Support decoding images to multiple formats, depending on usage

Our codec generator will now preserve any asked-for color space, and
convert the encoded data to that representation. Cacherator now
allows decoding an image to both legacy (nullptr color space), and
color-correct formats. In color-correct mode, we choose the best
decoded format, based on the original properties, and our backend's
capabilities. Preference is given to the native format, when it's
already texturable (sRGB 8888 or F16 linear). Otherwise, we prefer
linear F16, and fall back to sRGB when that's not an option.

BUG=skia:5907

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4438

Change-Id: I847c243dcfb72d8c0f1f6fc73c09547adea933f0
Reviewed-on: https://skia-review.googlesource.com/4438
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 19 insertions, 6 deletions

diff --git a/src/core/SkImageCacherator.h b/src/core/SkImageCacherator.h
index a8a05a1f90..fc03e8e5e9 100644
--- a/src/core/SkImageCacherator.h
+++ b/src/core/SkImageCacherator.h
@@ -12,6 +12,7 @@
 #include "SkMutex.h"
 #include "SkTemplates.h"
 
+class GrCaps;
 class GrContext;
 class GrTextureParams;
 class GrUniqueKey;
@@ -29,7 +30,16 @@ public:
     ~SkImageCacherator();
 
     const SkImageInfo& info() const { return fInfo; }
-    uint32_t uniqueID() const { return fUniqueID; }
+    uint32_t uniqueID() const { return fUniqueIDs[kLegacy_CachedFormat]; }
+
+    enum CachedFormat {
+        kLegacy_CachedFormat,    // The format from the generator, with any color space stripped out
+        kAsIs_CachedFormat,      // The format from the generator, with no modification
+        kLinearF16_CachedFormat, // Half float RGBA with linear gamma
+        kSRGB8888_CachedFormat,  // sRGB bytes
+
+        kNumCachedFormats,
+    };
 
     /**
      *  On success (true), bitmap will point to the pixels for this generator. If this returns
@@ -38,7 +48,7 @@ public:
      *  If not NULL, the client will be notified (->notifyAddedToCache()) when resources are
      *  added to the cache on its behalf.
      */
-    bool lockAsBitmap(SkBitmap*, const SkImage* client,
+    bool lockAsBitmap(SkBitmap*, const SkImage* client, SkDestinationSurfaceColorMode colorMode,
                       SkImage::CachingHint = SkImage::kAllow_CachingHint);
 
     /**
@@ -64,7 +74,7 @@ public:
     SkData* refEncoded(GrContext*);
 
     // Only return true if the generate has already been cached.
-    bool lockAsBitmapOnlyIfAlreadyCached(SkBitmap*);
+    bool lockAsBitmapOnlyIfAlreadyCached(SkBitmap*, CachedFormat);
     // Call the underlying generator directly
     bool directGeneratePixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB,
                               int srcX, int srcY);
@@ -102,19 +112,22 @@ private:
 
     SkImageCacherator(Validator*);
 
-    bool generateBitmap(SkBitmap*);
-    bool tryLockAsBitmap(SkBitmap*, const SkImage*, SkImage::CachingHint);
+    bool generateBitmap(SkBitmap*, const SkImageInfo&);
+    bool tryLockAsBitmap(SkBitmap*, const SkImage*, SkImage::CachingHint, CachedFormat,
+                         const SkImageInfo&);
 #if SK_SUPPORT_GPU
     // Returns the texture. If the cacherator is generating the texture and wants to cache it,
     // it should use the passed in key (if the key is valid).
     GrTexture* lockTexture(GrContext*, const GrUniqueKey& key, const SkImage* client,
                            SkImage::CachingHint, bool willBeMipped, SkDestinationSurfaceColorMode);
+    CachedFormat chooseCacheFormat(SkDestinationSurfaceColorMode, const GrCaps* = nullptr);
+    SkImageInfo buildCacheInfo(CachedFormat);
 #endif
 
     sk_sp<SharedGenerator> fSharedGenerator;
     const SkImageInfo      fInfo;
     const SkIPoint         fOrigin;
-    const uint32_t         fUniqueID;
+    uint32_t               fUniqueIDs[kNumCachedFormats];
 
     friend class GrImageTextureMaker;
     friend class SkImage;