Scanline decoding for wbmp

src/codec/SkCodec_wbmp.h

Index: src/codec/SkCodec_wbmp.h
diff --git a/src/codec/SkCodec_wbmp.h b/src/codec/SkCodec_wbmp.h
index fece249728e72e1f2d0fcd0700981a84a116a8da..11b26bf4b9bc8fcc970edc382b8c46f886891e6c 100644
--- a/src/codec/SkCodec_wbmp.h
+++ b/src/codec/SkCodec_wbmp.h
@@ -9,17 +9,27 @@
 #define SkCodec_wbmp_DEFINED
 
 #include "SkCodec.h"
+#include "SkScanlineDecoder.h"
 
 class SkWbmpCodec final : public SkCodec {
 public:
     static bool IsWbmp(SkStream*);
     static SkCodec* NewFromStream(SkStream*);
+
+    typedef void (*ExpandProc)(uint8_t*, const uint8_t*, int);

[scroggo, 2015/07/27 14:16:45]

I don't see why this needs to be public.

[msarett, 2015/07/27 23:42:30]

This has been removed.

 protected:
     SkEncodedFormat onGetEncodedFormat() const override;
     Result onGetPixels(const SkImageInfo&, void*, size_t,
                        const Options&, SkPMColor[], int*) override;
+    SkScanlineDecoder* onGetScanlineDecoder(const SkImageInfo& dstInfo,
+            const Options& options, SkPMColor ctable[], int* ctableCount);

[scroggo, 2015/07/27 14:16:45]

override?

[msarett, 2015/07/27 23:42:30]

Done.

 private:
+    bool setExpandProc(SkColorType colorType, SkPMColor* ctable, int* ctableCount);

[scroggo, 2015/07/27 14:16:45]

It is weird to me that this function is called "setExpandProc", but it does not
take a parameter of an ExpandProc.

Maybe a better name is updateExpandProc? It looks like it also fiddles with the
color table?

[emmaleer, 2015/07/27 14:41:37]

Could you add a comment about what this function does

[msarett, 2015/07/27 23:42:30]

This has been replaced by initializeSwizzler().

     SkWbmpCodec(const SkImageInfo&, SkStream*);
+
+    ExpandProc fProc;

[scroggo, 2015/07/27 14:16:45]

Does fProc need to be a member? It looks like it is only used in onGetPixels,
and it will be updated each time it is called.

Maybe the expandProc function should be static, and return the ExpandProc. If it
returns NULL, that is an indication of failure.

[msarett, 2015/07/27 23:42:30]

I use this pattern to create the swizzler.

+
+    friend class SkWbmpScanlineDecoder;
     typedef SkCodec INHERITED;
 };