// Create a basic rectangular canvas that can be drawn to. // It will be a canvas made up of ASCII characters! // An empty canvas will be filled with spaces, you will then // be able to draw things using different ASCII characters, // e.g. draw a line consisting of '*' or 'F' etc. // Note that this code doesn't have good enough error checking yet! // It is just to give an idea of what is possible. // Currently, only able to draw with an asterisk. import java.util.*; import static java.lang.Math.abs; // The point class. public class Point { public int x, y; public Point(int x_init, int y_init) { x = x_init; y = y_init; } // Draw this single point. public void Draw(AsteriskCanvas canvas) { //System.out.format("(%d, %d) == '*'\n", x, y); canvas.SetPoint(x, y); } } // The line class. public class Line { private Point start, end; public Line(int x0, int y0, int x1, int y1) { start = new Point(x0, y0); end = new Point(x1, y1); } // Draw the line to the canvas. // // Line drawing algorithm taken from: // https://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm#C // public void Draw(AsteriskCanvas canvas) { int x0 = start.x; int y0 = start.y; int x1 = end.x; int y1 = end.y; int dx = abs(x1-x0), sx = x0dy ? dx : -dy)/2, e2; for( ; ; ) { //setPixel(x0, y0); //System.out.format("(%d, %d) == '*'\n", x, y); canvas.SetPoint(x0, y0); if (x0 == x1 && y0 == y1) break; e2 = err; if (e2 >-dx) { err -= dy; x0 += sx; } if (e2 < dy) { err += dx; y0 += sy; } } } } // The character canvas. // This is a grid of characters, spaces mean the area is blank, // an asterisk means the canvas is drawn on. public class AsteriskCanvas { private char[][] charArray = new char [20][20]; public AsteriskCanvas() { // Clear the canvas. Clear(); } // Clear the canvas. public void Clear() { for (int y = 0; y < 20; y++) { for (int x = 0; x < 20; x++) { charArray[x][y] = ' '; } } } private void DrawLine(Line line) { line.Draw(this); } public void DrawLines(List lines) { Line line; for (int i = 0; i < lines.size(); i++) { line = lines.get(i); DrawLine(line); } } public void SetPoint(int x, int y) { charArray[x][y] = '*'; } // Display the canvas. public void Display() { System.out.println(); for (int y = 0; y < 20; y++) { for (int x = 0; x < 20; x++) { System.out.print(charArray[x][y]); } System.out.println(); } } } public class Program { public static void main(String[] args) { List linesForLetterM = new ArrayList(); // Create an 'M' shape, using four lines. Line line1 = new Line(0, 0, 0, 19); linesForLetterM.add(line1); Line line2 = new Line(0, 0, 9, 9); linesForLetterM.add(line2); Line line3 = new Line(9, 9, 19, 0); linesForLetterM.add(line3); Line line4 = new Line(19, 19, 19, 0); linesForLetterM.add(line4); // Create a blank character canvas. AsteriskCanvas canvas = new AsteriskCanvas(); // Draw all the lines. canvas.DrawLines(linesForLetterM); // Display the canvas (and everything drawn onto it). canvas.Display(); } }

Asterisk Canvas (Drawing With ASCII)