VirtualBox:~/SDL/tutorial15/15_rotation_and_flipping$ g++ -lSDL2 -lSDL2_image -I/usr/include/SDL2 -D_REENTRANT 15_rotation_and_flipping.cpp
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `LTexture::loadFromFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
15_rotation_and_flipping.cpp:(.text+0x89): undefined reference to `IMG_Load'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x99): undefined reference to `SDL_GetError'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0xe3): undefined reference to `SDL_MapRGB'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0xf6): undefined reference to `SDL_SetColorKey'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x10c): undefined reference to `SDL_CreateTextureFromSurface'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x11c): undefined reference to `SDL_GetError'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x16c): undefined reference to `SDL_FreeSurface'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `LTexture::free()':
15_rotation_and_flipping.cpp:(.text+0x1b7): undefined reference to `SDL_DestroyTexture'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `LTexture::setColor(unsigned char, unsigned char, unsigned char)':
15_rotation_and_flipping.cpp:(.text+0x214): undefined reference to `SDL_SetTextureColorMod'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `LTexture::setBlendMode(SDL_BlendMode)':
15_rotation_and_flipping.cpp:(.text+0x23f): undefined reference to `SDL_SetTextureBlendMode'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `LTexture::setAlpha(unsigned char)':
15_rotation_and_flipping.cpp:(.text+0x26c): undefined reference to `SDL_SetTextureAlphaMod'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `LTexture::render(int, int, SDL_Rect*, double, SDL_Point*, SDL_RendererFlip)':
15_rotation_and_flipping.cpp:(.text+0x310): undefined reference to `SDL_RenderCopyEx'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `init()':
15_rotation_and_flipping.cpp:(.text+0x36d): undefined reference to `SDL_Init'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x379): undefined reference to `SDL_GetError'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x3a9): undefined reference to `SDL_SetHint'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x3ea): undefined reference to `SDL_CreateWindow'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x402): undefined reference to `SDL_GetError'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x438): undefined reference to `SDL_CreateRenderer'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x450): undefined reference to `SDL_GetError'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x48e): undefined reference to `SDL_SetRenderDrawColor'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x49f): undefined reference to `IMG_Init'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x4b0): undefined reference to `SDL_GetError'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `close()':
15_rotation_and_flipping.cpp:(.text+0x5cc): undefined reference to `SDL_DestroyRenderer'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x5db): undefined reference to `SDL_DestroyWindow'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x5f6): undefined reference to `IMG_Quit'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x5fb): undefined reference to `SDL_Quit'
/usr/bin/ld: /tmp/ccxrAWJZ.o: in function `main':
15_rotation_and_flipping.cpp:(.text+0x685): undefined reference to `SDL_PollEvent'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x74d): undefined reference to `SDL_SetRenderDrawColor'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x75c): undefined reference to `SDL_RenderClear'
/usr/bin/ld: 15_rotation_and_flipping.cpp:(.text+0x7d3): undefined reference to `SDL_RenderPresent'
collect2: error: ld returned 1 exit status