VectorDrawable.cpp revision ef062ebd20032efe697741d6c3dfd1faec54f590 
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    mProperties.strokeWidth = strokeWidth;
163    mProperties.strokeColor = strokeColor;
164    mProperties.strokeAlpha = strokeAlpha;
165    mProperties.fillColor = fillColor;
166    mProperties.fillAlpha = fillAlpha;
167    mProperties.strokeMiterLimit = strokeMiterLimit;
168    mProperties.strokeLineCap = strokeLineCap;
169    mProperties.strokeLineJoin = strokeLineJoin;
170
171    // If any trim property changes, mark trim dirty and update the trim path
172    setTrimPathStart(trimPathStart);
173    setTrimPathEnd(trimPathEnd);
174    setTrimPathOffset(trimPathOffset);
175}
176
177inline SkColor applyAlpha(SkColor color, float alpha) {
178    int alphaBytes = SkColorGetA(color);
179    return SkColorSetA(color, alphaBytes * alpha);
180}
181
182void FullPath::drawPath(SkCanvas* outCanvas, const SkPath& renderPath, float strokeScale,
183                        const SkMatrix& matrix){
184    // Draw path's fill, if fill color or gradient is valid
185    bool needsFill = false;
186    if (mFillGradient != nullptr) {
187        mPaint.setColor(applyAlpha(SK_ColorBLACK, mProperties.fillAlpha));
188        SkShader* newShader = mFillGradient->newWithLocalMatrix(matrix);
189        mPaint.setShader(newShader);
190        needsFill = true;
191    } else if (mProperties.fillColor != SK_ColorTRANSPARENT) {
192        mPaint.setColor(applyAlpha(mProperties.fillColor, mProperties.fillAlpha));
193        needsFill = true;
194    }
195
196    if (needsFill) {
197        mPaint.setStyle(SkPaint::Style::kFill_Style);
198        mPaint.setAntiAlias(true);
199        outCanvas->drawPath(renderPath, mPaint);
200    }
201
202    // Draw path's stroke, if stroke color or gradient is valid
203    bool needsStroke = false;
204    if (mStrokeGradient != nullptr) {
205        mPaint.setColor(applyAlpha(SK_ColorBLACK, mProperties.strokeAlpha));
206        SkShader* newShader = mStrokeGradient->newWithLocalMatrix(matrix);
207        mPaint.setShader(newShader);
208        needsStroke = true;
209    } else if (mProperties.strokeColor != SK_ColorTRANSPARENT) {
210        mPaint.setColor(applyAlpha(mProperties.strokeColor, mProperties.strokeAlpha));
211        needsStroke = true;
212    }
213    if (needsStroke) {
214        mPaint.setStyle(SkPaint::Style::kStroke_Style);
215        mPaint.setAntiAlias(true);
216        mPaint.setStrokeJoin(SkPaint::Join(mProperties.strokeLineJoin));
217        mPaint.setStrokeCap(SkPaint::Cap(mProperties.strokeLineCap));
218        mPaint.setStrokeMiter(mProperties.strokeMiterLimit);
219        mPaint.setStrokeWidth(mProperties.strokeWidth * strokeScale);
220        outCanvas->drawPath(renderPath, mPaint);
221    }
222}
223
224/**
225 * Applies trimming to the specified path.
226 */
227void FullPath::applyTrim() {
228    if (mProperties.trimPathStart == 0.0f && mProperties.trimPathEnd == 1.0f) {
229        // No trimming necessary.
230        return;
231    }
232    SkPathMeasure measure(mSkPath, false);
233    float len = SkScalarToFloat(measure.getLength());
234    float start = len * fmod((mProperties.trimPathStart + mProperties.trimPathOffset), 1.0f);
235    float end = len * fmod((mProperties.trimPathEnd + mProperties.trimPathOffset), 1.0f);
236
237    mTrimmedSkPath.reset();
238    if (start > end) {
239        measure.getSegment(start, len, &mTrimmedSkPath, true);
240        measure.getSegment(0, end, &mTrimmedSkPath, true);
241    } else {
242        measure.getSegment(start, end, &mTrimmedSkPath, true);
243    }
244    mTrimDirty = false;
245}
246
247REQUIRE_COMPATIBLE_LAYOUT(FullPath::Properties);
248
249static_assert(sizeof(float) == sizeof(int32_t), "float is not the same size as int32_t");
250static_assert(sizeof(SkColor) == sizeof(int32_t), "SkColor is not the same size as int32_t");
251
252bool FullPath::getProperties(int8_t* outProperties, int length) {
253    int propertyDataSize = sizeof(Properties);
254    if (length != propertyDataSize) {
255        LOG_ALWAYS_FATAL("Properties needs exactly %d bytes, a byte array of size %d is provided",
256                propertyDataSize, length);
257        return false;
258    }
259    Properties* out = reinterpret_cast<Properties*>(outProperties);
260    *out = mProperties;
261    return true;
262}
263
264void FullPath::setColorPropertyValue(int propertyId, int32_t value) {
265    Property currentProperty = static_cast<Property>(propertyId);
266    if (currentProperty == Property::StrokeColor) {
267        mProperties.strokeColor = value;
268    } else if (currentProperty == Property::FillColor) {
269        mProperties.fillColor = value;
270    } else {
271        LOG_ALWAYS_FATAL("Error setting color property on FullPath: No valid property with id: %d",
272                propertyId);
273    }
274}
275
276void FullPath::setPropertyValue(int propertyId, float value) {
277    Property property = static_cast<Property>(propertyId);
278    switch (property) {
279    case Property::StrokeWidth:
280        setStrokeWidth(value);
281        break;
282    case Property::StrokeAlpha:
283        setStrokeAlpha(value);
284        break;
285    case Property::FillAlpha:
286        setFillAlpha(value);
287        break;
288    case Property::TrimPathStart:
289        setTrimPathStart(value);
290        break;
291    case Property::TrimPathEnd:
292        setTrimPathEnd(value);
293        break;
