TextDropShadowCache.h revision 416a847633680d94efb926837efdc18726d54918 
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_HWUI_TEXT_DROP_SHADOW_CACHE_H
18#define ANDROID_HWUI_TEXT_DROP_SHADOW_CACHE_H
19
20#include <GLES2/gl2.h>
21
22#include <SkPaint.h>
23
24#include <utils/String16.h>
25
26#include "utils/Compare.h"
27#include "utils/GenerationCache.h"
28#include "FontRenderer.h"
29#include "Texture.h"
30
31namespace android {
32namespace uirenderer {
33
34struct ShadowText {
35    ShadowText(): radius(0), len(0), textSize(0.0f), typeface(NULL) {
36    }
37
38    ShadowText(SkPaint* paint, uint32_t radius, uint32_t len, const char* srcText,
39            const float* positions):
40            radius(radius), len(len), positions(positions) {
41        // TODO: Propagate this through the API, we should not cast here
42        text = (const char16_t*) srcText;
43
44        textSize = paint->getTextSize();
45        typeface = paint->getTypeface();
46
47        flags = 0;
48        if (paint->isFakeBoldText()) {
49            flags |= Font::kFakeBold;
50        }
51
52        const float skewX = paint->getTextSkewX();
53        italicStyle = *(uint32_t*) &skewX;
54
55        const float scaleXFloat = paint->getTextScaleX();
56        scaleX = *(uint32_t*) &scaleXFloat;
57    }
58
59    ~ShadowText() {
60    }
61
62    uint32_t radius;
63    uint32_t len;
64    float textSize;
65    SkTypeface* typeface;
66    uint32_t flags;
67    uint32_t italicStyle;
68    uint32_t scaleX;
69    const char16_t* text;
70    const float* positions;
71    String16 str;
72    Vector<float> positionsCopy;
73
74    void copyTextLocally() {
75        str.setTo((const char16_t*) text, len >> 1);
76        text = str.string();
77        if (positions != NULL) {
78            positionsCopy.clear();
79            positionsCopy.appendArray(positions, len);
80            positions = positionsCopy.array();
81        }
82    }
83
84    bool operator<(const ShadowText& rhs) const {
85        LTE_INT(len) {
86            LTE_INT(radius) {
87                LTE_FLOAT(textSize) {
88                    LTE_INT(typeface) {
89                        LTE_INT(flags) {
90                            LTE_INT(italicStyle) {
91                                LTE_INT(scaleX) {
92                                    int cmp = memcmp(text, rhs.text, len);
93                                    if (cmp < 0) return true;
94                                    if (cmp == 0 && rhs.positions != NULL) {
95                                        if (positions == NULL) return true;
96                                        return memcmp(positions, rhs.positions, len << 2) < 0;
97                                    }
98                                }
99                            }
100                        }
101                    }
102                }
103            }
104        }
105        return false;
106    }
107}; // struct ShadowText
108
109/**
110 * Alpha texture used to represent a shadow.
111 */
112struct ShadowTexture: public Texture {
113    ShadowTexture(): Texture() {
114    }
115
116    float left;
117    float top;
118}; // struct ShadowTexture
119
120class TextDropShadowCache: public OnEntryRemoved<ShadowText, ShadowTexture*> {
121public:
122    TextDropShadowCache();
123    TextDropShadowCache(uint32_t maxByteSize);
124    ~TextDropShadowCache();
125
126    /**
127     * Used as a callback when an entry is removed from the cache.
128     * Do not invoke directly.
129     */
130    void operator()(ShadowText& text, ShadowTexture*& texture);
131
132    ShadowTexture* get(SkPaint* paint, const char* text, uint32_t len,
133            int numGlyphs, uint32_t radius, const float* positions);
134
135    /**
136     * Clears the cache. This causes all textures to be deleted.
137     */
138    void clear();
139
140    void setFontRenderer(FontRenderer& fontRenderer) {
141        mRenderer = &fontRenderer;
142    }
143
144    /**
145     * Sets the maximum size of the cache in bytes.
146     */
147    void setMaxSize(uint32_t maxSize);
148    /**
149     * Returns the maximum size of the cache in bytes.
150     */
151    uint32_t getMaxSize();
152    /**
153     * Returns the current size of the cache in bytes.
154     */
155    uint32_t getSize();
156
157private:
158    void init();
159
160    GenerationCache<ShadowText, ShadowTexture*> mCache;
161
162    uint32_t mSize;
163    uint32_t mMaxSize;
164    FontRenderer* mRenderer;
165    bool mDebugEnabled;
166}; // class TextDropShadowCache
167
168}; // namespace uirenderer
169}; // namespace android
170
171#endif // ANDROID_HWUI_TEXT_DROP_SHADOW_CACHE_H
172