VectorDrawable.cpp revision 28d4ea558435b1b245bd5774c0db056a2ffdb385 
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    mStrokeWidth = path.mStrokeWidth;
142    mStrokeColor = path.mStrokeColor;
143    mStrokeAlpha = path.mStrokeAlpha;
144    mFillColor = path.mFillColor;
145    mFillAlpha = path.mFillAlpha;
146    mTrimPathStart = path.mTrimPathStart;
147    mTrimPathEnd = path.mTrimPathEnd;
148    mTrimPathOffset = path.mTrimPathOffset;
149    mStrokeMiterLimit = path.mStrokeMiterLimit;
150    mStrokeLineCap = path.mStrokeLineCap;
151    mStrokeLineJoin = path.mStrokeLineJoin;
152
153    SkRefCnt_SafeAssign(mStrokeGradient, path.mStrokeGradient);
154    SkRefCnt_SafeAssign(mFillGradient, path.mFillGradient);
155}
156
157const SkPath& FullPath::getUpdatedPath() {
158    if (!mSkPathDirty && !mTrimDirty) {
159        return mTrimmedSkPath;
160    }
161    Path::getUpdatedPath();
162    if (mTrimPathStart != 0.0f || mTrimPathEnd != 1.0f) {
163        applyTrim();
164        return mTrimmedSkPath;
165    } else {
166        return mSkPath;
167    }
168}
169
170void FullPath::updateProperties(float strokeWidth, SkColor strokeColor, float strokeAlpha,
171        SkColor fillColor, float fillAlpha, float trimPathStart, float trimPathEnd,
172        float trimPathOffset, float strokeMiterLimit, int strokeLineCap, int strokeLineJoin) {
173    mStrokeWidth = strokeWidth;
174    mStrokeColor = strokeColor;
175    mStrokeAlpha = strokeAlpha;
176    mFillColor = fillColor;
177    mFillAlpha = fillAlpha;
178    mStrokeMiterLimit = strokeMiterLimit;
179    mStrokeLineCap = SkPaint::Cap(strokeLineCap);
180    mStrokeLineJoin = SkPaint::Join(strokeLineJoin);
181
182    // If any trim property changes, mark trim dirty and update the trim path
183    setTrimPathStart(trimPathStart);
184    setTrimPathEnd(trimPathEnd);
185    setTrimPathOffset(trimPathOffset);
186}
187
188inline SkColor applyAlpha(SkColor color, float alpha) {
189    int alphaBytes = SkColorGetA(color);
190    return SkColorSetA(color, alphaBytes * alpha);
191}
192
193void FullPath::drawPath(SkCanvas* outCanvas, const SkPath& renderPath, float strokeScale,
194                        const SkMatrix& matrix){
195    // Draw path's fill, if fill color or gradient is valid
196    bool needsFill = false;
197    if (mFillGradient != nullptr) {
198        mPaint.setColor(applyAlpha(SK_ColorBLACK, mFillAlpha));
199        SkShader* newShader = mFillGradient->newWithLocalMatrix(matrix);
200        mPaint.setShader(newShader);
201        needsFill = true;
202    } else if (mFillColor != SK_ColorTRANSPARENT) {
203        mPaint.setColor(applyAlpha(mFillColor, mFillAlpha));
204        needsFill = true;
205    }
206
207    if (needsFill) {
208        mPaint.setStyle(SkPaint::Style::kFill_Style);
209        mPaint.setAntiAlias(true);
210        outCanvas->drawPath(renderPath, mPaint);
211    }
212
213    // Draw path's stroke, if stroke color or gradient is valid
214    bool needsStroke = false;
215    if (mStrokeGradient != nullptr) {
216        mPaint.setColor(applyAlpha(SK_ColorBLACK, mStrokeAlpha));
217        SkShader* newShader = mStrokeGradient->newWithLocalMatrix(matrix);
218        mPaint.setShader(newShader);
219        needsStroke = true;
220    } else if (mStrokeColor != SK_ColorTRANSPARENT) {
221        mPaint.setColor(applyAlpha(mStrokeColor, mStrokeAlpha));
222        needsStroke = true;
223    }
224    if (needsStroke) {
225        mPaint.setStyle(SkPaint::Style::kStroke_Style);
226        mPaint.setAntiAlias(true);
227        mPaint.setStrokeJoin(mStrokeLineJoin);
228        mPaint.setStrokeCap(mStrokeLineCap);
229        mPaint.setStrokeMiter(mStrokeMiterLimit);
230        mPaint.setStrokeWidth(mStrokeWidth * strokeScale);
231        outCanvas->drawPath(renderPath, mPaint);
232    }
233}
234
235/**
236 * Applies trimming to the specified path.
