unify pixelref and image ID space, so we can share IDs when we share pixels

src/image/SkImage.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkImageGenerator.h"
 #include "SkImagePriv.h"
 #include "SkImage_Base.h"
+#include "SkNextID.h"
 #include "SkPixelRef.h"
 #include "SkReadPixelsRec.h"
 #include "SkString.h"
 #include "SkSurface.h"
 
 #if SK_SUPPORT_GPU
 #include "GrTexture.h"
 #include "GrContext.h"
 #include "SkImage_Gpu.h"
 #endif
 
-uint32_t SkImage::NextUniqueID() {
-    static int32_t gUniqueID;
-
-    // never return 0;
-    uint32_t id;
-    do {
-        id = sk_atomic_inc(&gUniqueID) + 1;
-    } while (0 == id);
-    return id;
+SkImage::SkImage(int width, int height, uint32_t uniqueID)
+    : fWidth(width)
+    , fHeight(height)
+    , fUniqueID(kNeedNewImageUniqueID == uniqueID ? SkNextID::ImageID() : uniqueID)
+{
+    SkASSERT(width > 0);
+    SkASSERT(height > 0);
 }
 
 const void* SkImage::peekPixels(SkImageInfo* info, size_t* rowBytes) const {
     SkImageInfo infoStorage;
     size_t rowBytesStorage;
     if (NULL == info) {
         info = &infoStorage;
     }
     if (NULL == rowBytes) {
         rowBytes = &rowBytesStorage;
@@ skipping 197 matching lines @@
         SkAutoTUnref<GrTexture> unrefCopy;
         if (!bm.isImmutable()) {
             const bool notBudgeted = false;
             tex = GrDeepCopyTexture(tex, notBudgeted);
             if (NULL == tex) {
                 return NULL;
             }
             unrefCopy.reset(tex);
         }
         const SkImageInfo info = bm.info();
-        return SkNEW_ARGS(SkImage_Gpu, (info.width(), info.height(), info.alphaType(),
-                                        tex, 0, SkSurface::kNo_Budgeted));
+        return SkNEW_ARGS(SkImage_Gpu, (info.width(), info.height(), bm.getGenerationID(),
+                                        info.alphaType(), tex, 0, SkSurface::kNo_Budgeted));
     }
 #endif
 
     // This will check for immutable (share or copy)
     return SkNewImageFromRasterBitmap(bm, nullptr, kUnlocked_SharedPixelRefMode);
 }
 
 bool SkImage::asLegacyBitmap(SkBitmap* bitmap, LegacyBitmapMode mode) const {
     return as_IB(this)->onAsLegacyBitmap(bitmap, mode);
 }
@@ skipping 28 matching lines @@
 
 SkImage* SkImage::NewFromAdoptedTexture(GrContext*, const GrBackendTextureDesc&, SkAlphaType) {
     return NULL;
 }
 
 SkImage* SkImage::NewFromTextureCopy(GrContext*, const GrBackendTextureDesc&, SkAlphaType) {
     return NULL;
 }
 
 #endif