diff --git a/game/Bitmap.js b/game/Bitmap.js
deleted file mode 100644
index 6556195..0000000
--- a/game/Bitmap.js
+++ /dev/null
@@ -1,78 +0,0 @@
-import BoundingRectangle from './BoundingRectangle.js'
-
-export default class Bitmap {
-  constructor(width, height, rgba = null) {
-    this._w = width
-    this._h = height
-    this._com = 4 // number of components per pixel (RGBA)
-    this._boundingRect = new BoundingRectangle(0, this._w - 1, 0, this._h - 1)
-    const len = this._w * this._h * this._com
-    this._data = new Uint8ClampedArray(len)
-
-    if (rgba) {
-      for (let i = 0; i < len; i += 4) {
-        this._data[i] = rgba[0]
-        this._data[i + 1] = rgba[1]
-        this._data[i + 2] = rgba[2]
-        this._data[i + 3] = rgba[3]
-      }
-    }
-
-    // public
-    this.width = this._w
-    this.height = this._h
-  }
-
-  toImage() {
-    const canvas = document.createElement('canvas');
-    const ctx = canvas.getContext('2d');
-
-    canvas.width = this._w;
-    canvas.height = this._h;
-
-    const imgData = ctx.createImageData(canvas.width, canvas.height);
-    imgData.data.set(this._data);
-    ctx.putImageData(imgData, 0, 0);
-
-    return new Promise((resolve) => {
-
-      const img = document.createElement('img')
-      img.onload = () => {
-        resolve(img)
-      }
-      img.src = canvas.toDataURL()
-      return img
-    })
-  }
-
-  getPix(x, y, out) {
-    if (x < 0 || y < 0 || x >= this._w || y >= this._h) {
-      return false
-    }
-    x = Math.round(x)
-    y = Math.round(y)
-    const idx = (y * 4 * this._w) + (x * 4)
-    out[0] = this._data[idx]
-    out[1] = this._data[idx + 1]
-    out[2] = this._data[idx + 2]
-    out[3] = this._data[idx + 3]
-    return true
-  }
-
-  putPix(x, y, rgba) {
-    if (x < 0 || y < 0 || x >= this._w || y >= this._h) {
-      return
-    }
-    x = Math.round(x)
-    y = Math.round(y)
-    const idx = (y * this._com * this._w) + (x * this._com)
-    this._data[idx] = rgba[0]
-    this._data[idx + 1] = rgba[1]
-    this._data[idx + 2] = rgba[2]
-    this._data[idx + 3] = rgba[3]
-  }
-
-  getBoundingRect() {
-    return this._boundingRect
-  }
-}
diff --git a/game/BoundingRectangle.js b/game/BoundingRectangle.js
deleted file mode 100644
index 8312034..0000000
--- a/game/BoundingRectangle.js
+++ /dev/null
@@ -1,46 +0,0 @@
-import Point from './Point.js'
-
-export default class BoundingRectangle {
-    constructor(x0, x1, y0, y1) {
-        this.x0 = x0
-        this.x1 = x1
-        this.y0 = y0
-        this.y1 = y1
-        this.width = (x1 - x0) + 1
-        this.height = (y1 - y0) + 1
-    }
-
-    div(d) {
-        this.x0 /= d
-        this.x1 /= d
-        this.y0 /= d
-        this.y1 /= d
-    }
-    
-    move(x, y) {
-        this.x0 += x
-        this.x1 += x
-        this.y0 += y
-        this.y1 += y
-    }
-    
-    moved(x, y) {
-        return new BoundingRectangle(
-            this.x0 + x,
-            this.x1 + x,
-            this.y0 + y,
-            this.y1 + y
-        )
-    }
-
-    center() {
-        return new Point(
-            this.x0 + this.width / 2,
-            this.y0 + this.height / 2,
-        )
-    }
-    
-    centerDistance(other) {
-        return this.center().distance(other.center())
-    }
-}
\ No newline at end of file
diff --git a/game/Camera.js b/game/Camera.js
index cd4cc4a..b51adc5 100644
--- a/game/Camera.js
+++ b/game/Camera.js
@@ -1,5 +1,3 @@
-import BoundingRectangle from "./BoundingRectangle.js"
-
 export default class Camera {
     constructor(canvas) {
         this.x = 0
@@ -17,12 +15,12 @@ export default class Camera {
     }
 
