c_str(), mData.points.size());
70}
71
72float Path::getMatrixScale(const SkMatrix& groupStackedMatrix) {
73    // Given unit vectors A = (0, 1) and B = (1, 0).
74    // After matrix mapping, we got A' and B'. Let theta = the angel b/t A' and B'.
75    // Therefore, the final scale we want is min(|A'| * sin(theta), |B'| * sin(theta)),
76    // which is (|A'| * |B'| * sin(theta)) / max (|A'|, |B'|);
77    // If  max (|A'|, |B'|) = 0, that means either x or y has a scale of 0.
78    //
79    // For non-skew case, which is most of the cases, matrix scale is computing exactly the
80    // scale on x and y axis, and take the minimal of these two.
81    // For skew case, an unit square will mapped to a parallelogram. And this function will
82    // return the minimal height of the 2 bases.
83    SkVector skVectors[2];
84    skVectors[0].set(0, 1);
85    skVectors[1].set(1, 0);
86    groupStackedMatrix.mapVectors(skVectors, 2);
87    float scaleX = hypotf(skVectors[0].fX, skVectors[0].fY);
88    float scaleY = hypotf(skVectors[1].fX, skVectors[1].fY);
89    float crossProduct = skVectors[0].cross(skVectors[1]);
90    float maxScale = fmax(scaleX, scaleY);
91
92    float matrixScale = 0;
93    if (maxScale > 0) {
94        matrixScale = fabs(crossProduct) / maxScale;
95    }
96    return matrixScale;
97}
98Path::Path(const char* pathStr, size_t strLength) {
99    PathParser::ParseResult result;
100    PathParser::getPathDataFromString(&mData, &result, pathStr, strLength);
101    if (!result.failureOccurred) {
102        VectorDrawableUtils::verbsToPath(&mSkPath, mData);
103    }
104}
105
106Path::Path(const Data& data) {
107    mData = data;
108    // Now we need to construct a path
109    VectorDrawableUtils::verbsToPath(&mSkPath, data);
110}
111
112Path::Path(const Path& path) : Node(path) {
113    mData = path.mData;
114    VectorDrawableUtils::verbsToPath(&mSkPath, mData);
115}
116
117bool Path::canMorph(const Data& morphTo) {
118    return VectorDrawableUtils::canMorph(mData, morphTo);
119}
120
121bool Path::canMorph(const Path& path) {
122    return canMorph(path.mData);
123}
124
125const SkPath& Path::getUpdatedPath() {
126    if (mSkPathDirty) {
127        mSkPath.reset();
128        VectorDrawableUtils::verbsToPath(&mSkPath, mData);
129        mSkPathDirty = false;
130    }
131    return mSkPath;
132}
133
134void Path::setPath(const char* pathStr, size_t strLength) {
135    PathParser::ParseResult result;
136    mSkPathDirty = true;
137    PathParser::getPathDataFromString(&mData, &result, pathStr, strLength);
138}
139
140FullPath::FullPath(const FullPath& path) : Path(path) {
141    mProperties = path.mProperties;
142    SkRefCnt_SafeAssign(mStrokeGradient, path.mStrokeGradient);
143    SkRefCnt_SafeAssign(mFillGradient, path.mFillGradient);
144}
145
146const SkPath& FullPath::getUpdatedPath() {
147    if (!mSkPathDirty && !mTrimDirty) {
148        return mTrimmedSkPath;
149    }
150    Path::getUpdatedPath();
151    if (mProperties.trimPathStart != 0.0f || mProperties.trimPathEnd != 1.0f) {
152        applyTrim();
153        return mTrimmedSkPath;
154    } else {
155        return mSkPath;
156    }
157}
158
159void FullPath::updateProperties(float strokeWidth, SkColor strokeColor, float strokeAlpha,
160        SkColor fillColor, float fillAlpha, float trimPathStart, float trimPathEnd,
