Implement sk_tool_utils::copy_to_g8(), used by gms

BUG=skia:

Change-Id: Ic5b2b07fb3f408edf1f2b982235424c22795fe50
Reviewed-on: https://skia-review.googlesource.com/7187
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

2 files changed, 4 insertions, 35 deletions

diff --git a/gm/filterbitmap.cpp b/gm/filterbitmap.cpp
index ec20e6efbe..c9ff295b48 100644
--- a/gm/filterbitmap.cpp
+++ b/gm/filterbitmap.cpp
@@ -11,6 +11,7 @@
 #include "SkGradientShader.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
+#include "sk_tool_utils.h"
 
 static void setTypeface(SkPaint* paint, const char name[], SkFontStyle style) {
     sk_tool_utils::set_portable_typeface(paint, name, style);
@@ -169,7 +170,7 @@ public:
           }
           if (fConvertToG8) {
               SkBitmap tmp;
-              fBM.copyTo(&tmp, kGray_8_SkColorType);
+              sk_tool_utils::copy_to_g8(&tmp, fBM);
               fBM = tmp;
           }
       }
@@ -203,7 +204,7 @@ protected:
 
         if (fConvertToG8) {
             SkBitmap tmp;
-            fBM.copyTo(&tmp, kGray_8_SkColorType);
+            sk_tool_utils::copy_to_g8(&tmp, fBM);
             fBM = tmp;
         }
       }
diff --git a/gm/showmiplevels.cpp b/gm/showmiplevels.cpp
index 0394b57318..36e81010e8 100644
--- a/gm/showmiplevels.cpp
+++ b/gm/showmiplevels.cpp
@@ -216,41 +216,9 @@ DEF_GM( return new ShowMipLevels(256); )
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-static void copy_32_to_g8(void* dst, size_t dstRB, const void* src, const SkImageInfo& srcInfo,
-                          size_t srcRB) {
-    uint8_t* dst8 = (uint8_t*)dst;
-    const uint32_t* src32 = (const uint32_t*)src;
-
-    const int w = srcInfo.width();
-    const int h = srcInfo.height();
-    const bool isBGRA = (kBGRA_8888_SkColorType == srcInfo.colorType());
-
-    for (int y = 0; y < h; ++y) {
-        if (isBGRA) {
-            // BGRA
-            for (int x = 0; x < w; ++x) {
-                uint32_t s = src32[x];
-                dst8[x] = SkComputeLuminance((s >> 16) & 0xFF, (s >> 8) & 0xFF, s & 0xFF);
-            }
-        } else {
-            // RGBA
-            for (int x = 0; x < w; ++x) {
-                uint32_t s = src32[x];
-                dst8[x] = SkComputeLuminance(s & 0xFF, (s >> 8) & 0xFF, (s >> 16) & 0xFF);
-            }
-        }
-        src32 = (const uint32_t*)((const char*)src32 + srcRB);
-        dst8 += dstRB;
-    }
-}
-
 void copy_to(SkBitmap* dst, SkColorType dstColorType, const SkBitmap& src) {
     if (kGray_8_SkColorType == dstColorType) {
-        SkImageInfo grayInfo = src.info().makeColorType(kGray_8_SkColorType);
-        dst->allocPixels(grayInfo);
-        copy_32_to_g8(dst->getPixels(), dst->rowBytes(), src.getPixels(), src.info(),
-                      src.rowBytes());
-        return;
+        return sk_tool_utils::copy_to_g8(dst, src);
     }
 
     src.copyTo(dst, dstColorType);