1 /*
2 * Copyright (C) 2012 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 "Layer.h"
18
19 #include "renderstate/RenderState.h"
20 #include "utils/Color.h"
21 #include "utils/MathUtils.h"
22
23 #include <log/log.h>
24
25 namespace android {
26 namespace uirenderer {
27
Layer(RenderState & renderState,sk_sp<SkColorFilter> colorFilter,int alpha,SkBlendMode mode)28 Layer::Layer(RenderState& renderState, sk_sp<SkColorFilter> colorFilter, int alpha,
29 SkBlendMode mode)
30 : mRenderState(renderState)
31 , mColorFilter(colorFilter)
32 , alpha(alpha)
33 , mode(mode) {
34 // TODO: This is a violation of Android's typical ref counting, but it
35 // preserves the old inc/dec ref locations. This should be changed...
36 incStrong(nullptr);
37 renderState.registerLayer(this);
38 transform.setIdentity();
39 }
40
~Layer()41 Layer::~Layer() {
42 mRenderState.unregisterLayer(this);
43 }
44
postDecStrong()45 void Layer::postDecStrong() {
46 mRenderState.postDecStrong(this);
47 }
48
getMode() const49 SkBlendMode Layer::getMode() const {
50 if (mBlend || mode != SkBlendMode::kSrcOver) {
51 return mode;
52 } else {
53 return SkBlendMode::kSrc;
54 }
55 }
56
isIntegerAligned(SkScalar x)57 static inline SkScalar isIntegerAligned(SkScalar x) {
58 return MathUtils::isZero(roundf(x) - x);
59 }
60
61 // Disable filtering when there is no scaling in screen coordinates and the corners have the same
62 // fraction (for translate) or zero fraction (for any other rect-to-rect transform).
shouldFilterRect(const SkMatrix & matrix,const SkRect & srcRect,const SkRect & dstRect)63 static bool shouldFilterRect(const SkMatrix& matrix, const SkRect& srcRect, const SkRect& dstRect) {
64 if (!matrix.rectStaysRect()) return true;
65 SkRect dstDevRect = matrix.mapRect(dstRect);
66 float dstW, dstH;
67 if (MathUtils::isZero(matrix.getScaleX()) && MathUtils::isZero(matrix.getScaleY())) {
68 // Has a 90 or 270 degree rotation, although total matrix may also have scale factors
69 // in m10 and m01. Those scalings are automatically handled by mapRect so comparing
70 // dimensions is sufficient, but swap width and height comparison.
71 dstW = dstDevRect.height();
72 dstH = dstDevRect.width();
73 } else {
74 // Handle H/V flips or 180 rotation matrices. Axes may have been mirrored, but
75 // dimensions are still safe to compare directly.
76 dstW = dstDevRect.width();
77 dstH = dstDevRect.height();
78 }
79 if (!(MathUtils::areEqual(dstW, srcRect.width()) &&
80 MathUtils::areEqual(dstH, srcRect.height()))) {
81 return true;
82 }
83 // Device rect and source rect should be integer aligned to ensure there's no difference
84 // in how nearest-neighbor sampling is resolved.
85 return !(isIntegerAligned(srcRect.x()) &&
86 isIntegerAligned(srcRect.y()) &&
87 isIntegerAligned(dstDevRect.x()) &&
88 isIntegerAligned(dstDevRect.y()));
89 }
90
draw(SkCanvas * canvas)91 void Layer::draw(SkCanvas* canvas) {
92 GrRecordingContext* context = canvas->recordingContext();
93 if (context == nullptr) {
94 ALOGD("Attempting to draw LayerDrawable into an unsupported surface");
95 return;
96 }
97 SkMatrix layerTransform = getTransform();
98 //sk_sp<SkImage> layerImage = getImage();
99 const int layerWidth = getWidth();
100 const int layerHeight = getHeight();
101 if (layerImage) {
102 SkMatrix textureMatrixInv;
103 // TODO: after skia bug https://bugs.chromium.org/p/skia/issues/detail?id=7075 is fixed
104 // use bottom left origin and remove flipV and invert transformations.
105 SkMatrix flipV;
106 flipV.setAll(1, 0, 0, 0, -1, 1, 0, 0, 1);
107 textureMatrixInv.preConcat(flipV);
108 textureMatrixInv.preScale(1.0f / layerWidth, 1.0f / layerHeight);
109 textureMatrixInv.postScale(layerImage->width(), layerImage->height());
110 SkMatrix textureMatrix;
111 if (!textureMatrixInv.invert(&textureMatrix)) {
112 textureMatrix = textureMatrixInv;
113 }
114
115 SkMatrix matrix;
116 matrix = SkMatrix::Concat(layerTransform, textureMatrix);
117
118 SkPaint paint;
119 paint.setAlpha(getAlpha());
120 paint.setBlendMode(getMode());
121 paint.setColorFilter(getColorFilter());
122 const bool nonIdentityMatrix = !matrix.isIdentity();
123 if (nonIdentityMatrix) {
124 canvas->save();
125 canvas->concat(matrix);
126 }
127 const SkMatrix& totalMatrix = canvas->getTotalMatrix();
128
129 SkRect imageRect = SkRect::MakeIWH(layerImage->width(), layerImage->height());
130 SkSamplingOptions sampling;
131 if (getForceFilter() || shouldFilterRect(totalMatrix, imageRect, imageRect)) {
132 sampling = SkSamplingOptions(SkFilterMode::kLinear);
133 }
134 canvas->drawImage(layerImage.get(), 0, 0, sampling, &paint);
135 // restore the original matrix
136 if (nonIdentityMatrix) {
137 canvas->restore();
138 }
139 }
140 }
141
142 } // namespace uirenderer
143 } // namespace android
144