Added --deepColor option to SampleApp, triggers creation of a ten-bit/channel buffer on Windows.

samplecode/SampleApp.cpp

Index: samplecode/SampleApp.cpp
diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index ba2e6ccad1a2fb301e12bb87f5132ef1e4a261da..aa3177a8f58d8cacb84fd26c86266ccfadaa9793 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -12,6 +12,7 @@
 #include "SampleCode.h"
 #include "SkAnimTimer.h"
 #include "SkCanvas.h"
+#include "SkColorSpace.h"
 #include "SkCommandLineFlags.h"
 #include "SkData.h"
 #include "SkDocument.h"
@@ -36,7 +37,9 @@
 #   include "gl/GrGLInterface.h"
 #   include "gl/GrGLUtil.h"
 #   include "GrRenderTarget.h"
+#   include "effects/GrColorSpaceEffect.h"
 #   include "GrContext.h"
+#   include "GrDrawContext.h"
 #   include "SkGr.h"
 #   if SK_ANGLE
 #       include "gl/angle/GLTestContext_angle.h"
@@ -178,6 +181,7 @@ public:
         fCurIntf = nullptr;
         fCurRenderTarget = nullptr;
         fMSAASampleCount = 0;
+        fTenBitColor = false;
 #endif
         fBackend = kNone_BackEndType;
     }
@@ -190,7 +194,7 @@ public:
 #endif
     }
 
-    void setUpBackend(SampleWindow* win, int msaaSampleCount) override {
+    void setUpBackend(SampleWindow* win, int msaaSampleCount, bool tenBitColor) override {
         SkASSERT(kNone_BackEndType == fBackend);
 
         fBackend = kNone_BackEndType;
@@ -219,12 +223,13 @@ public:
                 break;
         }
         AttachmentInfo attachmentInfo;
-        bool result = win->attach(fBackend, msaaSampleCount, &attachmentInfo);
+        bool result = win->attach(fBackend, msaaSampleCount, tenBitColor, &attachmentInfo);

[Brian Osman, 2016/04/27 19:55:01]

Seems like I should add fColorBits to AttachmentInfo, so we can determine if we
actually got a 10 bpc window back?

         if (!result) {
             SkDebugf("Failed to initialize GL");
             return;
         }
         fMSAASampleCount = msaaSampleCount;
+        fTenBitColor = tenBitColor;
 
         SkASSERT(nullptr == fCurIntf);
         SkAutoTUnref<const GrGLInterface> glInterface;
@@ -294,9 +299,10 @@ public:
 #if SK_SUPPORT_GPU
         if (IsGpuDeviceType(dType) && fCurContext) {
             SkSurfaceProps props(win->getSurfaceProps());
-            if (kRGBA_F16_SkColorType == win->info().colorType()) {
+            if (kRGBA_F16_SkColorType == win->info().colorType() || fTenBitColor) {
                 // Need to make an off-screen F16 surface - the current render target is
-                // (probably) the wrong format.
+                // (probably) the wrong format. If we're using a 10-bit surface, we definitely
+                // need an off-screen surface, because 10-bit behaves strangely wrt gamma.
                 return SkSurface::MakeRenderTarget(fCurContext, SkBudgeted::kNo, win->info(),
                                                    fMSAASampleCount, &props).release();
             } else {
@@ -314,7 +320,33 @@ public:
             // in case we have queued drawing calls
             fCurContext->flush();
 
-            if (!IsGpuDeviceType(dType)) {
+            if (fTenBitColor) {
+                SkBitmap bm;
+                bm.allocPixels(win->info());
+                canvas->readPixels(&bm, 0, 0);

[Brian Osman, 2016/04/27 19:55:01]

This is really ugly, but I couldn't find a way to get from SkCanvas to any of
the "modern" types (SkSurface or SkImage)? The canvas is attached to the surface
we created above, but we've lost that reference, and can't get it back. Surface
has makeImageSnapshot, but that's it. So yeah - this code is stuck going through
SkBitmap and readPixels...

Another option is to alter the signatures of functions on SkView, so we pass the
surface in addition to (or instead of) the canvas, but that's somewhat
invasive...

[bsalomon, 2016/04/27 20:28:24]

My gut take is that this adds too much technical debt
(writePixelsWithColorSpace) than is justified by the end result of making
SampleApp work with ten bit. I think we should push harder on making it possible
to get a SkImage here. Even conceding that we can't directly get a SkImage from
the canvas, taking bm and here and wrapping it via
SkImage::MakeTextureFromPixmap and then having something like a

GrTexture* GrContext::applyColorSpace(GrTexture*, colorSpace)

function would be a big improvement.