161        float trimPathOffset, float strokeMiterLimit, int strokeLineCap, int strokeLineJoin,
162        int fillType) {
163    mProperties.strokeWidth = strokeWidth;
164    mProperties.strokeColor = strokeColor;
165    mProperties.strokeAlpha = strokeAlpha;
166    mProperties.fillColor = fillColor;
167    mProperties.fillAlpha = fillAlpha;
168    mProperties.strokeMiterLimit = strokeMiterLimit;
169    mProperties.strokeLineCap = strokeLineCap;
170    mProperties.strokeLineJoin = strokeLineJoin;
171    mProperties.fillType = fillType;
172
173    // If any trim property changes, mark trim dirty and update the trim path
174    setTrimPathStart(trimPathStart);
175    setTrimPathEnd(trimPathEnd);
176    setTrimPathOffset(trimPathOffset);
177}
178
179inline SkColor applyAlpha(SkColor color, float alpha) {
180    int alphaBytes = SkColorGetA(color);
181    return SkColorSetA(color, alphaBytes * alpha);
182}
183
184void FullPath::drawPath(SkCanvas* outCanvas, SkPath& renderPath, float strokeScale,
185                        const SkMatrix& matrix){
186    // Draw path's fill, if fill color or gradient is valid
187    bool needsFill = false;
188    if (mFillGradient != nullptr) {
189        mPaint.setColor(applyAlpha(SK_ColorBLACK, mProperties.fillAlpha));
190        SkShader* newShader = mFillGradient->newWithLocalMatrix(matrix);
191        mPaint.setShader(newShader);
192        needsFill = true;
193    } else if (mProperties.fillColor != SK_ColorTRANSPARENT) {
194        mPaint.setColor(applyAlpha(mProperties.fillColor, mProperties.fillAlpha));
195        needsFill = true;
196    }
197
198    if (needsFill) {
199        mPaint.setStyle(SkPaint::Style::kFill_Style);
200        mPaint.setAntiAlias(true);
201        SkPath::FillType ft = static_cast<SkPath::FillType>(mProperties.fillType);
202        renderPath.setFillType(ft);
203        outCanvas->drawPath(renderPath, mPaint);
204    }
205
206    // Draw path's stroke, if stroke color or gradient is valid
207    bool needsStroke = false;
208    if (mStrokeGradient != nullptr) {
209        mPaint.setColor(applyAlpha(SK_ColorBLACK, mProperties.strokeAlpha));
210        SkShader* newShader = mStrokeGradient->newWithLocalMatrix(matrix);
211        mPaint.setShader(newShader);
212        needsStroke = true;
213    } else if (mProperties.strokeColor != SK_ColorTRANSPARENT) {
214        mPaint.setColor(applyAlpha(mProperties.strokeColor, mProperties.strokeAlpha));
215        needsStroke = true;
216    }
217    if (needsStroke) {
218        mPaint.setStyle(SkPaint::Style::kStroke_Style);
219        mPaint.setAntiAlias(true);
220        mPaint.setStrokeJoin(SkPaint::Join(mProperties.strokeLineJoin));
221        mPaint.setStrokeCap(SkPaint::Cap(mProperties.strokeLineCap));
222        mPaint.setStrokeMiter(mProperties.strokeMiterLimit);
223        mPaint.setStrokeWidth(mProperties.strokeWidth * strokeScale);
224        outCanvas->drawPath(renderPath, mPaint);
225    }
226}
227
228/**
229 * Applies trimming to the specified path.
230 */
231void FullPath::applyTrim() {
232    if (mProperties.trimPathStart == 0.0f && mProperties.trimPathEnd == 1.0f) {
233        // No trimming necessary.
234        return;
235    }
236    mTrimDirty = false;
237    mTrimmedSkPath.reset();
238    if (mProperties.trimPathStart == mProperties.trimPathEnd) {
239        // Trimmed path should be empty.