     rect() {
-      return new BoundingRectangle(
-        - this.x,
-        - this.x + (this.width / this.zoom),
-        - this.y,
-        - this.y + (this.height / this.zoom),
-      )
+      return {
+        x: -this.x,
+        y: -this.y,
+        w: this.width / this.zoom,
+        h: this.height / this.zoom,
+      }
     }
 
     move(x, y) {
@@ -79,4 +77,11 @@ export default class Camera {
             y: (coord.y + this.y) * this.zoom,
         }
     }
+
+    worldDimToViewport(dim) {
+        return {
+            w: dim.w * this.zoom,
+            h: dim.h * this.zoom,
+        }
+    }
 }
diff --git a/game/CanvasAdapter.js b/game/CanvasAdapter.js
deleted file mode 100644
index 5fc73c8..0000000
--- a/game/CanvasAdapter.js
+++ /dev/null
@@ -1,99 +0,0 @@
-import BoundingRectangle from './BoundingRectangle.js'
-
-export default class CanvasAdapter {
-  constructor(canvas) {
-    this._canvas = canvas
-    /** @type {CanvasRenderingContext2D} */
-    this._ctx = this._canvas.getContext('2d')
-    this._w = this._canvas.width
-    this._h = this._canvas.height
-    this._boundingRect = new BoundingRectangle(0, this._w - 1, 0, this._h - 1)
-
-    this._imageData = this._ctx.createImageData(this._w, this._h)
-    this._data = this._imageData.data
-
-    this._dirty = false
-    this._dirtyRect = {x0: 0, x1: 0, y0: 0, y1: 0}
-    this.width = this._w
-    this.height = this._h
-  }
-
-  clear() {
-    this._imageData = this._ctx.createImageData(this._w, this._h)
-    this._data = this._imageData.data
-    this._dirty = false
-  }
-  clearRect(rects) {
-    for (let rect of rects) {
-      for (let x = rect.x0; x< rect.x1; x++) {
-        for (let y = rect.y0; y< rect.y1; y++) {
-          this.putPix(x, y, [0,0,0,0])
-        }
-      }
-    }
-  }
-
-  getPix(x, y, out) {
-    if (x < 0 || y < 0 || x >= this._w || y >= this._h) {
-      return false;
-    }
-    x = Math.round(x)
-    y = Math.round(y)
-    const idx = (y * 4 * this._w) + (x * 4)
-    out[0] = this._data[idx]
-    out[1] = this._data[idx + 1]
-    out[2] = this._data[idx + 2]
-    out[3] = this._data[idx + 3]
-    return true
-  }
-
-  putPix(x, y, rgba) {
-    if (x < 0 || y < 0 || x >= this._w || y >= this._h) {
-      return null;
-    }
-
-    x = Math.round(x)
-    y = Math.round(y)
-    const idx = (y * 4 * this._w) + (x * 4)
-    this._data[idx] = rgba[0]
-    this._data[idx + 1] = rgba[1]
-    this._data[idx + 2] = rgba[2]
-    this._data[idx + 3] = rgba[3]
-
-    if (this._dirty) {
-      // merge
-      this._dirtyRect.x0 = Math.min(this._dirtyRect.x0, x)
-      this._dirtyRect.x1 = Math.max(this._dirtyRect.x1, x)
-      this._dirtyRect.y0 = Math.min(this._dirtyRect.y0, y)
-      this._dirtyRect.y1 = Math.max(this._dirtyRect.y1, y)
-    } else {
-      // set
-      this._dirty = true
-      this._dirtyRect.x0 = x
-      this._dirtyRect.x1 = x
-      this._dirtyRect.y0 = y
-      this._dirtyRect.y1 = y
-    }
-  }
-
-  getBoundingRect() {
-    return this._boundingRect
-  }
-
-  apply() {
-    if (this._dirty) {
-      this._ctx.putImageData(
-        this._imageData,
-        0,
-        0,
-        this._dirtyRect.x0,
-        this._dirtyRect.y0,
-        this._dirtyRect.x1 - this._dirtyRect.x0,
-        this._dirtyRect.y1 - this._dirtyRect.y0
-      )
-      this._dirty = null
-    } else {
-      this._ctx.putImageData(this._imageData, 0, 0)
-    }
-  }
-}
diff --git a/game/Color.js b/game/Color.js
deleted file mode 100644
index 10484fb..0000000
--- a/game/Color.js
+++ /dev/null
@@ -1,22 +0,0 @@
-export function tint(c, f) {
-  return [
-    Math.max(0, Math.min(255, Math.round((255 - c[0]) * f))),
-    Math.max(0, Math.min(255, Math.round((255 - c[1]) * f))),
-    Math.max(0, Math.min(255, Math.round((255 - c[2]) * f))),
-    c[3]
-  ]
-}
-
-export function shade(c, f) {
-  return [
-    Math.max(0, Math.min(255, Math.round(c[0] * f))),
-    Math.max(0, Math.min(255, Math.round(c[1] * f))),
-    Math.max(0, Math.min(255, Math.round(c[2] * f))),
-    c[3]
-  ]
-}
-
-export default {
-  tint,
-  shade
-}
diff --git a/game/Graphics.js b/game/Graphics.js
index ff668f0..ed09947 100644
--- a/game/Graphics.js
+++ b/game/Graphics.js
@@ -1,10 +1,4 @@
-import Bitmap from './Bitmap.js'
-
-function copyUint8ClampedArray(src) {
-  const arr = new Uint8ClampedArray(src.length)
-  arr.set(new Uint8ClampedArray(src));
-  return arr
-}
+// import Bitmap from './Bitmap.js'
 
