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 "DeviceInfo.h"
22#include "GradientCache.h"
23#include "Properties.h"
24
25#include <cutils/properties.h>
26
27namespace android {
28namespace uirenderer {
29
30///////////////////////////////////////////////////////////////////////////////
31// Functions
32///////////////////////////////////////////////////////////////////////////////
33
34template <typename T>
35static inline T min(T a, T b) {
36    return a < b ? a : b;
37}
38
39///////////////////////////////////////////////////////////////////////////////
40// Cache entry
41///////////////////////////////////////////////////////////////////////////////
42
43hash_t GradientCacheEntry::hash() const {
44    uint32_t hash = JenkinsHashMix(0, count);
45    for (uint32_t i = 0; i < count; i++) {
46        hash = JenkinsHashMix(hash, android::hash_type(colors[i]));
47        hash = JenkinsHashMix(hash, android::hash_type(positions[i]));
48    }
49    return JenkinsHashWhiten(hash);
50}
51
52int GradientCacheEntry::compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
53    int deltaInt = int(lhs.count) - int(rhs.count);
54    if (deltaInt != 0) return deltaInt;
55
56    deltaInt = memcmp(lhs.colors.get(), rhs.colors.get(), lhs.count * sizeof(uint32_t));
57    if (deltaInt != 0) return deltaInt;
58
59    return memcmp(lhs.positions.get(), rhs.positions.get(), lhs.count * sizeof(float));
60}
61
62///////////////////////////////////////////////////////////////////////////////
63// Constructors/destructor
64///////////////////////////////////////////////////////////////////////////////
65
66GradientCache::GradientCache(const Extensions& extensions)
67        : mCache(LruCache<GradientCacheEntry, Texture*>::kUnlimitedCapacity)
68        , mSize(0)
69        , mMaxSize(MB(1))
70        , mUseFloatTexture(extensions.hasFloatTextures())
71        , mHasNpot(extensions.hasNPot())
72        , mHasLinearBlending(extensions.hasLinearBlending()) {
73    mMaxTextureSize = DeviceInfo::get()->maxTextureSize();
74
75    mCache.setOnEntryRemovedListener(this);
76}
77
78GradientCache::~GradientCache() {
79    mCache.clear();
80}
81
82///////////////////////////////////////////////////////////////////////////////
83// Size management
84///////////////////////////////////////////////////////////////////////////////
85
86uint32_t GradientCache::getSize() {
87    return mSize;
88}
89
90uint32_t GradientCache::getMaxSize() {
91    return mMaxSize;
92}
93
94///////////////////////////////////////////////////////////////////////////////
95// Callbacks
96///////////////////////////////////////////////////////////////////////////////
97
98void GradientCache::operator()(GradientCacheEntry&, Texture*& texture) {
99    if (texture) {
100        mSize -= texture->objectSize();
101        texture->deleteTexture();
102        delete texture;
103    }
104}
105
106///////////////////////////////////////////////////////////////////////////////
107// Caching
108///////////////////////////////////////////////////////////////////////////////
109
110Texture* GradientCache::get(uint32_t* colors, float* positions, int count) {
111    GradientCacheEntry gradient(colors, positions, count);
112    Texture* texture = mCache.get(gradient);
113
114    if (!texture) {
115        texture = addLinearGradient(gradient, colors, positions, count);
116    }
117
118    return texture;
119}
120
121void GradientCache::clear() {
122    mCache.clear();
123}
124
125void GradientCache::getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info) {
126    uint32_t width = 256 * (count - 1);
127
128    // If the npot extension is not supported we cannot use non-clamp
129    // wrap modes. We therefore find the nearest largest power of 2
130    // unless width is already a power of 2
131    if (!mHasNpot && (width & (width - 1)) != 0) {
132        width = 1 << (32 - __builtin_clz(width));
133    }
134
135    bool hasAlpha = false;
136    for (int i = 0; i < count; i++) {
137        if (((colors[i] >> 24) & 0xff) < 255) {
138            hasAlpha = true;
139            break;
140        }
141    }
142
143    info.width = min(width, uint32_t(mMaxTextureSize));
