olcConsoleGameEngineSDL.h

/*
OneLoneCoder.com - Command Line Game Engine
"Who needs a frame buffer?" - @Javidx9

For the *nix and Mac users - like most Linux software, this
may not be fully compatible or fully featured, and development
will invariably lag behind the rest - sorry.

NOTE: DOES NOT SUPPORT SOUND YET
NOTE: DOES NOT SUUPORT MOUSE INPUT YET

I recommend compiling as follows, of course you need SDL from your vendor

 g++ thing.cpp -DUNICODE -I/usr/include/SDL2 -lSDL2 -lpthread -std=C++11

I'd like to explain how this version came about, because without the help of
some awesome individuals, this would not be a thing!

=========== IMPORTANT!!! PLEASE READ ==========================================

Firstly, Thanks to Jack Clarke (JackOJC on Discord and Github). He had the 
idea of porting over the olcConsoleGameEngine to non-windows operating systems.

He developed a prototype which can be found here:
https://github.com/Jackojc/olcNotSoConsoleGameEngine
which really proved that it could be possible.

I then added functionality to ensure that this header is 99% compatible with
my existing code base, so almost all the videos I've made should be compatible
with this version of the olcConsoleGameEngine, without modificatcion.

Finally I'd also like to thank MrBadNews on Discord for testing and finding
many bugs, and creating workarounds, and Slavka on Discord for help debug SDL
double buffering issues - stupid SDL :P

Please remember I, javidx9, am not a Linux or SDL specialist. Therfore please
report bugs, or ask for help on the Discord Server, as I probably don't use 
the same non-windows operating systems as you, and each have their own methods
for building and installing.

===============================================================================

License
~~~~~~~
One Lone Coder Console Game Engine  Copyright (C) 2018  Javidx9
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions; See license for details.

Original works located at:
https://www.github.com/onelonecoder
https://www.onelonecoder.com
https://www.youtube.com/javidx9

GNU GPLv3
https://github.com/OneLoneCoder/videos/blob/master/LICENSE

From Javidx9 :)
~~~~~~~~~~~~~~~
Hello! Ultimately I don't care what you use this for. It's intended to be
educational, and perhaps to the oddly minded - a little bit of fun.
Please hack this, change it and use it in any way you see fit. You acknowledge
that I am not responsible for anything bad that happens as a result of
your actions. However this code is protected by GNU GPLv3, see the license in the
github repo. This means you must attribute me if you use it. You can view this
license here: https://github.com/OneLoneCoder/videos/blob/master/LICENSE

Cheers!

Background
~~~~~~~~~~
If you've seen any of my videos - I like to do things using the windows console. It's quick
and easy, and allows you to focus on just the code that matters - ideal when you're
experimenting. Thing is, I have to keep doing the same initialisation and display code
each time, so this class wraps that up.

Author
~~~~~~
Twitter: @javidx9	http://twitter.com/javidx9
Blog:				http://www.onelonecoder.com
YouTube:			http://www.youtube.com/javidx9

Videos:
~~~~~~
Original:				https://youtu.be/cWc0hgYwZyc
Added mouse support:	https://youtu.be/tdqc9hZhHxM
Beginners Guide:		https://youtu.be/u5BhrA8ED0o

Shout Outs!
~~~~~~~~~~~
Thanks to cool people who helped with testing, bug-finding and fixing!
wowLinh, JavaJack59, idkwid, kingtatgi, Return Null, CPP Guy

Last Updated: 01/07/2018

Usage:
~~~~~~
This class is abstract, so you must inherit from it. Override the OnUserCreate() function
with all the stuff you need for your application (for thready reasons it's best to do
this in this function and not your class constructor). Override the OnUserUpdate(float fElapsedTime)
function with the good stuff, it gives you the elapsed time since the last call so you
can modify your stuff dynamically. Both functions should return true, unless you need
the application to close.

int main()
{
// Use olcConsoleGameEngine derived app
OneLoneCoder_Example game;

// Create a console with resolution 160x100 characters
// Each character occupies 8x8 pixels
game.ConstructConsole(160, 100, 8, 8);

// Start the engine!
game.Start();

return 0;
}


The draw routines treat characters like pixels. By default they are set to white solid
blocks - but you can draw any unicode character, using any of the colours listed below.

There may be bugs!

See my other videos for examples!
http://www.youtube.com/javidx9

Lots of programs to try:
http://www.github.com/OneLoneCoder/videos

Chat on the Discord server:
https://discord.gg/WhwHUMV

Be bored by Twitch:
http://www.twitch.tv/javidx9

*/

#pragma once

#ifndef UNICODE
#error Please enable UNICODE for your compiler! VS: Project Properties -> General -> \
Character Set -> Use Unicode. Thanks! For now, Ill try enabling it for you - Javidx9
#define UNICODE
#define _UNICODE
#endif

#define __STDC_LIB_EXT1__ 
#define __STDC_WANT_LIB_EXT1__ 1
#define _CRT_SECURE_NO_WARNINGS

// NOTE: You will need to have SDL2 installed on your machine for this to work
// https://www.libsdl.org/download-2.0.php
#ifdef _WIN32
#include <SDL.h>
#else
#include <SDL2/SDL.h>
#endif
#undef main

#include <stdio.h>
#include <iostream>
#include <chrono>
#include <vector>
#include <list>
#include <thread>
#include <atomic>
#include <condition_variable>
#include <string>

#define KEY_OFFSET 256
#define VK_SPACE SDL_SCANCODE_SPACE 		  + KEY_OFFSET
#define VK_BACK SDL_SCANCODE_BACKSPACE		  + KEY_OFFSET
#define VK_DELETE SDL_SCANCODE_DELETE		  + KEY_OFFSET
#define VK_HOME SDL_SCANCODE_HOME			  + KEY_OFFSET
#define VK_END SDL_SCANCODE_END				  + KEY_OFFSET
#define VK_RETURN SDL_SCANCODE_RETURN		  + KEY_OFFSET
#define VK_TAB SDL_SCANCODE_TAB				  + KEY_OFFSET
#define VK_INSERT SDL_SCANCODE_INSERT		  + KEY_OFFSET
#define VK_LSHIFT SDL_SCANCODE_LSHIFT		  + KEY_OFFSET
#define VK_RSHIFT SDL_SCANCODE_RSHIFT		  + KEY_OFFSET
#define VK_LCONTROL SDL_SCANCODE_LCTRL		  + KEY_OFFSET
#define VK_RCONTROL SDL_SCANCODE_RCTRL		  + KEY_OFFSET
#define VK_PRIOR SDL_SCANCODE_PAGEUP		  + KEY_OFFSET
#define VK_NEXT SDL_SCANCODE_PAGEDOWN		  + KEY_OFFSET
#define VK_ESCAPE SDL_SCANCODE_ESCAPE		  + KEY_OFFSET
#define VK_UP SDL_SCANCODE_UP				  + KEY_OFFSET
#define VK_DOWN	SDL_SCANCODE_DOWN			  + KEY_OFFSET
#define VK_LEFT SDL_SCANCODE_LEFT			  + KEY_OFFSET
#define VK_RIGHT SDL_SCANCODE_RIGHT			  + KEY_OFFSET
#define VK_F1 SDL_SCANCODE_F1				  + KEY_OFFSET
#define VK_F2 SDL_SCANCODE_F2				  + KEY_OFFSET
#define VK_F3 SDL_SCANCODE_F3				  + KEY_OFFSET
#define VK_F4 SDL_SCANCODE_F4				  + KEY_OFFSET
#define VK_F5 SDL_SCANCODE_F5				  + KEY_OFFSET
#define VK_F6 SDL_SCANCODE_F6				  + KEY_OFFSET
#define VK_F7 SDL_SCANCODE_F7				  + KEY_OFFSET
#define VK_F8 SDL_SCANCODE_F8				  + KEY_OFFSET
#define VK_F9 SDL_SCANCODE_F9				  + KEY_OFFSET
#define VK_F10 SDL_SCANCODE_F10				  + KEY_OFFSET
#define VK_F11 SDL_SCANCODE_F11				  + KEY_OFFSET
#define VK_F12 SDL_SCANCODE_F12				  + KEY_OFFSET

struct CHAR_INFO 
{
	unsigned short glyph;
	short colour;
};

enum COLOUR
{
	FG_BLACK = 0x0000,
	FG_DARK_BLUE = 0x0001,
	FG_DARK_GREEN = 0x0002,
	FG_DARK_CYAN = 0x0003,
	FG_DARK_RED = 0x0004,
	FG_DARK_MAGENTA = 0x0005,
	FG_DARK_YELLOW = 0x0006,
