Reland "Respect full precision for RGB16 PNGs" (part 3)

This lands the rest of the original CL.
It fixes some flawed logic in SkSwizzler handling Gray8
images.

Original CL:
https://skia-review.googlesource.com/c/7085/

BUG=skia:

CQ_INCLUDE_TRYBOTS=skia.primary:Test-Ubuntu-Clang-GCE-CPU-AVX2-x86_64-Debug-MSAN,Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD,Build-Ubuntu-Clang-x86_64-Release-Fast

Change-Id: Ie2f0c545ea474f1872f284dfb286987b6eadf03d
Reviewed-on: https://skia-review.googlesource.com/7320
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>

1 files changed, 48 insertions, 9 deletions

diff --git a/src/codec/SkSwizzler.cpp b/src/codec/SkSwizzler.cpp
index 21c999403e..31fc063aec 100644
--- a/src/codec/SkSwizzler.cpp
+++ b/src/codec/SkSwizzler.cpp
@@ -51,6 +51,17 @@ static void sample4(void* dst, const uint8_t* src, int width, int bpp, int delta
     }
 }
 
+static void sample6(void* dst, const uint8_t* src, int width, int bpp, int deltaSrc, int offset,
+        const SkPMColor ctable[]) {
+    src += offset;
+    uint8_t* dst8 = (uint8_t*) dst;
+    for (int x = 0; x < width; x++) {
+        memcpy(dst8, src, 6);
+        dst8 += 6;
+        src += deltaSrc;
+    }
+}
+
 static void sample8(void* dst, const uint8_t* src, int width, int bpp, int deltaSrc, int offset,
         const SkPMColor ctable[]) {
     src += offset;
@@ -809,21 +820,42 @@ SkSwizzler* SkSwizzler::CreateSwizzler(const SkEncodedInfo& encodedInfo,
     int srcBPP;
     const int dstBPP = SkColorTypeBytesPerPixel(dstInfo.colorType());
     if (skipFormatConversion) {
-        srcBPP = dstBPP;
-        switch (dstInfo.colorType()) {
-            case kGray_8_SkColorType:
-                proc = &sample1;
-                fastProc = &copy;
+        switch (encodedInfo.color()) {
+            case SkEncodedInfo::kGray_Color:
+            case SkEncodedInfo::kYUV_Color:
+                // We have a jpeg that has already been converted to the dstColorType.
+                srcBPP = dstBPP;
+                switch (dstInfo.colorType()) {
+                    case kGray_8_SkColorType:
+                        proc = &sample1;
+                        fastProc = &copy;
+                        break;
+                    case kRGB_565_SkColorType:
+                        proc = &sample2;
+                        fastProc = &copy;
+                        break;
+                    case kRGBA_8888_SkColorType:
+                    case kBGRA_8888_SkColorType:
+                        proc = &sample4;
+                        fastProc = &copy;
+                        break;
+                    default:
+                        return nullptr;
+                }
                 break;
-            case kRGB_565_SkColorType:
-                proc = &sample2;
+            case SkEncodedInfo::kInvertedCMYK_Color:
+            case SkEncodedInfo::kYCCK_Color:
+                // We have a jpeg that remains in its original format.
+                srcBPP = 4;
+                proc = &sample4;
                 fastProc = &copy;
                 break;
-            case kRGBA_8888_SkColorType:
-            case kBGRA_8888_SkColorType:
+            case SkEncodedInfo::kRGBA_Color:
+                // We have a png that should remain in its original format.
                 SkASSERT(16 == encodedInfo.bitsPerComponent() ||
                           8 == encodedInfo.bitsPerComponent());
                 if (8 == encodedInfo.bitsPerComponent()) {
+                    srcBPP = 4;
                     proc = &sample4;
                 } else {
                     srcBPP = 8;
@@ -831,6 +863,13 @@ SkSwizzler* SkSwizzler::CreateSwizzler(const SkEncodedInfo& encodedInfo,
                 }
                 fastProc = &copy;
                 break;
+            case SkEncodedInfo::kRGB_Color:
+                // We have a png that remains in its original format.
+                SkASSERT(16 == encodedInfo.bitsPerComponent());
+                srcBPP = 6;
+                proc = &sample6;
+                fastProc = &copy;
+                break;
             default:
                 return nullptr;
         }