 function createCanvas(width = 0, height = 0) {
     const c = document.createElement('canvas')
@@ -13,227 +7,33 @@ function createCanvas(width = 0, height = 0) {
     return c
 }
 
-function dataToBitmap(w, h, data) {
-  const bitmap = new Bitmap(w, h)
-  bitmap._data = copyUint8ClampedArray(data)
-  return bitmap
-}
-
-function canvasToBitmap(
-  /** @type {HTMLCanvasElement} */ c,
-  /** @type {CanvasRenderingContext2D} */ ctx
-) {
-  const data = ctx.getImageData(0, 0, c.width, c.height).data
-  return dataToBitmap(c.width, c.height, data)
-}
-
-function imageToBitmap(img) {
-  const c = createCanvas(img.width, img.height)
-  const ctx = c.getContext('2d')
-  ctx.drawImage(img, 0, 0)
-  return canvasToBitmap(c, ctx)
-}
-
 async function loadImageToBitmap(imagePath) {
   const img = new Image()
   await new Promise((resolve) => {
     img.onload = resolve
     img.src = imagePath
   });
-  return imageToBitmap(img)
+  return await createImageBitmap(img, 0, 0, img.width, img.height)
 }
 
-function resizeBitmap (bitmap, width, height) {
-  const tmp = new Bitmap(width, height)
-  mapBitmapToBitmap(
-    bitmap,
-    bitmap.getBoundingRect(),
-    tmp,
-    tmp.getBoundingRect()
-  )
-  return tmp
+async function resizeBitmap (bitmap, width, height) {
+  const c = createCanvas(width, height)
+  const ctx = c.getContext('2d')
+  ctx.drawImage(bitmap, 0, 0, bitmap.width, bitmap.height, 0, 0, width, height)
+  return await createImageBitmap(c)
 }
 