	FG_GREY = 0x0007, // Thanks MS :-/
	FG_DARK_GREY = 0x0008,
	FG_BLUE = 0x0009,
	FG_GREEN = 0x000A,
	FG_CYAN = 0x000B,
	FG_RED = 0x000C,
	FG_MAGENTA = 0x000D,
	FG_YELLOW = 0x000E,
	FG_WHITE = 0x000F,
	BG_BLACK = 0x0000,
	BG_DARK_BLUE = 0x0010,
	BG_DARK_GREEN = 0x0020,
	BG_DARK_CYAN = 0x0030,
	BG_DARK_RED = 0x0040,
	BG_DARK_MAGENTA = 0x0050,
	BG_DARK_YELLOW = 0x0060,
	BG_GREY = 0x0070,
	BG_DARK_GREY = 0x0080,
	BG_BLUE = 0x0090,
	BG_GREEN = 0x00A0,
	BG_CYAN = 0x00B0,
	BG_RED = 0x00C0,
	BG_MAGENTA = 0x00D0,
	BG_YELLOW = 0x00E0,
	BG_WHITE = 0x00F0,
};

enum PIXEL_TYPE
{
	PIXEL_SOLID = 0x2588,
	PIXEL_THREEQUARTERS = 0x2593,
	PIXEL_HALF = 0x2592,
	PIXEL_QUARTER = 0x2591,
};

constexpr SDL_Color colour_lookup[] = {
	SDL_Color{ 0,0,0,255 },      // 0
	SDL_Color{ 0,0,127,255 },    // 1
	SDL_Color{ 0,127,0,255 },    // 2
	SDL_Color{ 0,127,127,255 },  // 3
	SDL_Color{ 127,0,0,255 },    // 4
	SDL_Color{ 127,0,127,255 },  // 5
	SDL_Color{ 127,127,0,255 },  // 6
	SDL_Color{ 192,192,192,255 },// 7
	SDL_Color{ 127,127,127,255 },      // 8
	SDL_Color{ 0,0,255,255 },    // 9
	SDL_Color{ 0,255,0,255 },    // A
	SDL_Color{ 0,255,255,255 },  // B
	SDL_Color{ 255,0,0,255 },    // C
	SDL_Color{ 255,0,255,255 },  // D
	SDL_Color{ 255,255,0,255 },  // E
	SDL_Color{ 255,255,255,255 },// F
};

class olcSprite
{
public:
	olcSprite()
	{

	}

	olcSprite(int w, int h)
	{
		Create(w, h);
	}

	olcSprite(std::wstring sFile)
	{
		if (!Load(sFile))
			Create(8, 8);
	}

	int nWidth = 0;
	int nHeight = 0;

private:
	unsigned short *m_Glyphs = nullptr;
	short *m_Colours = nullptr;

	void Create(int w, int h)
	{
		nWidth = w;
		nHeight = h;
		m_Glyphs = new unsigned short[w*h];
		m_Colours = new short[w*h];
		for (int i = 0; i < w*h; i++)
		{
			m_Glyphs[i] = L' ';
			m_Colours[i] = FG_BLACK;
		}
	}

public:
	void SetGlyph(int x, int y, wchar_t c)
	{
		if (x <0 || x >= nWidth || y < 0 || y >= nHeight)
			return;
		else
			m_Glyphs[y * nWidth + x] = c;
	}

	void SetColour(int x, int y, short c)
	{
		if (x <0 || x >= nWidth || y < 0 || y >= nHeight)
			return;
		else
			m_Colours[y * nWidth + x] = c;
	}

	wchar_t GetGlyph(int x, int y)
	{
		if (x <0 || x >= nWidth || y < 0 || y >= nHeight)
			return L' ';
		else
			return m_Glyphs[y * nWidth + x];
	}

	short GetColour(int x, int y)
	{
		if (x <0 || x >= nWidth || y < 0 || y >= nHeight)
			return FG_BLACK;
		else
			return m_Colours[y * nWidth + x];
	}

	wchar_t SampleGlyph(float x, float y)
	{
		int sx = (int)(x * (float)nWidth);
		int sy = (int)(y * (float)nHeight - 1.0f);
		if (sx <0 || sx >= nWidth || sy < 0 || sy >= nHeight)
			return L' ';
		else
			return m_Glyphs[sy * nWidth + sx];
	}

	short SampleColour(float x, float y)
	{
		int sx = (int)(x * (float)nWidth);
		int sy = (int)(y * (float)nHeight - 1.0f);
		if (sx <0 || sx >= nWidth || sy < 0 || sy >= nHeight)
			return FG_BLACK;
		else
			return m_Colours[sy * nWidth + sx];
	}

	bool Save(std::wstring sFile)
	{
		FILE *f = nullptr;

		char buff[256];
#ifdef _WIN32
		size_t t;
		wcstombs_s(&t, buff, sFile.c_str(), 256);
#else
		wcstombs(buff, sFile.c_str(), 256);
#endif
				
#ifdef _WIN32
		fopen_s(&f, buff, "wb");
#else
		f = std::fopen(buff, "wb");
#endif
		if (f == nullptr)
			return false;

		fwrite(&nWidth, sizeof(int), 1, f);
		fwrite(&nHeight, sizeof(int), 1, f);
		fwrite(m_Colours, sizeof(short), nWidth * nHeight, f);
		fwrite(m_Glyphs, sizeof(wchar_t), nWidth * nHeight, f);

		fclose(f);

		return true;
	}

	bool Load(std::wstring sFile)
	{
		delete[] m_Glyphs;
		delete[] m_Colours;
		nWidth = 0;
		nHeight = 0;

		FILE *f = nullptr;
		char buff[256];
#ifdef _WIN32
		size_t t;
		wcstombs_s(&t, buff, sFile.c_str(), 256);
#else
		wcstombs(buff, sFile.c_str(), 256);
#endif

#ifdef _WIN32
		fopen_s(&f, buff, "rb");
#else
		f = std::fopen(buff, "rb");
#endif
		if (f == nullptr)