144    info.hasAlpha = hasAlpha;
145}
146
147Texture* GradientCache::addLinearGradient(GradientCacheEntry& gradient, uint32_t* colors,
148                                          float* positions, int count) {
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
170                        ", objectSize %d"
171                        " width = %" PRIu32 " bytesPerPixel() = %zu",
172                        size, texture->objectSize(), info.width, bytesPerPixel());
173    mCache.put(gradient, texture);
174
175    return texture;
176}
177
178size_t GradientCache::bytesPerPixel() const {
179    // We use 4 channels (RGBA)
180    return 4 * (mUseFloatTexture ? /* fp16 */ 2 : sizeof(uint8_t));
181}
182
183size_t GradientCache::sourceBytesPerPixel() const {
184    // We use 4 channels (RGBA) and upload from floats (not half floats)
185    return 4 * (mUseFloatTexture ? sizeof(float) : sizeof(uint8_t));
186}
187
188void GradientCache::mixBytes(const FloatColor& start, const FloatColor& end, float amount,
189                             uint8_t*& dst) const {
190    float oppAmount = 1.0f - amount;
191    float a = start.a * oppAmount + end.a * amount;
192    *dst++ = uint8_t(OECF(start.r * oppAmount + end.r * amount) * 255.0f);
193    *dst++ = uint8_t(OECF(start.g * oppAmount + end.g * amount) * 255.0f);
194    *dst++ = uint8_t(OECF(start.b * oppAmount + end.b * amount) * 255.0f);
195    *dst++ = uint8_t(a * 255.0f);
196}
197
198void GradientCache::mixFloats(const FloatColor& start, const FloatColor& end, float amount,
199                              uint8_t*& dst) const {
200    float oppAmount = 1.0f - amount;
201    float a = start.a * oppAmount + end.a * amount;
202    float* d = (float*)dst;
203#ifdef ANDROID_ENABLE_LINEAR_BLENDING
204    // We want to stay linear
205    *d++ = (start.r * oppAmount + end.r * amount);
206    *d++ = (start.g * oppAmount + end.g * amount);
207    *d++ = (start.b * oppAmount + end.b * amount);
208#else
209    *d++ = OECF(start.r * oppAmount + end.r * amount);
210    *d++ = OECF(start.g * oppAmount + end.g * amount);
211    *d++ = OECF(start.b * oppAmount + end.b * amount);
212#endif
213    *d++ = a;
214    dst += 4 * sizeof(float);
215}
216
217void GradientCache::generateTexture(uint32_t* colors, float* positions, const uint32_t width,
218                                    const uint32_t height, Texture* texture) {
219    const GLsizei rowBytes = width * sourceBytesPerPixel();
220    uint8_t pixels[rowBytes * height];
221
222    static ChannelMixer gMixers[] = {
223            // colors are stored gamma-encoded
224            &android::uirenderer::GradientCache::mixBytes,
225            // colors are stored in linear (linear blending on)
226            // or gamma-encoded (linear blending off)
227            &android::uirenderer::GradientCache::mixFloats,
228    };
229    ChannelMixer mix = gMixers[mUseFloatTexture];
230
231    FloatColor start;
232    start.set(colors[0]);
233
234    FloatColor end;
235    end.set(colors[1]);
236
237    int currentPos = 1;
238    float startPos = positions[0];
239    float distance = positions[1] - startPos;
240
241    uint8_t* dst = pixels;
242    for (uint32_t x = 0; x < width; x++) {
243        float pos = x / float(width - 1);
244        if (pos > positions[currentPos]) {
245            start = end;
246            startPos = positions[currentPos];
247
248            currentPos++;
249
250            end.set(colors[currentPos]);
251            distance = positions[currentPos] - startPos;
252        }
253
254        float amount = (pos - startPos) / distance;
255        (this->*mix)(start, end, amount, dst);
256    }
257
258    memcpy(pixels + rowBytes, pixels, rowBytes);
259
260    if (mUseFloatTexture) {
261        texture->upload(GL_RGBA16F, width, height, GL_RGBA, GL_FLOAT, pixels);
262    } else {
263        GLint internalFormat = mHasLinearBlending ? GL_SRGB8_ALPHA8 : GL_RGBA;
264        texture->upload(internalFormat, width, height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
265    }
266
267    texture->setFilter(GL_LINEAR);
268    texture->setWrap(GL_CLAMP_TO_EDGE);
269}
270
271};  // namespace uirenderer
272};  // namespace android
273