-function mapBitmapToBitmap(
-  /** @type {Bitmap} */src,
-  /** @type {BoundingRectangle} */ rect_src,
-  /** @type {Bitmap} */ dst,
-  /** @type {BoundingRectangle} */ rect_dst
-) {
-  const tmp = new Uint8ClampedArray(4)
-  const w_f = rect_src.width / rect_dst.width
-  const h_f = rect_src.height / rect_dst.height
-
-  const startX = Math.max(rect_dst.x0, Math.floor((-rect_src.x0 / w_f) + rect_dst.x0))
-  const startY = Math.max(rect_dst.y0, Math.floor((-rect_src.y0 / h_f) + rect_dst.y0))
-
-  const endX = Math.min(rect_dst.x1, Math.ceil(((src.width - rect_src.x0) / w_f) + rect_dst.x0))
-  const endY = Math.min(rect_dst.y1, Math.ceil(((src.height - rect_src.y0) / h_f) + rect_dst.y0))
-
-  for (let x = startX; x < endX; x++) {
-    for (let y = startY; y < endY; y++) {
-      const src_x = rect_src.x0 + Math.floor((x - rect_dst.x0) * w_f)
-      const src_y = rect_src.y0 + Math.floor((y - rect_dst.y0) * h_f)
-      if (src.getPix(src_x, src_y, tmp)) {
-        if (tmp[3] === 255) {
-          dst.putPix(x, y, tmp)
-        }
-      }
-    }
-  }
-}
-
-function mapBitmapToBitmapCapped(
-  /** @type {Bitmap} */ src,
-  /** @type {BoundingRectangle} */ rect_src,
-  /** @type {Bitmap} */ dst,
-  /** @type {BoundingRectangle} */ rect_dst,
-  rects_cap
-) {
-  if (!rects_cap) {
-    return mapBitmapToBitmap(src, rect_src, dst, rect_dst)
-  }
-  const tmp = new Uint8ClampedArray(4)
-  const w_f = rect_src.width / rect_dst.width
-  const h_f = rect_src.height / rect_dst.height
-
-  for (let rect_cap of rects_cap) {
-    const startX = Math.floor(Math.max(rect_cap.x0, rect_dst.x0, (-rect_src.x0 / w_f) + rect_dst.x0))
-    const startY = Math.floor(Math.max(rect_cap.y0, rect_dst.y0, (-rect_src.y0 / h_f) + rect_dst.y0))
-
-    const endX = Math.ceil(Math.min(rect_cap.x1, rect_dst.x1, ((src.width - rect_src.x0) / w_f) + rect_dst.x0))
-    const endY = Math.ceil(Math.min(rect_cap.y1, rect_dst.y1, ((src.height - rect_src.y0) / h_f) + rect_dst.y0))
-
-    for (let x = startX; x < endX; x++) {
-      for (let y = startY; y < endY; y++) {
-        const src_x = rect_src.x0 + Math.floor((x - rect_dst.x0) * w_f)
-        const src_y = rect_src.y0 + Math.floor((y - rect_dst.y0) * h_f)
-        if (src.getPix(src_x, src_y, tmp)) {
-          if (tmp[3] === 255) {
-            dst.putPix(x, y, tmp)
-          }
-        }
-      }
-    }
-  }
-}
-
-function fillBitmap (bitmap, rgba) {
-  const len = bitmap.width * bitmap.height * 4
-  bitmap._data = new Uint8ClampedArray(len)
-  for (let i = 0; i < len; i+=4) {
-      bitmap._data[i] = rgba[0]
-      bitmap._data[i + 1] = rgba[1]
-      bitmap._data[i + 2] = rgba[2]
-      bitmap._data[i + 3] = rgba[3]
-  }
-}
-
-function fillBitmapCapped(bitmap, rgba, rects_cap) {
-  if (!rects_cap) {
-    return fillBitmap(bitmap, rgba)
-  }
-  for (let rect_cap of rects_cap) {
-    let startX = Math.floor(rect_cap.x0)
-    let startY = Math.floor(rect_cap.y0)
-
-    let endX = Math.ceil(rect_cap.x1)
-    let endY = Math.ceil(rect_cap.y1)
-
-    for (let x = startX; x < endX; x++) {
-      for (let y = startY; y < endY; y++) {
-        bitmap.putPix(x, y, rgba)
-      }
-    }
-  }
-}
-
-function mapBitmapToAdapterCapped (
-  /** @type {Bitmap} */ src,
-  /** @type {BoundingRectangle} */ rect_src,
-  /** @type {CanvasAdapter} */ dst,
-  /** @type {BoundingRectangle} */ rect_dst,
-  rects_cap
-) {
-  if (!rects_cap) {
-    return mapBitmapToAdapter(src, rect_src, dst, rect_dst)
-  }
-  const tmp = new Uint8ClampedArray(4)
-  const w_f = rect_src.width / rect_dst.width
-  const h_f = rect_src.height / rect_dst.height
-
-  for (let rect_cap of rects_cap) {
-    let startX = Math.floor(Math.max(rect_cap.x0, rect_dst.x0, (-rect_src.x0 / w_f) + rect_dst.x0))
-    let startY = Math.floor(Math.max(rect_cap.y0, rect_dst.y0, (-rect_src.y0 / h_f) + rect_dst.y0))
-
-    let endX = Math.ceil(Math.min(rect_cap.x1, rect_dst.x1, ((src.width - rect_src.x0) / w_f) + rect_dst.x0))
-    let endY = Math.ceil(Math.min(rect_cap.y1, rect_dst.y1, ((src.height - rect_src.y0) / h_f) + rect_dst.y0))
-
-    for (let x = startX; x < endX; x++) {
-      for (let y = startY; y < endY; y++) {
-        const src_x = rect_src.x0 + Math.floor((x - rect_dst.x0) * w_f)
-        const src_y = rect_src.y0 + Math.floor((y - rect_dst.y0) * h_f)
-        if (src.getPix(src_x, src_y, tmp)) {
-          if (tmp[3] === 255) {
-            dst.putPix(x, y, tmp)
-          }
-        }
-      }
-    }
-  }
-}
-
-function mapBitmapToAdapter(
-  /** @type {Bitmap} */ src,
-  /** @type {BoundingRectangle} */ rect_src,
-  /** @type {CanvasAdapter} */ dst,
-  /** @type {BoundingRectangle} */ rect_dst
-) {
-  const tmp = new Uint8ClampedArray(4)
-  const w_f = rect_src.width / rect_dst.width
-  const h_f = rect_src.height / rect_dst.height
-
-  let startX = Math.max(rect_dst.x0, Math.floor((-rect_src.x0 / w_f) + rect_dst.x0))
-  let startY = Math.max(rect_dst.y0, Math.floor((-rect_src.y0 / h_f) + rect_dst.y0))
-
-  let endX = Math.min(rect_dst.x1, Math.ceil(((src.width - rect_src.x0) / w_f) + rect_dst.x0))
-  let endY = Math.min(rect_dst.y1, Math.ceil(((src.height - rect_src.y0) / h_f) + rect_dst.y0))
-
-  for (let x = startX; x < endX; x++) {
-    for (let y = startY; y < endY; y++) {
-      const src_x = rect_src.x0 + Math.floor((x - rect_dst.x0) * w_f)
-      const src_y = rect_src.y0 + Math.floor((y - rect_dst.y0) * h_f)
-      if (src.getPix(src_x, src_y, tmp)) {
-        if (tmp[3] === 255) {
-          dst.putPix(x, y, tmp)
-        }
-      }
-    }
-  }
-}
-
-function drawBitmap(adapter, bitmap, pos) {
-  const rect = bitmap.getBoundingRect()
-  mapBitmapToAdapter(
-    bitmap,
-    rect,
-    adapter,
-    rect.moved(pos.x, pos.y)
-  )
+async function createBitmap(width, height, color) {
+  const c = createCanvas(width, height)
+  const ctx = c.getContext('2d')
+  ctx.fillStyle = color
+  ctx.fillRect(0, 0, width, height)
+  return await createImageBitmap(c)
 }
 
