Framebuffer

CMakeLists.txt

@@ -304,6 +304,10 @@ OCV_OPTION(WITH_GTK "Include GTK support" ON
 OCV_OPTION(WITH_GTK_2_X "Use GTK version 2" OFF
   VISIBLE_IF UNIX AND NOT APPLE AND NOT ANDROID
   VERIFY HAVE_GTK AND NOT HAVE_GTK3)
+OCV_OPTION(WITH_FRAMEBUFFER "Include framebuffer support" OFF
+  VISIBLE_IF UNIX AND NOT APPLE AND NOT ANDROID)
+OCV_OPTION(WITH_FRAMEBUFFER_XVFB "Include virtual framebuffer support" OFF
+  VISIBLE_IF UNIX AND NOT APPLE AND NOT ANDROID)
 OCV_OPTION(WITH_WAYLAND "Include Wayland support" OFF
         VISIBLE_IF UNIX AND NOT APPLE AND NOT ANDROID
         VERIFY HAVE_WAYLAND)
@@ -1449,6 +1453,13 @@ if(WITH_GTK OR HAVE_GTK)
   endif()
 endif()
 
+if(WITH_FRAMEBUFFER OR HAVE_FRAMEBUFFER)
+  status("    Framebuffer UI:" HAVE_FRAMEBUFFER THEN YES ELSE NO)
+  if(WITH_FRAMEBUFFER_XVFB OR HAVE_FRAMEBUFFER_XVFB)
+    status("    Virtual framebuffer UI:" HAVE_FRAMEBUFFER_XVFB THEN YES ELSE NO)
+  endif()
+endif()
+
 if(WITH_OPENGL OR HAVE_OPENGL)
   status("    OpenGL support:" HAVE_OPENGL THEN "YES (${OPENGL_LIBRARIES})" ELSE NO)
 endif()

cmake/checks/framebuffer.cpp

@@ -0,0 +1,9 @@
+#include <X11/XWDFile.h>
+#include <X11/X.h>
+
+int main(void)
+{
+    XWDFileHeader *xwd_header;
+    XWDColor *xwd_colors;
+    return 0;
+}

modules/highgui/CMakeLists.txt

@@ -49,6 +49,16 @@ list(REMOVE_ITEM highgui_ext_hdrs "${CMAKE_CURRENT_LIST_DIR}/include/opencv2/${n
 
 set(OPENCV_HIGHGUI_BUILTIN_BACKEND "")
 
+if(WITH_FRAMEBUFFER AND HAVE_FRAMEBUFFER)
+  set(OPENCV_HIGHGUI_BUILTIN_BACKEND "FB")
+  add_definitions(-DHAVE_FRAMEBUFFER)
+  list(APPEND highgui_srcs ${CMAKE_CURRENT_LIST_DIR}/src/window_framebuffer.cpp)
+  list(APPEND highgui_hdrs ${CMAKE_CURRENT_LIST_DIR}/src/window_framebuffer.hpp)
+  if(HAVE_FRAMEBUFFER_XVFB)
+    add_definitions(-DHAVE_FRAMEBUFFER_XVFB)
+  endif()
+endif()
+
 if(WITH_WAYLAND AND HAVE_WAYLAND)
   set(OPENCV_HIGHGUI_BUILTIN_BACKEND "Wayland")
   add_definitions(-DHAVE_WAYLAND)

modules/highgui/cmake/detect_framebuffer.cmake

@@ -0,0 +1,14 @@
+# --- FB ---
+set(HAVE_FRAMEBUFFER ON)
+if(WITH_FRAMEBUFFER_XVFB)
+  try_compile(HAVE_FRAMEBUFFER_XVFB
+    "${CMAKE_CURRENT_BINARY_DIR}"
+    "${OpenCV_SOURCE_DIR}/cmake/checks/framebuffer.cpp")
+  if(HAVE_FRAMEBUFFER_XVFB)
+    message(STATUS "Check virtual framebuffer - done")
+  else()
+    message(STATUS
+      "Check virtual framebuffer - failed\n"
+      "Please install the xorg-x11-proto-devel or x11proto-dev package\n")
+  endif()
+endif()

modules/highgui/cmake/init.cmake

@@ -39,6 +39,8 @@ endmacro()
 add_backend("gtk" WITH_GTK)
 add_backend("win32ui" WITH_WIN32UI)
 add_backend("wayland" WITH_WAYLAND)
+add_backend("framebuffer" WITH_FRAMEBUFFER)
+
 # TODO cocoa
 # TODO qt
 # TODO opengl

modules/highgui/src/backend.hpp

@@ -127,6 +127,10 @@ std::shared_ptr<UIBackend> createUIBackendGTK();
 std::shared_ptr<UIBackend> createUIBackendQT();
 #endif
 
+#ifdef HAVE_FRAMEBUFFER
+std::shared_ptr<UIBackend> createUIBackendFramebuffer();
+#endif
+
 #endif  // BUILD_PLUGIN
 
 }  // namespace highgui_backend

modules/highgui/src/registry.impl.hpp

@@ -44,6 +44,10 @@ std::vector<BackendInfo>& getBuiltinBackendsInfo()
         DECLARE_DYNAMIC_BACKEND("GTK2")
 #endif
 
+#ifdef HAVE_FRAMEBUFFER
+        DECLARE_STATIC_BACKEND("FB", createUIBackendFramebuffer)
+#endif
+
 #if 0  // TODO
 #ifdef HAVE_QT
         DECLARE_STATIC_BACKEND("QT", createUIBackendQT)