try texture-maker to generalize stretching for npot and min-tex-size

src/gpu/SkGr.cpp

Index: src/gpu/SkGr.cpp
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index e0892d8ab974e88db4034b429cba09727ab8cb93..a26cdb8b8aa9e48c13d1abbf6fdcfc9cad2689f8 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -503,31 +503,6 @@ static SkBitmap stretch_on_cpu(const SkBitmap& bmp, const Stretch& stretch) {
     return stretched;
 }
 
-static GrTexture* create_bitmap_texture(GrContext* ctx,
-                                        const SkBitmap& bmp,
-                                        const Stretch& stretch,
-                                        const GrUniqueKey& unstretchedKey,
-                                        const GrUniqueKey& stretchedKey) {
-    if (Stretch::kNone_Type != stretch.fType) {
-        SkAutoTUnref<GrTexture> unstretched;
-        // Check if we have the unstretched version in the cache, if not create it.
-        if (unstretchedKey.isValid()) {
-            unstretched.reset(ctx->textureProvider()->findAndRefTextureByUniqueKey(unstretchedKey));
-        }
-        if (!unstretched) {
-            unstretched.reset(create_unstretched_bitmap_texture(ctx, bmp, unstretchedKey));
-            if (!unstretched) {
-                // We might not have been able to create a unstrecthed texture because it is smaller
-                // than the min texture size. In that case do cpu stretching.
-                SkBitmap stretchedBmp = stretch_on_cpu(bmp, stretch);
-                return create_unstretched_bitmap_texture(ctx, stretchedBmp, stretchedKey);
-            }
-        }
-        return stretch_texture(unstretched, stretch, bmp.pixelRef(), stretchedKey);
-    }
-    return create_unstretched_bitmap_texture(ctx, bmp, unstretchedKey);
-}
-
 bool GrIsImageInCache(const GrContext* ctx, uint32_t imageID, const SkIRect& subset,
                       GrTexture* nativeTexture, const GrTextureParams* params) {
     Stretch stretch;
@@ -562,57 +537,159 @@ bool GrIsBitmapInCache(const GrContext* ctx, const SkBitmap& bitmap,
                             params);
 }
 
-GrTexture* GrRefCachedBitmapTexture(GrContext* ctx,
-                                    const SkBitmap& bitmap,
-                                    const GrTextureParams* params) {
+class GrTextureMaker {
+public:
+    GrTextureMaker(int width, int height) : fWidth(width), fHeight(height) {}
+
+    int width() const { return fWidth; }
+    int height() const { return fHeight; }
+
+    GrTexture* refCachedTexture(GrContext*, const GrTextureParams*);
+
+protected:
+    /**
+     *  Return the maker's "original" unstretched texture. It is the responsibility of the maker
+     *  to make this efficient ... if the texture is being generated, the maker must handle
+     *  caching it.
+     */
+    virtual GrTexture* onRefUnstretchedTexture(GrContext*) = 0;
+
+    /**
+     *  If we need to stretch the maker's original texture, the maker is asked to return a key
+     *  that identifies its origianl + the stretch parameter. If the maker does not want to cache
+     *  the stretched version (e.g. the maker is volatile), this should ignore the key parameter
+     *  and return false.
+     */
+    virtual bool onMakeStretchedKey(const Stretch&, GrUniqueKey* stretchedKey) = 0;
+
+    /**
+     *  Return a new (uncached) texture that is the stretch of the maker's original.
+     *
+     *  The base-class handles general logic for this, and only needs access to the following
+     *  methods:
+     *  - onRefUnstretchedTexture()
+     *  - onGetROBitmkap()

[bsalomon, 2015/09/29 19:23:29]

ROBitmap

[reed1, 2015/09/29 19:38:13]

Done.

+     *
+     *  Subclass may override this if they can handle stretching more efficiently.
+     */
+    virtual GrTexture* onGenerateStretchedTexture(GrContext*, const Stretch&);
+
+    /**
+     *  If a stretched version of the texture is generated, it may be cached (assuming that
+     *  onMakeStretchedKey() returns true). In that case, the maker is notified in case it
+     *  wants to note that for when the maker is destroyed.
+     */
+    virtual void onNotifyStretchCached(const GrUniqueKey& stretchedKey) = 0;
+
+    /**
+     *  Some GPUs are unreliable w/ very small texture sizes. If we run into that case, this
+     *  method will be called (in service of onGenerateStretchedTexture) to return a raster version
+     *  of the original texture.
+     */
+    virtual bool onGetROBitmap(SkBitmap*) = 0;
 
-    Stretch stretch;
-    get_stretch(ctx, bitmap.width(), bitmap.height(), params, &stretch);
+private:
+    const int fWidth;
+    const int fHeight;
+};
 
