1 /*
2  * Copyright (C) 2010 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 <utils/JenkinsHash.h>
18 
19 #include "Caches.h"
20 #include "Debug.h"
21 #include "GradientCache.h"
22 #include "Properties.h"
23 
24 #include <cutils/properties.h>
25 
26 namespace android {
27 namespace uirenderer {
28 
29 ///////////////////////////////////////////////////////////////////////////////
30 // Functions
31 ///////////////////////////////////////////////////////////////////////////////
32 
33 template<typename T>
min(T a,T b)34 static inline T min(T a, T b) {
35     return a < b ? a : b;
36 }
37 
38 ///////////////////////////////////////////////////////////////////////////////
39 // Cache entry
40 ///////////////////////////////////////////////////////////////////////////////
41 
hash() const42 hash_t GradientCacheEntry::hash() const {
43     uint32_t hash = JenkinsHashMix(0, count);
44     for (uint32_t i = 0; i < count; i++) {
45         hash = JenkinsHashMix(hash, android::hash_type(colors[i]));
46         hash = JenkinsHashMix(hash, android::hash_type(positions[i]));
47     }
48     return JenkinsHashWhiten(hash);
49 }
50 
compare(const GradientCacheEntry & lhs,const GradientCacheEntry & rhs)51 int GradientCacheEntry::compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
52     int deltaInt = int(lhs.count) - int(rhs.count);
53     if (deltaInt != 0) return deltaInt;
54 
55     deltaInt = memcmp(lhs.colors.get(), rhs.colors.get(), lhs.count * sizeof(uint32_t));
56     if (deltaInt != 0) return deltaInt;
57 
58     return memcmp(lhs.positions.get(), rhs.positions.get(), lhs.count * sizeof(float));
59 }
60 
61 ///////////////////////////////////////////////////////////////////////////////
62 // Constructors/destructor
63 ///////////////////////////////////////////////////////////////////////////////
64 
GradientCache(Extensions & extensions)65 GradientCache::GradientCache(Extensions& extensions)
66         : mCache(LruCache<GradientCacheEntry, Texture*>::kUnlimitedCapacity)
67         , mSize(0)
68         , mMaxSize(Properties::gradientCacheSize)
69         , mUseFloatTexture(extensions.hasFloatTextures())
70         , mHasNpot(extensions.hasNPot()){
71     glGetIntegerv(GL_MAX_TEXTURE_SIZE, &mMaxTextureSize);
72 
73     mCache.setOnEntryRemovedListener(this);
74 }
75 
~GradientCache()76 GradientCache::~GradientCache() {
77     mCache.clear();
78 }
79 
80 ///////////////////////////////////////////////////////////////////////////////
81 // Size management
82 ///////////////////////////////////////////////////////////////////////////////
83 
getSize()84 uint32_t GradientCache::getSize() {
85     return mSize;
86 }
87 
getMaxSize()88 uint32_t GradientCache::getMaxSize() {
89     return mMaxSize;
90 }
91 
92 ///////////////////////////////////////////////////////////////////////////////
93 // Callbacks
94 ///////////////////////////////////////////////////////////////////////////////
95 
operator ()(GradientCacheEntry &,Texture * & texture)96 void GradientCache::operator()(GradientCacheEntry&, Texture*& texture) {
97     if (texture) {
98         mSize -= texture->objectSize();
99         texture->deleteTexture();
100         delete texture;
101     }
102 }
103 
104 ///////////////////////////////////////////////////////////////////////////////
105 // Caching
106 ///////////////////////////////////////////////////////////////////////////////
107 
get(uint32_t * colors,float * positions,int count)108 Texture* GradientCache::get(uint32_t* colors, float* positions, int count) {
109     GradientCacheEntry gradient(colors, positions, count);
110     Texture* texture = mCache.get(gradient);
111 
112     if (!texture) {
113         texture = addLinearGradient(gradient, colors, positions, count);
114     }
115 
116     return texture;
117 }
118 
clear()119 void GradientCache::clear() {
120     mCache.clear();
121 }
122 
getGradientInfo(const uint32_t * colors,const int count,GradientInfo & info)123 void GradientCache::getGradientInfo(const uint32_t* colors, const int count,
124         GradientInfo& info) {
125     uint32_t width = 256 * (count - 1);
126 
127     // If the npot extension is not supported we cannot use non-clamp
128     // wrap modes. We therefore find the nearest largest power of 2
129     // unless width is already a power of 2
130     if (!mHasNpot && (width & (width - 1)) != 0) {
131         width = 1 << (32 - __builtin_clz(width));
132     }
133 
134     bool hasAlpha = false;
135     for (int i = 0; i < count; i++) {
136         if (((colors[i] >> 24) & 0xff) < 255) {
137             hasAlpha = true;
138             break;
139         }
140     }
141 
142     info.width = min(width, uint32_t(mMaxTextureSize));
143     info.hasAlpha = hasAlpha;
144 }
145 
addLinearGradient(GradientCacheEntry & gradient,uint32_t * colors,float * positions,int count)146 Texture* GradientCache::addLinearGradient(GradientCacheEntry& gradient,
147         uint32_t* colors, float* positions, int count) {
148 
149     GradientInfo info;
150     getGradientInfo(colors, count, info);
151 
152     Texture* texture = new Texture(Caches::getInstance());
153     texture->blend = info.hasAlpha;
154     texture->generation = 1;
155 
156     // Assume the cache is always big enough
