Simplify viewer's handling of backbuffer surface and color space

WindowContext still supports color spaces, but not other color
types. Any off-screen rendering is the app's responsibility.

This change also adds (working) F16 support to viewer. Note that
the previous 10-bit and FP16 support in WindowContext was broken.
There was no code to push the off-screen canvas to the window.
If you ever made it to the unreachable off-screen code path in
createSurface, it would have simply stopped drawing.

The decision to limit the window's gamut to sRGB is mostly driven
by my desire to add real-time editing of gamut. This design lets
us do that, without tearing down and rebuilding the window for
every change. An application could still supply a different gamut
via setDisplayParams and render directly to the back buffer with
proper color correction.

BUG=skia:

Change-Id: I94df35c7a42faee396009acc83683e40bb3c284d
Reviewed-on: https://skia-review.googlesource.com/8153
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/tools/viewer/sk_app/GLWindowContext.cpp b/tools/viewer/sk_app/GLWindowContext.cpp
index dd51b7e160..501f272a3e 100644
--- a/tools/viewer/sk_app/GLWindowContext.cpp
+++ b/tools/viewer/sk_app/GLWindowContext.cpp
@@ -39,11 +39,8 @@ void GLWindowContext::initializeContext() {
 
     // We may not have real sRGB support (ANGLE, in particular), so check for
     // that, and fall back to L32:
-    //
-    // ... and, if we're using a 10-bit/channel FB0, it doesn't do sRGB conversion on write,
-    // so pretend that it's non-sRGB 8888:
-    fPixelConfig = fContext->caps()->srgbSupport() && fDisplayParams.fColorSpace &&
-                   (fColorBits != 30) ? kSRGBA_8888_GrPixelConfig : kRGBA_8888_GrPixelConfig;
+    fPixelConfig = fContext->caps()->srgbSupport() && fDisplayParams.fColorSpace
+                   ? kSRGBA_8888_GrPixelConfig : kRGBA_8888_GrPixelConfig;
 }
 
 void GLWindowContext::destroyContext() {
@@ -63,8 +60,6 @@ void GLWindowContext::destroyContext() {
 
 sk_sp<SkSurface> GLWindowContext::getBackbufferSurface() {
     if (nullptr == fSurface) {
-        fActualColorBits = SkTMax(fColorBits, 24);
-
         if (fContext) {
             GrBackendRenderTargetDesc desc;
             desc.fWidth = this->fWidth;
@@ -77,7 +72,9 @@ sk_sp<SkSurface> GLWindowContext::getBackbufferSurface() {
             GR_GL_CALL(fBackendContext.get(), GetIntegerv(GR_GL_FRAMEBUFFER_BINDING, &buffer));
             desc.fRenderTargetHandle = buffer;
 
-            fSurface = this->createRenderSurface(desc, fActualColorBits);
+            fSurface = SkSurface::MakeFromBackendRenderTarget(fContext, desc,
+                                                              fDisplayParams.fColorSpace,
+                                                              &fSurfaceProps);
         }
     }