+                if (SkImageInfoIsGammaCorrect(win->info())) {
+                    // For now, assuming source and destination are both sRGB.
+                    // TODO: Fetch destination space from device, or allow it to be specified
+                    //       on the command line, etc...
+                    sk_sp<SkColorSpace> srgb(SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named));
+
+                    fCurRenderTarget->writePixelsWithColorSpace(
+                        0, 0, bm.width(), bm.height(),
+                        SkImageInfo2GrPixelConfig(bm.info(), *fCurContext->caps()),
+                        srgb.get(), srgb.get(), bm.getPixels(), bm.rowBytes(),
+                        GrContext::kManualDstGamma_ColorSpaceOpsFlag);
+                } else {
+                    // We rendered to L32 (legacy mode). That matches the semantics of the windowing
+                    // system's 10-bit buffer (data is treated as sRGB, but not gamma-corrected on
+                    // write). We can just do a writePixels, which is just a copy of values.
+                    fCurRenderTarget->writePixels(0, 0, bm.width(), bm.height(),
+                                                  SkImageInfo2GrPixelConfig(bm.info(),
+                                                                            *fCurContext->caps()),
+                                                  bm.getPixels(),
+                                                  bm.rowBytes(),
+                                                  GrContext::kFlushWrites_PixelOp);
+                }
+            } else 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(),
@@ -346,7 +378,7 @@ public:
 #if SK_SUPPORT_GPU
         if (fCurContext) {
             AttachmentInfo attachmentInfo;
-            win->attach(fBackend, fMSAASampleCount, &attachmentInfo);
+            win->attach(fBackend, fMSAASampleCount, fTenBitColor, &attachmentInfo);
             SkSafeUnref(fCurRenderTarget);
             fCurRenderTarget = win->renderTarget(attachmentInfo, fCurIntf, fCurContext);
         }
@@ -376,6 +408,7 @@ private:
     const GrGLInterface*    fCurIntf;
     GrRenderTarget*         fCurRenderTarget;
     int fMSAASampleCount;
+    bool fTenBitColor;
 #endif
 
     SkOSWindow::SkBackEndTypes fBackend;
@@ -773,6 +806,7 @@ static void restrict_samples(SkTDArray<const SkViewFactory*>& factories, const S
 
 DEFINE_string(slide, "", "Start on this sample.");
 DEFINE_int32(msaa, 0, "Request multisampling with this count.");
+DEFINE_bool(tenBit, false, "Request 10-bit/channel display buffer.");
 DEFINE_string(pictureDir, "", "Read pictures from here.");
 DEFINE_string(picture, "", "Path to single picture.");
 DEFINE_string(sequence, "", "Path to file containing the desired samples/gms to show.");
@@ -861,6 +895,7 @@ SampleWindow::SampleWindow(void* hwnd, int argc, char** argv, DeviceManager* dev
     }
 
     fMSAASampleCount = FLAGS_msaa;
+    fTenBitColor = FLAGS_tenBit;
 
     if (FLAGS_list) {
         listTitles();
@@ -1023,7 +1058,7 @@ SampleWindow::SampleWindow(void* hwnd, int argc, char** argv, DeviceManager* dev
         devManager->ref();
         fDevManager = devManager;
     }
-    fDevManager->setUpBackend(this, fMSAASampleCount);
+    fDevManager->setUpBackend(this, fMSAASampleCount, fTenBitColor);
 
     // If another constructor set our dimensions, ensure that our
     // onSizeChange gets called.
@@ -1847,7 +1882,7 @@ void SampleWindow::setDeviceType(DeviceType type) {
 
     fDevManager->tearDownBackend(this);
     fDeviceType = type;
-    fDevManager->setUpBackend(this, fMSAASampleCount);
+    fDevManager->setUpBackend(this, fMSAASampleCount, fTenBitColor);
 
     this->updateTitle();
     this->inval(nullptr);
@@ -1857,7 +1892,7 @@ void SampleWindow::setDeviceColorType(SkColorType ct, SkColorProfileType pt) {
     this->setColorType(ct, pt);
 
     fDevManager->tearDownBackend(this);
-    fDevManager->setUpBackend(this, fMSAASampleCount);
+    fDevManager->setUpBackend(this, fMSAASampleCount, fTenBitColor);
 
     this->updateTitle();
     this->inval(nullptr);
@@ -1884,7 +1919,7 @@ void SampleWindow::toggleFPS() {
 void SampleWindow::toggleDistanceFieldFonts() {
     // reset backend
     fDevManager->tearDownBackend(this);
-    fDevManager->setUpBackend(this, fMSAASampleCount);
+    fDevManager->setUpBackend(this, fMSAASampleCount, fTenBitColor);
 
     SkSurfaceProps props = this->getSurfaceProps();
     uint32_t flags = props.flags() ^ SkSurfaceProps::kUseDeviceIndependentFonts_Flag;
@@ -1897,7 +1932,7 @@ void SampleWindow::toggleDistanceFieldFonts() {
 void SampleWindow::setPixelGeometry(int pixelGeometryIndex) {
     // reset backend
     fDevManager->tearDownBackend(this);
-    fDevManager->setUpBackend(this, fMSAASampleCount);
+    fDevManager->setUpBackend(this, fMSAASampleCount, fTenBitColor);
 
     const SkSurfaceProps& oldProps = this->getSurfaceProps();
     SkSurfaceProps newProps(oldProps.flags(), SkSurfaceProps::kLegacyFontHost_InitType);
@@ -2162,6 +2197,10 @@ void SampleWindow::updateTitle() {
 
     title.appendf(" %s", find_config_name(this->info()));
 
+    if (fTenBitColor) {
+        title.append(" 10 bpc");
+    }
+
     if (gTreatSkColorAsSRGB) {
         title.append(" sRGB");
     }