-    GrTexture* result = bitmap.getTexture();
-    if (result) {
-        if (Stretch::kNone_Type == stretch.fType) {
-            return SkRef(result);
+GrTexture* GrTextureMaker::onGenerateStretchedTexture(GrContext* ctx, const Stretch& stretch) {
+    if (this->width() < ctx->caps()->minTextureSize() ||
+        this->height() < ctx->caps()->minTextureSize())
+    {
+        // we can't trust our ability to use HW to perform the stretch, so we request
+        // a raster instead, and perform the stretch on the CPU.
+        SkBitmap bitmap;
+        if (!this->onGetROBitmap(&bitmap)) {
+            return nullptr;
         }
-        GrUniqueKey stretchedKey;
-        // Don't create a key for the resized version if the bmp is volatile.
-        if (!bitmap.isVolatile()) {
-            const GrUniqueKey& key = result->getUniqueKey();
-            if (key.isValid()) {
-                make_stretched_key(key, stretch, &stretchedKey);
-                GrTexture* stretched =
-                    ctx->textureProvider()->findAndRefTextureByUniqueKey(stretchedKey);
-                if (stretched) {
-                    return stretched;
-                }
-            }
+        SkBitmap stretchedBmp = stretch_on_cpu(bitmap, stretch);
+        return create_unstretched_bitmap_texture(ctx, stretchedBmp, GrUniqueKey());
+    } else {
+        SkAutoTUnref<GrTexture> unstretched(this->onRefUnstretchedTexture(ctx));
+        if (!unstretched) {
+            return nullptr;
         }
-        return stretch_texture(result, stretch, bitmap.pixelRef(), stretchedKey);
+        return stretch_texture(unstretched, stretch, nullptr, GrUniqueKey());
     }
+}
 

[bsalomon, 2015/09/29 19:23:29]

extra \n

[reed1, 2015/09/29 19:38:13]

Done.

-    GrUniqueKey key, resizedKey;
 
-    if (!bitmap.isVolatile()) {
-        // If the bitmap isn't changing try to find a cached copy first.
-        make_image_keys(bitmap.getGenerationID(), bitmap.getSubset(), stretch, &key, &resizedKey);
+GrTexture* GrTextureMaker::refCachedTexture(GrContext* ctx, const GrTextureParams* params) {
+    Stretch stretch;
+    get_stretch(ctx, this->width(), this->height(), params, &stretch);
 
-        result = ctx->textureProvider()->findAndRefTextureByUniqueKey(
-            resizedKey.isValid() ? resizedKey : key);
+    if (Stretch::kNone_Type == stretch.fType) {
+        return this->onRefUnstretchedTexture(ctx);
+    }
+
+    GrUniqueKey stretchedKey;
+    if (this->onMakeStretchedKey(stretch, &stretchedKey)) {
+        GrTexture* result = ctx->textureProvider()->findAndRefTextureByUniqueKey(stretchedKey);
         if (result) {
             return result;
         }
     }
 
-    result = create_bitmap_texture(ctx, bitmap, stretch, key, resizedKey);
-    if (result) {
-        return result;
+    GrTexture* result = this->onGenerateStretchedTexture(ctx, stretch);
+    if (!result) {
+        return nullptr;
     }
 
-    SkErrorInternals::SetError( kInternalError_SkError,
-                                "---- failed to create texture for cache [%d %d]\n",
-                                bitmap.width(), bitmap.height());
+    if (stretchedKey.isValid()) {
+        ctx->textureProvider()->assignUniqueKeyToTexture(stretchedKey, result);
+        this->onNotifyStretchCached(stretchedKey);
+    }
+    return result;
+}
+
+class Bitmap_GrTextureMaker : public GrTextureMaker {
+public:
+    Bitmap_GrTextureMaker(const SkBitmap& bitmap)
+        : INHERITED(bitmap.width(), bitmap.height())
+        , fBitmap(bitmap)
+    {}
+
+protected:
+    GrTexture* onRefUnstretchedTexture(GrContext* ctx) override {
+        GrTexture* tex = fBitmap.getTexture();
+        if (tex) {
+            return SkRef(tex);
+        }
+
+        GrUniqueKey unstretchedKey;
+        make_unstretched_key(&unstretchedKey, fBitmap.getGenerationID(), fBitmap.getSubset());
+        return create_unstretched_bitmap_texture(ctx, fBitmap, unstretchedKey);
+    }
+
+    bool onMakeStretchedKey(const Stretch& stretch, GrUniqueKey* stretchedKey) override {
+        if (fBitmap.isVolatile()) {
+            return false;
+        }
 
-    return nullptr;
+        GrUniqueKey unstretchedKey;
+        make_unstretched_key(&unstretchedKey, fBitmap.getGenerationID(), fBitmap.getSubset());
+        return make_stretched_key(unstretchedKey, stretch, stretchedKey);
+    }
+
+    void onNotifyStretchCached(const GrUniqueKey& stretchedKey) override {
+        fBitmap.pixelRef()->addGenIDChangeListener(new BitmapInvalidator(stretchedKey));
+    }
+
+    bool onGetROBitmap(SkBitmap* bitmap) override {
+        *bitmap = fBitmap;
+        return true;
+    }
+
+private:
+    const SkBitmap fBitmap;
+
+    typedef GrTextureMaker INHERITED;
+};
+
+GrTexture* GrRefCachedBitmapTexture(GrContext* ctx, const SkBitmap& bitmap,
+                                    const GrTextureParams* params) {
+    return Bitmap_GrTextureMaker(bitmap).refCachedTexture(ctx, params);
 }
 
 // TODO: make this be the canonical signature, and turn the version that takes GrTextureParams*