237 */
238void FullPath::applyTrim() {
239    if (mTrimPathStart == 0.0f && mTrimPathEnd == 1.0f) {
240        // No trimming necessary.
241        return;
242    }
243    SkPathMeasure measure(mSkPath, false);
244    float len = SkScalarToFloat(measure.getLength());
245    float start = len * fmod((mTrimPathStart + mTrimPathOffset), 1.0f);
246    float end = len * fmod((mTrimPathEnd + mTrimPathOffset), 1.0f);
247
248    mTrimmedSkPath.reset();
249    if (start > end) {
250        measure.getSegment(start, len, &mTrimmedSkPath, true);
251        measure.getSegment(0, end, &mTrimmedSkPath, true);
252    } else {
253        measure.getSegment(start, end, &mTrimmedSkPath, true);
254    }
255    mTrimDirty = false;
256}
257
258inline int putData(int8_t* outBytes, int startIndex, float value) {
259    int size = sizeof(float);
260    memcpy(&outBytes[startIndex], &value, size);
261    return size;
262}
263
264inline int putData(int8_t* outBytes, int startIndex, int value) {
265    int size = sizeof(int);
266    memcpy(&outBytes[startIndex], &value, size);
267    return size;
268}
269
270struct FullPathProperties {
271    // TODO: Consider storing full path properties in this struct instead of the fields.
272    float strokeWidth;
273    SkColor strokeColor;
274    float strokeAlpha;
275    SkColor fillColor;
276    float fillAlpha;
277    float trimPathStart;
278    float trimPathEnd;
279    float trimPathOffset;
280    int32_t strokeLineCap;
281    int32_t strokeLineJoin;
282    float strokeMiterLimit;
283};
284
285REQUIRE_COMPATIBLE_LAYOUT(FullPathProperties);
286
287static_assert(sizeof(float) == sizeof(int32_t), "float is not the same size as int32_t");
288static_assert(sizeof(SkColor) == sizeof(int32_t), "SkColor is not the same size as int32_t");
289
290bool FullPath::getProperties(int8_t* outProperties, int length) {
291    int propertyDataSize = sizeof(FullPathProperties);
292    if (length != propertyDataSize) {
293        LOG_ALWAYS_FATAL("Properties needs exactly %d bytes, a byte array of size %d is provided",
294                propertyDataSize, length);
295        return false;
296    }
297    // TODO: consider replacing the property fields with a FullPathProperties struct.
298    FullPathProperties properties;
299    properties.strokeWidth = mStrokeWidth;
300    properties.strokeColor = mStrokeColor;
301    properties.strokeAlpha = mStrokeAlpha;
302    properties.fillColor = mFillColor;
303    properties.fillAlpha = mFillAlpha;
304    properties.trimPathStart = mTrimPathStart;
305    properties.trimPathEnd = mTrimPathEnd;
306    properties.trimPathOffset = mTrimPathOffset;
307    properties.strokeLineCap = mStrokeLineCap;
308    properties.strokeLineJoin = mStrokeLineJoin;
309    properties.strokeMiterLimit = mStrokeMiterLimit;
310
311    memcpy(outProperties, &properties, length);
312    return true;
313}
314
315void ClipPath::drawPath(SkCanvas* outCanvas, const SkPath& renderPath,
316        float strokeScale, const SkMatrix& matrix){
317    outCanvas->clipPath(renderPath, SkRegion::kIntersect_Op);
318}
319
320Group::Group(const Group& group) : Node(group) {
321    mRotate = group.mRotate;
322    mPivotX = group.mPivotX;
323    mPivotY = group.mPivotY;
324    mScaleX = group.mScaleX;
325    mScaleY = group.mScaleY;
326    mTranslateX = group.mTranslateX;
327    mTranslateY = group.mTranslateY;
328}
329
330void Group::draw(SkCanvas* outCanvas, const SkMatrix& currentMatrix, float scaleX,
331        float scaleY) {
332    // TODO: Try apply the matrix to the canvas instead of passing it down the tree
333
334    // Calculate current group's matrix by preConcat the parent's and
335    // and the current one on the top of the stack.
