lots of sRGB and F16 blits

src/core/SkCanvas.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkCanvasPriv.h"
@@ skipping 1149 matching lines @@
     SkCanvas c(dst);
 
     SkAutoTUnref<SkImageFilter> localF(filter->newWithLocalMatrix(ctm));
     SkPaint p;
     p.setImageFilter(localF);
     const SkScalar x = SkIntToScalar(src->getOrigin().x());
     const SkScalar y = SkIntToScalar(src->getOrigin().y());
     c.drawBitmap(srcBM, x, y, &p);
 }
 
+static SkImageInfo make_layer_info(const SkImageInfo& prev, int w, int h, bool isOpaque) {
+    SkAlphaType alphaType = isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
+    if (prev.bytesPerPixel() < 4) {
+        // promote to 32bits
+        return SkImageInfo::MakeN32(w, h, alphaType);
+    } else {
+        // keep the same characteristics as the prev
+        return SkImageInfo::Make(w, h, prev.colorType(), alphaType, prev.profileType());
+    }
+}
+
 void SkCanvas::internalSaveLayer(const SaveLayerRec& rec, SaveLayerStrategy strategy) {
     const SkRect* bounds = rec.fBounds;
     const SkPaint* paint = rec.fPaint;
     SaveLayerFlags saveLayerFlags = rec.fSaveLayerFlags;
 
 #ifndef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     saveLayerFlags &= ~kDontClipToLayer_PrivateSaveLayerFlag;
 #endif
 
     // do this before we create the layer. We don't call the public save() since
@@ skipping 15 matching lines @@
 
     bool isOpaque = SkToBool(saveLayerFlags & kIsOpaque_SaveLayerFlag);
     SkPixelGeometry geo = fProps.pixelGeometry();
     if (paint) {
         // TODO: perhaps add a query to filters so we might preserve opaqueness...
         if (paint->getImageFilter() || paint->getColorFilter()) {
             isOpaque = false;
             geo = kUnknown_SkPixelGeometry;
         }
     }
-    SkImageInfo info = SkImageInfo::MakeN32(ir.width(), ir.height(),
-                        isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
 
     SkBaseDevice* device = this->getTopDevice();
     if (nullptr == device) {
         SkDebugf("Unable to find device for layer.");
         return;
     }
 
+    SkImageInfo info = make_layer_info(device->imageInfo(), ir.width(), ir.height(), isOpaque);
+
     bool forceSpriteOnRestore = false;
     {
         const bool preserveLCDText = kOpaque_SkAlphaType == info.alphaType() ||
                                      (saveLayerFlags & kPreserveLCDText_SaveLayerFlag);
         const SkBaseDevice::TileUsage usage = SkBaseDevice::kNever_TileUsage;
         const SkBaseDevice::CreateInfo createInfo = SkBaseDevice::CreateInfo(info, usage, geo,
                                                                             preserveLCDText, false);
         SkBaseDevice* newDev = device->onCreateDevice(createInfo, paint);
         if (nullptr == newDev) {
             // If onCreateDevice didn't succeed, try raster (e.g. PDF couldn't handle the paint)
@@ skipping 1740 matching lines @@
     }
 
     if (matrix) {
         canvas->concat(*matrix);
     }
 }
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }