StatefulBaseRenderer.cpp revision d6b65f67717025b1162f86f04e2caa5723566cac 
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 "StatefulBaseRenderer.h"
20
21namespace android {
22namespace uirenderer {
23
24StatefulBaseRenderer::StatefulBaseRenderer() :
25        mDirtyClip(false), mWidth(-1), mHeight(-1),
26        mSaveCount(1), mFirstSnapshot(new Snapshot), mSnapshot(mFirstSnapshot) {
27}
28
29void StatefulBaseRenderer::initializeSaveStack(float clipLeft, float clipTop,
30        float clipRight, float clipBottom) {
31    mSnapshot = new Snapshot(mFirstSnapshot,
32            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
33    mSnapshot->setClip(clipLeft, clipTop, clipRight, clipBottom);
34    mSnapshot->fbo = getTargetFbo();
35    mSaveCount = 1;
36}
37
38void StatefulBaseRenderer::initializeViewport(int width, int height) {
39    mWidth = width;
40    mHeight = height;
41
42    mFirstSnapshot->height = height;
43    mFirstSnapshot->viewport.set(0, 0, width, height);
44}
45
46///////////////////////////////////////////////////////////////////////////////
47// Save (layer)
48///////////////////////////////////////////////////////////////////////////////
49
50/**
51 * Non-virtual implementation of save, guaranteed to save without side-effects
52 *
53 * The approach here and in restoreSnapshot(), allows subclasses to directly manipulate the save
54 * stack, and ensures restoreToCount() doesn't call back into subclass overrides.
55 */
56int StatefulBaseRenderer::saveSnapshot(int flags) {
57    mSnapshot = new Snapshot(mSnapshot, flags);
58    return mSaveCount++;
59}
60
61int StatefulBaseRenderer::save(int flags) {
62    return saveSnapshot(flags);
63}
64
65/**
66 * Non-virtual implementation of restore, guaranteed to restore without side-effects.
67 */
68void StatefulBaseRenderer::restoreSnapshot() {
69    sp<Snapshot> toRemove = mSnapshot;
70    sp<Snapshot> toRestore = mSnapshot->previous;
71
72    mSaveCount--;
73    mSnapshot = toRestore;
74
75    // subclass handles restore implementation
76    onSnapshotRestored(*toRemove, *toRestore);
77}
78
79void StatefulBaseRenderer::restore() {
80    if (mSaveCount > 1) {
81        restoreSnapshot();
82    }
83}
84
85void StatefulBaseRenderer::restoreToCount(int saveCount) {
86    if (saveCount < 1) saveCount = 1;
87
88    while (mSaveCount > saveCount) {
89        restoreSnapshot();
90    }
91}
92
93///////////////////////////////////////////////////////////////////////////////
94// Matrix
95///////////////////////////////////////////////////////////////////////////////
96
97void StatefulBaseRenderer::getMatrix(SkMatrix* matrix) const {
98    mSnapshot->transform->copyTo(*matrix);
99}
100
101void StatefulBaseRenderer::translate(float dx, float dy, float dz) {
102    mSnapshot->transform->translate(dx, dy, dz);
103}
104
105void StatefulBaseRenderer::rotate(float degrees) {
106    mSnapshot->transform->rotate(degrees, 0.0f, 0.0f, 1.0f);
107}
108
109void StatefulBaseRenderer::scale(float sx, float sy) {
110    mSnapshot->transform->scale(sx, sy, 1.0f);
111}
112
113void StatefulBaseRenderer::skew(float sx, float sy) {
114    mSnapshot->transform->skew(sx, sy);
115}
116
117void StatefulBaseRenderer::setMatrix(SkMatrix* matrix) {
118    if (matrix) {
119        mSnapshot->transform->load(*matrix);
120    } else {
121        mSnapshot->transform->loadIdentity();
122    }
123}
124
125void StatefulBaseRenderer::setMatrix(const Matrix4& matrix) {
126    mSnapshot->transform->load(matrix);
127}
128
129void StatefulBaseRenderer::concatMatrix(SkMatrix* matrix) {
130    mat4 transform(*matrix);
131    mSnapshot->transform->multiply(transform);
132}
133
134void StatefulBaseRenderer::concatMatrix(const Matrix4& matrix) {
135    mSnapshot->transform->multiply(matrix);
136}
137
138///////////////////////////////////////////////////////////////////////////////
139// Clip
140///////////////////////////////////////////////////////////////////////////////
141
