make SkiaSalGraphicsImpl use GPU-backed SkSurface also for offscreen

Skia's sk_app::WindowContext can create GPU-backed SkSurface only
for windows, but we also use virtual devices that are not windows.
Fortunately, SkSurface can be created GPU-backed from GrContext*
and sk_gpu_test::GrContextFactory seems to provide it easily.
It is not completely clear to me what the rules are on mixing
SkSurface's with different GrContext* (see the comment
in SkiaSalGraphicsImpl::copyBits()), but it seems to work fine.

Change-Id: I8110b67c41ab092e0c4b6a0973d6bed8a408c4c1

RepositoryExternal.mk

@@ -119,6 +119,7 @@ $(call gb_LinkTarget_set_include,$(1),\
 	-I$(call gb_UnpackedTarball_get_dir,skia)/include/gpu \
 	-I$(call gb_UnpackedTarball_get_dir,skia)/include/config \
 	-I$(call gb_UnpackedTarball_get_dir,skia)/include/third_party/vulkan \
+	-I$(call gb_UnpackedTarball_get_dir,skia)/tools/gpu \
 	-I$(call gb_UnpackedTarball_get_dir,skia) \
 	$$(INCLUDE) \
 )

external/skia/Library_skia.mk

@@ -62,6 +62,7 @@ ifeq ($(OS),LINUX)
 $(eval $(call gb_Library_add_libs,skia,\
     -lm \
     -ldl \
+    -lGLU \
     -lGLX \
     -lGL \
     -lX11-xcb \
@@ -813,6 +814,12 @@ $(eval $(call gb_Library_add_generated_exception_objects,skia,\
 ))
 
 $(eval $(call gb_Library_add_generated_exception_objects,skia,\
+    UnpackedTarball/skia/tools/gpu/GrContextFactory \
+    UnpackedTarball/skia/tools/gpu/TestContext \
+    UnpackedTarball/skia/tools/gpu/gl/GLTestContext \
+    UnpackedTarball/skia/tools/gpu/gl/command_buffer/GLTestContext_command_buffer \
+    UnpackedTarball/skia/tools/gpu/mock/MockTestContext \
+    UnpackedTarball/skia/tools/gpu/vk/VkTestContext \
     UnpackedTarball/skia/tools/gpu/vk/VkTestUtils \
     UnpackedTarball/skia/tools/sk_app/GLWindowContext \
     UnpackedTarball/skia/tools/sk_app/VulkanWindowContext \
@@ -841,6 +848,7 @@ $(eval $(call gb_Library_add_generated_exception_objects,skia,\
 ))
 
 $(eval $(call gb_Library_add_generated_exception_objects,skia,\
+    UnpackedTarball/skia/tools/gpu/gl/win/CreatePlatformGLTestContext_win \
     UnpackedTarball/skia/tools/sk_app/win/GLWindowContext_win \
     UnpackedTarball/skia/tools/sk_app/win/RasterWindowContext_win \
     UnpackedTarball/skia/tools/sk_app/win/VulkanWindowContext_win \
@@ -863,6 +871,7 @@ $(eval $(call gb_Library_add_generated_exception_objects,skia,\
 ))
 
 $(eval $(call gb_Library_add_generated_exception_objects,skia,\
+    UnpackedTarball/skia/tools/gpu/gl/glx/CreatePlatformGLTestContext_glx \
     UnpackedTarball/skia/tools/sk_app/unix/GLWindowContext_unix \
     UnpackedTarball/skia/tools/sk_app/unix/RasterWindowContext_unix \
     UnpackedTarball/skia/tools/sk_app/unix/VulkanWindowContext_unix \

external/skia/make-api-visible.patch.1

@@ -1,3 +1,29 @@
+diff --git a/tools/gpu/GrContextFactory.h b/tools/gpu/GrContextFactory.h
+index d1b7fd5fa0..1b0bc249d2 100644
+--- a/tools/gpu/GrContextFactory.h
++++ b/tools/gpu/GrContextFactory.h
+@@ -26,7 +26,7 @@ class ContextInfo;
+  * factory is destroyed (though the caller can always grab a ref on the returned
+  * Gr and GL contexts to make them outlive the factory).
+  */
+-class GrContextFactory : SkNoncopyable {
++class SK_API GrContextFactory : SkNoncopyable {
+ public:
+     // The availability of context types is subject to platform and build configuration
+     // restrictions.
+diff --git a/tools/gpu/gl/GLTestContext.cpp b/tools/gpu/gl/GLTestContext.cpp
+index d4aa605188..5d246f9737 100644
+--- a/tools/gpu/gl/GLTestContext.cpp
++++ b/tools/gpu/gl/GLTestContext.cpp
+@@ -298,7 +298,7 @@ void GLTestContext::teardown() {
+ void GLTestContext::testAbandon() {
+     INHERITED::testAbandon();
+     if (fGL) {
+-        fGL->abandon();
++//        fGL->abandon();
+     }
+ }
+ 
 diff --git a/tools/sk_app/unix/WindowContextFactory_unix.h b/tools/sk_app/unix/WindowContextFactory_unix.h
 index 47310970d5..e02e6eb5b7 100644
 --- a/tools/sk_app/unix/WindowContextFactory_unix.h

vcl/Library_vcl.mk

@@ -586,7 +586,8 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/skia/SkiaHelper \
     $(if $(filter SKIA,$(BUILD_TYPE)), \
         vcl/skia/salbmp \
-        vcl/skia/gdiimpl) \
+        vcl/skia/gdiimpl \
+        vcl/skia/vulkan) \
  ))
 
 # runtime dependency

vcl/inc/skia/vulkan.hxx

@@ -0,0 +1,29 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDED_VCL_INC_SKIA_VULKAN_HXX
+#define INCLUDED_VCL_INC_SKIA_VULKAN_HXX
+
+#include <GrContext.h>
+
+#include <vcl/dllapi.h>
+
+// Create and handle GrContext for Vulkan drawing to offscreen surfaces.
+// Skia already provides WindowContext class that does this for surfaces
+// used for drawing to windows, but it does not seem to provide a simple
+// way to get GrContext without a window.
+class VCL_PLUGIN_PUBLIC SkiaVulkanGrContext
+{
+public:
+    static GrContext* getGrContext();
+};
+
+#endif // INCLUDED_VCL_INC_SKIA_VULKAN_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/skia/gdiimpl.cxx

@@ -407,6 +407,8 @@ void SkiaSalGraphicsImpl::drawPixel(long nX, long nY, Color nColor)
     paint.setColor(toSkColor(nColor));
     // Apparently drawPixel() is actually expected to set the pixel and not draw it.
     paint.setBlendMode(SkBlendMode::kSrc); // set as is, including alpha
+    if (isGPU()) // TODO this may need caching?
+        ++nX; // https://bugs.chromium.org/p/skia/issues/detail?id=9611
     canvas->drawPoint(nX, nY, paint);
     postDraw();
 }
@@ -677,7 +679,6 @@ void SkiaSalGraphicsImpl::copyArea(long nDestX, long nDestY, long nSrcX, long nS
                                      << Size(nSrcWidth, nSrcHeight));
     sk_sp<SkImage> image
         = mSurface->makeImageSnapshot(SkIRect::MakeXYWH(nSrcX, nSrcY, nSrcWidth, nSrcHeight));
-    // TODO makeNonTextureImage() ?
     mSurface->getCanvas()->drawImage(image, nDestX, nDestY);
     postDraw();
 }
@@ -690,14 +691,18 @@ void SkiaSalGraphicsImpl::copyBits(const SalTwoRect& rPosAry, SalGraphics* pSrcG
     {
         assert(dynamic_cast<SkiaSalGraphicsImpl*>(pSrcGraphics->GetImpl()));
         src = static_cast<SkiaSalGraphicsImpl*>(pSrcGraphics->GetImpl());
+        src->checkSurface();
+        // TODO Without this flush() Skia asserts if both src and destination are
+        // GPU-backed SkSurface that come from different GrContext (e.g. when
+        // src comes from SkiaVulkanGrContext and target is a window). I don't
+        // know if it's a Skia bug or our GrContext usage is incorrect.
+        src->mSurface->flush();
     }
     else
         src = this;
-    src->checkSurface();
     SAL_INFO("vcl.skia", "copybits(" << this << "): (" << src << "):" << rPosAry);
     sk_sp<SkImage> image = src->mSurface->makeImageSnapshot(
         SkIRect::MakeXYWH(rPosAry.mnSrcX, rPosAry.mnSrcY, rPosAry.mnSrcWidth, rPosAry.mnSrcHeight));
-    // TODO makeNonTextureImage() ?
     mSurface->getCanvas()->drawImageRect(image,
                                          SkRect::MakeXYWH(rPosAry.mnDestX, rPosAry.mnDestY,
                                                           rPosAry.mnDestWidth,
@@ -1055,7 +1060,8 @@ bool SkiaSalGraphicsImpl::supportsOperation(OutDevSupportType eType) const
 bool SkiaSalGraphicsImpl::isGPU() const
 {
     return mSurface.get()
-           && mSurface->getBackendRenderTarget(SkSurface::kFlushRead_BackendHandleAccess).isValid();
+           && mSurface->getBackendRenderTarget(SkSurface::kFlushWrite_BackendHandleAccess)
+                  .isValid();
 }
 
