functions.cpp

#include <SDL2/SDL.h>
#include <iostream>

int posX = 100;
int posY = 200;
int sizeX = 300;
int sizeY = 400;

SDL_Window* window;
SDL_Renderer* renderer;

bool InitEverything();
bool InitSDL();
bool CreateWindow();
bool CreateRenderer();
void SetupRenderer();

void Render();
void RunGame();

SDL_Rect playerPos;

int main( int argc, char* args[] )
{
	if ( !InitEverything() ) 
		return -1;


	// Initlaize our playe
	playerPos.x = 20;
	playerPos.y = 20;
	playerPos.w = 20;
	playerPos.h = 20;

	RunGame();
}
void Render()
{
	// Clear the window and make it all green
	SDL_RenderClear( renderer );

	// Change color to blue
	SDL_SetRenderDrawColor( renderer, 0, 0, 255, 255 );

	// Render our "player"
	SDL_RenderFillRect( renderer, &playerPos );

	// Change color to green
	SDL_SetRenderDrawColor( renderer, 0, 255, 0, 255 );

	// Render the changes above
	SDL_RenderPresent( renderer);
}
bool InitEverything()
{
	if ( !InitSDL() )
		return false;

	if ( !CreateWindow() )
		return false;

	if ( !CreateRenderer() )
		return false;

	SetupRenderer();

	return true;
}
bool InitSDL()
{
	if ( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )
	{
		std::cout << " Failed to initialize SDL : " << SDL_GetError() << std::endl;
		return false;
	}

	return true;
}
bool CreateWindow()
{
	window = SDL_CreateWindow( "Server", posX, posY, sizeX, sizeY, 0 );

	if ( window == nullptr )
	{
		std::cout << "Failed to create window : " << SDL_GetError();
		return false;
	}

	return true;
}
bool CreateRenderer()
{
	renderer = SDL_CreateRenderer( window, -1, 0 );

	if ( renderer == nullptr )
	{
		std::cout << "Failed to create renderer : " << SDL_GetError();
		return false;
	}

	return true;
}
void SetupRenderer()
{
	// Set size of renderer to the same as window
	SDL_RenderSetLogicalSize( renderer, sizeX, sizeY );

	// Set color of renderer to green
	SDL_SetRenderDrawColor( renderer, 0, 255, 0, 255 );
}
void RunGame()
{
	bool loop = true;

	while ( loop )
	{
		SDL_Event event;
		while ( SDL_PollEvent( &event ) )
		{
			if ( event.type == SDL_QUIT )
				loop = false;
			else if ( event.type == SDL_KEYDOWN )
			{
				switch ( event.key.keysym.sym )
				{
					case SDLK_RIGHT:
						++playerPos.x;
						break;
					case SDLK_LEFT:
						--playerPos.x;
						break;
						// Remeber 0,0 in SDL is left-top. So when the user pressus down, the y need to increase
					case SDLK_DOWN:
						++playerPos.y;
						break;
					case SDLK_UP:
						--playerPos.y;
						break;
					default :
						break;
				}
			}
		}

		Render();

		// Add a 16msec delay to make our game run at ~60 fps
		SDL_Delay( 16 );
	}
}