1/*
2 * Copyright (C) 2010, Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1.  Redistributions of source code must retain the above copyright
8 *     notice, this list of conditions and the following disclaimer.
9 * 2.  Redistributions in binary form must reproduce the above copyright
10 *     notice, this list of conditions and the following disclaimer in the
11 *     documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "config.h"
26
27#if USE(ACCELERATED_COMPOSITING)
28
29#include "TextureManager.h"
30
31#include "LayerRendererChromium.h"
32
33namespace WebCore {
34
35static size_t memoryUseBytes(IntSize size, unsigned textureFormat)
36{
37    // FIXME: This assumes all textures are 4 bytes/pixel, like RGBA.
38    return size.width() * size.height() * 4;
39}
40
41TextureManager::TextureManager(GraphicsContext3D* context, size_t memoryLimitBytes, int maxTextureSize)
42    : m_context(context)
43    , m_memoryLimitBytes(memoryLimitBytes)
44    , m_memoryUseBytes(0)
45    , m_maxTextureSize(maxTextureSize)
46    , m_nextToken(1)
47{
48}
49
50TextureToken TextureManager::getToken()
51{
52    return m_nextToken++;
53}
54
55void TextureManager::releaseToken(TextureToken token)
56{
57    TextureMap::iterator it = m_textures.find(token);
58    if (it != m_textures.end())
59        removeTexture(token, it->second);
60}
61
62bool TextureManager::hasTexture(TextureToken token)
63{
64    if (m_textures.contains(token)) {
65        // If someone asks about a texture put it at the end of the LRU list.
66        m_textureLRUSet.remove(token);
67        m_textureLRUSet.add(token);
68        return true;
69    }
70    return false;
71}
72
73bool TextureManager::isProtected(TextureToken token)
74{
75    return token && hasTexture(token) && m_textures.get(token).isProtected;
76}
77
78void TextureManager::protectTexture(TextureToken token)
79{
80    ASSERT(hasTexture(token));
81    ASSERT(!m_textures.get(token).isProtected);
82    TextureInfo info = m_textures.take(token);
83    info.isProtected = true;
84    m_textures.add(token, info);
85}
86
87void TextureManager::unprotectAllTextures()
88{
89    for (TextureMap::iterator it = m_textures.begin(); it != m_textures.end(); ++it)
90        it->second.isProtected = false;
91}
92
93bool TextureManager::reduceMemoryToLimit(size_t limit)
94{
95    while (m_memoryUseBytes > limit) {
96        ASSERT(!m_textureLRUSet.isEmpty());
97        bool foundCandidate = false;
98        for (ListHashSet<TextureToken>::iterator lruIt = m_textureLRUSet.begin(); lruIt != m_textureLRUSet.end(); ++lruIt) {
99            TextureToken token = *lruIt;
100            TextureInfo info = m_textures.get(token);
101            if (info.isProtected)
102                continue;
103            removeTexture(token, info);
104            foundCandidate = true;
105            break;
106        }
107        if (!foundCandidate)
108            return false;
109    }
110    return true;
111}
112
113void TextureManager::addTexture(TextureToken token, TextureInfo info)
114{
115    ASSERT(!m_textureLRUSet.contains(token));
116    ASSERT(!m_textures.contains(token));
117    m_memoryUseBytes += memoryUseBytes(info.size, info.format);
118    m_textures.set(token, info);
119    m_textureLRUSet.add(token);
120}
121
122void TextureManager::removeTexture(TextureToken token, TextureInfo info)
123{
124    ASSERT(m_textureLRUSet.contains(token));
125    ASSERT(m_textures.contains(token));
126    m_memoryUseBytes -= memoryUseBytes(info.size, info.format);
127    m_textures.remove(token);
128    ASSERT(m_textureLRUSet.contains(token));
129    m_textureLRUSet.remove(token);
130    GLC(m_context.get(), m_context->deleteTexture(info.textureId));
131}
132
133unsigned TextureManager::requestTexture(TextureToken token, IntSize size, unsigned format, bool* newTexture)
134{
135    if (size.width() > m_maxTextureSize || size.height() > m_maxTextureSize)
136        return 0;
137
138    TextureMap::iterator it = m_textures.find(token);
139    if (it != m_textures.end()) {
140        ASSERT(it->second.size != size || it->second.format != format);
141        removeTexture(token, it->second);
142    }
143
144    size_t memoryRequiredBytes = memoryUseBytes(size, format);
145    if (memoryRequiredBytes > m_memoryLimitBytes || !reduceMemoryToLimit(m_memoryLimitBytes - memoryRequiredBytes))
146        return 0;
147
148    unsigned textureId;
149    GLC(m_context.get(), textureId = m_context->createTexture());
150    GLC(m_context.get(), m_context->bindTexture(GraphicsContext3D::TEXTURE_2D, textureId));
151    // Do basic linear filtering on resize.
152    GLC(m_context.get(), m_context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_MIN_FILTER, GraphicsContext3D::LINEAR));
153    GLC(m_context.get(), m_context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_MAG_FILTER, GraphicsContext3D::LINEAR));
154    // NPOT textures in GL ES only work when the wrap mode is set to GraphicsContext3D::CLAMP_TO_EDGE.
155    GLC(m_context.get(), m_context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_WRAP_S, GraphicsContext3D::CLAMP_TO_EDGE));
156    GLC(m_context.get(), m_context->texParameteri(GraphicsContext3D::TEXTURE_2D, GraphicsContext3D::TEXTURE_WRAP_T, GraphicsContext3D::CLAMP_TO_EDGE));
157    GLC(m_context.get(), m_context->texImage2DResourceSafe(GraphicsContext3D::TEXTURE_2D, 0, format, size.width(), size.height(), 0, format, GraphicsContext3D::UNSIGNED_BYTE));
158    TextureInfo info;
159    info.size = size;
160    info.format = format;
161    info.textureId = textureId;
162    info.isProtected = true;
163    addTexture(token, info);
164    return textureId;
165}
166
167}
168
169#endif // USE(ACCELERATED_COMPOSITING)
170