WT-10254: Remove Skia

The Skia WRasterImage implementation is unmaintained, and it was pinned
to a very specific version. We have Direct2D/DirectWrite support on
Windows, so we can remove it, otherwise we're just pulling around dead
weight.

CMakeLists.txt

@@ -193,8 +193,6 @@ SET(ZLIB_PREFIX ${USERLIB_PREFIX} CACHE PATH
   "Installation prefix of zlib library (overrides USERLIB_PREFIX)")
 SET(GM_PREFIX ${USERLIB_PREFIX} CACHE PATH
   "Installation prefix of GraphicsMagick library (overrides USERLIB_PREFIX)")
-SET(SKIA_PREFIX ${USERLIB_PREFIX} CACHE PATH
-  "Prefix of skia library (overrides USERLIB_PREFIX)")
 SET(ASIO_PREFIX ${USERLIB_PREFIX} CACHE PATH
   "Prefix of Asio (overrides USERLIB_PREFIX), only used when WT_ASIO_IMPLEMENTATION is standalone")
 SET(UNWIND_PREFIX ${UNWIND_PREFIX} CACHE PATH
@@ -248,7 +246,6 @@ INCLUDE(cmake/WtFindAsciidoc.txt)
 INCLUDE(cmake/WtFindHaru.txt)
 INCLUDE(cmake/WtFindGm.txt)
 INCLUDE(cmake/WtFindGL.txt)
-INCLUDE(cmake/WtFindSkia.txt)
 
 set(OPENSSL_ROOT_DIR ${SSL_PREFIX})
 find_package(OpenSSL)
@@ -330,37 +327,26 @@ ELSE(BOOST_WT_MT_FOUND)
   ADD_DEFINITIONS(-DBOOST_DISABLE_THREADS -DSQLITE_THREADSAFE=0)
 ENDIF(BOOST_WT_MT_FOUND)
 
-# decide on GraphicsMagick vs skia
-# todo: set default to whatever was found
 IF (WIN32)
   SET(WT_WRASTERIMAGE_DEFAULT_IMPLEMENTATION "Direct2D")
 ELSE (WIN32)
   SET(WT_WRASTERIMAGE_DEFAULT_IMPLEMENTATION "none")
 ENDIF (WIN32)
 
 SET(WT_WRASTERIMAGE_IMPLEMENTATION ${WT_WRASTERIMAGE_DEFAULT_IMPLEMENTATION} CACHE STRING "Implementation for WRasterImage server-side rendering")
-IF (CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION LESS 8)
-  MESSAGE(STATUS "Informational: WT_WRASTERIMAGE_IMPLEMENTATION should be either GraphicsMagick, skia, or Direct2D")
-ELSE (CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION LESS 8)
-  SET_PROPERTY(CACHE WT_WRASTERIMAGE_IMPLEMENTATION PROPERTY STRINGS GraphicsMagick skia Direct2D none)
-ENDIF (CMAKE_MAJOR_VERSION EQUAL 2 AND CMAKE_MINOR_VERSION LESS 8)
+SET_PROPERTY(CACHE WT_WRASTERIMAGE_IMPLEMENTATION PROPERTY STRINGS GraphicsMagick Direct2D none)
 
 IF (${WT_WRASTERIMAGE_IMPLEMENTATION} STREQUAL "GraphicsMagick")
   IF (NOT GM_FOUND)
     MESSAGE(FATAL_ERROR "WT_WRASTERIMAGE_IMPLEMENTATION set to GraphicsMagick but GM is not found. Indicate the location of your graphicsmagick library using -DGM_PREFIX=...")
   ENDIF (NOT GM_FOUND)
   SET(WT_HAS_WRASTERIMAGE true)
-ELSEIF (${WT_WRASTERIMAGE_IMPLEMENTATION} STREQUAL "skia")
-  IF (NOT SKIA_FOUND)
-    MESSAGE(FATAL_ERROR "WT_WRASTERIMAGE_IMPLEMENTATION set to skia but skia is not found. Indicate the location of your skia library using -DSKIA_PREFIX=...")
-  ENDIF (NOT SKIA_FOUND)
-  SET(WT_HAS_WRASTERIMAGE true)
 ELSEIF (${WT_WRASTERIMAGE_IMPLEMENTATION} STREQUAL "Direct2D")
   IF (WIN32)
     SET(WT_HAS_WRASTERIMAGE true)
   ENDIF (WIN32)
 ELSE (${WT_WRASTERIMAGE_IMPLEMENTATION} STREQUAL "GraphicsMagick")
-    MESSAGE("** Disabled WRasterimage support. Set WT_WRASTERIMAGE_IMPLEMENTATION to GraphicsMagick, skia, or Direct2D.")
+    MESSAGE("** Disabled WRasterimage support. Set WT_WRASTERIMAGE_IMPLEMENTATION to GraphicsMagick or Direct2D.")
 ENDIF (${WT_WRASTERIMAGE_IMPLEMENTATION} STREQUAL "GraphicsMagick")
 