240        return;
241    }
242    SkPathMeasure measure(mSkPath, false);
243    float len = SkScalarToFloat(measure.getLength());
244    float start = len * fmod((mProperties.trimPathStart + mProperties.trimPathOffset), 1.0f);
245    float end = len * fmod((mProperties.trimPathEnd + mProperties.trimPathOffset), 1.0f);
246
247    if (start > end) {
248        measure.getSegment(start, len, &mTrimmedSkPath, true);
249        if (end > 0) {
250            measure.getSegment(0, end, &mTrimmedSkPath, true);
251        }
252    } else {
253        measure.getSegment(start, end, &mTrimmedSkPath, true);
254    }
255}
256
257REQUIRE_COMPATIBLE_LAYOUT(FullPath::Properties);
258
259static_assert(sizeof(float) == sizeof(int32_t), "float is not the same size as int32_t");
260static_assert(sizeof(SkColor) == sizeof(int32_t), "SkColor is not the same size as int32_t");
261
262bool FullPath::getProperties(int8_t* outProperties, int length) {
263    int propertyDataSize = sizeof(Properties);
264    if (length != propertyDataSize) {
265        LOG_ALWAYS_FATAL("Properties needs exactly %d bytes, a byte array of size %d is provided",
266                propertyDataSize, length);
267        return false;
268    }
269    Properties* out = reinterpret_cast<Properties*>(outProperties);
270    *out = mProperties;
271    return true;
272}
273
274void FullPath::setColorPropertyValue(int propertyId, int32_t value) {
275    Property currentProperty = static_cast<Property>(propertyId);
276    if (currentProperty == Property::StrokeColor) {
277        mProperties.strokeColor = value;
278    } else if (currentProperty == Property::FillColor) {
279        mProperties.fillColor = value;
280    } else {
281        LOG_ALWAYS_FATAL("Error setting color property on FullPath: No valid property with id: %d",
282                propertyId);
283    }
284}
285
286void FullPath::setPropertyValue(int propertyId, float value) {
287    Property property = static_cast<Property>(propertyId);
288    switch (property) {
289    case Property::StrokeWidth:
290        setStrokeWidth(value);
291        break;
292    case Property::StrokeAlpha:
293        setStrokeAlpha(value);
294        break;
295    case Property::FillAlpha:
296        setFillAlpha(value);
297        break;
298    case Property::TrimPathStart:
299        setTrimPathStart(value);
300        break;
301    case Property::TrimPathEnd:
302        setTrimPathEnd(value);
303        break;
304    case Property::TrimPathOffset:
305        setTrimPathOffset(value);
306        break;
307    default:
308        LOG_ALWAYS_FATAL("Invalid property id: %d for animation", propertyId);
309        break;
310    }
311}
312
313void ClipPath::drawPath(SkCanvas* outCanvas, SkPath& renderPath,
314        float strokeScale, const SkMatrix& matrix){
315    outCanvas->clipPath(renderPath, SkRegion::kIntersect_Op);
316}
317
318Group::Group(const Group& group) : Node(group) {
319    mProperties = group.mProperties;
320}
321
322void Group::draw(SkCanvas* outCanvas, const SkMatrix& currentMatrix, float scaleX,
323        float scaleY) {
324    // TODO: Try apply the matrix to the canvas instead of passing it down the tree
325
326    // Calculate current group's matrix by preConcat the parent's and
327    // and the current one on the top of the stack.
328    // Basically the Mfinal = Mviewport * M0 * M1 * M2;
329    // Mi the local matrix at level i of the group tree.
330    SkMatrix stackedMatrix;
331    getLocalMatrix(&stackedMatrix);
332    stackedMatrix.postConcat(currentMatrix);
333
334    // Save the current clip information, which is local to this group.
335    outCanvas->save();
336    // Draw the group tree in the same order as the XML file.
337    for (auto& child : mChildren) {
338        child->draw(outCanvas, stackedMatrix, scaleX, scaleY);
339    }
340    // Restore the previous clip information.