 export default {
+  createBitmap,
   createCanvas,
-  dataToBitmap,
-  canvasToBitmap,
-  imageToBitmap,
   loadImageToBitmap,
   resizeBitmap,
-  mapBitmapToBitmap,
-  mapBitmapToBitmapCapped,
-  fillBitmap,
-  fillBitmapCapped,
-  mapBitmapToAdapter,
-  mapBitmapToAdapterCapped,
-  drawBitmap,
 }
diff --git a/game/Point.js b/game/Point.js
index fa855b1..68c8526 100644
--- a/game/Point.js
+++ b/game/Point.js
@@ -19,9 +19,4 @@ export default class Point {
             this.y - other.y
         )
     }
-    distance(other) {
-        const diffX = this.x - other.x
-        const diffY = this.y - other.y
-        return Math.sqrt(diffX * diffX + diffY * diffY)
-    }
 }
diff --git a/game/index.js b/game/index.js
index ba8a40c..4e0b0cb 100644
--- a/game/index.js
+++ b/game/index.js
@@ -1,7 +1,4 @@
 "use strict"
-import CanvasAdapter from './CanvasAdapter.js'
-import BoundingRectangle from './BoundingRectangle.js'
-import Bitmap from './Bitmap.js'
 import {run} from './gameloop.js'
 import Camera from './Camera.js'
 import EventAdapter from './EventAdapter.js'
@@ -12,18 +9,44 @@ import Communication from './Communication.js'
 if (typeof GAME_ID === 'undefined') throw '[ GAME_ID not set ]'
 if (typeof WS_ADDRESS === 'undefined') throw '[ WS_ADDRESS not set ]'
 
