SkGr.cpp revision 50a3043194cf278a74ff51c33c6cdb52cbe1f8f9 
1/*
2 * Copyright 2010 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkGr.h"
9#include "SkConfig8888.h"
10#include "SkMessageBus.h"
11#include "SkPixelRef.h"
12#include "GrResourceCache.h"
13
14/*  Fill out buffer with the compressed format Ganesh expects from a colortable
15 based bitmap. [palette (colortable) + indices].
16
17 At the moment Ganesh only supports 8bit version. If Ganesh allowed we others
18 we could detect that the colortable.count is <= 16, and then repack the
19 indices as nibbles to save RAM, but it would take more time (i.e. a lot
20 slower than memcpy), so skipping that for now.
21
22 Ganesh wants a full 256 palette entry, even though Skia's ctable is only as big
23 as the colortable.count says it is.
24 */
25static void build_compressed_data(void* buffer, const SkBitmap& bitmap) {
26    SkASSERT(SkBitmap::kIndex8_Config == bitmap.config());
27
28    SkAutoLockPixels alp(bitmap);
29    if (!bitmap.readyToDraw()) {
30        SkDEBUGFAIL("bitmap not ready to draw!");
31        return;
32    }
33
34    SkColorTable* ctable = bitmap.getColorTable();
35    char* dst = (char*)buffer;
36
37    uint32_t* colorTableDst = reinterpret_cast<uint32_t*>(dst);
38    const uint32_t* colorTableSrc = reinterpret_cast<const uint32_t*>(ctable->lockColors());
39    SkConvertConfig8888Pixels(colorTableDst, 0, SkCanvas::kRGBA_Premul_Config8888,
40                              colorTableSrc, 0, SkCanvas::kNative_Premul_Config8888,
41                              ctable->count(), 1);
42    ctable->unlockColors();
43
44    // always skip a full 256 number of entries, even if we memcpy'd fewer
45    dst += kGrColorTableSize;
46
47    if ((unsigned)bitmap.width() == bitmap.rowBytes()) {
48        memcpy(dst, bitmap.getPixels(), bitmap.getSize());
49    } else {
50        // need to trim off the extra bytes per row
51        size_t width = bitmap.width();
52        size_t rowBytes = bitmap.rowBytes();
53        const char* src = (const char*)bitmap.getPixels();
54        for (int y = 0; y < bitmap.height(); y++) {
55            memcpy(dst, src, width);
56            src += rowBytes;
57            dst += width;
58        }
59    }
60}
61
62////////////////////////////////////////////////////////////////////////////////
63
64static void generate_bitmap_cache_id(const SkBitmap& bitmap, GrCacheID* id) {
65    // Our id includes the offset, width, and height so that bitmaps created by extractSubset()
66    // are unique.
67    uint32_t genID = bitmap.getGenerationID();
68    size_t offset = bitmap.pixelRefOffset();
69    int16_t width = static_cast<int16_t>(bitmap.width());
70    int16_t height = static_cast<int16_t>(bitmap.height());
71
72    GrCacheID::Key key;
73    memcpy(key.fData8, &genID, 4);
74    memcpy(key.fData8 + 4, &width, 2);
75    memcpy(key.fData8 + 6, &height, 2);
76    memcpy(key.fData8 + 8, &offset, sizeof(size_t));
77    static const size_t kKeyDataSize = 8 + sizeof(size_t);
78    memset(key.fData8 + kKeyDataSize, 0, sizeof(key) - kKeyDataSize);
79    GR_STATIC_ASSERT(sizeof(key) >= 8 + sizeof(size_t));
80    static const GrCacheID::Domain gBitmapTextureDomain = GrCacheID::GenerateDomain();
81    id->reset(gBitmapTextureDomain, key);
82}
83
84static void generate_bitmap_texture_desc(const SkBitmap& bitmap, GrTextureDesc* desc) {
85    desc->fFlags = kNone_GrTextureFlags;
86    desc->fWidth = bitmap.width();
87    desc->fHeight = bitmap.height();
88    desc->fConfig = SkBitmapConfig2GrPixelConfig(bitmap.config());
89    desc->fSampleCnt = 0;
90}
91
92namespace {
93
94// When the SkPixelRef genID changes, invalidate a corresponding GrResource described by key.
95class GrResourceInvalidator : public SkPixelRef::GenIDChangeListener {
96public:
97    explicit GrResourceInvalidator(GrResourceKey key) : fKey(key) {}
98private:
99    GrResourceKey fKey;
100
101    virtual void onChange() SK_OVERRIDE {
102        const GrResourceInvalidatedMessage message = { fKey };
103        SkMessageBus<GrResourceInvalidatedMessage>::Post(message);
104    }
105};
106
107}  // namespace
108
109static void add_genID_listener(GrResourceKey key, SkPixelRef* pixelRef) {
110    SkASSERT(NULL != pixelRef);
111    pixelRef->addGenIDChangeListener(SkNEW_ARGS(GrResourceInvalidator, (key)));
112}
113
114static GrTexture* sk_gr_create_bitmap_texture(GrContext* ctx,
115                                              bool cache,
116                                              const GrTextureParams* params,
117                                              const SkBitmap& origBitmap) {
118    SkBitmap tmpBitmap;
119
120    const SkBitmap* bitmap = &origBitmap;
121
122    GrTextureDesc desc;
123    generate_bitmap_texture_desc(*bitmap, &desc);
124
125    if (SkBitmap::kIndex8_Config == bitmap->config()) {
126        // build_compressed_data doesn't do npot->pot expansion
127        // and paletted textures can't be sub-updated
128        if (ctx->supportsIndex8PixelConfig(params, bitmap->width(), bitmap->height())) {
129            size_t imagesize = bitmap->width() * bitmap->height() + kGrColorTableSize;
130            SkAutoMalloc storage(imagesize);
131
132            build_compressed_data(storage.get(), origBitmap);
133
134            // our compressed data will be trimmed, so pass width() for its
135            // "rowBytes", since they are the same now.
