ToolPreview: a class for holding the effect of a tool

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@629 d9718cc8-9f43-0410-858b-315f434eb58c

src/micropolisj/engine/TileConstants.java

@@ -39,6 +39,7 @@ public class TileConstants
 	//
 	// terrain mapping
 	//
+	public static final short CLEAR = -1;
 	public static final char DIRT = 0;
 	public static final char RIVER = 2;
 	public static final char REDGE = 3;

src/micropolisj/engine/ToolEffectIfc.java

@@ -0,0 +1,19 @@
+package micropolisj.engine;
+
+public interface ToolEffectIfc
+{
+	/**
+	 * Gets the tile at a relative location.
+	 */
+	int getTile(int dx, int dy);
+
+	/**
+	 * Sets the tile value at a relative location.
+	 */
+	void setTile(int dx, int dy, int tileValue);
+
+	/**
+	 * Deduct an amount from the controller's cash funds.
+	 */
+	void spend(int amount);
+}

src/micropolisj/engine/ToolPreview.java

@@ -0,0 +1,103 @@
+package micropolisj.engine;
+
+import java.util.Arrays;
+import static micropolisj.engine.TileConstants.*;
+
+public class ToolPreview implements ToolEffectIfc
+{
+	public int originX;
+	public int originY;
+	public int offsetX;
+	public int offsetY;
+	public short [][] tiles;
+	public int cost;
+
+	ToolPreview(int x, int y)
+	{
+		this.originX = x;
+		this.originY = y;
+		this.tiles = new short[1][1];
+		this.tiles[0][0] = CLEAR;
+	}
+
+	//implements ToolEffectIfc
+	public int getTile(int dx, int dy)
+	{
+		if (inRange(dx, dy)) {
+			return tiles[offsetY+dy][offsetX+dx];
+		}
+		else {
+			return CLEAR;
+		}
+	}
+
+	boolean inRange(int dx, int dy)
+	{
+		return offsetY+dy >= 0 &&
+			offsetY+dy < tiles.length &&
+			offsetX+dx >= 0 &&
+			offsetX+dx < tiles[0].length;
+	}
+
+	void expandTo(int dx, int dy)
+	{
+		for (int i = 0; i < tiles.length; i++) {
+			short[] A = tiles[i];
+			if (offsetX+dx >= A.length) {
+				int newLen = offsetX+dx+1;
+				short[] AA = new short[newLen];
+				System.arraycopy(A, 0, AA, 0, A.length);
+				Arrays.fill(AA, A.length, newLen, CLEAR);
+				tiles[i] = AA;
+			}
+			else if (offsetX+dx < 0) {
+				int addl = -(offsetX+dx);
+				int newLen = A.length + addl;
+				short[] AA = new short[newLen];
+				System.arraycopy(A, 0, AA, addl, A.length);
+				Arrays.fill(AA, 0, addl, CLEAR);
+				tiles[i] = AA;
+			}
+		}
+
+		if (offsetX+dx < 0) {
+			int addl = -(offsetX+dx);
+			offsetX += addl;
+		}
+
+		if (offsetY+dy >= tiles.length) {
+			int newLen = offsetY+dy+1;
+			short[][] newTiles = new short[newLen][tiles[0].length];
+			System.arraycopy(tiles, 0, newTiles, 0, tiles.length);
+			for (int i = tiles.length; i < newLen; i++) {
+				Arrays.fill(newTiles[i], CLEAR);
+			}
+			tiles = newTiles;
+		}
+		else if (offsetY+dy < 0) {
+			int addl = -(offsetY+dy);
+			int newLen = tiles.length + addl;
+			short[][] newTiles = new short[newLen][tiles[0].length];
+			System.arraycopy(tiles, addl, newTiles, 0, tiles.length);
+			for (int i = 0; i < addl; i++) {
+				Arrays.fill(newTiles[i], CLEAR);
+			}
+			tiles = newTiles;
+
+			offsetY += addl;
+		}
+	}
+
+	//implements ToolEffectIfc
+	public void setTile(int dx, int dy, int tileValue)
+	{
+		expandTo(dx, dy);
+		tiles[offsetY+dy][offsetX+dx] = (short)tileValue;
+	}
+
+	//implements ToolEffectIfc
+	public void spend(int amount)
+	{
+		cost += amount;
+	}
+}