 IF((CMAKE_CXX_STANDARD EQUAL 17) OR (CMAKE_CXX_STANDARD GREATER 17))

ReleaseNotes.html

@@ -34,6 +34,12 @@ <h2>Release 4.8.0 (June 9, 2022)</h2>
     Tabs have been replaced by spaces in the source code. Previously, we had a mix of tabs and spaces,
     where newer code used only spaces, and older code changed 8 spaces into a tab.
   </li>
+  <li>
+    <a href="https://redmine.webtoolkit.eu/issues/10248" target="_blank">Issue #10254</a>:
+    The Skia-based <a href="Wt_1_1WRasterImage.html">WRasterImage</a> implementation has been removed,
+    since it was unmaintained and dependent on very specific Skia versions, and we have good alternatives
+    with GraphicsMagick and Direct2D.
+  </li>
 </ul>
 
 <h2>Release 4.7.1 (April 15, 2022)</h2>

src/CMakeLists.txt

@@ -466,8 +466,6 @@ ENDIF(HAVE_HARU)
 
 IF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "GraphicsMagick")
   SET(libsources ${libsources} Wt/WRasterImage.h Wt/WRasterImage-gm.C)
-ELSEIF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "skia")
-  SET(libsources ${libsources} Wt/WRasterImage.h Wt/WRasterImage-skia.C)
 ELSEIF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "Direct2D")
   SET(libsources ${libsources} Wt/WRasterImage.h Wt/WRasterImage-d2d1.C)
 ENDIF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "GraphicsMagick")
@@ -633,14 +631,10 @@ IF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "GraphicsMagick")
   TARGET_LINK_LIBRARIES(wt PRIVATE ${GM_LIBRARIES})
   INCLUDE_DIRECTORIES(${GM_INCLUDE_DIRS})
   ADD_DEFINITIONS(-DHAVE_GRAPHICSMAGICK)
-ELSEIF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "skia")
-  TARGET_LINK_LIBRARIES(wt PRIVATE ${SKIA_LIBRARIES})
-  INCLUDE_DIRECTORIES(${SKIA_INCLUDE_DIRS})
-  ADD_DEFINITIONS(${SKIA_DEFINES})
 ELSEIF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "Direct2D")
   TARGET_LINK_LIBRARIES(wt PRIVATE d2d1 dwrite windowscodecs shlwapi)
 ELSE("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "GraphicsMagick")
-  MESSAGE("** Disabling raster image support (WRasterImage): set WT_WRASTERIMAGE_IMPLEMENTATION to GraphicsMagick or skia.")
+  MESSAGE("** Disabling raster image support (WRasterImage): set WT_WRASTERIMAGE_IMPLEMENTATION to GraphicsMagick or Direct2D.")
 ENDIF("${WT_WRASTERIMAGE_IMPLEMENTATION}" STREQUAL "GraphicsMagick")
 
 IF(HAVE_GL)
@@ -650,7 +644,7 @@ IF(HAVE_GL)
   ENDIF(USE_SYSTEM_GLEW)
   TARGET_LINK_LIBRARIES(wt PRIVATE ${GL_LIBRARIES})
 ELSE(HAVE_GL)
-  MESSAGE("** Disabling server-side opengl rendering for WGLWidget: requires gl, glew and WRasterImage (GraphicsMagick or skia).")
+  MESSAGE("** Disabling server-side opengl rendering for WGLWidget: requires gl, glew and WRasterImage (GraphicsMagick or Direct2D).")
 ENDIF(HAVE_GL)
 
 IF(WT_FONTSUPPORT_SIMPLE)

src/Wt/WPaintedWidget.C

@@ -766,7 +766,7 @@ std::unique_ptr<WPaintDevice> WWidgetRasterPainter
   return std::unique_ptr<WPaintDevice>
     (new WRasterImage("png", widget_->renderWidth_, widget_->renderHeight_));
 #else
-  throw WException("Wt was built without WRasterImage (graphicsmagick, skia or Direct2D)");
+  throw WException("Wt was built without WRasterImage (graphicsmagick or Direct2D)");
 #endif
 }
 
@@ -777,7 +777,7 @@ std::unique_ptr<WPaintDevice> WWidgetRasterPainter
 #ifdef WT_HAS_WRASTERIMAGE
     device_ = createPaintDevice(paintUpdate);
 #else
-    throw WException("Wt was built without WRasterImage (graphicsmagick, skia or Direct2D)");
+    throw WException("Wt was built without WRasterImage (graphicsmagick or Direct2D)");
 #endif
   }