136
137            if (cache) {
138                GrCacheID cacheID;
139                generate_bitmap_cache_id(origBitmap, &cacheID);
140
141                GrResourceKey key;
142                GrTexture* result = ctx->createTexture(params, desc, cacheID,
143                                                       storage.get(), bitmap->width(), &key);
144                add_genID_listener(key, origBitmap.pixelRef());
145                return result;
146            } else {
147                GrTexture* result = ctx->lockAndRefScratchTexture(desc,
148                                                            GrContext::kExact_ScratchTexMatch);
149                result->writePixels(0, 0, bitmap->width(),
150                                    bitmap->height(), desc.fConfig,
151                                    storage.get());
152                return result;
153            }
154        } else {
155            origBitmap.copyTo(&tmpBitmap, SkBitmap::kARGB_8888_Config);
156            // now bitmap points to our temp, which has been promoted to 32bits
157            bitmap = &tmpBitmap;
158            desc.fConfig = SkBitmapConfig2GrPixelConfig(bitmap->config());
159        }
160    }
161
162    SkAutoLockPixels alp(*bitmap);
163    if (!bitmap->readyToDraw()) {
164        return NULL;
165    }
166    if (cache) {
167        // This texture is likely to be used again so leave it in the cache
168        GrCacheID cacheID;
169        generate_bitmap_cache_id(origBitmap, &cacheID);
170
171        GrResourceKey key;
172        GrTexture* result = ctx->createTexture(params, desc, cacheID,
173                                               bitmap->getPixels(), bitmap->rowBytes(), &key);
174        add_genID_listener(key, origBitmap.pixelRef());
175        return result;
176   } else {
177        // This texture is unlikely to be used again (in its present form) so
178        // just use a scratch texture. This will remove the texture from the
179        // cache so no one else can find it. Additionally, once unlocked, the
180        // scratch texture will go to the end of the list for purging so will
181        // likely be available for this volatile bitmap the next time around.
182        GrTexture* result = ctx->lockAndRefScratchTexture(desc, GrContext::kExact_ScratchTexMatch);
183        result->writePixels(0, 0,
184                            bitmap->width(), bitmap->height(),
185                            desc.fConfig,
186                            bitmap->getPixels(),
187                            bitmap->rowBytes());
188        return result;
189    }
190}
191
192bool GrIsBitmapInCache(const GrContext* ctx,
193                       const SkBitmap& bitmap,
194                       const GrTextureParams* params) {
195    GrCacheID cacheID;
196    generate_bitmap_cache_id(bitmap, &cacheID);
197
198    GrTextureDesc desc;
199    generate_bitmap_texture_desc(bitmap, &desc);
200    return ctx->isTextureInCache(desc, cacheID, params);
201}
202
203GrTexture* GrLockAndRefCachedBitmapTexture(GrContext* ctx,
204                                           const SkBitmap& bitmap,
205                                           const GrTextureParams* params) {
206    GrTexture* result = NULL;
207
208    bool cache = !bitmap.isVolatile();
209
210    if (cache) {
211        // If the bitmap isn't changing try to find a cached copy first.
212
213        GrCacheID cacheID;
214        generate_bitmap_cache_id(bitmap, &cacheID);
215
216        GrTextureDesc desc;
217        generate_bitmap_texture_desc(bitmap, &desc);
218
219        result = ctx->findAndRefTexture(desc, cacheID, params);
220    }
221    if (NULL == result) {
222        result = sk_gr_create_bitmap_texture(ctx, cache, params, bitmap);
223    }
224    if (NULL == result) {
225        GrPrintf("---- failed to create texture for cache [%d %d]\n",
226                    bitmap.width(), bitmap.height());
227    }
228    return result;
229}
230
231void GrUnlockAndUnrefCachedBitmapTexture(GrTexture* texture) {
232    SkASSERT(NULL != texture->getContext());
233
234    texture->getContext()->unlockScratchTexture(texture);
235    texture->unref();
236}
237
238///////////////////////////////////////////////////////////////////////////////
239
240GrPixelConfig SkBitmapConfig2GrPixelConfig(SkBitmap::Config config) {
241    switch (config) {
242        case SkBitmap::kA8_Config:
243            return kAlpha_8_GrPixelConfig;
244        case SkBitmap::kIndex8_Config:
245            return kIndex_8_GrPixelConfig;
246        case SkBitmap::kRGB_565_Config:
247            return kRGB_565_GrPixelConfig;
248        case SkBitmap::kARGB_4444_Config:
249            return kRGBA_4444_GrPixelConfig;
250        case SkBitmap::kARGB_8888_Config:
251            return kSkia8888_GrPixelConfig;
252        default:
253            // kNo_Config, kA1_Config missing
254            return kUnknown_GrPixelConfig;
255    }
256}
257