341    outCanvas->restore();
342}
343
344void Group::dump() {
345    ALOGD("Group %s has %zu children: ", mName.c_str(), mChildren.size());
346    for (size_t i = 0; i < mChildren.size(); i++) {
347        mChildren[i]->dump();
348    }
349}
350
351void Group::updateLocalMatrix(float rotate, float pivotX, float pivotY,
352        float scaleX, float scaleY, float translateX, float translateY) {
353    setRotation(rotate);
354    setPivotX(pivotX);
355    setPivotY(pivotY);
356    setScaleX(scaleX);
357    setScaleY(scaleY);
358    setTranslateX(translateX);
359    setTranslateY(translateY);
360}
361
362void Group::getLocalMatrix(SkMatrix* outMatrix) {
363    outMatrix->reset();
364    // TODO: use rotate(mRotate, mPivotX, mPivotY) and scale with pivot point, instead of
365    // translating to pivot for rotating and scaling, then translating back.
366    outMatrix->postTranslate(-mProperties.pivotX, -mProperties.pivotY);
367    outMatrix->postScale(mProperties.scaleX, mProperties.scaleY);
368    outMatrix->postRotate(mProperties.rotate, 0, 0);
369    outMatrix->postTranslate(mProperties.translateX + mProperties.pivotX,
370            mProperties.translateY + mProperties.pivotY);
371}
372
373void Group::addChild(Node* child) {
374    mChildren.emplace_back(child);
375}
376
377bool Group::getProperties(float* outProperties, int length) {
378    int propertyCount = static_cast<int>(Property::Count);
379    if (length != propertyCount) {
380        LOG_ALWAYS_FATAL("Properties needs exactly %d bytes, a byte array of size %d is provided",
381                propertyCount, length);
382        return false;
383    }
384    Properties* out = reinterpret_cast<Properties*>(outProperties);
385    *out = mProperties;
386    return true;
387}
388
389// TODO: Consider animating the properties as float pointers
390float Group::getPropertyValue(int propertyId) const {
391    Property currentProperty = static_cast<Property>(propertyId);
392    switch (currentProperty) {
393    case Property::Rotate:
394        return mProperties.rotate;
395    case Property::PivotX:
396        return mProperties.pivotX;
397    case Property::PivotY:
398        return mProperties.pivotY;
399    case Property::ScaleX:
400        return mProperties.scaleX;
401    case Property::ScaleY:
402        return mProperties.scaleY;
403    case Property::TranslateX:
404        return mProperties.translateX;
405    case Property::TranslateY:
406        return mProperties.translateY;
407    default:
408        LOG_ALWAYS_FATAL("Invalid property index: %d", propertyId);
409        return 0;
410    }
411}
412
413void Group::setPropertyValue(int propertyId, float value) {
414    Property currentProperty = static_cast<Property>(propertyId);
415    switch (currentProperty) {
416    case Property::Rotate:
417        mProperties.rotate = value;
418        break;
419    case Property::PivotX:
420        mProperties.pivotX = value;
421        break;
422    case Property::PivotY:
423        mProperties.pivotY = value;
424        break;
425    case Property::ScaleX:
426        mProperties.scaleX = value;
427        break;
428    case Property::ScaleY:
429        mProperties.scaleY = value;
430        break;
431    case Property::TranslateX:
432        mProperties.translateX = value;
433        break;
434    case Property::TranslateY:
435        mProperties.translateY = value;
436        break;
437    default:
438        LOG_ALWAYS_FATAL("Invalid property index: %d", propertyId);
439    }
440}
441
442bool Group::isValidProperty(int propertyId) {
443    return propertyId >= 0 && propertyId < static_cast<int>(Property::Count);
444}
445
446void Tree::draw(Canvas* outCanvas, SkColorFilter* colorFilter,
447        const SkRect& bounds, bool needsMirroring, bool canReuseCache) {
448    // The imageView can scale the canvas in different ways, in order to
449    // avoid blurry scaling, we have to draw into a bitmap with exact pixel
450    // size first. This bitmap size is determined by the bounds and the
451    // canvas scale.