			return false;

		fread(&nWidth, sizeof(int), 1, f);
		fread(&nHeight, sizeof(int), 1, f);

		Create(nWidth, nHeight);

		fread(m_Colours, sizeof(short), nWidth * nHeight, f);
		fread(m_Glyphs, sizeof(wchar_t), nWidth * nHeight, f);

		fclose(f);
		return true;
	}
};


class olcConsoleGameEngine
{
public:
	olcConsoleGameEngine()
	{
		m_nScreenWidth = 80;
		m_nScreenHeight = 30;

		
		memset(m_keyNewState, 0, 512 * sizeof(bool));
		memset(m_keyOldState, 0, 512 * sizeof(bool));
		memset(m_keys._state, 0, 512 * sizeof(sKeyState));
		m_mousePosX = 0;
		m_mousePosY = 0;

		m_sAppName = L"Default";
	}

	int ConstructConsole(int width, int height, int fontw, int fonth)
	{
		m_nScreenWidth = width;
		m_nScreenHeight = height;
		m_nFontWidth = fontw;
		m_nFontHeight = fonth;

		


		// Allocate memory for screen buffer
		m_bufScreen[0] = new CHAR_INFO[m_nScreenWidth*m_nScreenHeight];
		m_bufScreen[1] = new CHAR_INFO[m_nScreenWidth*m_nScreenHeight];
		// NOTE(MrBadNewS): set buffers to zero, old way
		memset(m_bufScreen[0], 0, m_nScreenWidth*m_nScreenHeight*sizeof(CHAR_INFO));
		memset(m_bufScreen[1], 0, m_nScreenWidth*m_nScreenHeight*sizeof(CHAR_INFO));
		m_nCurrentBuffer = 0;

		return 1;
	}

	virtual void Draw(int x, int y, wchar_t c = PIXEL_SOLID, short col = 0x000F)
	{
		if (x >= 0 && x < m_nScreenWidth && y >= 0 && y < m_nScreenHeight)
		{
			m_bufScreen[m_nCurrentBuffer][y * m_nScreenWidth + x].glyph = c;
			m_bufScreen[m_nCurrentBuffer][y * m_nScreenWidth + x].colour = col;
		}
	}

	void Fill(int x1, int y1, int x2, int y2, wchar_t c = PIXEL_SOLID, short col = 0x000F)
	{
		Clip(x1, y1);
		Clip(x2, y2);
		for (int x = x1; x < x2; x++)
			for (int y = y1; y < y2; y++)
				Draw(x, y, c, col);
	}

	void DrawString(int x, int y, std::wstring c, short col = 0x000F)
	{
		for (size_t i = 0; i < c.size(); i++)
		{			
			m_bufScreen[m_nCurrentBuffer][y * m_nScreenWidth + x + i].glyph = c[i];
			m_bufScreen[m_nCurrentBuffer][y * m_nScreenWidth + x + i].colour = col;
		}
	}

	void DrawStringAlpha(int x, int y, std::wstring c, short col = 0x000F)
	{
		for (size_t i = 0; i < c.size(); i++)
		{
			if (c[i] != L' ')
			{
				m_bufScreen[m_nCurrentBuffer][y * m_nScreenWidth + x + i].glyph = c[i];
				m_bufScreen[m_nCurrentBuffer][y * m_nScreenWidth + x + i].colour = col;
			}
		}
	}

	void Clip(int &x, int &y)
	{
		if (x < 0) x = 0;
		if (x >= m_nScreenWidth) x = m_nScreenWidth;
		if (y < 0) y = 0;
		if (y >= m_nScreenHeight) y = m_nScreenHeight;
	}

	void DrawLine(int x1, int y1, int x2, int y2, wchar_t c = PIXEL_SOLID, short col = 0x000F)
	{
		int x, y, dx, dy, dx1, dy1, px, py, xe, ye, i;
		dx = x2 - x1;
		dy = y2 - y1;
		dx1 = abs(dx);
		dy1 = abs(dy);
		px = 2 * dy1 - dx1;
		py = 2 * dx1 - dy1;
		if (dy1 <= dx1)
		{
			if (dx >= 0)
			{
				x = x1;
				y = y1;
				xe = x2;
			}
			else
			{
				x = x2;
				y = y2;
				xe = x1;
			}
			Draw(x, y, c, col);
			for (i = 0; x<xe; i++)
			{
				x = x + 1;
				if (px<0)
					px = px + 2 * dy1;
				else
				{
					if ((dx<0 && dy<0) || (dx>0 && dy>0))
						y = y + 1;
					else
						y = y - 1;
					px = px + 2 * (dy1 - dx1);
				}
				Draw(x, y, c, col);
			}
		}
		else
		{
			if (dy >= 0)
			{
				x = x1;
				y = y1;
				ye = y2;
			}
			else
			{
				x = x2;
				y = y2;
				ye = y1;
			}
			Draw(x, y, c, col);
			for (i = 0; y<ye; i++)
			{
				y = y + 1;
				if (py <= 0)
					py = py + 2 * dx1;
				else
				{
					if ((dx<0 && dy<0) || (dx>0 && dy>0))
						x = x + 1;
					else
						x = x - 1;
					py = py + 2 * (dx1 - dy1);
				}
				Draw(x, y, c, col);
			}
		}
	}

	void DrawCircle(int xc, int yc, int r, wchar_t c = PIXEL_SOLID, short col = 0x000F)
	{
		int x = 0;
		int y = r;
		int p = 3 - 2 * r;
		if (!r) return;

		while (y >= x) // only formulate 1/8 of circle
		{
			Draw(xc - x, yc - y, c, col);//upper left left
