Projections, OpenCV: build against >=opencv-3.0.0 fails

[billyonthemountain]

OS: Gentoo Linux
Qt version : 5.5.1
OpenCV : 3.1.0-r1
Compiler : gcc-5.3.0

make[1]: Entering directory '/home/paccolat/devel/mldemos/build/_AlgorithmsPlugins/Projections'
g++ -c -pipe -Wno-all -Wno-unused-variable -Wno-unused-parameter -Wtrigraphs -Wreturn-type -Wnon-virtual-dtor -Wunused-value -Wunknown-pragmas -Wno-shadow -O2 -D_REENTRANT -fPIC -DWITHBOOST -DQT_NO_DEBUG -DQT_PLUGIN -DQT_SVG_LIB -DQT_OPENGL_LIB -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I/home/paccolat/devel/mldemos/_AlgorithmsPlugins/Projections -I. -I/home/paccolat/devel/mldemos -I/home/paccolat/devel/mldemos/Core -I../../Core -I/home/paccolat/devel/mldemos/_3rdParty -I../../_3rdParty -I/home/paccolat/devel/mldemos/_AlgorithmsPlugins/Projections -I/home/paccolat/devel/mldemos/Core -I/home/paccolat/devel/mldemos/MLDemos -I/home/paccolat/devel/mldemos/_3rdParty -isystem /usr/include/qt5 -isystem /usr/include/qt5/QtSvg -isystem /usr/include/qt5/QtOpenGL -isystem /usr/include/qt5/QtWidgets -isystem /usr/include/qt5/QtGui -isystem /usr/include/qt5/QtCore -Ibuild -Ibuild -I/usr/lib64/qt5/mkspecs/linux-g++ -o build/basicOpenCV.o /home/paccolat/devel/mldemos/_AlgorithmsPlugins/Projections/basicOpenCV.cpp
/home/paccolat/devel/mldemos/_AlgorithmsPlugins/Projections/basicOpenCV.cpp: In static member function ‘static void BasicOpenCV::DisplayHueSatHist(IplImage*)’:
/home/paccolat/devel/mldemos/_AlgorithmsPlugins/Projections/basicOpenCV.cpp:265:56: error: ‘cvCvtPixToPlane’ was not declared in this scope
cvCvtPixToPlane( hsv, h_plane, s_plane, v_plane, 0 );
^
/home/paccolat/devel/mldemos/_AlgorithmsPlugins/Projections/basicOpenCV.cpp:273:59: error: ‘cvQueryHistValue_2D’ was not declared in this scope
f32 bin_val = cvQueryHistValue_2D( hist, h, s );
^
Makefile.pluginProjections:1129: recipe for target 'build/basicOpenCV.o' failed