142bool StatefulBaseRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
143    if (CC_LIKELY(currentTransform()->rectToRect())) {
144        mDirtyClip |= mSnapshot->clip(left, top, right, bottom, op);
145        return !mSnapshot->clipRect->isEmpty();
146    }
147
148    SkPath path;
149    path.addRect(left, top, right, bottom);
150
151    return StatefulBaseRenderer::clipPath(&path, op);
152}
153
154bool StatefulBaseRenderer::clipPath(SkPath* path, SkRegion::Op op) {
155    SkMatrix transform;
156    currentTransform()->copyTo(transform);
157
158    SkPath transformed;
159    path->transform(transform, &transformed);
160
161    SkRegion clip;
162    if (!mSnapshot->previous->clipRegion->isEmpty()) {
163        clip.setRegion(*mSnapshot->previous->clipRegion);
164    } else {
165        if (mSnapshot->previous == firstSnapshot()) {
166            clip.setRect(0, 0, getWidth(), getHeight());
167        } else {
168            Rect* bounds = mSnapshot->previous->clipRect;
169            clip.setRect(bounds->left, bounds->top, bounds->right, bounds->bottom);
170        }
171    }
172
173    SkRegion region;
174    region.setPath(transformed, clip);
175
176    mDirtyClip |= mSnapshot->clipRegionTransformed(region, op);
177    return !mSnapshot->clipRect->isEmpty();
178}
179
180bool StatefulBaseRenderer::clipRegion(SkRegion* region, SkRegion::Op op) {
181    mDirtyClip |= mSnapshot->clipRegionTransformed(*region, op);
182    return !mSnapshot->clipRect->isEmpty();
183}
184
185///////////////////////////////////////////////////////////////////////////////
186// Quick Rejection
187///////////////////////////////////////////////////////////////////////////////
188
189/**
190 * Calculates whether content drawn within the passed bounds would be outside of, or intersect with
191 * the clipRect. Does not modify the scissor.
192 *
193 * @param clipRequired if not null, will be set to true if element intersects clip
194 *         (and wasn't rejected)
195 *
196 * @param snapOut if set, the geometry will be treated as having an AA ramp.
197 *         See Rect::snapGeometryToPixelBoundaries()
198 */
199bool StatefulBaseRenderer::calculateQuickRejectForScissor(float left, float top,
200        float right, float bottom, bool* clipRequired, bool snapOut) const {
201    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
202        return true;
203    }
204
205    Rect r(left, top, right, bottom);
206    currentTransform()->mapRect(r);
207    r.snapGeometryToPixelBoundaries(snapOut);
208
209    Rect clipRect(*currentClipRect());
210    clipRect.snapToPixelBoundaries();
211
212    if (!clipRect.intersects(r)) return true;
213
214    // clip is required if geometry intersects clip rect
215    if (clipRequired) *clipRequired = !clipRect.contains(r);
216    return false;
217}
218
219/**
220 * Returns false if drawing won't be clipped out.
221 *
222 * Makes the decision conservatively, by rounding out the mapped rect before comparing with the
223 * clipRect. To be used when perfect, pixel accuracy is not possible (esp. with tessellation) but
224 * rejection is still desired.
225 *
226 * This function, unlike quickRejectSetupScissor, should be used where precise geometry information
227 * isn't known (esp. when geometry adjusts based on scale). Generally, this will be first pass
228 * rejection where precise rejection isn't important, or precise information isn't available.
229 */
230bool StatefulBaseRenderer::quickRejectConservative(float left, float top,
231        float right, float bottom) const {
232    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
233        return true;
234    }
235
236    Rect r(left, top, right, bottom);
237    currentTransform()->mapRect(r);
238    r.roundOut(); // rounded out to be conservative
239
240    Rect clipRect(*currentClipRect());
241    clipRect.snapToPixelBoundaries();
242
243    if (!clipRect.intersects(r)) return true;
244
245    return false;
246}
247
248}; // namespace uirenderer
249}; // namespace android
250