CanvasState.cpp revision fca52b7583d1e5f5ff8ed06554875d2a30ef56fa 
1/*
2 * Copyright (C) 2014 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 <SkCanvas.h>
18
19#include "CanvasState.h"
20#include "utils/MathUtils.h"
21
22namespace android {
23namespace uirenderer {
24
25
26CanvasState::CanvasState(CanvasStateClient& renderer)
27        : mDirtyClip(false)
28        , mWidth(-1)
29        , mHeight(-1)
30        , mSaveCount(1)
31        , mFirstSnapshot(new Snapshot)
32        , mCanvas(renderer)
33        , mSnapshot(mFirstSnapshot) {
34
35}
36
37CanvasState::~CanvasState() {
38
39}
40
41void CanvasState::initializeSaveStack(float clipLeft, float clipTop,
42        float clipRight, float clipBottom, const Vector3& lightCenter) {
43    mSnapshot = new Snapshot(mFirstSnapshot,
44            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
45    mSnapshot->setClip(clipLeft, clipTop, clipRight, clipBottom);
46    mSnapshot->fbo = mCanvas.getTargetFbo();
47    mSnapshot->setRelativeLightCenter(lightCenter);
48    mSaveCount = 1;
49}
50
51void CanvasState::setViewport(int width, int height) {
52    mWidth = width;
53    mHeight = height;
54    mFirstSnapshot->initializeViewport(width, height);
55    mCanvas.onViewportInitialized();
56
57    // create a temporary 1st snapshot, so old snapshots are released,
58    // and viewport can be queried safely.
59    // TODO: remove, combine viewport + save stack initialization
60    mSnapshot = new Snapshot(mFirstSnapshot,
61            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
62    mSaveCount = 1;
63}
64
65///////////////////////////////////////////////////////////////////////////////
66// Save (layer)
67///////////////////////////////////////////////////////////////////////////////
68
69/**
70 * Guaranteed to save without side-effects
71 *
72 * This approach, here and in restoreSnapshot(), allows subclasses to directly manipulate the save
73 * stack, and ensures restoreToCount() doesn't call back into subclass overrides.
74 */
75int CanvasState::saveSnapshot(int flags) {
76    mSnapshot = new Snapshot(mSnapshot, flags);
77    return mSaveCount++;
78}
79
80int CanvasState::save(int flags) {
81    return saveSnapshot(flags);
82}
83
84/**
85 * Guaranteed to restore without side-effects.
86 */
87void CanvasState::restoreSnapshot() {
88    sp<Snapshot> toRemove = mSnapshot;
89    sp<Snapshot> toRestore = mSnapshot->previous;
90
91    mSaveCount--;
92    mSnapshot = toRestore;
93
94    // subclass handles restore implementation
95    mCanvas.onSnapshotRestored(*toRemove, *toRestore);
96}
97
98void CanvasState::restore() {
99    if (mSaveCount > 1) {
100        restoreSnapshot();
101    }
102}
103
104void CanvasState::restoreToCount(int saveCount) {
105    if (saveCount < 1) saveCount = 1;
106
107    while (mSaveCount > saveCount) {
108        restoreSnapshot();
109    }
110}
111
112///////////////////////////////////////////////////////////////////////////////
113// Matrix
114///////////////////////////////////////////////////////////////////////////////
115
116void CanvasState::getMatrix(SkMatrix* matrix) const {
117    mSnapshot->transform->copyTo(*matrix);
118}
119
120void CanvasState::translate(float dx, float dy, float dz) {
121    mSnapshot->transform->translate(dx, dy, dz);
122}
123
124void CanvasState::rotate(float degrees) {
125    mSnapshot->transform->rotate(degrees, 0.0f, 0.0f, 1.0f);
126}
127
128void CanvasState::scale(float sx, float sy) {
129    mSnapshot->transform->scale(sx, sy, 1.0f);
130}
131
132void CanvasState::skew(float sx, float sy) {
133    mSnapshot->transform->skew(sx, sy);
134}
135
136void CanvasState::setMatrix(const SkMatrix& matrix) {
137    mSnapshot->transform->load(matrix);
138}
139
140void CanvasState::setMatrix(const Matrix4& matrix) {
141    mSnapshot->transform->load(matrix);
142}
143
144void CanvasState::concatMatrix(const SkMatrix& matrix) {
145    mat4 transform(matrix);
146    mSnapshot->transform->multiply(transform);
147}
148
149void CanvasState::concatMatrix(const Matrix4& matrix) {
150    mSnapshot->transform->multiply(matrix);
