In Viewer, use a GL window for Raster mode

The GUI uses drawVertices, in a way that doesn't currently
work with the raster backend. Even if it worked, drawVertices
is fairly slow in raster mode, but extremely fast on GPU.
This makes the GUI always usable. The tradeoff is profiling
raster will be less accurate.

Bug: skia:
Change-Id: I69df777fc5be79f5bdd8d4505f6419bfa758c97e
Reviewed-on: https://skia-review.googlesource.com/68541
Reviewed-by: Yuqian Li <liyuqian@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 37 insertions, 35 deletions

diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index f13136931e..03b774804f 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -236,6 +236,12 @@ static bool primaries_equal(const SkColorSpacePrimaries& a, const SkColorSpacePr
     return memcmp(&a, &b, sizeof(SkColorSpacePrimaries)) == 0;
 }
 
+static Window::BackendType backend_type_for_window(Window::BackendType backendType) {
+    // In raster mode, we still use GL for the window.
+    // This lets us render the GUI faster (and correct).
+    return Window::kRaster_BackendType == backendType ? Window::kNativeGL_BackendType : backendType;
+}
+
 const char* kName = "name";
 const char* kValue = "value";
 const char* kOptions = "options";
@@ -477,7 +483,7 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
     fImGuiGamutPaint.setColor(SK_ColorWHITE);
     fImGuiGamutPaint.setFilterQuality(kLow_SkFilterQuality);
 
-    fWindow->attach(fBackendType);
+    fWindow->attach(backend_type_for_window(fBackendType));
 }
 
 void Viewer::initSlides() {
@@ -745,40 +751,33 @@ void Viewer::setBackend(sk_app::Window::BackendType backendType) {
 
     fWindow->detach();
 
-#if defined(SK_BUILD_FOR_WIN) && defined(SK_VULKAN)
+#if defined(SK_BUILD_FOR_WIN)
     // Switching between OpenGL, Vulkan, and ANGLE in the same window is problematic at this point
     // on Windows, so we just delete the window and recreate it.
-    if (sk_app::Window::kVulkan_BackendType == fBackendType ||
-        sk_app::Window::kNativeGL_BackendType == fBackendType
-#if SK_ANGLE
-        || sk_app::Window::kANGLE_BackendType == fBackendType
-#endif
-        ) {
-        DisplayParams params = fWindow->getRequestedDisplayParams();
-        delete fWindow;
-        fWindow = Window::CreateNativeWindow(nullptr);
-
-        // re-register callbacks
-        fCommands.attach(fWindow);
-        fWindow->registerBackendCreatedFunc(on_backend_created_func, this);
-        fWindow->registerPaintFunc(on_paint_handler, this);
-        fWindow->registerTouchFunc(on_touch_handler, this);
-        fWindow->registerUIStateChangedFunc(on_ui_state_changed_handler, this);
-        fWindow->registerMouseFunc(on_mouse_handler, this);
-        fWindow->registerMouseWheelFunc(on_mouse_wheel_handler, this);
-        fWindow->registerKeyFunc(on_key_handler, this);
-        fWindow->registerCharFunc(on_char_handler, this);
-        // Don't allow the window to re-attach. If we're in MSAA mode, the params we grabbed above
-        // will still include our correct sample count. But the re-created fWindow will lose that
-        // information. On Windows, we need to re-create the window when changing sample count,
-        // so we'll incorrectly detect that situation, then re-initialize the window in GL mode,
-        // rendering this tear-down step pointless (and causing the Vulkan window context to fail
-        // as if we had never changed windows at all).
-        fWindow->setRequestedDisplayParams(params, false);
-    }
+    DisplayParams params = fWindow->getRequestedDisplayParams();
+    delete fWindow;
+    fWindow = Window::CreateNativeWindow(nullptr);
+
+    // re-register callbacks
+    fCommands.attach(fWindow);
+    fWindow->registerBackendCreatedFunc(on_backend_created_func, this);
+    fWindow->registerPaintFunc(on_paint_handler, this);
+    fWindow->registerTouchFunc(on_touch_handler, this);
+    fWindow->registerUIStateChangedFunc(on_ui_state_changed_handler, this);
+    fWindow->registerMouseFunc(on_mouse_handler, this);
+    fWindow->registerMouseWheelFunc(on_mouse_wheel_handler, this);
+    fWindow->registerKeyFunc(on_key_handler, this);
+    fWindow->registerCharFunc(on_char_handler, this);
+    // Don't allow the window to re-attach. If we're in MSAA mode, the params we grabbed above
+    // will still include our correct sample count. But the re-created fWindow will lose that
+    // information. On Windows, we need to re-create the window when changing sample count,
+    // so we'll incorrectly detect that situation, then re-initialize the window in GL mode,
+    // rendering this tear-down step pointless (and causing the Vulkan window context to fail
+    // as if we had never changed windows at all).
+    fWindow->setRequestedDisplayParams(params, false);
 #endif
 
-    fWindow->attach(fBackendType);
+    fWindow->attach(backend_type_for_window(fBackendType));
 }
 
 void Viewer::setColorMode(ColorMode colorMode) {
@@ -817,9 +816,11 @@ void Viewer::drawSlide(SkCanvas* canvas) {
     }
 
     // If we're in F16, or we're zooming, or we're in color correct 8888 and the gamut isn't sRGB,
-    // we need to render offscreen
+    // we need to render offscreen. We also need to render offscreen if we're in any raster mode,
+    // because the window surface is actually GL.
     sk_sp<SkSurface> offscreenSurface = nullptr;
-    if (ColorMode::kColorManagedLinearF16 == fColorMode ||
+    if (Window::kRaster_BackendType == fBackendType ||
+        ColorMode::kColorManagedLinearF16 == fColorMode ||
         fShowZoomWindow ||
         (ColorMode::kColorManagedSRGB8888 == fColorMode &&
          !primaries_equal(fColorSpacePrimaries, gSrgbPrimaries))) {
@@ -832,7 +833,8 @@ void Viewer::drawSlide(SkCanvas* canvas) {
             (ColorMode::kColorManagedSRGB8888_NonLinearBlending == fColorMode) ? nullptr : cs;
         SkImageInfo info = SkImageInfo::Make(fWindow->width(), fWindow->height(), colorType,
                                              kPremul_SkAlphaType, std::move(offscreenColorSpace));
-        offscreenSurface = canvas->makeSurface(info);
+        offscreenSurface = Window::kRaster_BackendType == fBackendType ? SkSurface::MakeRaster(info)
+                                                                       : canvas->makeSurface(info);
         slideCanvas = offscreenSurface->getCanvas();
     }
 
@@ -1484,7 +1486,7 @@ void Viewer::onUIStateChanged(const SkString& stateName, const SkString& stateVa
                 if (fBackendType != i) {
                     fBackendType = (sk_app::Window::BackendType)i;
                     fWindow->detach();
-                    fWindow->attach(fBackendType);
+                    fWindow->attach(backend_type_for_window(fBackendType));
                 }
                 break;
             }