experiments to speed up drawing 32bit images into 565

New (legacy style) blitters only coded for shaders (and very restricted blendmodes)

Bug: skia:
See https://buganizer.corp.google.com/issues/64884885

Change-Id: Ie2546093bfe1e670a825dfd9542d252d53732c40
Reviewed-on: https://skia-review.googlesource.com/54103
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Herb Derby <herb@google.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/src/core/SkCoreBlitters.h b/src/core/SkCoreBlitters.h
index 47b20176e6..9d227e9b43 100644
--- a/src/core/SkCoreBlitters.h
+++ b/src/core/SkCoreBlitters.h
@@ -137,6 +137,27 @@ private:
     typedef SkShaderBlitter INHERITED;
 };
 
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+typedef void (*SkS32D16BlendProc)(uint16_t*, const SkPMColor*, int, uint8_t);
+
+class SkRGB565_Shader_Blitter : public SkShaderBlitter {
+public:
+    SkRGB565_Shader_Blitter(const SkPixmap& device, const SkPaint&, SkShaderBase::Context*);
+    ~SkRGB565_Shader_Blitter() override;
+    void blitH(int x, int y, int width) override;
+    void blitAntiH(int x, int y, const SkAlpha[], const int16_t[]) override;
+
+    static bool Supports(const SkPixmap& device, const SkPaint&);
+
+private:
+    SkPMColor*          fBuffer;
+    SkS32D16BlendProc   fBlend;
+    SkS32D16BlendProc   fBlendCoverage;
+
+    typedef SkShaderBlitter INHERITED;
+};
+
 ///////////////////////////////////////////////////////////////////////////////
 
 // Neither of these ever returns nullptr, but this first factory may return a SkNullBlitter.