452    outCanvas->getMatrix(&mCanvasMatrix);
453    mBounds = bounds;
454    float canvasScaleX = 1.0f;
455    float canvasScaleY = 1.0f;
456    if (mCanvasMatrix.getSkewX() == 0 && mCanvasMatrix.getSkewY() == 0) {
457        // Only use the scale value when there's no skew or rotation in the canvas matrix.
458        // TODO: Add a cts test for drawing VD on a canvas with negative scaling factors.
459        canvasScaleX = fabs(mCanvasMatrix.getScaleX());
460        canvasScaleY = fabs(mCanvasMatrix.getScaleY());
461    }
462    int scaledWidth = (int) (mBounds.width() * canvasScaleX);
463    int scaledHeight = (int) (mBounds.height() * canvasScaleY);
464    scaledWidth = std::min(Tree::MAX_CACHED_BITMAP_SIZE, scaledWidth);
465    scaledHeight = std::min(Tree::MAX_CACHED_BITMAP_SIZE, scaledHeight);
466
467    if (scaledWidth <= 0 || scaledHeight <= 0) {
468        return;
469    }
470
471    mPaint.setColorFilter(colorFilter);
472
473    int saveCount = outCanvas->save(SaveFlags::MatrixClip);
474    outCanvas->translate(mBounds.fLeft, mBounds.fTop);
475
476    // Handle RTL mirroring.
477    if (needsMirroring) {
478        outCanvas->translate(mBounds.width(), 0);
479        outCanvas->scale(-1.0f, 1.0f);
480    }
481
482    // At this point, canvas has been translated to the right position.
483    // And we use this bound for the destination rect for the drawBitmap, so
484    // we offset to (0, 0);
485    mBounds.offsetTo(0, 0);
486    createCachedBitmapIfNeeded(scaledWidth, scaledHeight);
487
488    outCanvas->drawVectorDrawable(this);
489
490    outCanvas->restoreToCount(saveCount);
491}
492
493SkPaint* Tree::getPaint() {
494    SkPaint* paint;
495    if (mRootAlpha == 1.0f && mPaint.getColorFilter() == NULL) {
496        paint = NULL;
497    } else {
498        mPaint.setFilterQuality(kLow_SkFilterQuality);
499        mPaint.setAlpha(mRootAlpha * 255);
500        paint = &mPaint;
501    }
502    return paint;
503}
504
505const SkBitmap& Tree::getBitmapUpdateIfDirty() {
506    mCachedBitmap.eraseColor(SK_ColorTRANSPARENT);
507    SkCanvas outCanvas(mCachedBitmap);
508    float scaleX = (float) mCachedBitmap.width() / mViewportWidth;
509    float scaleY = (float) mCachedBitmap.height() / mViewportHeight;
510    mRootNode->draw(&outCanvas, SkMatrix::I(), scaleX, scaleY);
511    mCacheDirty = false;
512    return mCachedBitmap;
513}
514
515void Tree::createCachedBitmapIfNeeded(int width, int height) {
516    if (!canReuseBitmap(width, height)) {
517        SkImageInfo info = SkImageInfo::Make(width, height,
518                kN32_SkColorType, kPremul_SkAlphaType);
519        mCachedBitmap.setInfo(info);
520        // TODO: Count the bitmap cache against app's java heap
521        mCachedBitmap.allocPixels(info);
522        mCacheDirty = true;
523    }
524}
525
526bool Tree::canReuseBitmap(int width, int height) {
527    return width == mCachedBitmap.width() && height == mCachedBitmap.height();
528}
529
530}; // namespace VectorDrawable
531
532}; // namespace uirenderer
533}; // namespace android
534