Several fixes for fp 16 rendering:

samplecode/SampleApp.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleApp.h"
 
 #include "OverView.h"
@@ skipping 276 matching lines @@
         fCurRenderTarget = nullptr;
 #endif
         win->release();
         fBackend = kNone_BackEndType;
     }
 
     SkSurface* createSurface(SampleWindow::DeviceType dType, SampleWindow* win) override {
 #if SK_SUPPORT_GPU
         if (IsGpuDeviceType(dType) && fCurContext) {
             SkSurfaceProps props(win->getSurfaceProps());
-            return SkSurface::MakeRenderTargetDirect(fCurRenderTarget, &props).release();
+            if (kRGBA_F16_SkColorType == win->info().colorType()) {
+                // Need to make an off-screen F16 surface - the current render target is
+                // (probably) the wrong format.
+                return SkSurface::MakeRenderTarget(fCurContext, SkBudgeted::kNo, win->info(),
+                                                   fMSAASampleCount, &props).release();
+            } else {
+                return SkSurface::MakeRenderTargetDirect(fCurRenderTarget, &props).release();
+            }
         }
 #endif
         return nullptr;
     }
 
     void publishCanvas(SampleWindow::DeviceType dType,
                        SkCanvas* canvas, SampleWindow* win) override {
 #if SK_SUPPORT_GPU
         if (fCurContext) {
             // in case we have queued drawing calls
             fCurContext->flush();
 
             if (!IsGpuDeviceType(dType)) {
                 // need to send the raster bits to the (gpu) window
                 const SkBitmap& bm = win->getBitmap();
                 fCurRenderTarget->writePixels(0, 0, bm.width(), bm.height(),
                                              SkImageInfo2GrPixelConfig(bm.colorType(),
                                                                        bm.alphaType(),
                                                                        bm.profileType(),
                                                                        *fCurContext->caps()),
                                              bm.getPixels(),
                                              bm.rowBytes(),
                                              GrContext::kFlushWrites_PixelOp);
+            } else if (kRGBA_F16_SkColorType == win->info().colorType()) {
+                SkBitmap bm;
+                bm.allocPixels(win->info());
+                canvas->readPixels(&bm, 0, 0);
+                fCurRenderTarget->writePixels(0, 0, bm.width(), bm.height(),
+                                              SkImageInfo2GrPixelConfig(bm.info(),
+                                                                        *fCurContext->caps()),
+                                              bm.getPixels(),
+                                              bm.rowBytes(),
+                                              GrContext::kFlushWrites_PixelOp);
             }
         }
 #endif
 
         win->present();
     }
 
     void windowSizeChanged(SampleWindow* win) override {
 #if SK_SUPPORT_GPU
         if (fCurContext) {
@@ skipping 2046 matching lines @@
 #ifdef SK_BUILD_FOR_MAC
     setenv("ANDROID_ROOT", "/android/device/data", 0);
 #endif
     SkGraphics::Init();
     SkEvent::Init();
 }
 
 void application_term() {
     SkEvent::Term();
 }