From e33fb44c16b3743425e9bab194d041cf16a0d349 Mon Sep 17 00:00:00 2001
From: Chris Wanstrath <chris@ozmm.org>
Date: Mon, 29 Sep 2025 00:07:31 -0700
Subject: [PATCH] wow, tetris

---
 app/nose/bin/tetris.ts | 167 +++++++++++++++++++++++++----------------
 1 file changed, 102 insertions(+), 65 deletions(-)

diff --git a/app/nose/bin/tetris.ts b/app/nose/bin/tetris.ts
index 1201b28..cb05feb 100644
--- a/app/nose/bin/tetris.ts
+++ b/app/nose/bin/tetris.ts
@@ -10,6 +10,7 @@ const CELL = 25
 const DOWN_TICK = 10
 const MOVE_TICK = 3
 const TETRIS_FRAMES = 5
+const LOCK_DELAY = 5
 
 type Shape = { x: number, y: number, shape: string, rotation: number }
 
@@ -20,6 +21,7 @@ let downTick = 0
 let moveTick = 0
 let tetrisRows: number[] = []
 let tetrisTimer = 0
+let lockTimer = 0
 
 const COLORS: Record<string, string> = {
   I: "cyan",
@@ -154,22 +156,10 @@ export function init() {
   downTick = 0
   moveTick = 0
   tetrisTimer = TETRIS_FRAMES
+  lockTimer = 0
   tetrisRows.length = 0
   grid.length = 0
 
-  grid[ROWS - 1] = [
-    "magenta",
-    "magenta",
-    "magenta",
-    "magenta",
-    "",
-    "magenta",
-    "magenta",
-    "magenta",
-    "magenta",
-    "magenta",
-  ]
-
   player = newShape()
 }
 
@@ -182,66 +172,54 @@ export function update(_delta: number, input: InputState) {
       player.rotation = 0
   }
 
-  // save to grid
-  const shape = SHAPES[player.shape]![player.rotation]!
-  if (shape) {
-    let hit = false
-    outer: for (const row in shape) {
-      for (const col in shape[row]!) {
-        const filled = shape[row][col]
-        if (!filled) continue
-
-        const x = player.x + Number(col)
-        const y = player.y + Number(row)
-
-        grid[y + 1] ??= []
-
-        if ((y + 1) >= ROWS || grid[y + 1]![x]) {
-          hit = true
-          break outer
-        }
-      }
+  // tetris animation
+  if (tetrisRows.length > 0) {
+    tetrisTimer--
+    if (tetrisTimer <= 0) {
+      removeTetrisRows()
+      tetrisRows = []
     }
+  } else if (anyFullRows()) {
+    tetrisRows = findFullRows()
+    tetrisTimer = TETRIS_FRAMES
+  }
 
-    if (tetrisRows.length > 0) {
-      tetrisTimer--
-      if (tetrisTimer <= 0) {
-        removeTetrisRows()
-        tetrisRows = []
-      }
-    } else if (anyFullRows()) {
-      tetrisRows = findFullRows()
-      tetrisTimer = TETRIS_FRAMES
-    }
+  const hit = blocked()
+  if (!hit) lockTimer = LOCK_DELAY
 
-    if (hit) {
-      const shape = SHAPES[player.shape]![player.rotation]!
-      for (const row in shape) {
-        for (const col in shape[row]!) {
-          const filled = shape[row][col]
-          if (!filled) continue
-
-          const x = player.x + Number(col)
-          const y = player.y + Number(row)
-
-          grid[y] ??= []
-          grid[y][x] = COLORS[player.shape]!
-        }
-      }
-
-      player = newShape()
+  if (hit) {
+    if (lockTimer > 0) {
+      lockTimer--
+    } else {
+      lockShape()
+      return
     }
   }
 
   if (++moveTick % MOVE_TICK === 0) {
-    if (keys.has("ArrowLeft") || keys.has("a")) player.x = Math.max(0, player.x - 1)
-    if (keys.has("ArrowRight") || keys.has("d")) player.x = Math.min(COLS, player.x + 1)
-    if (keys.has("ArrowDown") || keys.has("s")) { player.y += 1 }
+    if (
+      (keys.has("ArrowLeft") || keys.has("a")) &&
+      !collision(player.x - 1, player.y, player.rotation)
+    )
+      player.x = Math.max(0, player.x - 1)
+
+    if (
+      (keys.has("ArrowRight") || keys.has("d")) &&
+      !collision(player.x + 1, player.y, player.rotation)
+    )
+      player.x = Math.min(COLS, player.x + 1)
+
+    if (
+      (keys.has("ArrowDown") || keys.has("s")) &&
+      !collision(player.x, player.y + 1, player.rotation)
+    )
+      player.y += 1
   }
 
-  if (++downTick % DOWN_TICK === 0) {
-    player.y += 1
-  }
+  if (++downTick % DOWN_TICK === 0)
+    if (!collision(player.x, player.y + 1, player.rotation)) {
+      player.y++
+    }
 }
 
 export function draw(game: GameContext) {
@@ -315,7 +293,6 @@ function findFullRows(): number[] {
   return rows
 }
 
-
 function removeTetrisRows() {
   const newGrid: string[][] = []
 
@@ -331,6 +308,66 @@ function removeTetrisRows() {
   tetrisRows = []
 }
 
+function collision(x: number, y: number, rotation: number): boolean {
+  const shape = SHAPES[player.shape]![rotation]!
+
+  for (let row = 0; row < shape.length; row++) {
+    for (let col = 0; col < shape[row]!.length; col++) {
+      if (!shape[row]![col]) continue
+
+      const nx = x + col
+      const ny = y + row
+
+      if (nx < 0 || nx >= COLS) return true
+      if (ny >= ROWS) return true
+      if (grid[ny]?.[nx]) return true
+    }
+  }
+
+  return false
+}
+
+function lockShape() {
+  const shape = SHAPES[player.shape]![player.rotation]!
+  for (const row in shape) {
+    for (const col in shape[row]!) {
+      const filled = shape[row][col]
+      if (!filled) continue
+
+      const x = player.x + Number(col)
+      const y = player.y + Number(row)
+
+      grid[y] ??= []
+      grid[y][x] = COLORS[player.shape]!
+    }
+  }
+
+  player = newShape()
+}
+
+function blocked(): boolean {
+  const shape = SHAPES[player.shape]![player.rotation]!
+  let hit = false
+
+  outer: for (const row in shape) {
+    for (const col in shape[row]!) {
+      const filled = shape[row][col]
+      if (!filled) continue
+
+      const x = player.x + Number(col)
+      const y = player.y + Number(row)
+
+      grid[y + 1] ??= []
+
+      if ((y + 1) >= ROWS || grid[y + 1]![x]) {
+        hit = true
+        break outer
+      }
+    }
+  }
+
+  return hit
+}
 
 function drawBlock(game: GameContext, x: number, y: number, color: string) {
   game.rectfill(