feat: add collision handling to rotation

src/main/java/eu/midnightdust/yaytris/Tetris.java

@@ -50,7 +50,7 @@ public class Tetris {
             @Override
             public void run() {
                 if (space.getCurrentTetromino() != null) {
-                    space.getCurrentTetromino().fall(1);
+                    space.getCurrentTetromino().fall();
                     ui.getGamePanel().repaint();
                 }
             }

src/main/java/eu/midnightdust/yaytris/game/Tetromino.java

@@ -18,8 +18,8 @@ public class Tetromino {
         this.centerPos = Vec2i.of(2, 0);
     }
 
-    public void fall(int length) {
+    public boolean fall() {
-        Vec2i newPos = centerPos.offset(Vec2i.of(0, length));
+        Vec2i newPos = centerPos.offset(Vec2i.of(0, 1));
         if (collidesVertically(newPos)) {
             SoundEffect.BEEP.play();
             int[] affectedLines = new int[this.collision.length];
@@ -32,9 +32,11 @@ public class Tetromino {
             Tetris.getSpace().increaseScore(20-fallLength);
             if (fallLength >= 1) Tetris.getSpace().spawnTetromino();
             else Tetris.stopGame();
+            return false;
         }
         fallLength += 1;
         centerPos = newPos;
+        return true;
     }
 
     public void move(int xOffset) {
@@ -68,8 +70,8 @@ public class Tetromino {
         boolean collides = newPos.getX() < 0 || newPos.getX() + collision[0].length > Tetris.getSpace().getMapWidth(); // Side check
         if (!collides) { // Check for other tetrominos
             for (int i = 0; i < collision.length; i++) {
-                int maxCollisionX = xOffset > 0 ? collision[i].length - 1 : 0;
+                int maxCollisionX = xOffset >= 0 ? collision[i].length - 1 : 0;
-                while (collision[i][maxCollisionX] == 0) maxCollisionX += xOffset > 0 ? -1 : 1; // Figure out the collision box's bounding
+                while (collision[i][maxCollisionX] == 0) maxCollisionX += xOffset >= 0 ? -1 : 1; // Figure out the collision box's bounding
 
                 if (newPos.getY()+maxCollisionX >= Tetris.getSpace().getMapHeight()) continue;
                 collides |= Tetris.getSpace().getGameMap()[newPos.getY() + i][newPos.getX() + maxCollisionX] != null;
@@ -88,7 +90,14 @@ public class Tetromino {
                 newCollision[j][M-i-1] = collision[i][j];
             }
         }
+        int[][] prevCollision = this.collision;
         this.collision = newCollision;
+        int offset = 0;
+        for (int i = 0; i < 4; i++) {
+            if (collidesHorizontally(this.centerPos.offset(Vec2i.of(offset, 0)), -i)) offset = -i;
+        }
+        if (collidesVertically(this.centerPos.offset(Vec2i.of(offset, 0))) || collidesHorizontally(this.centerPos.offset(Vec2i.of(offset, 0)), offset)) this.collision = prevCollision;
+        else this.centerPos = centerPos.offset(Vec2i.of(offset, 0));
     }
 
     public Color[] getLine(int line) {
@@ -103,4 +112,10 @@ public class Tetromino {
         }
         return l;
     }
+
+    public void fallToBottom() {
+        while (true) {
+            if (!fall()) break;
+        }
+    }
 }

src/main/java/eu/midnightdust/yaytris/ui/TetrisUI.java

@@ -163,10 +163,10 @@ public class TetrisUI extends JFrame implements KeyListener {
                 break;
             case KeyEvent.VK_DOWN:
             case KeyEvent.VK_S:
-                Tetris.getSpace().getCurrentTetromino().fall(1);
+                Tetris.getSpace().getCurrentTetromino().fall();
                 break;
             case KeyEvent.VK_SPACE:
-                Tetris.getSpace().getCurrentTetromino().fall(12);
+                Tetris.getSpace().getCurrentTetromino().fallToBottom();
                 break;
         }
         gamePanel.repaint();