Setup column collision ranges for collision checking.

src/sig/BlockClump.java

@@ -1,25 +1,57 @@
 package sig;
 
 import java.awt.Graphics;
+import java.util.Arrays;
 import java.util.List;
 
 public class BlockClump {
-    List<Block> blocks;
+    private List<Block> blocks;
     double x,y; //the lower-left origin of this block clump. Every block positions relative to this.
     double yspd;
-    public BlockClump(List<Block> blockList, double x, double y, double startspd) {
-        this.blocks = blockList;
+    int[][] collisionColumnRanges;
+    public BlockClump(List<Block> blockList, double x, double y, double startspd, int width) {
+        collisionColumnRanges = new int[width][];
+
+        for (int i=0;i<width;i++) {
+            collisionColumnRanges[i] = new int[]{-1,-1};
+        }
+
+        addBlock(blockList.toArray(new Block[blockList.size()]));
         this.x=x;
         this.y=y;
         this.yspd=startspd;
     }
-    @Override
-    public String toString() {
-        return "BlockClump [blocks=" + blocks + ", x=" + x + ", y=" + y + ", yspd=" + yspd + "]";
+    public void updateBlockCollision() {
+        //Call this whenever the block structure changes. This will define what the top and bottom positions
+        //of each vertical column are for faster collision checking.
+        collisionColumnRanges = new int[collisionColumnRanges.length][];
+
+        for (int i=0;i<collisionColumnRanges.length;i++) {
+            collisionColumnRanges[i] = new int[]{-1,-1};
+        }
+        for (Block b : blocks) {updateBlockCollisionRangeWithBlock(b);}
+    }
+    public void addBlock(Block...blocks) {
+        //Adds the block to the strucutre. Update collision column ranges to reflect the new bounds.
+        for (Block b : blocks) {updateBlockCollisionRangeWithBlock(b);}
     }
     public void drawBlocks(Graphics g, int originX, int originY, int block_width, int block_height) {
         for (Block b : blocks) {
             b.draw(g,originX+x*block_width,originY-y,block_width,block_height);
         }
     }
+
+    private void updateBlockCollisionRangeWithBlock(Block b) {
+        if (collisionColumnRanges[b.x][0]==-1||collisionColumnRanges[b.x][0]>b.y) {
+            collisionColumnRanges[b.x][0]=b.y;
+        } else
+        if (collisionColumnRanges[b.x][1]==-1||collisionColumnRanges[b.x][1]<b.y) {
+            collisionColumnRanges[b.x][1]=b.y;
+        }
+    }
+    
+    @Override
+    public String toString() {
+        return "BlockClump [blocks=" + blocks + ", x=" + x + ", y=" + y + ", yspd=" + yspd + "]";
+    }
 }

src/sig/Board.java

@@ -39,7 +39,7 @@ public class Board {
             }
         }
 
-        BlockClump defaultClump = new BlockClump(initialBlocks,0,260,0);
+        BlockClump defaultClump = new BlockClump(initialBlocks,0,260,0,width);
 
         blockData.add(defaultClump);
     }