294    case Property::TrimPathOffset:
295        setTrimPathOffset(value);
296        break;
297    default:
298        LOG_ALWAYS_FATAL("Invalid property id: %d for animation", propertyId);
299        break;
300    }
301}
302
303void ClipPath::drawPath(SkCanvas* outCanvas, const SkPath& renderPath,
304        float strokeScale, const SkMatrix& matrix){
305    outCanvas->clipPath(renderPath, SkRegion::kIntersect_Op);
306}
307
308Group::Group(const Group& group) : Node(group) {
309    mProperties = group.mProperties;
310}
311
312void Group::draw(SkCanvas* outCanvas, const SkMatrix& currentMatrix, float scaleX,
313        float scaleY) {
314    // TODO: Try apply the matrix to the canvas instead of passing it down the tree
315
316    // Calculate current group's matrix by preConcat the parent's and
317    // and the current one on the top of the stack.
318    // Basically the Mfinal = Mviewport * M0 * M1 * M2;
319    // Mi the local matrix at level i of the group tree.
320    SkMatrix stackedMatrix;
321    getLocalMatrix(&stackedMatrix);
322    stackedMatrix.postConcat(currentMatrix);
323
324    // Save the current clip information, which is local to this group.
325    outCanvas->save();
326    // Draw the group tree in the same order as the XML file.
327    for (auto& child : mChildren) {
328        child->draw(outCanvas, stackedMatrix, scaleX, scaleY);
329    }
330    // Restore the previous clip information.
331    outCanvas->restore();
332}
333
334void Group::dump() {
335    ALOGD("Group %s has %zu children: ", mName.c_str(), mChildren.size());
336    for (size_t i = 0; i < mChildren.size(); i++) {
337        mChildren[i]->dump();
338    }
339}
340
341void Group::updateLocalMatrix(float rotate, float pivotX, float pivotY,
342        float scaleX, float scaleY, float translateX, float translateY) {
343    setRotation(rotate);
344    setPivotX(pivotX);
345    setPivotY(pivotY);
346    setScaleX(scaleX);
347    setScaleY(scaleY);
348    setTranslateX(translateX);
349    setTranslateY(translateY);
350}
351
352void Group::getLocalMatrix(SkMatrix* outMatrix) {
353    outMatrix->reset();
354    // TODO: use rotate(mRotate, mPivotX, mPivotY) and scale with pivot point, instead of
355    // translating to pivot for rotating and scaling, then translating back.
356    outMatrix->postTranslate(-mProperties.pivotX, -mProperties.pivotY);
357    outMatrix->postScale(mProperties.scaleX, mProperties.scaleY);
358    outMatrix->postRotate(mProperties.rotate, 0, 0);
359    outMatrix->postTranslate(mProperties.translateX + mProperties.pivotX,
360            mProperties.translateY + mProperties.pivotY);
361}
362
363void Group::addChild(Node* child) {
364    mChildren.emplace_back(child);
365}
366
367bool Group::getProperties(float* outProperties, int length) {
368    int propertyCount = static_cast<int>(Property::Count);
369    if (length != propertyCount) {
370        LOG_ALWAYS_FATAL("Properties needs exactly %d bytes, a byte array of size %d is provided",
371                propertyCount, length);
372        return false;
373    }
374    Properties* out = reinterpret_cast<Properties*>(outProperties);
375    *out = mProperties;
376    return true;
377}
378
379// TODO: Consider animating the properties as float pointers
380float Group::getPropertyValue(int propertyId) const {
381    Property currentProperty = static_cast<Property>(propertyId);
382    switch (currentProperty) {
383    case Property::Rotate:
384        return mProperties.rotate;
385    case Property::PivotX:
386        return mProperties.pivotX;
387    case Property::PivotY:
388        return mProperties.pivotY;
389    case Property::ScaleX:
390        return mProperties.scaleX;
391    case Property::ScaleY:
392        return mProperties.scaleY;
393    case Property::TranslateX:
394        return mProperties.translateX;
395    case Property::TranslateY:
396        return mProperties.translateY;
397    default:
398        LOG_ALWAYS_FATAL("Invalid property index: %d", propertyId);
399        return 0;
400    }
401}
402
403void Group::setPropertyValue(int propertyId, float value) {
404    Property currentProperty = static_cast<Property>(propertyId);
405    switch (currentProperty) {
406    case Property::Rotate:
407        mProperties.rotate = value;
408        break;
409    case Property::PivotX:
410        mProperties.pivotX = value;
411        break;
412    case Property::PivotY:
413        mProperties.pivotY = value;
414        break;
415    case Property::ScaleX:
416        mProperties.scaleX = value;
417        break;
418    case Property::ScaleY:
419        mProperties.scaleY = value;
420        break;
421    case Property::TranslateX:
422        mProperties.translateX = value;
423        break;
424    case Property::TranslateY:
425        mProperties.translateY = value;
426        break;
427    default:
428        LOG_ALWAYS_FATAL("Invalid property index: %d", propertyId);
429    }
430}
431
432bool Group::isValidProperty(int propertyId) {
433    return propertyId >= 0 && propertyId < static_cast<int>(Property::Count);
434}
435
436void Tree::draw(Canvas* outCanvas, SkColorFilter* colorFilter,
437        const SkRect& bounds, bool needsMirroring, bool canReuseCache) {
438    // The imageView can scale the canvas in different ways, in order to
439    // avoid blurry scaling, we have to draw into a bitmap with exact pixel
440    // size first. This bitmap size is determined by the bounds and the
441    // canvas scale.
