Initial data commit

Task/Bitmap-Bresenhams-line-algorithm/Java/bitmap-bresenhams-line-algorithm.java

@@ -0,0 +1,115 @@
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
+import javax.swing.WindowConstants;
+
+public class Bresenham {
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(Bresenham::run);
+    }
+
+    private static void run() {
+        JFrame f = new JFrame();
+        f.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
+        f.setTitle("Bresenham");
+
+        f.getContentPane().add(new BresenhamPanel());
+        f.pack();
+
+        f.setLocationRelativeTo(null);
+        f.setVisible(true);
+    }
+}
+
+class BresenhamPanel extends JPanel {
+
+    private final int pixelSize = 10;
+
+    BresenhamPanel() {
+        setPreferredSize(new Dimension(600, 500));
+        setBackground(Color.WHITE);
+    }
+
+    @Override
+    public void paintComponent(Graphics g) {
+        super.paintComponent(g);
+
+        int w = (getWidth() - 1) / pixelSize;
+        int h = (getHeight() - 1) / pixelSize;
+        int maxX = (w - 1) / 2;
+        int maxY = (h - 1) / 2;
+        int x1 = -maxX, x2 = maxX * -2 / 3, x3 = maxX * 2 / 3, x4 = maxX;
+        int y1 = -maxY, y2 = maxY * -2 / 3, y3 = maxY * 2 / 3, y4 = maxY;
+
+        drawLine(g, 0, 0, x3, y1); // NNE
+        drawLine(g, 0, 0, x4, y2); // ENE
+        drawLine(g, 0, 0, x4, y3); // ESE
+        drawLine(g, 0, 0, x3, y4); // SSE
+        drawLine(g, 0, 0, x2, y4); // SSW
+        drawLine(g, 0, 0, x1, y3); // WSW
+        drawLine(g, 0, 0, x1, y2); // WNW
+        drawLine(g, 0, 0, x2, y1); // NNW
+    }
+
+    private void plot(Graphics g, int x, int y) {
+        int w = (getWidth() - 1) / pixelSize;
+        int h = (getHeight() - 1) / pixelSize;
+        int maxX = (w - 1) / 2;
+        int maxY = (h - 1) / 2;
+
+        int borderX = getWidth() - ((2 * maxX + 1) * pixelSize + 1);
+        int borderY = getHeight() - ((2 * maxY + 1) * pixelSize + 1);
+        int left = (x + maxX) * pixelSize + borderX / 2;
+        int top = (y + maxY) * pixelSize + borderY / 2;
+
+        g.setColor(Color.black);
+        g.drawOval(left, top, pixelSize, pixelSize);
+    }
+
+    private void drawLine(Graphics g, int x1, int y1, int x2, int y2) {
+        // delta of exact value and rounded value of the dependent variable
+        int d = 0;
+
+        int dx = Math.abs(x2 - x1);
+        int dy = Math.abs(y2 - y1);
+
+        int dx2 = 2 * dx; // slope scaling factors to
+        int dy2 = 2 * dy; // avoid floating point
+
+        int ix = x1 < x2 ? 1 : -1; // increment direction
+        int iy = y1 < y2 ? 1 : -1;
+
+        int x = x1;
+        int y = y1;
+
+        if (dx >= dy) {
+            while (true) {
+                plot(g, x, y);
+                if (x == x2)
+                    break;
+                x += ix;
+                d += dy2;
+                if (d > dx) {
+                    y += iy;
+                    d -= dx2;
+                }
+            }
+        } else {
+            while (true) {
+                plot(g, x, y);
+                if (y == y2)
+                    break;
+                y += iy;
+                d += dx2;
+                if (d > dy) {
+                    x += ix;
+                    d -= dy2;
+                }
+            }
+        }
+    }
+}