151}
152
153///////////////////////////////////////////////////////////////////////////////
154// Clip
155///////////////////////////////////////////////////////////////////////////////
156
157bool CanvasState::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
158    mDirtyClip |= mSnapshot->clip(left, top, right, bottom, op);
159    return !mSnapshot->clipIsEmpty();
160}
161
162bool CanvasState::clipPath(const SkPath* path, SkRegion::Op op) {
163    mDirtyClip |= mSnapshot->clipPath(*path, op);
164    return !mSnapshot->clipIsEmpty();
165}
166
167bool CanvasState::clipRegion(const SkRegion* region, SkRegion::Op op) {
168    mDirtyClip |= mSnapshot->clipRegionTransformed(*region, op);
169    return !mSnapshot->clipIsEmpty();
170}
171
172void CanvasState::setClippingOutline(LinearAllocator& allocator, const Outline* outline) {
173    Rect bounds;
174    float radius;
175    if (!outline->getAsRoundRect(&bounds, &radius)) return; // only RR supported
176
177    bool outlineIsRounded = MathUtils::isPositive(radius);
178    if (!outlineIsRounded || currentTransform()->isSimple()) {
179        // TODO: consider storing this rect separately, so that this can't be replaced with clip ops
180        clipRect(bounds.left, bounds.top, bounds.right, bounds.bottom, SkRegion::kIntersect_Op);
181    }
182    if (outlineIsRounded) {
183        setClippingRoundRect(allocator, bounds, radius, false);
184    }
185}
186
187void CanvasState::setClippingRoundRect(LinearAllocator& allocator,
188        const Rect& rect, float radius, bool highPriority) {
189    mSnapshot->setClippingRoundRect(allocator, rect, radius, highPriority);
190}
191
192void CanvasState::setProjectionPathMask(LinearAllocator& allocator, const SkPath* path) {
193    mSnapshot->setProjectionPathMask(allocator, path);
194}
195
196///////////////////////////////////////////////////////////////////////////////
197// Quick Rejection
198///////////////////////////////////////////////////////////////////////////////
199
200/**
201 * Calculates whether content drawn within the passed bounds would be outside of, or intersect with
202 * the clipRect. Does not modify the scissor.
203 *
204 * @param clipRequired if not null, will be set to true if element intersects clip
205 *         (and wasn't rejected)
206 *
207 * @param snapOut if set, the geometry will be treated as having an AA ramp.
208 *         See Rect::snapGeometryToPixelBoundaries()
209 */
210bool CanvasState::calculateQuickRejectForScissor(float left, float top,
211        float right, float bottom,
212        bool* clipRequired, bool* roundRectClipRequired,
213        bool snapOut) const {
214    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
215        return true;
216    }
217
218    Rect r(left, top, right, bottom);
219    currentTransform()->mapRect(r);
220    r.snapGeometryToPixelBoundaries(snapOut);
221
222    Rect clipRect(currentClipRect());
223    clipRect.snapToPixelBoundaries();
224
225    if (!clipRect.intersects(r)) return true;
226
227    // clip is required if geometry intersects clip rect
228    if (clipRequired) {
229        *clipRequired = !clipRect.contains(r);
230    }
231
232    // round rect clip is required if RR clip exists, and geometry intersects its corners
233    if (roundRectClipRequired) {
234        *roundRectClipRequired = mSnapshot->roundRectClipState != nullptr
235                && mSnapshot->roundRectClipState->areaRequiresRoundRectClip(r);
236    }
237    return false;
238}
239
240bool CanvasState::quickRejectConservative(float left, float top,
241        float right, float bottom) const {
242    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
243        return true;
244    }
245
246    Rect r(left, top, right, bottom);
247    currentTransform()->mapRect(r);
248    r.roundOut(); // rounded out to be conservative
249
250    Rect clipRect(currentClipRect());
251    clipRect.snapToPixelBoundaries();
252
253    if (!clipRect.intersects(r)) return true;
254
255    return false;
256}
257
258} // namespace uirenderer
259} // namespace android
260