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#define LOG_TAG "OpenGLRenderer"
18
19#include <utils/threads.h>
20
21#include "Caches.h"
22#include "Debug.h"
23#include "GradientCache.h"
24#include "Properties.h"
25
26namespace android {
27namespace uirenderer {
28
29///////////////////////////////////////////////////////////////////////////////
30// Defines
31///////////////////////////////////////////////////////////////////////////////
32
33#define GRADIENT_TEXTURE_HEIGHT 2
34#define GRADIENT_BYTES_PER_PIXEL 4
35
36///////////////////////////////////////////////////////////////////////////////
37// Functions
38///////////////////////////////////////////////////////////////////////////////
39
40template<typename T>
41static inline T min(T a, T b) {
42    return a < b ? a : b;
43}
44
45///////////////////////////////////////////////////////////////////////////////
46// Constructors/destructor
47///////////////////////////////////////////////////////////////////////////////
48
49GradientCache::GradientCache():
50        mCache(GenerationCache<GradientCacheEntry, Texture*>::kUnlimitedCapacity),
51        mSize(0), mMaxSize(MB(DEFAULT_GRADIENT_CACHE_SIZE)) {
52    char property[PROPERTY_VALUE_MAX];
53    if (property_get(PROPERTY_GRADIENT_CACHE_SIZE, property, NULL) > 0) {
54        INIT_LOGD("  Setting gradient cache size to %sMB", property);
55        setMaxSize(MB(atof(property)));
56    } else {
57        INIT_LOGD("  Using default gradient cache size of %.2fMB", DEFAULT_GRADIENT_CACHE_SIZE);
58    }
59
60    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &mMaxTextureSize);
61
62    mCache.setOnEntryRemovedListener(this);
63}
64
65GradientCache::GradientCache(uint32_t maxByteSize):
66        mCache(GenerationCache<GradientCacheEntry, Texture*>::kUnlimitedCapacity),
67        mSize(0), mMaxSize(maxByteSize) {
68    mCache.setOnEntryRemovedListener(this);
69}
70
71GradientCache::~GradientCache() {
72    mCache.clear();
73}
74
75///////////////////////////////////////////////////////////////////////////////
76// Size management
77///////////////////////////////////////////////////////////////////////////////
78
79uint32_t GradientCache::getSize() {
80    return mSize;
81}
82
83uint32_t GradientCache::getMaxSize() {
84    return mMaxSize;
85}
86
87void GradientCache::setMaxSize(uint32_t maxSize) {
88    mMaxSize = maxSize;
89    while (mSize > mMaxSize) {
90        mCache.removeOldest();
91    }
92}
93
94///////////////////////////////////////////////////////////////////////////////
95// Callbacks
96///////////////////////////////////////////////////////////////////////////////
97
98void GradientCache::operator()(GradientCacheEntry& shader, Texture*& texture) {
99    if (texture) {
100        const uint32_t size = texture->width * texture->height * GRADIENT_BYTES_PER_PIXEL;
101        mSize -= size;
102    }
103
104    if (texture) {
105        glDeleteTextures(1, &texture->id);
106        delete texture;
107    }
108}
109
110///////////////////////////////////////////////////////////////////////////////
111// Caching
112///////////////////////////////////////////////////////////////////////////////
113
114Texture* GradientCache::get(uint32_t* colors, float* positions, int count) {
115
116    GradientCacheEntry gradient(colors, positions, count);
117    Texture* texture = mCache.get(gradient);
118
119    if (!texture) {
120        texture = addLinearGradient(gradient, colors, positions, count);
121    }
122
123    return texture;
124}
125
126void GradientCache::clear() {
127    mCache.clear();
128}
129
130void GradientCache::getGradientInfo(const uint32_t* colors, const int count,
131        GradientInfo& info) {
132    uint32_t width = 256 * (count - 1);
133
