// ******** This source code corresponds to tutorial 5 of the developer guide **********

// The font used for displaying text
declare global MyFont font;

// The X and Y position of a click
declare global PosX int;
declare global PosY int;

// The pen for the grid
declare global GridPen pen;

// The O and X images
declare global SymbolX image;
declare global SymbolO image;

// The grid array
declare global GridStatus[9] int;
int global FREESQUARE = 0;
int global XSQUARE = 1;
int global OSQUARE = 2;

// ************************************************************************************************************
// Called once when the plugin is started. Do one time setup here.
// ************************************************************************************************************

function Init()
{
	createfont(MyFont, "Arial", 12);
	createpen(GridPen, 0, 2, RGB(255, 255, 255));
	
	// Create the O and X symbols from the GIFs. Parameter 1 is the image variable
	// to load into, parameter 2 is the path to the image to load.
	createimage(SymbolX, "SSE\\TicTacImages\\tictac-x.gif");
	createimage(SymbolO, "SSE\\TicTacImages\\tictac-o.gif");
	
	// Initialize the grid array. The array has 9 elements on a zero based index, which means
	// elements 0 to 8 are the only valid indexes.
	for(int iGridElement = 0; iGridElement < 9; iGridElement = iGridElement + 1)
	{
		// Set each element to a free square
		GridStatus[iGridElement] = FREESQUARE;
	}
}

// ************************************************************************************************************
// The plugin must draw all output here ONLY. This is the only valid drawing function.
// ************************************************************************************************************

function Render()
{
	int iWidth = getpanelwidth();
	int iHeight = getpanelheight();

	// Set the number of pixels in from the left of the display panel the grid should be at
	int iGridTopX = 10;
	int iGridWidth = iWidth - iGridTopX - 10;

	// The grid should be 1/4 of the way from the top of the display panel, and take up half the
	// total height of the panel.
	int iGridTopY = iHeight / 4;
	int iGridHeight = iHeight / 2;

	selectpen(GridPen);

	// First draw the vertical lines at 1/3 and 2/3 of the grid width
	int iGridThirdW = iGridWidth / 3;
	drawline(iGridTopX + iGridThirdW, iGridTopY, iGridTopX + iGridThirdW, iGridTopY + iGridHeight);
	drawline(iGridTopX + (iGridThirdW * 2), iGridTopY, iGridTopX + (iGridThirdW * 2), iGridTopY + iGridHeight);

	// Next draw the horizontal lines at 1/3 and 2/3 of the grid height
	int iGridThirdH = iGridHeight / 3;
	drawline(iGridTopX, iGridTopY + iGridThirdH, iGridTopX + iGridWidth, iGridTopY + iGridThirdH);
	drawline(iGridTopX, iGridTopY + (iGridThirdH * 2), iGridTopX + iGridWidth, iGridTopY + (iGridThirdH * 2));

	int iSymbolPosX = iGridTopX;
	int iSymbolPosY = iGridTopY;
	
	// Iterate through the grid array and draw any symbols we find. The iGridElement++
	// statement is shorthand for "iGridElement = iGridElement + 1", ie: increase the
	// value of iGridElement by one.
	for(int iGridElement = 0; iGridElement < 9; iGridElement++)
	{
		// Is this grid element an X? If so, draw the X symbol
		if(GridStatus[iGridElement] == XSQUARE)
			drawimage(SymbolX, iSymbolPosX, iSymbolPosY);
		
		// Is this grid element an O? If so, draw the O symbol
		if(GridStatus[iGridElement] == OSQUARE)
			drawimage(SymbolO, iSymbolPosX, iSymbolPosY);
		
		// Note: This is not the best way to calculate where to draw the symbols! It's
		// the easiest to understand though, which is the purpose of this tutorial.
		
		// Update the positioning variables. If we're currently processing element 2 or 5,
		// the next symbol must be reset to the left hand side of the grid, on the next line.
		if(iGridElement == 2 or iGridElement == 5)
		{
			iSymbolPosX = iGridTopX;
			iSymbolPosY = iSymbolPosY + (iGridHeight / 3);
		}
		else
			iSymbolPosX = iSymbolPosX + iGridWidth / 3;
	}
}

// ************************************************************************************************************
// Called when left mouse button is released. Params give X,Y pos of cursor at release.
// ************************************************************************************************************

function OnMouseLButtonUp(int iX, int iY)
{
	// Store the click position for use in the Render handler
	PosX = iX;
	PosY = iY;
	
	// Tell Brass to redraw our panel immediately
	redraw();
}