			Draw(xc - y, yc - x, c, col);//upper upper left
			Draw(xc + y, yc - x, c, col);//upper upper right
			Draw(xc + x, yc - y, c, col);//upper right right
			Draw(xc - x, yc + y, c, col);//lower left left
			Draw(xc - y, yc + x, c, col);//lower lower left
			Draw(xc + y, yc + x, c, col);//lower lower right
			Draw(xc + x, yc + y, c, col);//lower right right
			if (p < 0) p += 4 * x++ + 6;
			else p += 4 * (x++ - y--) + 10;
		}
	}

	void FillCircle(int xc, int yc, int r, wchar_t c = PIXEL_SOLID, short col = 0x000F)
	{
		// Taken from wikipedia
		int x = 0;
		int y = r;
		int p = 3 - 2 * r;
		if (!r) return;

		auto drawline = [&](int sx, int ex, int ny)
		{
			for (int i = sx; i <= ex; i++)
				Draw(i, ny, c, col);
		};

		while (y >= x)
		{
			// Modified to draw scan-lines instead of edges
			drawline(xc - x, xc + x, yc - y);
			drawline(xc - y, xc + y, yc - x);
			drawline(xc - x, xc + x, yc + y);
			drawline(xc - y, xc + y, yc + x);
			if (p < 0) p += 4 * x++ + 6;
			else p += 4 * (x++ - y--) + 10;
		}
	};

	void DrawSprite(int x, int y, olcSprite *sprite)
	{
		if (sprite == nullptr)
			return;

		for (int i = 0; i < sprite->nWidth; i++)
		{
			for (int j = 0; j < sprite->nHeight; j++)
			{
				if (sprite->GetGlyph(i, j) != L' ')
					Draw(x + i, y + j, sprite->GetGlyph(i, j), sprite->GetColour(i, j));
			}
		}
	}

	void DrawPartialSprite(int x, int y, olcSprite *sprite, int ox, int oy, int w, int h)
	{
		if (sprite == nullptr)
			return;

		for (int i = 0; i < w; i++)
		{
			for (int j = 0; j < h; j++)
			{
				if (sprite->GetGlyph(i + ox, j + oy) != L' ')
					Draw(x + i, y + j, sprite->GetGlyph(i + ox, j + oy), sprite->GetColour(i + ox, j + oy));
			}
		}
	}

	void DrawWireFrameModel(const std::vector<std::pair<float, float>> &vecModelCoordinates, float x, float y, float r = 0.0f, float s = 1.0f, short col = FG_WHITE)
	{
		// pair.first = x coordinate
		// pair.second = y coordinate

		// Create translated model vector of coordinate pairs
		std::vector<std::pair<float, float>> vecTransformedCoordinates;
		int verts = vecModelCoordinates.size();
		vecTransformedCoordinates.resize(verts);

		// Rotate
		for (int i = 0; i < verts; i++)
		{
			vecTransformedCoordinates[i].first = vecModelCoordinates[i].first * cosf(r) - vecModelCoordinates[i].second * sinf(r);
			vecTransformedCoordinates[i].second = vecModelCoordinates[i].first * sinf(r) + vecModelCoordinates[i].second * cosf(r);
		}

		// Scale
		for (int i = 0; i < verts; i++)
		{
			vecTransformedCoordinates[i].first = vecTransformedCoordinates[i].first * s;
			vecTransformedCoordinates[i].second = vecTransformedCoordinates[i].second * s;
		}

		// Translate
		for (int i = 0; i < verts; i++)
		{
			vecTransformedCoordinates[i].first = vecTransformedCoordinates[i].first + x;
			vecTransformedCoordinates[i].second = vecTransformedCoordinates[i].second + y;
		}

		// Draw Closed Polygon
		for (int i = 0; i < verts + 1; i++)
		{
			int j = (i + 1);
			DrawLine((int)vecTransformedCoordinates[i % verts].first, (int)vecTransformedCoordinates[i % verts].second,
				(int)vecTransformedCoordinates[j % verts].first, (int)vecTransformedCoordinates[j % verts].second, PIXEL_SOLID, col);
		}
	}

	~olcConsoleGameEngine()
	{
		
	}

public:
	void Start()
	{
		m_bAtomActive = true;

		// Star the thread
		std::thread t = std::thread(&olcConsoleGameEngine::GameThread, this);

		// Wait for thread to be exited
		t.join();
	}

	int ScreenWidth()
	{
		return m_nScreenWidth;
	}

	int ScreenHeight()
	{
		return m_nScreenHeight;
	}

private:
	void GameThread()
	{
		// Start SDL
		SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS);

		char bufAppName[256];
#ifdef _WIN32
		size_t t;
		wcstombs_s(&t, bufAppName, m_sAppName.c_str(), 256);
#else
		wcstombs(bufAppName, m_sAppName.c_str(), 256);