134    if (!Caches::getInstance().extensions.hasNPot()) {
135        width = 1 << (31 - __builtin_clz(width));
136    }
137
138    bool hasAlpha = false;
139    for (int i = 0; i < count; i++) {
140        if (((colors[i] >> 24) & 0xff) < 255) {
141            hasAlpha = true;
142            break;
143        }
144    }
145
146    info.width = min(width, uint32_t(mMaxTextureSize));
147    info.hasAlpha = hasAlpha;
148}
149
150Texture* GradientCache::addLinearGradient(GradientCacheEntry& gradient,
151        uint32_t* colors, float* positions, int count) {
152
153    GradientInfo info;
154    getGradientInfo(colors, count, info);
155
156    Texture* texture = new Texture;
157    texture->width = info.width;
158    texture->height = GRADIENT_TEXTURE_HEIGHT;
159    texture->blend = info.hasAlpha;
160    texture->generation = 1;
161
162    // Asume the cache is always big enough
163    const uint32_t size = texture->width * texture->height * GRADIENT_BYTES_PER_PIXEL;
164    while (mSize + size > mMaxSize) {
165        mCache.removeOldest();
166    }
167
168    generateTexture(colors, positions, count, texture);
169
170    mSize += size;
171    mCache.put(gradient, texture);
172
173    return texture;
174}
175
176void GradientCache::generateTexture(uint32_t* colors, float* positions,
177        int count, Texture* texture) {
178
179    const uint32_t width = texture->width;
180    const GLsizei rowBytes = width * GRADIENT_BYTES_PER_PIXEL;
181    uint32_t pixels[width * texture->height];
182
183    int currentPos = 1;
184
185    float startA = (colors[0] >> 24) & 0xff;
186    float startR = (colors[0] >> 16) & 0xff;
187    float startG = (colors[0] >>  8) & 0xff;
188    float startB = (colors[0] >>  0) & 0xff;
189
190    float endA = (colors[1] >> 24) & 0xff;
191    float endR = (colors[1] >> 16) & 0xff;
192    float endG = (colors[1] >>  8) & 0xff;
193    float endB = (colors[1] >>  0) & 0xff;
194
195    float start = positions[0];
196    float distance = positions[1] - start;
197
198    uint8_t* p = (uint8_t*) pixels;
199    for (uint32_t x = 0; x < width; x++) {
200        float pos = x / float(width - 1);
201        if (pos > positions[currentPos]) {
202            startA = endA;
203            startR = endR;
204            startG = endG;
205            startB = endB;
206            start = positions[currentPos];
207
208            currentPos++;
209
210            endA = (colors[currentPos] >> 24) & 0xff;
211            endR = (colors[currentPos] >> 16) & 0xff;
212            endG = (colors[currentPos] >>  8) & 0xff;
213            endB = (colors[currentPos] >>  0) & 0xff;
214            distance = positions[currentPos] - start;
215        }
216
217        float amount = (pos - start) / distance;
218        float oppAmount = 1.0f - amount;
219
220        const float alpha = startA * oppAmount + endA * amount;
221        const float a = alpha / 255.0f;
222        *p++ = uint8_t(a * (startR * oppAmount + endR * amount));
223        *p++ = uint8_t(a * (startG * oppAmount + endG * amount));
224        *p++ = uint8_t(a * (startB * oppAmount + endB * amount));
225        *p++ = uint8_t(alpha);
226    }
227
228    for (int i = 1; i < GRADIENT_TEXTURE_HEIGHT; i++) {
229        memcpy(pixels + width * i, pixels, rowBytes);
230    }
231
232    glGenTextures(1, &texture->id);
233
234    glBindTexture(GL_TEXTURE_2D, texture->id);
235    glPixelStorei(GL_UNPACK_ALIGNMENT, GRADIENT_BYTES_PER_PIXEL);
236
237    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, texture->height, 0,
238            GL_RGBA, GL_UNSIGNED_BYTE, pixels);
239
240    texture->setFilter(GL_LINEAR);
241    texture->setWrap(GL_CLAMP_TO_EDGE);
242}
243
244}; // namespace uirenderer
245}; // namespace android
246