157     const uint32_t size = info.width * 2 * bytesPerPixel();
158     while (getSize() + size > mMaxSize) {
159         LOG_ALWAYS_FATAL_IF(!mCache.removeOldest(),
160                 "Ran out of things to remove from the cache? getSize() = %" PRIu32
161                 ", size = %" PRIu32 ", mMaxSize = %" PRIu32 ", width = %" PRIu32,
162                 getSize(), size, mMaxSize, info.width);
163     }
164 
165     generateTexture(colors, positions, info.width, 2, texture);
166 
167     mSize += size;
168     LOG_ALWAYS_FATAL_IF((int)size != texture->objectSize(),
169             "size != texture->objectSize(), size %" PRIu32 ", objectSize %d"
170             " width = %" PRIu32 " bytesPerPixel() = %zu",
171             size, texture->objectSize(), info.width, bytesPerPixel());
172     mCache.put(gradient, texture);
173 
174     return texture;
175 }
176 
bytesPerPixel() const177 size_t GradientCache::bytesPerPixel() const {
178     // We use 4 channels (RGBA)
179     return 4 * (mUseFloatTexture ? sizeof(float) : sizeof(uint8_t));
180 }
181 
splitToBytes(uint32_t inColor,GradientColor & outColor) const182 void GradientCache::splitToBytes(uint32_t inColor, GradientColor& outColor) const {
183     outColor.r = (inColor >> 16) & 0xff;
184     outColor.g = (inColor >>  8) & 0xff;
185     outColor.b = (inColor >>  0) & 0xff;
186     outColor.a = (inColor >> 24) & 0xff;
187 }
188 
splitToFloats(uint32_t inColor,GradientColor & outColor) const189 void GradientCache::splitToFloats(uint32_t inColor, GradientColor& outColor) const {
190     outColor.r = ((inColor >> 16) & 0xff) / 255.0f;
191     outColor.g = ((inColor >>  8) & 0xff) / 255.0f;
192     outColor.b = ((inColor >>  0) & 0xff) / 255.0f;
193     outColor.a = ((inColor >> 24) & 0xff) / 255.0f;
194 }
195 
mixBytes(GradientColor & start,GradientColor & end,float amount,uint8_t * & dst) const196 void GradientCache::mixBytes(GradientColor& start, GradientColor& end, float amount,
197         uint8_t*& dst) const {
198     float oppAmount = 1.0f - amount;
199     const float alpha = start.a * oppAmount + end.a * amount;
200     const float a = alpha / 255.0f;
201 
202     *dst++ = uint8_t(a * (start.r * oppAmount + end.r * amount));
203     *dst++ = uint8_t(a * (start.g * oppAmount + end.g * amount));
204     *dst++ = uint8_t(a * (start.b * oppAmount + end.b * amount));
205     *dst++ = uint8_t(alpha);
206 }
207 
mixFloats(GradientColor & start,GradientColor & end,float amount,uint8_t * & dst) const208 void GradientCache::mixFloats(GradientColor& start, GradientColor& end, float amount,
209         uint8_t*& dst) const {
210     float oppAmount = 1.0f - amount;
211     const float a = start.a * oppAmount + end.a * amount;
212 
213     float* d = (float*) dst;
214     *d++ = a * (start.r * oppAmount + end.r * amount);
215     *d++ = a * (start.g * oppAmount + end.g * amount);
216     *d++ = a * (start.b * oppAmount + end.b * amount);
217     *d++ = a;
218 
219     dst += 4 * sizeof(float);
220 }
221 
generateTexture(uint32_t * colors,float * positions,const uint32_t width,const uint32_t height,Texture * texture)222 void GradientCache::generateTexture(uint32_t* colors, float* positions,
223         const uint32_t width, const uint32_t height, Texture* texture) {
224     const GLsizei rowBytes = width * bytesPerPixel();
225     uint8_t pixels[rowBytes * height];
226 
227     static ChannelSplitter gSplitters[] = {
228             &android::uirenderer::GradientCache::splitToBytes,
229             &android::uirenderer::GradientCache::splitToFloats,
230     };
231     ChannelSplitter split = gSplitters[mUseFloatTexture];
232 
233     static ChannelMixer gMixers[] = {
234             &android::uirenderer::GradientCache::mixBytes,
235             &android::uirenderer::GradientCache::mixFloats,
236     };
237     ChannelMixer mix = gMixers[mUseFloatTexture];
238 
239     GradientColor start;
240     (this->*split)(colors[0], start);
241 
242     GradientColor end;
243     (this->*split)(colors[1], end);
244 
245     int currentPos = 1;
246     float startPos = positions[0];
247     float distance = positions[1] - startPos;
248 
249     uint8_t* dst = pixels;
250     for (uint32_t x = 0; x < width; x++) {
251         float pos = x / float(width - 1);
252         if (pos > positions[currentPos]) {
253             start = end;
254             startPos = positions[currentPos];
255 
256             currentPos++;
257 
258             (this->*split)(colors[currentPos], end);
259             distance = positions[currentPos] - startPos;
260         }
261 
262         float amount = (pos - startPos) / distance;
263         (this->*mix)(start, end, amount, dst);
264     }
265 
266     memcpy(pixels + rowBytes, pixels, rowBytes);
267 
268     if (mUseFloatTexture) {
269         // We have to use GL_RGBA16F because GL_RGBA32F does not support filtering
270         texture->upload(GL_RGBA16F, width, height, GL_RGBA, GL_FLOAT, pixels);
271     } else {
272         texture->upload(GL_RGBA, width, height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
273     }
274 
275     texture->setFilter(GL_LINEAR);
276     texture->setWrap(GL_CLAMP_TO_EDGE);
277 }
278 
279 }; // namespace uirenderer
280 }; // namespace android
281