#endif

		// Create Window
		m_window = SDL_CreateWindow(
			bufAppName,
			SDL_WINDOWPOS_UNDEFINED,
			SDL_WINDOWPOS_UNDEFINED,
			m_nScreenWidth * m_nFontWidth,
			m_nScreenHeight * m_nFontHeight,
			SDL_WINDOW_SHOWN
		);

		// Create renderer
		m_render = SDL_CreateRenderer(m_window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE);

		// Now hear this, because its annoying!
		// On windows, SDL does not create a double buffer by default, which
		// permits incremental rendering, a frankly necessary feature which
		// is used extensively by tile renderers (such as this system) to
		// get the most performance. On My Linux VM its fine too. However
		// on Linux with HW, it caused a non-clear bug, as my incremental
		// framing method was rendering differences to successive buffers
		// in SDL causing all sorts of on screen artefacts. SDL - You're shit.
		m_screen = SDL_CreateTexture(m_render, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, m_nScreenWidth * m_nFontWidth, m_nScreenHeight * m_nFontHeight);

		// Load Font File
		LoadFontFile("./olcfont_consolas.bmp");

		// Create user resources as part of this thread
		if (!OnUserCreate())
			m_bAtomActive = false;

		auto tp1 = std::chrono::system_clock::now();
		auto tp2 = std::chrono::system_clock::now();

		while (m_bAtomActive)
		{
			// Run as fast as possible
			while (m_bAtomActive)
			{
				// Handle Timing
				tp2 = std::chrono::system_clock::now();
				std::chrono::duration<float> elapsedTime = tp2 - tp1;
				tp1 = tp2;
				float fElapsedTime = elapsedTime.count();

				SDL_Event e;
				while (SDL_PollEvent(&e))
				{
					switch (e.type)
					{
						case SDL_QUIT:
							m_bAtomActive = false;
						break;

						case SDL_KEYDOWN:
						{
							int k = e.key.keysym.scancode; // SDL Scancode
							m_keyNewState[k] = true;
						}
						break;

						case SDL_KEYUP:
						{
							int k = e.key.keysym.scancode; // SDL Scancode
							m_keyNewState[k] = false;
						}
						break;

					}
				}

				// Handle Keyboard Input
				for (int k = 0; k < 512; k++)
				{					
					m_keys._state[k].bPressed = false;
					m_keys._state[k].bReleased = false;

					if (m_keyNewState[k] != m_keyOldState[k])
					{
						if (m_keyNewState[k] == true)
						{
							m_keys._state[k].bPressed = !m_keys._state[k].bHeld;
							m_keys._state[k].bHeld = true;
						}
						else
						{
							m_keys._state[k].bReleased = true;
							m_keys._state[k].bHeld = false;
						}
					}

					m_keyOldState[k] = m_keyNewState[k];
				}

				// Handle Mouse Input - Check for window events
			/*	INPUT_RECORD inBuf[32];
				DWORD events = 0;
				GetNumberOfConsoleInputEvents(m_hConsoleIn, &events);
				if (events > 0)
					ReadConsoleInput(m_hConsoleIn, inBuf, events, &events);*/

				// Handle events - we only care about mouse clicks and movement
				// for now
				//for (DWORD i = 0; i < events; i++)
				//{
				//	switch (inBuf[i].EventType)
				//	{
				//	case FOCUS_EVENT:
				//	{
				//		m_bConsoleInFocus = inBuf[i].Event.FocusEvent.bSetFocus;
				//	}
				//	break;

				//	case MOUSE_EVENT:
				//	{
				//		switch (inBuf[i].Event.MouseEvent.dwEventFlags)
				//		{
				//		case MOUSE_MOVED:
				//		{
				//			m_mousePosX = inBuf[i].Event.MouseEvent.dwMousePosition.X;
				//			m_mousePosY = inBuf[i].Event.MouseEvent.dwMousePosition.Y;
				//		}
				//		break;

				//		case 0:
				//		{
				//			for (int m = 0; m < 5; m++)
				//				m_mouseNewState[m] = (inBuf[i].Event.MouseEvent.dwButtonState & (1 << m)) > 0;

				//		}
				//		break;

				//		default:
				//			break;
				//		}
				//	}
				//	break;

				//	default:
				//		break;
				//		// We don't care just at the moment
				//	}
				//}

				/*for (int m = 0; m < 5; m++)
				{
					m_mouse[m].bPressed = false;
