Now it compiles :)
Some warnings remain:

compiz.merge-plugin-simple-animations/plugins/simple-animations/src/flyin.cpp: In member function ‘virtual void FlyInAnim::applyTransform()’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/flyin.cpp:81:42: warning: ‘offsetY’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/flyin.cpp:80:42: warning: ‘offsetX’ may be used uninitialized in this function [-Wmaybe-uninitialized]

compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp: In member function ‘virtual void RotateInAnim::prePaintWindow()’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:112:11: warning: variable ‘originX’ set but not used [-Wunused-but-set-variable]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:112:20: warning: variable ‘originY’ set but not used [-Wunused-but-set-variable]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp: In member function ‘virtual void RotateInAnim::postPaintWindow()’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:172:11: warning: variable ‘originX’ set but not used [-Wunused-but-set-variable]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:172:20: warning: variable ‘originY’ set but not used [-Wunused-but-set-variable]
[100%] Building CXX object plugins/simple-animations/CMakeFiles/animationsim.dir/__/__/generated/animationsim_options.cpp.o
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:214:55: warning: ‘angleY’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:213:55: warning: ‘angleX’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp: In member function ‘virtual void RotateInAnim::prePaintWindow()’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:154:55: warning: ‘angleY’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:153:55: warning: ‘angleX’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp: In member function ‘virtual void RotateInAnim::applyTransform()’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:102:51: warning: ‘originY’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:102:51: warning: ‘originX’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:84:38: warning: ‘angleY’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/rotatein.cpp:83:38: warning: ‘angleX’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/sheet.cpp: In member function ‘virtual void SheetAnim::step()’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/sheet.cpp:151:13: warning: ‘parent’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/sheet.cpp: In constructor ‘SheetAnim::SheetAnim(CompWindow*, WindowEvent, float, AnimEffect, const CompRect&)’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/sheet.cpp:62:13: warning: ‘parent’ may be used uninitialized in this function [-Wmaybe-uninitialized]
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/sheet.cpp: In constructor ‘SheetAnim::SheetAnim(CompWindow*, WindowEvent, float, AnimEffect, const CompRect&)’:
compiz.merge-plugin-simple-animations/plugins/simple-animations/src/sheet.cpp:62:13: warning: ‘parent’ may be used uninitialized in this function [-Wmaybe-uninitialized]
Linking CXX shared library libanimationsim.so
[100%] Built target animationsim