Code refactoring.

[sixth-3d-demos.git] / src / main / java / eu / svjatoslav / sixth / e3d / examples / life_demo / Matrix.java

diff --git a/src/main/java/eu/svjatoslav/sixth/e3d/examples/life_demo/Matrix.java b/src/main/java/eu/svjatoslav/sixth/e3d/examples/life_demo/Matrix.java
new file mode 100644 (file)
index 0000000..8736b96
--- /dev/null
+++ b/src/main/java/eu/svjatoslav/sixth/e3d/examples/life_demo/Matrix.java
@@ -0,0 +1,156 @@
+package eu.svjatoslav.sixth.e3d.examples.life_demo;
+
+import eu.svjatoslav.sixth.e3d.geometry.Point3D;
+import eu.svjatoslav.sixth.e3d.renderer.raster.shapes.composite.base.AbstractCompositeShape;
+import eu.svjatoslav.sixth.e3d.renderer.raster.shapes.composite.base.SubShape;
+
+/**
+ * This is our 2D game of life world. It contains 2D array of {@link Cell}'s.
+ */
+class Matrix extends AbstractCompositeShape {
+
+    /**
+     * Empty space between cells.
+     */
+    private static final int BORDER = 5;
+
+    /**
+     * Matrix size X and Y. (Amount of cells.)
+     */
+    private static final int SIZE = 30;
+
+    /**
+     * Object marker in 3D scene. Allows to locate all stars from the scene.
+     */
+    private static final String GROUP_STARS = "stars";
+
+    /**
+     * Object marker in 3D scene. Allows to locate surface on the scene.
+     */
+    private static final String GROUP_SURFACE = "surface";
+
+    /**
+     * 2 dimensional matrix of cells
+     */
+    private final Cell[][] cells = new Cell[SIZE][];
+
+    public Matrix(final Point3D location) {
+        super(location);
+
+
+        for (int x = 0; x < SIZE; x++) {
+            cells[x] = new Cell[SIZE];
+
+            // init Y row
+            for (int z = 0; z < SIZE; z++) {
+                // create cell and register it
+                final Cell cell = new Cell(getCellLocation(x, z));
+                cells[x][z] = cell;
+                addShape(cell);
+            }
+        }
+
+        setGroupForUngrouped(GROUP_SURFACE);
+    }
+
+    /**
+     * Clear matrix.
+     */
+    public void clear() {
+
+        // mark every cell as inactive
+        for (int x = 0; x < SIZE; x++)
+            for (int y = 0; y < SIZE; y++)
+                cells[x][y].setActive(false);
+
+        // remove history stars
+        removeGroup(GROUP_STARS);
+    }
+
+    /**
+     * Compute survived cells based on the rules of Conway's Game of Life.
+     */
+    private void computeSurvivedCells() {
+
+        for (int y = 0; y < SIZE; y++)
+            for (int x = 0; x < SIZE; x++)
+                processCell(x, y);
+
+        for (int y = 0; y < SIZE; y++)
+            for (int x = 0; x < SIZE; x++)
+                cells[x][y].setActive(cells[x][y].survives);
+
+    }
+
+    private void processCell(int x, int y) {
+        int aliveNeighbours = countNeighbours(x, y);
+
+        if (cells[x][y].isActive()) {
+            cells[x][y].survives = ((aliveNeighbours == 2) || (aliveNeighbours == 3));
+        } else {
+            cells[x][y].survives = aliveNeighbours == 3;
+        }
+    }
+
+    private int countNeighbours(int x, int y) {
+        int result = 0;
+        for (int ny = y - 1; ny <= y + 1; ny++)
+            for (int nx = x - 1; nx <= x + 1; nx++)
+                if (isCellAlive(nx, ny)) result++;
+
+        if (isCellAlive(x, y)) result--;
+
+        return result;
+    }
+
+    private boolean isCellAlive(int x, int y) {
+        if (x < 0) return false;
+        if (x >= SIZE) return false;
+        if (y < 0) return false;
+        if (y >= SIZE) return false;
+        return cells[x][y].isActive();
+    }
+
+    /**
+     * Evolve matrix for one iteration
+     */
+    public void evolve(final boolean preserveHistory) {
+        if (preserveHistory)
+            markActiveCells();
+
+        shiftStarsUp();
+
+        computeSurvivedCells();
+    }
+
+    private Point3D getCellLocation(final int x, final int z) {
+        final int shift = -((SIZE / 2) * (Cell.SIZE + BORDER));
+
+        return new Point3D(
+                (x * (Cell.SIZE + BORDER)) + shift,
+                0,
+                (z * (Cell.SIZE + BORDER)) + shift);
+    }
+
+    /**
+     * Leave trail of active cells as stars above matrix.
+     */
+    private void markActiveCells() {
+        // mark survived cells
+        for (int x = 0; x < SIZE; x++)
+            for (int y = 0; y < SIZE; y++)
+                if (cells[x][y].isActive())
+                    addShape(new Star(getCellLocation(x, y)));
+
+        setGroupForUngrouped(GROUP_STARS);
+    }
+
+    /**
+     * Find all history tracking stars and shift them up.
+     */
+    private void shiftStarsUp() {
+
+        for (final SubShape subShape : getGroup(GROUP_STARS))
+            ((Star) subShape.getShape()).getLocation().translateY(-10);
+    }
+}