442    outCanvas->getMatrix(&mCanvasMatrix);
443    mBounds = bounds;
444    float canvasScaleX = 1.0f;
445    float canvasScaleY = 1.0f;
446    if (mCanvasMatrix.getSkewX() == 0 && mCanvasMatrix.getSkewY() == 0) {
447        // Only use the scale value when there's no skew or rotation in the canvas matrix.
448        // TODO: Add a cts test for drawing VD on a canvas with negative scaling factors.
449        canvasScaleX = fabs(mCanvasMatrix.getScaleX());
450        canvasScaleY = fabs(mCanvasMatrix.getScaleY());
451    }
452    int scaledWidth = (int) (mBounds.width() * canvasScaleX);
453    int scaledHeight = (int) (mBounds.height() * canvasScaleY);
454    scaledWidth = std::min(Tree::MAX_CACHED_BITMAP_SIZE, scaledWidth);
455    scaledHeight = std::min(Tree::MAX_CACHED_BITMAP_SIZE, scaledHeight);
456
457    if (scaledWidth <= 0 || scaledHeight <= 0) {
458        return;
459    }
460
461    mPaint.setColorFilter(colorFilter);
462
463    int saveCount = outCanvas->save(SaveFlags::MatrixClip);
464    outCanvas->translate(mBounds.fLeft, mBounds.fTop);
465
466    // Handle RTL mirroring.
467    if (needsMirroring) {
468        outCanvas->translate(mBounds.width(), 0);
469        outCanvas->scale(-1.0f, 1.0f);
470    }
471
472    // At this point, canvas has been translated to the right position.
473    // And we use this bound for the destination rect for the drawBitmap, so
474    // we offset to (0, 0);
475    mBounds.offsetTo(0, 0);
476    createCachedBitmapIfNeeded(scaledWidth, scaledHeight);
477
478    outCanvas->drawVectorDrawable(this);
479
480    outCanvas->restoreToCount(saveCount);
481}
482
483SkPaint* Tree::getPaint() {
484    SkPaint* paint;
485    if (mRootAlpha == 1.0f && mPaint.getColorFilter() == NULL) {
486        paint = NULL;
487    } else {
488        mPaint.setFilterQuality(kLow_SkFilterQuality);
489        mPaint.setAlpha(mRootAlpha * 255);
490        paint = &mPaint;
491    }
492    return paint;
493}
494
495const SkBitmap& Tree::getBitmapUpdateIfDirty() {
496    mCachedBitmap.eraseColor(SK_ColorTRANSPARENT);
497    SkCanvas outCanvas(mCachedBitmap);
498    float scaleX = (float) mCachedBitmap.width() / mViewportWidth;
499    float scaleY = (float) mCachedBitmap.height() / mViewportHeight;
500    mRootNode->draw(&outCanvas, SkMatrix::I(), scaleX, scaleY);
501    mCacheDirty = false;
502    return mCachedBitmap;
503}
504
505void Tree::createCachedBitmapIfNeeded(int width, int height) {
506    if (!canReuseBitmap(width, height)) {
507        SkImageInfo info = SkImageInfo::Make(width, height,
508                kN32_SkColorType, kPremul_SkAlphaType);
509        mCachedBitmap.setInfo(info);
510        // TODO: Count the bitmap cache against app's java heap
511        mCachedBitmap.allocPixels(info);
512        mCacheDirty = true;
513    }
514}
515
516bool Tree::canReuseBitmap(int width, int height) {
517    return width == mCachedBitmap.width() && height == mCachedBitmap.height();
518}
519
520}; // namespace VectorDrawable
521
522}; // namespace uirenderer
523}; // namespace android
524