336    // Basically the Mfinal = Mviewport * M0 * M1 * M2;
337    // Mi the local matrix at level i of the group tree.
338    SkMatrix stackedMatrix;
339    getLocalMatrix(&stackedMatrix);
340    stackedMatrix.postConcat(currentMatrix);
341
342    // Save the current clip information, which is local to this group.
343    outCanvas->save();
344    // Draw the group tree in the same order as the XML file.
345    for (Node* child : mChildren) {
346        child->draw(outCanvas, stackedMatrix, scaleX, scaleY);
347    }
348    // Restore the previous clip information.
349    outCanvas->restore();
350}
351
352void Group::dump() {
353    ALOGD("Group %s has %zu children: ", mName.c_str(), mChildren.size());
354    for (size_t i = 0; i < mChildren.size(); i++) {
355        mChildren[i]->dump();
356    }
357}
358
359void Group::updateLocalMatrix(float rotate, float pivotX, float pivotY,
360        float scaleX, float scaleY, float translateX, float translateY) {
361    setRotation(rotate);
362    setPivotX(pivotX);
363    setPivotY(pivotY);
364    setScaleX(scaleX);
365    setScaleY(scaleY);
366    setTranslateX(translateX);
367    setTranslateY(translateY);
368}
369
370void Group::getLocalMatrix(SkMatrix* outMatrix) {
371    outMatrix->reset();
372    // TODO: use rotate(mRotate, mPivotX, mPivotY) and scale with pivot point, instead of
373    // translating to pivot for rotating and scaling, then translating back.
374    outMatrix->postTranslate(-mPivotX, -mPivotY);
375    outMatrix->postScale(mScaleX, mScaleY);
376    outMatrix->postRotate(mRotate, 0, 0);
377    outMatrix->postTranslate(mTranslateX + mPivotX, mTranslateY + mPivotY);
378}
379
380void Group::addChild(Node* child) {
381    mChildren.push_back(child);
382}
383
384bool Group::getProperties(float* outProperties, int length) {
385    int propertyCount = static_cast<int>(Property::Count);
386    if (length != propertyCount) {
387        LOG_ALWAYS_FATAL("Properties needs exactly %d bytes, a byte array of size %d is provided",
388                propertyCount, length);
389        return false;
390    }
391    for (int i = 0; i < propertyCount; i++) {
392        Property currentProperty = static_cast<Property>(i);
393        switch (currentProperty) {
394        case Property::Rotate_Property:
395            outProperties[i] = mRotate;
396            break;
397        case Property::PivotX_Property:
398            outProperties[i] = mPivotX;
399            break;
400        case Property::PivotY_Property:
401            outProperties[i] = mPivotY;
402            break;
403        case Property::ScaleX_Property:
404            outProperties[i] = mScaleX;
405            break;
406        case Property::ScaleY_Property:
407            outProperties[i] = mScaleY;
408            break;
409        case Property::TranslateX_Property:
410            outProperties[i] = mTranslateX;
411            break;
412        case Property::TranslateY_Property:
413            outProperties[i] = mTranslateY;
414            break;
415        default:
416            LOG_ALWAYS_FATAL("Invalid input index: %d", i);
417            return false;
418        }
419    }
420    return true;
421}
422
423void Tree::draw(Canvas* outCanvas, SkColorFilter* colorFilter,
424        const SkRect& bounds, bool needsMirroring, bool canReuseCache) {
425    // The imageView can scale the canvas in different ways, in order to
426    // avoid blurry scaling, we have to draw into a bitmap with exact pixel
427    // size first. This bitmap size is determined by the bounds and the
428    // canvas scale.