 #ifdef DBG_UTIL

vcl/skia/vulkan.cxx

@@ -0,0 +1,39 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Some of this code is based on Skia source code, covered by the following
+ * license notice (see readlicense_oo for the full license):
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ */
+
+#include <skia/vulkan.hxx>
+
+#include <GrContextFactory.h>
+
+#include <vcl/lazydelete.hxx>
+
+static GrContext* createGrContext()
+{
+    static vcl::DeleteOnDeinit<sk_gpu_test::GrContextFactory> factory(
+        new sk_gpu_test::GrContextFactory);
+    // The factory owns the context.
+    return factory.get()->get(sk_gpu_test::GrContextFactory::kVulkan_ContextType);
+}
+
+GrContext* SkiaVulkanGrContext::getGrContext()
+{
+    static GrContext* context = createGrContext();
+    return context;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/skia/win/gdiimpl.cxx

@@ -12,6 +12,7 @@
 #include <tools/sk_app/win/WindowContextFactory_win.h>
 #include <tools/sk_app/WindowContext.h>
 #include <win/saldata.hxx>
+#include <skia/vulkan.hxx>
 
 #include <SkColorFilter.h>
 #include <SkPixelRef.h>
@@ -44,14 +45,30 @@ void WinSkiaSalGraphicsImpl::Init()
 
 void WinSkiaSalGraphicsImpl::createSurface()
 {
+    destroySurface();
     if (isOffscreen())
+    {
+        switch (renderMethodToUse())
+        {
+            case RenderVulkan:
+                mSurface = SkSurface::MakeRenderTarget(
+                    SkiaVulkanGrContext::getGrContext(), SkBudgeted::kNo,
+                    SkImageInfo::MakeN32Premul(GetWidth(), GetHeight()));
+                assert(mSurface.get());
+#ifdef DBG_UTIL
+                prefillSurface();
+#endif
+                return;
+            default:
+                break;
+        }
         return SkiaSalGraphicsImpl::createSurface();
+    }
     // When created, Init() gets called with size (0,0), which is invalid size
     // for Skia. Creating the actual surface is delayed, so the size should be always
     // valid here, but better check.
     assert(GetWidth() != 0 && GetHeight() != 0);
     sk_app::DisplayParams displayParams;
-    destroySurface();
     switch (renderMethodToUse())
     {
         case RenderRaster:

vcl/skia/x11/gdiimpl.cxx

@@ -21,6 +21,8 @@
 #include <tools/sk_app/unix/WindowContextFactory_unix.h>
 #include <tools/sk_app/WindowContext.h>
 
+#include <skia/vulkan.hxx>
+
 X11SkiaSalGraphicsImpl::X11SkiaSalGraphicsImpl(X11SalGraphics& rParent)
     : SkiaSalGraphicsImpl(rParent, rParent.GetGeometryProvider())
     , mX11Parent(rParent)
@@ -38,8 +40,25 @@ void X11SkiaSalGraphicsImpl::Init()
 
 void X11SkiaSalGraphicsImpl::createSurface()
 {
+    destroySurface();
     if (isOffscreen())
+    {
+        switch (renderMethodToUse())
+        {
+            case RenderVulkan:
+                mSurface = SkSurface::MakeRenderTarget(
+                    SkiaVulkanGrContext::getGrContext(), SkBudgeted::kNo,
+                    SkImageInfo::MakeN32Premul(GetWidth(), GetHeight()));
+                assert(mSurface.get());
+#ifdef DBG_UTIL
+                prefillSurface();
+#endif
+                return;
+            default:
+                break;
+        }
         return SkiaSalGraphicsImpl::createSurface();
+    }
     sk_app::DisplayParams displayParams;
     // TODO The Skia Xlib code actually requires the non-native color type to work properly.
     // Use a macro to hide an unreachable code warning.
@@ -59,7 +78,6 @@ void X11SkiaSalGraphicsImpl::createSurface()
     // Avoid this somehow.
     winInfo.fWidth = GetWidth();
     winInfo.fHeight = GetHeight();
-    destroySurface();
     switch (renderMethodToUse())
     {
         case RenderRaster: