#include "grid.h"

Grid::Grid(int r, int c)
{
	rowSize = r;
	colSize = c;
	grid = new char*[rowSize]; 
	for(int i = 0; i < rowSize; i++)
		grid[i] = new char[colSize];
	clear();
}

Grid& Grid::operator=(const Grid& g)
{
	if (this != &g)
	{
		free();
		copy(g);
	}
	return *this;
}

void Grid::clear(char c /* = ' ' */)
{
	for(int i = 0; i < rowSize; i++)
		for(int j = 0; j < colSize; j++)
			grid[i][j] = c;
}

// horizontal plot
void Grid::hPlot(int row, int col, const string& s)
{
	for(int i = 0; i < s.size(); i++)
		plot(row, col++, s[i]);
}

// vertical plot
void Grid::vPlot(int row, int col, const string& s)
{
	for(int i = 0; i < s.size(); i++)
		plot(row++, col, s[i]);
}

void Grid::free()
{
	if (grid)
	{
		for(int i = 0; i < rowSize; i++)
			delete[] grid[i]; // delete[][] grid doesn't work
		delete[] grid;
	}
}

void Grid::copy(const Grid& g)
{
	rowSize = g.rowSize;
	colSize = g.colSize;
	grid = new char*[rowSize];
	for(int i = 0; i < rowSize; i++)
		grid[i] = new char[colSize];
	for(i = 0; i < rowSize; i++)
		for(int j = 0; j < colSize; j++)
			grid[i][j] = g.grid[i][j];
}

// Stolen from Horstmann's book.
//(He got it from Foley & Van Dam's book)
void Grid::plotLine(int xstart, int ystart, 
							int xend, int yend, char c)
{
	int dx = xend - xstart; // run
	int dy = yend - ystart; // rise

	if (abs(dy) < abs(dx)) // |slope| < 1
	{
		if (dx < 0) // xend < xstart
		{
			plotLine(xend, yend, xstart, ystart, c);
			return;
		}
		// plot (x, y) for increments of x & y
		double y = ystart + 0.5;
		double m = double(dy)/double(dx); // = slope
		for(int x = xstart; x != xend; x++, y += m)
			plot(int(y), x, c);
	}
	else // 1 <= |slope|
	{
		if (dy < 0) // yend < ytart
		{
			plotLine(xend, yend, xstart, ystart, c);
			return;
		}
		// plot (x, y) for increments of x & y
		double x = xstart + 0.5;
		double m = double(dx)/double(dy); // = slope
		for(int y = ystart; y != yend; y++, x += m)
			plot(int(y), x, c);
	}
	plot(yend, xend, c);
}

void Grid::show(ostream& os)
{
	for(int i = 0; i < getRowGetSize(); i++)
	{
		for(int j = 0; j < getColGetSize(); j++)
			os << getChar(i, j);
		os << '\n';
	}
}