olcSimpleEngine.h

/*
	olcPixelGameEngine.h

	+-------------------------------------------------------------+
	|           OneLoneCoder Pixel Game Engine v1.11              |
	| "Like the command prompt console one, but not..." - javidx9 |
	+-------------------------------------------------------------+

	What is this?
	~~~~~~~~~~~~~
	The olcConsoleGameEngine has been a surprsing and wonderful
	success for me, and I'm delighted how people have reacted so
	positively towards it, so thanks for that.

	However, there are limitations that I simply cannot avoid.
	Firstly, I need to maintain several different versions of
	it to accommodate users on Windows7, 8, 10, Linux, Mac,
	Visual Studio & Code::Blocks. Secondly, this year I've been
	pushing the console to the limits of its graphical capabilities
	and the effect is becoming underwhelming. The engine itself
	is not slow at all, but the process that Windows uses to
	draw the command prompt to the screen is, and worse still,
	it's dynamic based upon the variation of character colours
	and glyphs. Sadly I have no control over this, and recent
	videos that are extremely graphical (for a command prompt :P )
	have been dipping to unacceptable framerates. As the channel
	has been popular with aspiring game developers, I'm concerned
	that the visual appeal of the command prompt is perhaps
	limited to us oldies, and I dont want to alienate younger
	learners. Finally, I'd like to demonstrate many more
	algorithms and image processing that exist in the graphical
	domain, for which the console is insufficient.

	For this reason, I have created olcPixelGameEngine! The look
	and feel to the programmer is almost identical, so all of my
	existing code from the videos is easily portable, and the
	programmer uses this file in exactly the same way. But I've
	decided that rather than just build a command prompt emulator,
	that I would at least harness some modern(ish) portable
	technologies.

	As a result, the olcPixelGameEngine supports 32-bit colour, is
	written in a cross-platform style, uses modern(ish) C++
	conventions and most importantly, renders much much faster. I
	will use this version when my applications are predominantly
	graphics based, but use the console version when they are
	predominantly text based - Don't worry, loads more command
	prompt silliness to come yet, but evolution is important!!

	License (OLC-3)
	~~~~~~~~~~~~~~~

	Copyright 2018 OneLoneCoder.com

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions or derivations of source code must retain the above
	copyright notice, this list of conditions and the following disclaimer.

	2. Redistributions or derivative works in binary form must reproduce
	the above copyright notice. This list of conditions and the following
	disclaimer must be reproduced in the documentation and/or other
	materials provided with the distribution.

	3. Neither the name of the copyright holder nor the names of its
	contributors may be used to endorse or promote products derived
	from this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	Links
	~~~~~
	YouTube:	https://www.youtube.com/javidx9
	Discord:	https://discord.gg/WhwHUMV
	Twitter:	https://www.twitter.com/javidx9
	Twitch:		https://www.twitch.tv/javidx9
	GitHub:		https://www.github.com/onelonecoder
	Homepage:	https://www.onelonecoder.com

	Relevant Videos
	~~~~~~~~~~~~~~~
	https://youtu.be/kRH6oJLFYxY Introducing olcPixelGameEngine

	Compiling in Linux
	~~~~~~~~~~~~~~~~~~
	You will need a modern C++ compiler, so update yours!
	To compile use the command:

	g++ -o YourProgName YourSource.cpp -lX11 -lGL -lpthread -lpng

	On some Linux configurations, the frame rate is locked to the refresh
	rate of the monitor. This engine tries to unlock it but may not be
	able to, in which case try launching your program like this:

	vblank_mode=0 ./YourProgName


	Compiling in Code::Blocks on Windows
	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	Well I wont judge you, but make sure your Code::Blocks installation
	is really up to date - you may even consider updating your C++ toolchain
	to use MinGW32-W64, so google this. You will also need to enable C++14
	in your build options, and add to your linker the following libraries:
	user32 gdi32 opengl32 gdiplus

	Thanks
	~~~~~~
	I'd like to extend thanks to Eremiell, slavka, gurkanctn, Phantim, 
	JackOJC, KrossX, Huhlig, Dragoneye, Appa, JustinRichardsMusic, SliceNDice
	& MagetzUb for advice, ideas and testing, and I'd like to extend 
	my appreciation to the 14K YouTube followers and 1K Discord server
	members who give me the motivation to keep going with all this :D

	Special thanks to those who bring gifts!
	GnarGnarHead.......Domina
	Gorbit99...........Bastion

	Author
	~~~~~~ 
	David Barr, aka javidx9, ©OneLoneCoder 2018
*/

////////////////////////////////////////////////////////////////////////////////////////// 

/* Example Usage (main.cpp)
	#define OLC_PGE_APPLICATION
	#include "olcPixelGameEngine.h"
	// Override base class with your custom functionality
	class Example : public olc::PixelGameEngine
	{
	public:
		Example()
		{
			sAppName = "Example";
		}
	public:
		bool OnUserCreate() override
		{
			// Called once at the start, so create things here
			return true;
		}
		bool OnUserUpdate(float fElapsedTime) override
		{
			// called once per frame, draws random coloured pixels
			for (int x = 0; x < ScreenWidth(); x++)
				for (int y = 0; y < ScreenHeight(); y++)
					Draw(x, y, olc::Pixel(rand() % 255, rand() % 255, rand()% 255));
			return true;
		}
	};
	int main()
	{
		Example demo;
		if (demo.Construct(256, 240, 4, 4))
			demo.Start();
		return 0;
	}
*/
#pragma once

#pragma comment(lib, "user32.lib")		// Visual Studio Only
#pragma comment(lib, "gdi32.lib")		// For other Windows Compilers please add
#pragma comment(lib, "opengl32.lib")	// these libs to your linker input
#pragma comment(lib, "gdiplus.lib")

// Include WinAPI
#include <windows.h>
#include <gdiplus.h>

// OpenGL Extension
#include <GL/gl.h>
typedef BOOL(WINAPI wglSwapInterval_t) (int interval);
static wglSwapInterval_t *wglSwapInterval;


// Standard includes
#include <cmath>
#include <cstdint>
#include <string>
#include <iostream>
#include <streambuf>
#include <chrono>
#include <vector>
#include <list>
#include <thread>
#include <atomic>
#include <condition_variable>
#include <fstream>
#include <map>
#include <functional>

#include <sstream> //for to_string_with_precision

#undef min
#undef max

namespace olc // All OneLoneCoder stuff will now exist in the "olc" namespace
{
	struct Pixel
	{
		union
		{
			uint32_t n = 0xFF000000;
			struct
			{
				uint8_t r;	uint8_t g;	uint8_t b;	uint8_t a;
			};
		};

		Pixel();
		Pixel(uint8_t red, uint8_t green, uint8_t blue, uint8_t alpha = 255);
		Pixel(uint32_t p);
		enum Mode { NORMAL, MASK, ALPHA, CUSTOM };
	};

	// Some constants for symbolic naming of Pixels
	static const Pixel
		WHITE(255, 255, 255),
		GREY(192, 192, 192), DARK_GREY(128, 128, 128), VERY_DARK_GREY(64, 64, 64),
		RED(255, 0, 0), DARK_RED(128, 0, 0), VERY_DARK_RED(64, 0, 0),
		YELLOW(255, 255, 0), DARK_YELLOW(128, 128, 0), VERY_DARK_YELLOW(64, 64, 0),
		GREEN(0, 255, 0), DARK_GREEN(0, 128, 0), VERY_DARK_GREEN(0, 64, 0),
		CYAN(0, 255, 255), DARK_CYAN(0, 128, 128), VERY_DARK_CYAN(0, 64, 64),
		BLUE(0, 0, 255), DARK_BLUE(0, 0, 128), VERY_DARK_BLUE(0, 0, 64),
		MAGENTA(255, 0, 255), DARK_MAGENTA(128, 0, 128), VERY_DARK_MAGENTA(64, 0, 64),
		BLACK(0, 0, 0),
		BLANK(0, 0, 0, 0);

	enum rcode
	{
		FAIL = 0,
		OK = 1,
		NO_FILE = -1,
	};

	//=============================================================

	struct HWButton
	{
		bool bPressed = false;	// Set once during the frame the event occurs
		bool bReleased = false;	// Set once during the frame the event occurs
		bool bHeld = false;		// Set tru for all frames between pressed and released events
	};

	//=============================================================

	class ResourcePack
	{
	public:
		ResourcePack();
		~ResourcePack();
		struct sEntry : public std::streambuf {
			uint32_t nID, nFileOffset, nFileSize; uint8_t* data; void _config() { this->setg((char*)data, (char*)data, (char*)(data + nFileSize)); }};

	public:
		olc::rcode AddToPack(std::string sFile);

	public:
		olc::rcode SavePack(std::string sFile);
		olc::rcode LoadPack(std::string sFile);
		olc::rcode ClearPack();

	public:
		olc::ResourcePack::sEntry GetStreamBuffer(std::string sFile);

	private:

		std::map<std::string, sEntry> mapFiles;
	};

	//=============================================================

	// A bitmap-like structure that stores a 2D array of Pixels
	class Sprite
	{
	public:
		Sprite();
		Sprite(std::string sImageFile);
		Sprite(std::string sImageFile, olc::ResourcePack *pack);
		Sprite(int32_t w, int32_t h);
		~Sprite();

	public:
		olc::rcode LoadFromFile(std::string sImageFile, olc::ResourcePack *pack = nullptr);
		olc::rcode LoadFromPGESprFile(std::string sImageFile, olc::ResourcePack *pack = nullptr);
		olc::rcode SaveToPGESprFile(std::string sImageFile);

	public:
		int32_t width = 0;
		int32_t height = 0;
		enum Mode { NORMAL, PERIODIC };

	public:
		void SetSampleMode(olc::Sprite::Mode mode = olc::Sprite::Mode::NORMAL);
		Pixel GetPixel(int32_t x, int32_t y);
		void  SetPixel(int32_t x, int32_t y, Pixel p);
		Pixel Sample(float x, float y);
		Pixel* GetData();
	
	private:
		Pixel *pColData = nullptr;
		Mode modeSample = Mode::NORMAL;

#ifdef OLC_DBG_OVERDRAW
	public:
		static int nOverdrawCount;
#endif

	};

	//=============================================================

	enum Key
	{
		A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z,
		K0, K1, K2, K3, K4, K5, K6, K7, K8, K9,
		F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12,
		UP, DOWN, LEFT, RIGHT,
		SPACE, TAB, SHIFT, CTRL, INS, DEL, HOME, END, PGUP, PGDN,
		BACK, ESCAPE, ENTER, PAUSE, SCROLL,
	};


	//=============================================================

	class PixelGameEngine
	{
	public:
		PixelGameEngine();
		std::string to_string_with_precision(float a_value, int n = 6);

	public:
		olc::rcode	Construct(uint32_t screen_w, uint32_t screen_h, uint32_t pixel_w, uint32_t pixel_h);
		olc::rcode	Start();

	public: // Override Interfaces
		// Called once on application startup, use to load your resources
		virtual bool OnUserCreate();
		// Called every frame, and provides you with a time per frame value
		virtual bool OnUserUpdate(float fElapsedTime);
		// Called once on application termination, so you can be a clean coder
		virtual bool OnUserDestroy();

	public: // Hardware Interfaces
		// Returns true if window is currently in focus
		bool IsFocused();
		// Get the state of a specific keyboard button
		HWButton GetKey(Key k);
		// Get the state of a specific mouse button
		HWButton GetMouse(uint32_t b);
		// Get Mouse X coordinate in "pixel" space
		int32_t GetMouseX();
		// Get Mouse Y coordinate in "pixel" space
		int32_t GetMouseY();

	public: // Utility
		// Returns the width of the screen in "pixels"
		int32_t ScreenWidth();
		// Returns the height of the screen in "pixels"
		int32_t ScreenHeight();
		// Returns the width of the currently selected drawing target in "pixels"
		int32_t GetDrawTargetWidth();
		// Returns the height of the currently selected drawing target in "pixels"
		int32_t GetDrawTargetHeight();
		// Returns the currently active draw target
		Sprite* GetDrawTarget();

	public: // Draw Routines
		// Specify which Sprite should be the target of drawing functions, use nullptr
		// to specify the primary screen
		void SetDrawTarget(Sprite *target);
		// Change the pixel mode for different optimisations
		// olc::Pixel::NORMAL = No transparency
		// olc::Pixel::MASK   = Transparent if alpha is < 255
		// olc::Pixel::ALPHA  = Full transparency
		void SetPixelMode(Pixel::Mode m);
		// Use a custom blend function
		void SetPixelMode(std::function<olc::Pixel(const int x, const int y, const olc::Pixel& pSource, const olc::Pixel& pDest)> pixelMode);
		// Change the blend factor form between 0.0f to 1.0f;
		void SetPixelBlend(float fBlend);
		// Offset texels by sub-pixel amount (advanced, do not use)
		void SetSubPixelOffset(float ox, float oy);

		// Draws a single Pixel
		virtual void Draw(int32_t x, int32_t y, Pixel p = olc::WHITE);
		// Draws a line from (x1,y1) to (x2,y2)
		void DrawLine(int32_t x1, int32_t y1, int32_t x2, int32_t y2, Pixel p = olc::WHITE);
		// Draws a circle located at (x,y) with radius
		void DrawCircle(int32_t x, int32_t y, int32_t radius, Pixel p = olc::WHITE);
		// Fills a circle located at (x,y) with radius
		void FillCircle(int32_t x, int32_t y, int32_t radius, Pixel p = olc::WHITE);
		// Draws a rectangle at (x,y) to (x+w,y+h)
		void DrawRect(int32_t x, int32_t y, int32_t w, int32_t h, Pixel p = olc::WHITE);
		// Fills a rectangle at (x,y) to (x+w,y+h)
		void FillRect(int32_t x, int32_t y, int32_t w, int32_t h, Pixel p = olc::WHITE);
		// Draws a triangle between points (x1,y1), (x2,y2) and (x3,y3)
		void DrawTriangle(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t x3, int32_t y3, Pixel p = olc::WHITE);
		// Flat fills a triangle between points (x1,y1), (x2,y2) and (x3,y3)
		void FillTriangle(int32_t x1, int32_t y1, int32_t x2, int32_t y2, int32_t x3, int32_t y3, Pixel p = olc::WHITE);
		// Draws an entire sprite at location (x,y)
		void DrawSprite(int32_t x, int32_t y, std::shared_ptr <Sprite> sprite, uint32_t scale = 1);
		// Draws an area of a sprite at location (x,y), where the
		// selected area is (ox,oy) to (ox+w,oy+h)
		void DrawPartialSprite(int32_t x, int32_t y, Sprite *sprite, int32_t ox, int32_t oy, int32_t w, int32_t h, uint32_t scale = 1);
		// Draws a single line of text
		void DrawString(int32_t x, int32_t y, std::string sText, Pixel col = olc::WHITE, uint32_t scale = 1);
		// Clears entire draw target to Pixel
		void Clear(Pixel p);

	public: // Branding
		std::string sAppName;

	private: // Inner mysterious workings
		Sprite		*pDefaultDrawTarget = nullptr;
		Sprite		*pDrawTarget = nullptr;
		Pixel::Mode	nPixelMode = Pixel::NORMAL;
		float		fBlendFactor = 1.0f;
		uint32_t	nScreenWidth = 256;
		uint32_t	nScreenHeight = 240;
		uint32_t	nPixelWidth = 4;
		uint32_t	nPixelHeight = 4;
		int32_t	nMousePosX = 0;
		int32_t	nMousePosY = 0;
		float		fPixelX = 1.0f;
		float		fPixelY = 1.0f;
		float		fSubPixelOffsetX = 0.0f;
		float		fSubPixelOffsetY = 0.0f;
		bool		bHasInputFocus = false;
		bool		bHasMouseFocus = false;
		float		fFrameTimer = 1.0f;
		int			nFrameCount = 0;
		Sprite		*fontSprite = nullptr;
		std::function<olc::Pixel(const int x, const int y, const olc::Pixel&, const olc::Pixel&)> funcPixelMode;

		static std::map<uint16_t, uint8_t> mapKeys;
		bool		pKeyNewState[256]{ 0 };
		bool		pKeyOldState[256]{ 0 };
		HWButton	pKeyboardState[256];

		bool		pMouseNewState[5]{ 0 };
		bool		pMouseOldState[5]{ 0 };
		HWButton	pMouseState[5];

#ifdef _WIN32
		HDC			glDeviceContext = nullptr;
		HGLRC		glRenderContext = nullptr;
#else
		GLXContext	glDeviceContext = nullptr;
		GLXContext	glRenderContext = nullptr;
#endif
		GLuint		glBuffer;

		void		EngineThread();

		// If anything sets this flag to false, the engine
		// "should" shut down gracefully
		static std::atomic<bool> bAtomActive;

		// Common initialisation functions
		void olc_UpdateMouse(int32_t x, int32_t y);
		bool olc_OpenGLCreate();
		void olc_ConstructFontSheet();

#ifdef _WIN32
		// Windows specific window handling
		HWND olc_hWnd = nullptr;
		HWND olc_WindowCreate();
		std::wstring wsAppName;
		static LRESULT CALLBACK olc_WindowEvent(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
#endif

	};


	class PGEX
	{
		friend class olc::PixelGameEngine;
	protected:
		static PixelGameEngine* pge;
	};

	//=============================================================
}