OffscreenBufferPool.cpp revision 64db2bf1118db88c937e2b8c61b299bb2a80e3cb 
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 "OffscreenBufferPool.h"
18
19#include "Caches.h"
20#include "Properties.h"
21#include "renderstate/RenderState.h"
22#include "utils/FatVector.h"
23
24#include <utils/Log.h>
25
26#include <GLES2/gl2.h>
27
28namespace android {
29namespace uirenderer {
30
31////////////////////////////////////////////////////////////////////////////////
32// OffscreenBuffer
33////////////////////////////////////////////////////////////////////////////////
34
35OffscreenBuffer::OffscreenBuffer(RenderState& renderState, Caches& caches,
36        uint32_t viewportWidth, uint32_t viewportHeight)
37        : GpuMemoryTracker(GpuObjectType::OffscreenBuffer)
38        , renderState(renderState)
39        , viewportWidth(viewportWidth)
40        , viewportHeight(viewportHeight)
41        , texture(caches) {
42    uint32_t width = computeIdealDimension(viewportWidth);
43    uint32_t height = computeIdealDimension(viewportHeight);
44    caches.textureState().activateTexture(0);
45    texture.resize(width, height, GL_RGBA);
46    texture.blend = true;
47    texture.setWrap(GL_CLAMP_TO_EDGE);
48    // not setting filter on texture, since it's set when drawing, based on transform
49}
50
51Rect OffscreenBuffer::getTextureCoordinates() {
52    const float texX = 1.0f / static_cast<float>(texture.width());
53    const float texY = 1.0f / static_cast<float>(texture.height());
54    return Rect(0, viewportHeight * texY, viewportWidth * texX, 0);
55}
56
57void OffscreenBuffer::dirty(Rect dirtyArea) {
58    dirtyArea.doIntersect(0, 0, viewportWidth, viewportHeight);
59    if (!dirtyArea.isEmpty()) {
60        region.orSelf(android::Rect(dirtyArea.left, dirtyArea.top,
61                dirtyArea.right, dirtyArea.bottom));
62    }
63}
64
65void OffscreenBuffer::updateMeshFromRegion() {
66    // avoid T-junctions as they cause artifacts in between the resultant
67    // geometry when complex transforms occur.
68    // TODO: generate the safeRegion only if necessary based on drawing transform
69    Region safeRegion = Region::createTJunctionFreeRegion(region);
70
71    size_t count;
72    const android::Rect* rects = safeRegion.getArray(&count);
73
74    const float texX = 1.0f / float(texture.width());
75    const float texY = 1.0f / float(texture.height());
76
77    FatVector<TextureVertex, 64> meshVector(count * 4); // uses heap if more than 64 vertices needed
78    TextureVertex* mesh = &meshVector[0];
79    for (size_t i = 0; i < count; i++) {
80        const android::Rect* r = &rects[i];
81
82        const float u1 = r->left * texX;
83        const float v1 = (viewportHeight - r->top) * texY;
84        const float u2 = r->right * texX;
85        const float v2 = (viewportHeight - r->bottom) * texY;
86
87        TextureVertex::set(mesh++, r->left, r->top, u1, v1);
88        TextureVertex::set(mesh++, r->right, r->top, u2, v1);
89        TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
90        TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
91    }
92    elementCount = count * 6;
93    renderState.meshState().genOrUpdateMeshBuffer(&vbo,
94            sizeof(TextureVertex) * count * 4,
95            &meshVector[0],
96            GL_DYNAMIC_DRAW); // TODO: GL_STATIC_DRAW if savelayer
97}
98
99uint32_t OffscreenBuffer::computeIdealDimension(uint32_t dimension) {
100    return uint32_t(ceilf(dimension / float(LAYER_SIZE)) * LAYER_SIZE);
101}
102
103OffscreenBuffer::~OffscreenBuffer() {
104    texture.deleteTexture();
105    renderState.meshState().deleteMeshBuffer(vbo);
106    elementCount = 0;
107    vbo = 0;
108}
109
110///////////////////////////////////////////////////////////////////////////////
111// OffscreenBufferPool
112///////////////////////////////////////////////////////////////////////////////
113
114OffscreenBufferPool::OffscreenBufferPool()
115    : mMaxSize(Properties::layerPoolSize) {
116}
117
118OffscreenBufferPool::~OffscreenBufferPool() {
119    clear(); // TODO: unique_ptr?
120}
121
122int OffscreenBufferPool::Entry::compare(const Entry& lhs, const Entry& rhs) {
123    int deltaInt = int(lhs.width) - int(rhs.width);
124    if (deltaInt != 0) return deltaInt;
125
126    return int(lhs.height) - int(rhs.height);
127}
128
129void OffscreenBufferPool::clear() {
130    for (auto entry : mPool) {
131        delete entry.layer;
132    }
133    mPool.clear();
134    mSize = 0;
135}
136
137OffscreenBuffer* OffscreenBufferPool::get(RenderState& renderState,
138        const uint32_t width, const uint32_t height) {
139    OffscreenBuffer* layer = nullptr;
140
141    Entry entry(width, height);
142    auto iter = mPool.find(entry);
143
144    if (iter != mPool.end()) {
145        entry = *iter;
146        mPool.erase(iter);
147
148        layer = entry.layer;
149        layer->viewportWidth = width;
150        layer->viewportHeight = height;
151        mSize -= layer->getSizeInBytes();
152    } else {
153        layer = new OffscreenBuffer(renderState, Caches::getInstance(), width, height);
154    }
155
156    return layer;
157}
158
159OffscreenBuffer* OffscreenBufferPool::resize(OffscreenBuffer* layer,
160        const uint32_t width, const uint32_t height) {
161    RenderState& renderState = layer->renderState;
162    if (layer->texture.width() == OffscreenBuffer::computeIdealDimension(width)
163            && layer->texture.height() == OffscreenBuffer::computeIdealDimension(height)) {
164        // resize in place
165        layer->viewportWidth = width;
166        layer->viewportHeight = height;
167        return layer;
168    }
169    putOrDelete(layer);
170    return get(renderState, width, height);
171}
172
173void OffscreenBufferPool::dump() {
174    for (auto entry : mPool) {
175        ALOGD("  Layer size %dx%d", entry.width, entry.height);
176    }
177}
178
179void OffscreenBufferPool::putOrDelete(OffscreenBuffer* layer) {
180    const uint32_t size = layer->getSizeInBytes();
181    // Don't even try to cache a layer that's bigger than the cache
182    if (size < mMaxSize) {
183        // TODO: Use an LRU
184        while (mSize + size > mMaxSize) {
185            OffscreenBuffer* victim = mPool.begin()->layer;
186            mSize -= victim->getSizeInBytes();
187            delete victim;
188            mPool.erase(mPool.begin());
189        }
190
191        // clear region, since it's no longer valid
192        layer->region.clear();
193
194        Entry entry(layer);
195
196        mPool.insert(entry);
197        mSize += size;
198    } else {
199        delete layer;
200    }
201}
202
203}; // namespace uirenderer
204}; // namespace android
205