429    outCanvas->getMatrix(&mCanvasMatrix);
430    mBounds = bounds;
431    float canvasScaleX = 1.0f;
432    float canvasScaleY = 1.0f;
433    if (mCanvasMatrix.getSkewX() == 0 && mCanvasMatrix.getSkewY() == 0) {
434        // Only use the scale value when there's no skew or rotation in the canvas matrix.
435        // TODO: Add a cts test for drawing VD on a canvas with negative scaling factors.
436        canvasScaleX = fabs(mCanvasMatrix.getScaleX());
437        canvasScaleY = fabs(mCanvasMatrix.getScaleY());
438    }
439    int scaledWidth = (int) (mBounds.width() * canvasScaleX);
440    int scaledHeight = (int) (mBounds.height() * canvasScaleY);
441    scaledWidth = std::min(Tree::MAX_CACHED_BITMAP_SIZE, scaledWidth);
442    scaledHeight = std::min(Tree::MAX_CACHED_BITMAP_SIZE, scaledHeight);
443
444    if (scaledWidth <= 0 || scaledHeight <= 0) {
445        return;
446    }
447
448    int saveCount = outCanvas->save(SaveFlags::MatrixClip);
449    outCanvas->translate(mBounds.fLeft, mBounds.fTop);
450
451    // Handle RTL mirroring.
452    if (needsMirroring) {
453        outCanvas->translate(mBounds.width(), 0);
454        outCanvas->scale(-1.0f, 1.0f);
455    }
456
457    // At this point, canvas has been translated to the right position.
458    // And we use this bound for the destination rect for the drawBitmap, so
459    // we offset to (0, 0);
460    mBounds.offsetTo(0, 0);
461
462    createCachedBitmapIfNeeded(scaledWidth, scaledHeight);
463    if (!mAllowCaching) {
464        updateCachedBitmap(scaledWidth, scaledHeight);
465    } else {
466        if (!canReuseCache || mCacheDirty) {
467            updateCachedBitmap(scaledWidth, scaledHeight);
468        }
469    }
470    drawCachedBitmapWithRootAlpha(outCanvas, colorFilter, mBounds);
471
472    outCanvas->restoreToCount(saveCount);
473}
474
475void Tree::drawCachedBitmapWithRootAlpha(Canvas* outCanvas, SkColorFilter* filter,
476        const SkRect& originalBounds) {
477    SkPaint* paint;
478    if (mRootAlpha == 1.0f && filter == NULL) {
479        paint = NULL;
480    } else {
481        mPaint.setFilterQuality(kLow_SkFilterQuality);
482        mPaint.setAlpha(mRootAlpha * 255);
483        mPaint.setColorFilter(filter);
484        paint = &mPaint;
485    }
486    outCanvas->drawBitmap(mCachedBitmap, 0, 0, mCachedBitmap.width(), mCachedBitmap.height(),
487            originalBounds.fLeft, originalBounds.fTop, originalBounds.fRight,
488            originalBounds.fBottom, paint);
489}
490
491void Tree::updateCachedBitmap(int width, int height) {
492    mCachedBitmap.eraseColor(SK_ColorTRANSPARENT);
493    SkCanvas outCanvas(mCachedBitmap);
494    float scaleX = width / mViewportWidth;
495    float scaleY = height / mViewportHeight;
496    mRootNode->draw(&outCanvas, SkMatrix::I(), scaleX, scaleY);
497    mCacheDirty = false;
498}
499
500void Tree::createCachedBitmapIfNeeded(int width, int height) {
501    if (!canReuseBitmap(width, height)) {
502        SkImageInfo info = SkImageInfo::Make(width, height,
503                kN32_SkColorType, kPremul_SkAlphaType);
504        mCachedBitmap.setInfo(info);
505        // TODO: Count the bitmap cache against app's java heap
506        mCachedBitmap.allocPixels(info);
507        mCacheDirty = true;
508    }
509}
510
511bool Tree::canReuseBitmap(int width, int height) {
512    return width == mCachedBitmap.width() && height == mCachedBitmap.height();
513}
514
515}; // namespace VectorDrawable
516
517}; // namespace uirenderer
518}; // namespace android
519