Main.cpp

////////////////////////////////////////////////////////////////////////////////
/*!
	@file	Main.cpp
	@author	Willow Hayward
			willhayw@gmail.com
    @par	This file contains the main implementation of the Computer Graphics Framework.
    @todo   Make the window resizable
            Create a base class for all objects that can be drawn
            Create a base class for all objects that can be animated
            Implement a unified object list for adding, drawing, and animating objects
            Define the number of clicks to create each object (default is 2, can override in derived class)
            Use best practice for animation timing - based on performance counter
            Move menu-related functions in Main.cpp and Windows.* to a new Menu class
*/
////////////////////////////////////////////////////////////////////////////////

// Includes
#include "Color.hpp"
#include "Line2D.hpp"
#include "Point2D.hpp"
#include "Shapes/Box2D.hpp"
#include "Shapes/Circle.hpp"
#include "Shapes/Ellipse.hpp"
#include "Window.hpp"
#include <memory>
#include <windows.h>

#define TICKS_PER_SEC	1000
#define FPS_30			(TICKS_PER_SEC/30.f)
#define TICKS_PER_ANIM	(10*TICKS_PER_SEC) // 10 seconds per animation

// Global objects
std::vector<std::unique_ptr<CGF::Shape>> shapeList;
std::vector<CGF::Box2D> boxList;
std::vector<CGF::Circle> circleList;
std::vector<CGF::Ellipse> ellipseList;
std::vector<CGF::Line2D> lineList;
CGF::Point2D firstPoint;
bool useFirstPoint(false);
CGF::Color redClr(255, 0, 0, 255);
CGF::Color blueClr(0, 0, 255, 255);
CGF::Color grnClr(0, 255, 0, 128);
CGF::Color blackClr(0, 0, 0, 255);
CGF::Color whiteClr(255, 255, 255, 255);

// Prototypes
void Update(CGF::Window & window, DWORD & oldTime);
void Draw(CGF::Window & window);
void DrawCross(CGF::Window & window, unsigned int centerX, unsigned int centerY, unsigned int radius, CGF::Color & color);
void SetPreviousPoint(unsigned int x, unsigned int y);
void ClearPreviousPoint();

void AddBox2D(CGF::Box2D & box);
void ClearBox2D();
void AddCircle(CGF::Circle & circle);
void ClearCircle();
void AddEllipse(CGF::Ellipse & ellipse);
void ClearEllipse();
void AddLine2D(CGF::Line2D & line);
void ClearLine2D();

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	WinMain
	@param	hInstance
			Window instance
	@param	hInstancePrev
			Not used
	@param	lpCmdLine
			Command line input -- not used
	@param	nCmdShow
			Not used
	@return	0 for success, anything else for error
*/
////////////////////////////////////////////////////////////////////////////////
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hInstancePrev, LPSTR lpCmdLine, int nCmdShow)
{
    // Create the main window
    CGF::Window window;
    if(!window.Create(hInstance, "Computer Graphics Framework", 800, 600))
        return 1;

    DWORD oldTime = 0; // Explicitly initialize oldTime
    oldTime = ::timeGetTime();

    while(window.Running())
    {
        Update(window, oldTime);
        Draw(window);
        
        // Swap the window surfaces
        window.Present();
    }

    return 0;
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Top-level function to read user input & update game objects 
	@param	window
			The active Window object
	@param	oldTime
			The previous time
*/
////////////////////////////////////////////////////////////////////////////////
void Update(CGF::Window & window, DWORD & oldTime)
{
	// Handle window messages
    window.ProcessMessages();

	// Update shapes
    for (const auto & shape : shapeList)
    {
        shape->Update();
    }

    // Update the animation time
	// Hold to 30fps
	DWORD newTime = 0; // Explicitly initialize newTime
	while (1)
	{
		// Get the updated time
		newTime = ::timeGetTime();
		if(newTime - oldTime < FPS_30)	// 1/30 second
			continue;

		// Re-set the time
		oldTime = newTime;
		break;
	}
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Top-level function to render all game objects 
	@param	window
			The active Window object
*/
////////////////////////////////////////////////////////////////////////////////
void Draw(CGF::Window & window)
{
	// Check which menu item was active and act appropriately
	if(IsMenuItemActive(LINE_DDA))
	{
		for (int i = 0; i < static_cast<int>(lineList.size()); i++)
		{
			lineList[i].SetColor(redClr);
			lineList[i].DrawDDA(window);
		}
	}

	if(IsMenuItemActive(LINE_BRESENHAM))
	{
		for (int i = 0; i < static_cast<int>(lineList.size()); i++)
		{
			lineList[i].SetColor(blueClr);
			lineList[i].DrawBresenham(window);
		}
	}

	if(IsMenuItemActive(LINE_ANIMATE))
	{
		for(int i = 0; i < static_cast<int>(boxList.size()); i++)
		{
			boxList[i].Draw(window);
			auto center = boxList[i].GetCenter();
			// The center of the crosshair should be drawn at the same pixel as the center of the box, which is truncated.
			DrawCross(window, (unsigned int)(center.GetX()), (unsigned int)(center.GetY()), 2, blackClr);
		}
	}

	if(IsMenuItemActive(OBJECT_CIRCLE))
    {
        for (int i = 0; i < static_cast<int>(circleList.size()); i++)
        {
            circleList[i].Draw(window);
        }
    }

    if(IsMenuItemActive(OBJECT_ELLIPSE))
    {
        for (int i = 0; i < static_cast<int>(ellipseList.size()); i++)
        {
            ellipseList[i].Draw(window);
        }
    }

    if(useFirstPoint)
	{
		// The center of the crosshair should be drawn at the same pixel as the endpoint of a line, which is rounded.
		unsigned int centerX = roundToUInt(firstPoint.GetX());
		unsigned int centerY = roundToUInt(firstPoint.GetY());
		DrawCross(window, centerX, centerY, 2, blackClr);
	}
}

void DrawCross(CGF::Window & window, unsigned int centerX, unsigned int centerY, unsigned int radius, CGF::Color &color)
{
	window.SetPixel(centerX, centerY, color);
	for (unsigned int i = 1; i <= radius; i++)
	{
		window.SetPixel(centerX - i, centerY, color);
		window.SetPixel(centerX + i, centerY, color);
		window.SetPixel(centerX, centerY - i, color);
		window.SetPixel(centerX, centerY + i, color);
	}
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Adds a line to the list
	@param	line	
			The line to add
*/
////////////////////////////////////////////////////////////////////////////////
void AddLine2D(CGF::Line2D & line)
{
    lineList.push_back(line);
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Erases the line list
	@param	line	
			The line list to erase
*/
////////////////////////////////////////////////////////////////////////////////
void ClearLine2D()
{
    lineList.clear();
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Adds a box to the list
	@param	box	
			The box to add
*/
////////////////////////////////////////////////////////////////////////////////
void AddBox2D(CGF::Box2D & box)
{
    boxList.push_back(box);
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Erases the box list
	@param	box	
			The box list to erase
*/
////////////////////////////////////////////////////////////////////////////////
void ClearBox2D()
{
    boxList.clear();
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Adds a circle to the list
	@param	circle	
			The circle to add
*/
////////////////////////////////////////////////////////////////////////////////
void AddCircle(CGF::Circle & circle)
{
    circleList.push_back(circle);
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Erases the circle list
*/
////////////////////////////////////////////////////////////////////////////////
void ClearCircle()
{
    circleList.clear();
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Adds an ellipse to the list
	@param	ellipse	
			The ellipse to add
*/
////////////////////////////////////////////////////////////////////////////////
void AddEllipse(CGF::Ellipse & ellipse)
{
    ellipseList.push_back(ellipse);
}

////////////////////////////////////////////////////////////////////////////////
/*!
	@brief	Erases the ellipse list
*/
////////////////////////////////////////////////////////////////////////////////
void ClearEllipse()
{
    ellipseList.clear();
}

////////////////////////////////////////////////////////////////////////////////
/*!
    @brief	Sets the previous point
    @param	x	
            The x-coordinate
    @param	y	
            The y-coordinate
*/
void SetPreviousPoint(unsigned int x, unsigned int y)
{
	firstPoint = CGF::Point2D(x, y);
	firstPoint.SetColor(blackClr);
	useFirstPoint = true;
}

////////////////////////////////////////////////////////////////////////////////
/*!
    @brief	Clears the previous point
*/
void ClearPreviousPoint()
{
	useFirstPoint = false;
	firstPoint = CGF::Point2D();
}