TextDropShadowCache.h revision 1e45aae5de003657e5d18f74d34998f5de5db5b7
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#ifndef ANDROID_UI_TEXT_DROP_SHADOW_CACHE_H
18#define ANDROID_UI_TEXT_DROP_SHADOW_CACHE_H
19
20#include <GLES2/gl2.h>
21
22#include <SkPaint.h>
23
24#include "GenerationCache.h"
25#include "FontRenderer.h"
26#include "Texture.h"
27
28namespace android {
29namespace uirenderer {
30
31struct ShadowText {
32    ShadowText() { }
33
34    ShadowText(SkPaint* paint, uint32_t radius, uint32_t len, const char* srcText):
35            paint(paint), radius(radius), len(len) {
36        text = new char[len];
37        memcpy(text, srcText, len);
38
39        hash = 0;
40        uint32_t multiplier = 1;
41        for (uint32_t i = 0; i < len; i++) {
42            hash += text[i] * multiplier;
43            uint32_t shifted = multiplier << 5;
44            multiplier = shifted - multiplier;
45        }
46    }
47
48    ShadowText(const ShadowText& shadow):
49            paint(shadow.paint), radius(shadow.radius), len(shadow.len), hash(shadow.hash) {
50        text = new char[len];
51        memcpy(text, shadow.text, shadow.len);
52    }
53
54    ~ShadowText() {
55        delete[] text;
56    }
57
58    SkPaint* paint;
59    uint32_t radius;
60    uint32_t len;
61    uint32_t hash;
62    char *text;
63
64    bool operator<(const ShadowText& rhs) const {
65        if (len < rhs.len) return true;
66        else if (len == rhs.len) {
67            if (radius < rhs.radius) return true;
68            else if (radius == rhs.radius) {
69                if (paint < rhs.paint) return true;
70                else if (paint == rhs.paint) {
71                    if (hash < rhs.hash) return true;
72                    if (hash == rhs.hash) {
73                        return strncmp(text, rhs.text, len) < 0;
74                    }
75                }
76            }
77        }
78        return false;
79    }
80}; // struct ShadowText
81
82/**
83 * Alpha texture used to represent a shadow.
84 */
85struct ShadowTexture: public Texture {
86    ShadowTexture(): Texture() {
87    }
88
89    float left;
90    float top;
91}; // struct ShadowTexture
92
93class TextDropShadowCache: public OnEntryRemoved<ShadowText, ShadowTexture*> {
94public:
95    TextDropShadowCache(uint32_t maxByteSize);
96    ~TextDropShadowCache();
97
98    /**
99     * Used as a callback when an entry is removed from the cache.
100     * Do not invoke directly.
101     */
102    void operator()(ShadowText& text, ShadowTexture*& texture);
103
104    ShadowTexture* get(SkPaint* paint, const char* text, uint32_t len,
105            int numGlyphs, uint32_t radius);
106
107    /**
108     * Clears the cache. This causes all textures to be deleted.
109     */
110    void clear();
111
112    void setFontRenderer(FontRenderer& fontRenderer) {
113        mRenderer = &fontRenderer;
114    }
115
116    /**
117     * Sets the maximum size of the cache in bytes.
118     */
119    void setMaxSize(uint32_t maxSize);
120    /**
121     * Returns the maximum size of the cache in bytes.
122     */
123    uint32_t getMaxSize();
124    /**
125     * Returns the current size of the cache in bytes.
126     */
127    uint32_t getSize();
128
129private:
130    GenerationCache<ShadowText, ShadowTexture*> mCache;
131
132    uint32_t mSize;
133    uint32_t mMaxSize;
134    FontRenderer* mRenderer;
135}; // class TextDropShadowCache
136
137}; // namespace uirenderer
138}; // namespace android
139
140#endif // ANDROID_UI_TEXT_DROP_SHADOW_CACHE_H
141