					m_mouse[m].bReleased = false;

					if (m_mouseNewState[m] != m_mouseOldState[m])
					{
						if (m_mouseNewState[m])
						{
							m_mouse[m].bPressed = true;
							m_mouse[m].bHeld = true;
						}
						else
						{
							m_mouse[m].bReleased = true;
							m_mouse[m].bHeld = false;
						}
					}

					m_mouseOldState[m] = m_mouseNewState[m];
				}
*/

				// Handle Frame Update
				if (!OnUserUpdate(fElapsedTime))
					m_bAtomActive = false;

				// Update Title & Present Screen Buffer
				char s[256];
				snprintf(s, 256, "OneLoneCoder.com - Console Game Engine (SDL) - %s - FPS: %3.2f", bufAppName, 1.0f / fElapsedTime);
				SDL_SetWindowTitle(m_window, s);

				// Render differences
				CHAR_INFO *buff_old, *buff_new;
				buff_new = m_bufScreen[m_nCurrentBuffer];
				buff_old = m_bufScreen[(m_nCurrentBuffer+1) % 2];

				SDL_SetRenderTarget(m_render, m_screen);

				for (int x = 0; x < m_nScreenWidth; x++)
				{
					for (int y = 0; y < m_nScreenHeight; y++)
					{
						int i = y * m_nScreenWidth + x;
						if (buff_new[i].colour != buff_old[i].colour || buff_new[i].glyph != buff_old[i].glyph)
						{
							// Draw Cell
							int cx = (buff_new[i].glyph-0) % 64;
							int cy = (buff_new[i].glyph-0) / 64;

							// Draw Foreground
							int cidx = (buff_new[i].colour & 0x00F0) >> 4;
							//SDL_Rect src_bg = { (cidx+45) * 8, 88, 8, 8 };
							SDL_Rect src_bg = { (cidx+0) * 16, 0, 16, 16 };
							SDL_Rect dst = { x * m_nFontWidth, y * m_nFontHeight, m_nFontWidth,	m_nFontHeight };
							SDL_SetTextureColorMod(m_fontFile, 255, 255, 255);
							SDL_SetTextureAlphaMod(m_fontFile, 255);
							SDL_RenderCopy(m_render, m_fontFile, &src_bg, &dst);

							// set colour of font
							SDL_Color fg_col = colour_lookup[buff_new[i].colour & 0x000F];
							SDL_SetTextureColorMod(m_fontFile, fg_col.r, fg_col.g, fg_col.b);
							SDL_SetTextureAlphaMod(m_fontFile, fg_col.a);

							// Draw glyph
							SDL_Rect src_fg = { cx * (16), cy * (16), 16, 16 };
							SDL_RenderCopy(m_render, m_fontFile, &src_fg, &dst);
						}
					}
				}

				// Present buffers
				SDL_SetRenderTarget(m_render, nullptr);
				SDL_RenderCopy(m_render, m_screen, nullptr, nullptr);
				SDL_RenderPresent(m_render);
				

				// Flip buffers
				m_nCurrentBuffer = (m_nCurrentBuffer + 1) % 2;
			}

			if (OnUserDestroy())
			{
				// User has permitted destroy, so exit and clean up
				SDL_DestroyTexture(m_fontFile);
				SDL_DestroyRenderer(m_render);
				SDL_DestroyWindow(m_window);
				SDL_Quit();

				delete[] m_bufScreen[0];
				delete[] m_bufScreen[1];
				m_cvGameFinished.notify_one();
			}
			else
			{
				// User denied destroy for some reason, so continue running
				m_bAtomActive = true;
			}
		}
	}

public:
	// User MUST OVERRIDE THESE!!
	virtual bool OnUserCreate() = 0;
	virtual bool OnUserUpdate(float fElapsedTime) = 0;

	// Optional for clean up 
	virtual bool OnUserDestroy()
	{
		return true;
	}


protected:

	struct sKeyState
	{
		bool bPressed;
		bool bReleased;
		bool bHeld;
	};

	struct sKeyStateWrap
	{
		sKeyState _state[512];

	public:
		sKeyState & operator[] (int nKeyID)
		{
			SDL_Scancode scode = SDL_SCANCODE_UNKNOWN;

			if (nKeyID > KEY_OFFSET)
			{
				int scode = (SDL_Scancode)nKeyID - KEY_OFFSET;
				return _state[scode];
			}			
			
			switch (nKeyID)
			{
			case L'A': scode = SDL_SCANCODE_A; break;
			case L'B': scode = SDL_SCANCODE_B; break;
			case L'C': scode = SDL_SCANCODE_C; break;
			case L'D': scode = SDL_SCANCODE_D; break;
			case L'E': scode = SDL_SCANCODE_E; break;
			case L'F': scode = SDL_SCANCODE_F; break;
			case L'G': scode = SDL_SCANCODE_G; break;
			case L'H': scode = SDL_SCANCODE_H; break;
			case L'I': scode = SDL_SCANCODE_I; break;
			case L'J': scode = SDL_SCANCODE_J; break;
			case L'K': scode = SDL_SCANCODE_K; break;
