CanvasState.cpp revision 69e5adffb19135d51bde8e458f4907d7265f3e23 
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#define LOG_TAG "OpenGLRenderer"
18
19#include <SkCanvas.h>
20
21#include "StatefulBaseRenderer.h"
22
23#include "utils/MathUtils.h"
24
25namespace android {
26namespace uirenderer {
27
28StatefulBaseRenderer::StatefulBaseRenderer()
29        : mDirtyClip(false)
30        , mWidth(-1)
31        , mHeight(-1)
32        , mSaveCount(1)
33        , mFirstSnapshot(new Snapshot)
34        , mSnapshot(mFirstSnapshot) {
35}
36
37void StatefulBaseRenderer::initializeSaveStack(float clipLeft, float clipTop,
38        float clipRight, float clipBottom, const Vector3& lightCenter) {
39    mSnapshot = new Snapshot(mFirstSnapshot,
40            SkCanvas::kMatrix_SaveFlag | SkCanvas::kClip_SaveFlag);
41    mSnapshot->setClip(clipLeft, clipTop, clipRight, clipBottom);
42    mSnapshot->fbo = getTargetFbo();
43    mSnapshot->setRelativeLightCenter(lightCenter);
44    mSaveCount = 1;
45}
46
47void StatefulBaseRenderer::setViewport(int width, int height) {
48    mWidth = width;
49    mHeight = height;
50    mFirstSnapshot->initializeViewport(width, height);
51    onViewportInitialized();
52}
53
54///////////////////////////////////////////////////////////////////////////////
55// Save (layer)
56///////////////////////////////////////////////////////////////////////////////
57
58/**
59 * Non-virtual implementation of save, guaranteed to save without side-effects
60 *
61 * The approach here and in restoreSnapshot(), allows subclasses to directly manipulate the save
62 * stack, and ensures restoreToCount() doesn't call back into subclass overrides.
63 */
64int StatefulBaseRenderer::saveSnapshot(int flags) {
65    mSnapshot = new Snapshot(mSnapshot, flags);
66    return mSaveCount++;
67}
68
69int StatefulBaseRenderer::save(int flags) {
70    return saveSnapshot(flags);
71}
72
73/**
74 * Non-virtual implementation of restore, guaranteed to restore without side-effects.
75 */
76void StatefulBaseRenderer::restoreSnapshot() {
77    sp<Snapshot> toRemove = mSnapshot;
78    sp<Snapshot> toRestore = mSnapshot->previous;
79
80    mSaveCount--;
81    mSnapshot = toRestore;
82
83    // subclass handles restore implementation
84    onSnapshotRestored(*toRemove, *toRestore);
85}
86
87void StatefulBaseRenderer::restore() {
88    if (mSaveCount > 1) {
89        restoreSnapshot();
90    }
91}
92
93void StatefulBaseRenderer::restoreToCount(int saveCount) {
94    if (saveCount < 1) saveCount = 1;
95
96    while (mSaveCount > saveCount) {
97        restoreSnapshot();
98    }
99}
100
101///////////////////////////////////////////////////////////////////////////////
102// Matrix
103///////////////////////////////////////////////////////////////////////////////
104
105void StatefulBaseRenderer::getMatrix(Matrix4* matrix) const {
106    matrix->load(*(mSnapshot->transform));
107}
108
109void StatefulBaseRenderer::getMatrix(SkMatrix* matrix) const {
110    mSnapshot->transform->copyTo(*matrix);
111}
112
113void StatefulBaseRenderer::translate(float dx, float dy, float dz) {
114    mSnapshot->transform->translate(dx, dy, dz);
115}
116
117void StatefulBaseRenderer::rotate(float degrees) {
118    mSnapshot->transform->rotate(degrees, 0.0f, 0.0f, 1.0f);
119}
120
121void StatefulBaseRenderer::scale(float sx, float sy) {
122    mSnapshot->transform->scale(sx, sy, 1.0f);
123}
124
125void StatefulBaseRenderer::skew(float sx, float sy) {
126    mSnapshot->transform->skew(sx, sy);
127}
128
129void StatefulBaseRenderer::setMatrix(const SkMatrix& matrix) {
130    mSnapshot->transform->load(matrix);
131}
132
133void StatefulBaseRenderer::setMatrix(const Matrix4& matrix) {
134    mSnapshot->transform->load(matrix);
135}
136
137void StatefulBaseRenderer::concatMatrix(const SkMatrix& matrix) {
138    mat4 transform(matrix);
139    mSnapshot->transform->multiply(transform);
140}
141
142void StatefulBaseRenderer::concatMatrix(const Matrix4& matrix) {
143    mSnapshot->transform->multiply(matrix);
144}
145
146///////////////////////////////////////////////////////////////////////////////
147// Clip
148///////////////////////////////////////////////////////////////////////////////
149
150bool StatefulBaseRenderer::clipRect(float left, float top, float right, float bottom, SkRegion::Op op) {
151    if (CC_LIKELY(currentTransform()->rectToRect())) {
152        mDirtyClip |= mSnapshot->clip(left, top, right, bottom, op);
153        return !mSnapshot->clipRect->isEmpty();
154    }
155
156    SkPath path;
157    path.addRect(left, top, right, bottom);
158
159    return StatefulBaseRenderer::clipPath(&path, op);
160}
161
162bool StatefulBaseRenderer::clipPath(const SkPath* path, SkRegion::Op op) {
163    SkMatrix transform;
