OffscreenBufferPool.cpp revision 38e0c32852e3b9d8ca4a9d3791577f52536419cb 
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    texture.resize(width, height, GL_RGBA);
45    texture.blend = true;
46    texture.setWrap(GL_CLAMP_TO_EDGE);
47    // not setting filter on texture, since it's set when drawing, based on transform
48}
49
50Rect OffscreenBuffer::getTextureCoordinates() {
51    const float texX = 1.0f / static_cast<float>(texture.width());
52    const float texY = 1.0f / static_cast<float>(texture.height());
53    return Rect(0, viewportHeight * texY, viewportWidth * texX, 0);
54}
55
56void OffscreenBuffer::updateMeshFromRegion() {
57    // avoid T-junctions as they cause artifacts in between the resultant
58    // geometry when complex transforms occur.
59    // TODO: generate the safeRegion only if necessary based on drawing transform
60    Region safeRegion = Region::createTJunctionFreeRegion(region);
61
62    size_t count;
63    const android::Rect* rects = safeRegion.getArray(&count);
64
65    const float texX = 1.0f / float(texture.width());
66    const float texY = 1.0f / float(texture.height());
67
68    FatVector<TextureVertex, 64> meshVector(count * 4); // uses heap if more than 64 vertices needed
69    TextureVertex* mesh = &meshVector[0];
70    for (size_t i = 0; i < count; i++) {
71        const android::Rect* r = &rects[i];
72
73        const float u1 = r->left * texX;
74        const float v1 = (viewportHeight - r->top) * texY;
75        const float u2 = r->right * texX;
76        const float v2 = (viewportHeight - r->bottom) * texY;
77
78        TextureVertex::set(mesh++, r->left, r->top, u1, v1);
79        TextureVertex::set(mesh++, r->right, r->top, u2, v1);
80        TextureVertex::set(mesh++, r->left, r->bottom, u1, v2);
81        TextureVertex::set(mesh++, r->right, r->bottom, u2, v2);
82    }
83    elementCount = count * 6;
84    renderState.meshState().genOrUpdateMeshBuffer(&vbo,
85            sizeof(TextureVertex) * count * 4,
86            &meshVector[0],
87            GL_DYNAMIC_DRAW); // TODO: GL_STATIC_DRAW if savelayer
88}
89
90uint32_t OffscreenBuffer::computeIdealDimension(uint32_t dimension) {
91    return uint32_t(ceilf(dimension / float(LAYER_SIZE)) * LAYER_SIZE);
92}
93
94OffscreenBuffer::~OffscreenBuffer() {
95    texture.deleteTexture();
96    renderState.meshState().deleteMeshBuffer(vbo);
97    elementCount = 0;
98    vbo = 0;
99}
100
101///////////////////////////////////////////////////////////////////////////////
102// OffscreenBufferPool
103///////////////////////////////////////////////////////////////////////////////
104
105OffscreenBufferPool::OffscreenBufferPool()
106    : mMaxSize(Properties::layerPoolSize) {
107}
108
109OffscreenBufferPool::~OffscreenBufferPool() {
110    clear(); // TODO: unique_ptr?
111}
112
113int OffscreenBufferPool::Entry::compare(const Entry& lhs, const Entry& rhs) {
114    int deltaInt = int(lhs.width) - int(rhs.width);
115    if (deltaInt != 0) return deltaInt;
116
117    return int(lhs.height) - int(rhs.height);
118}
119
120void OffscreenBufferPool::clear() {
121    for (auto entry : mPool) {
122        delete entry.layer;
123    }
124    mPool.clear();
125    mSize = 0;
126}
127
128OffscreenBuffer* OffscreenBufferPool::get(RenderState& renderState,
129        const uint32_t width, const uint32_t height) {
130    OffscreenBuffer* layer = nullptr;
131
132    Entry entry(width, height);
133    auto iter = mPool.find(entry);
134
135    if (iter != mPool.end()) {
136        entry = *iter;
137        mPool.erase(iter);
138
139        layer = entry.layer;
140        layer->viewportWidth = width;
141        layer->viewportHeight = height;
142        mSize -= layer->getSizeInBytes();
143    } else {
144        layer = new OffscreenBuffer(renderState, Caches::getInstance(), width, height);
145    }
146
147    return layer;
148}
149
150OffscreenBuffer* OffscreenBufferPool::resize(OffscreenBuffer* layer,
151        const uint32_t width, const uint32_t height) {
152    RenderState& renderState = layer->renderState;
153    if (layer->texture.width() == OffscreenBuffer::computeIdealDimension(width)
154            && layer->texture.height() == OffscreenBuffer::computeIdealDimension(height)) {
155        // resize in place
156        layer->viewportWidth = width;
157        layer->viewportHeight = height;
158        return layer;
159    }
160    putOrDelete(layer);
161    return get(renderState, width, height);
162}
163
164void OffscreenBufferPool::dump() {
165    for (auto entry : mPool) {
166        ALOGD("  Layer size %dx%d", entry.width, entry.height);
167    }
168}
169
170void OffscreenBufferPool::putOrDelete(OffscreenBuffer* layer) {
171    const uint32_t size = layer->getSizeInBytes();
172    // Don't even try to cache a layer that's bigger than the cache
173    if (size < mMaxSize) {
174        // TODO: Use an LRU
175        while (mSize + size > mMaxSize) {
176            OffscreenBuffer* victim = mPool.begin()->layer;
177            mSize -= victim->getSizeInBytes();
178            delete victim;
179            mPool.erase(mPool.begin());
180        }
181
182        // clear region, since it's no longer valid
183        layer->region.clear();
184
185        Entry entry(layer);
186
187        mPool.insert(entry);
188        mSize += size;
189    } else {
190        delete layer;
191    }
192}
193
194}; // namespace uirenderer
195}; // namespace android
196