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, 1 insertions, 3 deletions

diff --git a/tools/viewer/sk_app/GLWindowContext.h b/tools/viewer/sk_app/GLWindowContext.h
index 7a3256eb9e..a7d1c982c9 100644
--- a/tools/viewer/sk_app/GLWindowContext.h
+++ b/tools/viewer/sk_app/GLWindowContext.h
@@ -55,11 +55,9 @@ protected:
 
     // parameters obtained from the native window
     // Note that the platform .cpp file is responsible for
-    // initializing fSampleCount, fStencilBits, and fColorBits!
+    // initializing fSampleCount and fStencilBits!
     int                        fSampleCount;
     int                        fStencilBits;
-    int                        fColorBits;
-    int                        fActualColorBits;
 };
 
 }   // namespace sk_app