How do I install The Powder Toy?

I've been trying to install The Powder Toy. I am using the instructions shown on the wiki. I've performed the installation of all the stuff and did the required commands with git, but when I got to scons and ran it (I was in the proper directory,) it gave me a bunch of errors. Did I do something wrong in the installation process?

The errors are shown here:

scons: Reading SConscript files ...
Checking whether the C compiler works... (cached) yes
Checking whether the C++ compiler works... (cached) yes
Checking if 64 bit... (cached) yes
Adding 64 bit compile flags
Checking for C library SDL2... (cached) yes
Checking for C header file SDL2/SDL.h... (cached) yes
Checking for C library lua5.1... (cached) yes
Checking for C library dl... (cached) yes
Checking for C library fftw3f... (cached) yes
Checking for C library bz2... (cached) yes
Checking for C header file bzlib.h... (cached) yes
Checking for C library z... (cached) yes
Checking for C library pthread... (cached) yes
Checking for C library m... (cached) yes
Checking for C library X11... (cached) yes
Checking for C library rt... (cached) yes
scons: done reading SConscript files.
scons: Building targets ...
g++ -o build/src/PowderToySDL.o -c -std=c++11 -U__STRICT_ANSI__ -Wno-invalid-offsetof -Wno-unused-result -msse -msse2 -D_64BIT -D_REENTRANT -DSDL_INC -DLUA_R_INCL -DLIN -DX86 -DX86_SSE -DX86_SSE2 -DGRAVFFT -DLUACONSOLE -Ibuild/src -Isrc -Ibuild/data -Idata -Ibuild/generated -Igenerated -I/usr/include/SDL2 -I/usr/include/lua5.1 src/PowderToySDL.cpp
src/PowderToySDL.cpp: In function ‘void LoadWindowPosition()’:
src/PowderToySDL.cpp:94:80: error: ‘SDL_GetWindowBordersSize’ was not declared in this scope
  SDL_GetWindowBordersSize(sdl_window, &borderTop, &borderLeft, nullptr, nullptr);
                                                                                ^
src/PowderToySDL.cpp: In function ‘void SaveWindowPosition()’:
src/PowderToySDL.cpp:111:80: error: ‘SDL_GetWindowBordersSize’ was not declared in this scope
  SDL_GetWindowBordersSize(sdl_window, &borderTop, &borderLeft, nullptr, nullptr);
                                                                                ^
src/PowderToySDL.cpp: In function ‘int SDLOpen()’:
src/PowderToySDL.cpp:162:54: error: ‘SDL_GetDisplayUsableBounds’ was not declared in this scope
   if (!SDL_GetDisplayUsableBounds(displayIndex, &rect))
                                                      ^
src/PowderToySDL.cpp: In function ‘void SDLSetScreen(int, bool, bool, bool, bool)’:
src/PowderToySDL.cpp:218:98: error: ‘SDL_RenderSetIntegerScale’ was not declared in this scope
  SDL_RenderSetIntegerScale(sdl_renderer, forceIntegerScaling && fullscreen ? SDL_TRUE : SDL_FALSE);
                                                                                                  ^
src/PowderToySDL.cpp:225:69: error: ‘SDL_SetWindowResizable’ was not declared in this scope
  SDL_SetWindowResizable(sdl_window, resizable ? SDL_TRUE : SDL_FALSE);
                                                                     ^
src/PowderToySDL.cpp: In function ‘void RecreateWindow()’:
src/PowderToySDL.cpp:251:51: error: ‘SDL_RenderSetIntegerScale’ was not declared in this scope
   SDL_RenderSetIntegerScale(sdl_renderer, SDL_TRUE);
                                                   ^
scons: *** [build/src/PowderToySDL.o] Error 1
scons: building terminated because of errors.
strip: 'build/powder64': No such file