			case L'L': scode = SDL_SCANCODE_L; break;
			case L'M': scode = SDL_SCANCODE_M; break;
			case L'N': scode = SDL_SCANCODE_N; break;
			case L'O': scode = SDL_SCANCODE_O; break;
			case L'P': scode = SDL_SCANCODE_P; break;
			case L'Q': scode = SDL_SCANCODE_Q; break;
			case L'R': scode = SDL_SCANCODE_R; break;
			case L'S': scode = SDL_SCANCODE_S; break;
			case L'T': scode = SDL_SCANCODE_T; break;
			case L'U': scode = SDL_SCANCODE_U; break;
			case L'V': scode = SDL_SCANCODE_V; break;
			case L'W': scode = SDL_SCANCODE_W; break;
			case L'X': scode = SDL_SCANCODE_X; break;
			case L'Y': scode = SDL_SCANCODE_Y; break;
			case L'Z': scode = SDL_SCANCODE_Z; break;
			case L'0': scode = SDL_SCANCODE_0; break;
			case L'1': scode = SDL_SCANCODE_1; break;
			case L'2': scode = SDL_SCANCODE_2; break;
			case L'3': scode = SDL_SCANCODE_3; break;
			case L'4': scode = SDL_SCANCODE_4; break;
			case L'5': scode = SDL_SCANCODE_5; break;
			case L'6': scode = SDL_SCANCODE_6; break;
			case L'7': scode = SDL_SCANCODE_7; break;
			case L'8': scode = SDL_SCANCODE_8; break;
			case L'9': scode = SDL_SCANCODE_9; break;

			/*case L'\'': scode = SDL_SCANCODE_APOSTROPHE; break;
			case L'\\': scode = SDL_SCANCODE_BACKSLASH; break;
			case L',': scode = SDL_SCANCODE_COMMA; break;
			case L'=': scode = SDL_SCANCODE_EQUALS; break;
			case L'[': scode = SDL_SCANCODE_LEFTBRACKET; break;
			case L']': scode = SDL_SCANCODE_RIGHTBRACKET; break;
			case L'-': scode = SDL_SCANCODE_MINUS; break;
			case L'.': scode = SDL_SCANCODE_PERIOD; break;
			case L';': scode = SDL_SCANCODE_SEMICOLON; break;
			case L'/': scode = SDL_SCANCODE_SLASH; break;*/

			default: scode = (SDL_Scancode)nKeyID;
			}

			return _state[scode];
		}

	} m_keys; 

	int m_mousePosX;
	int m_mousePosY;

public:
	sKeyState GetKey(int nKeyID) 	
	{ 
		return m_keys[nKeyID]; 	
	}


	int GetMouseX() { return m_mousePosX; }
	int GetMouseY() { return m_mousePosY; }
	//sKeyState GetMouse(int nMouseButtonID) { return m_mouse[nMouseButtonID]; }
	bool IsFocused() { return m_bConsoleInFocus; }


protected:
	int Error(const wchar_t *msg)
	{
		wchar_t buf[256];
		wprintf(L"ERROR: %s\n\t%s\n", msg, buf);
		return 0;
	}

	void LoadFontFile(const std::string& fname)
	{
		// Load image.
		SDL_Surface* temp = SDL_LoadBMP(fname.c_str());
	
		// set color key to 255,0,255; this basically makes
		// it transparent.
		SDL_SetColorKey(temp, SDL_TRUE, SDL_MapRGB(temp->format, 255, 0, 255));
			
		// Convert to texture.
		m_fontFile = SDL_CreateTextureFromSurface(m_render,	temp);
		
		// Cleanup and return.
		SDL_FreeSurface(temp);
	}

	//static BOOL CloseHandler(DWORD evt)
	//{
	//	// Note this gets called in a seperate OS thread, so it must
	//	// only exit when the game has finished cleaning up, or else
	//	// the process will be killed before OnUserDestroy() has finished
	//	if (evt == CTRL_CLOSE_EVENT)
	//	{
	//		m_bAtomActive = false;

	//		// Wait for thread to be exited
	//		unique_lock<mutex> ul(m_muxGame);
	//		m_cvGameFinished.wait(ul);
	//	}
	//	return true;
	//}

protected:
	int m_nScreenWidth;
	int m_nScreenHeight;
	int m_nFontWidth;
	int m_nFontHeight;
	CHAR_INFO *m_bufScreen[2];
	int m_nCurrentBuffer = 0;
	std::wstring m_sAppName;
	bool m_keyOldState[512] = { 0 };
	bool m_keyNewState[512] = { 0 };
	bool m_mouseOldState[5] = { 0 };
	bool m_mouseNewState[5] = { 0 };
	bool m_bConsoleInFocus = true;
	static std::atomic<bool> m_bAtomActive;
	static std::condition_variable m_cvGameFinished;
	static std::mutex m_muxGame;

private:
	SDL_Window* m_window;
	SDL_Renderer* m_render;
	SDL_Texture *m_screen;
	SDL_Texture* m_fontFile;


};

std::atomic<bool> olcConsoleGameEngine::m_bAtomActive(false);
std::condition_variable olcConsoleGameEngine::m_cvGameFinished;
std::mutex olcConsoleGameEngine::m_muxGame;