164    currentTransform()->copyTo(transform);
165
166    SkPath transformed;
167    path->transform(transform, &transformed);
168
169    SkRegion clip;
170    if (!mSnapshot->previous->clipRegion->isEmpty()) {
171        clip.setRegion(*mSnapshot->previous->clipRegion);
172    } else {
173        if (mSnapshot->previous == firstSnapshot()) {
174            clip.setRect(0, 0, getWidth(), getHeight());
175        } else {
176            Rect* bounds = mSnapshot->previous->clipRect;
177            clip.setRect(bounds->left, bounds->top, bounds->right, bounds->bottom);
178        }
179    }
180
181    SkRegion region;
182    region.setPath(transformed, clip);
183
184    // region is the transformed input path, masked by the previous clip
185    mDirtyClip |= mSnapshot->clipRegionTransformed(region, op);
186    return !mSnapshot->clipRect->isEmpty();
187}
188
189bool StatefulBaseRenderer::clipRegion(const SkRegion* region, SkRegion::Op op) {
190    mDirtyClip |= mSnapshot->clipRegionTransformed(*region, op);
191    return !mSnapshot->clipRect->isEmpty();
192}
193
194void StatefulBaseRenderer::setClippingOutline(LinearAllocator& allocator, const Outline* outline) {
195    Rect bounds;
196    float radius;
197    if (!outline->getAsRoundRect(&bounds, &radius)) return; // only RR supported
198
199    if (!MathUtils::isPositive(radius)) {
200        // TODO: consider storing this rect separately, so that this can't be replaced with clip ops
201        clipRect(bounds.left, bounds.top, bounds.right, bounds.bottom, SkRegion::kIntersect_Op);
202        return;
203    }
204    setClippingRoundRect(allocator, bounds, radius);
205}
206
207void StatefulBaseRenderer::setClippingRoundRect(LinearAllocator& allocator,
208        const Rect& rect, float radius) {
209    mSnapshot->setClippingRoundRect(allocator, rect, radius);
210}
211
212
213///////////////////////////////////////////////////////////////////////////////
214// Quick Rejection
215///////////////////////////////////////////////////////////////////////////////
216
217/**
218 * Calculates whether content drawn within the passed bounds would be outside of, or intersect with
219 * the clipRect. Does not modify the scissor.
220 *
221 * @param clipRequired if not null, will be set to true if element intersects clip
222 *         (and wasn't rejected)
223 *
224 * @param snapOut if set, the geometry will be treated as having an AA ramp.
225 *         See Rect::snapGeometryToPixelBoundaries()
226 */
227bool StatefulBaseRenderer::calculateQuickRejectForScissor(float left, float top,
228        float right, float bottom,
229        bool* clipRequired, bool* roundRectClipRequired,
230        bool snapOut) const {
231    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
232        return true;
233    }
234
235    Rect r(left, top, right, bottom);
236    currentTransform()->mapRect(r);
237    r.snapGeometryToPixelBoundaries(snapOut);
238
239    Rect clipRect(*currentClipRect());
240    clipRect.snapToPixelBoundaries();
241
242    if (!clipRect.intersects(r)) return true;
243
244    // clip is required if geometry intersects clip rect
245    if (clipRequired) {
246        *clipRequired = !clipRect.contains(r);
247    }
248
249    // round rect clip is required if RR clip exists, and geometry intersects its corners
250    if (roundRectClipRequired) {
251        *roundRectClipRequired = mSnapshot->roundRectClipState != NULL
252                && mSnapshot->roundRectClipState->areaRequiresRoundRectClip(r);
253    }
254    return false;
255}
256
257/**
258 * Returns false if drawing won't be clipped out.
259 *
260 * Makes the decision conservatively, by rounding out the mapped rect before comparing with the
261 * clipRect. To be used when perfect, pixel accuracy is not possible (esp. with tessellation) but
262 * rejection is still desired.
263 *
264 * This function, unlike quickRejectSetupScissor, should be used where precise geometry information
265 * isn't known (esp. when geometry adjusts based on scale). Generally, this will be first pass
266 * rejection where precise rejection isn't important, or precise information isn't available.
267 */
268bool StatefulBaseRenderer::quickRejectConservative(float left, float top,
269        float right, float bottom) const {
270    if (mSnapshot->isIgnored() || bottom <= top || right <= left) {
271        return true;
272    }
273
274    Rect r(left, top, right, bottom);
275    currentTransform()->mapRect(r);
276    r.roundOut(); // rounded out to be conservative
277
278    Rect clipRect(*currentClipRect());
279    clipRect.snapToPixelBoundaries();
280
281    if (!clipRect.intersects(r)) return true;
282
283    return false;
284}
285
286}; // namespace uirenderer
287}; // namespace android
288