-if (typeof DEBUG === 'undefined') window.DEBUG = false
+if (typeof DEBUG === 'undefined') window.DEBUG = true
 
 function addCanvasToDom(canvas) {
     document.body.append(canvas)
     return canvas
 }
 
+function pointDistance(a, b) {
+  const diffX = a.x - b.x
+  const diffY = a.y - b.y
+  return Math.sqrt(diffX * diffX + diffY * diffY)
+}
+
+function rectMoved(rect, x, y) {
+  return {
+    x: rect.x + x,
+    y: rect.y + y,
+    w: rect.w,
+    h: rect.h,
+  }
+}
+
+const rectCenter = (rect) => {
+  return {
+    x: rect.x + (rect.w / 2),
+    y: rect.y + (rect.h / 2),
+  }
+}
+
+function rectCenterDistance(a, b) {
+  return pointDistance(rectCenter(a), rectCenter(b))
+}
+
 function pointInBounds(pt, rect) {
-  return pt.x >= rect.x0
-    && pt.x <= rect.x1
-    && pt.y >= rect.y0
-    && pt.y <= rect.y1
+  return pt.x >= rect.x
+    && pt.x <= rect.x + rect.w
+    && pt.y >= rect.y
+    && pt.y <= rect.y + rect.h
 }
 
 function getSurroundingTilesByIdx(puzzle, idx) {
@@ -42,8 +65,7 @@ function getSurroundingTilesByIdx(puzzle, idx) {
   ]
 }
 
-async function createPuzzleTileBitmaps(bitmap, tiles, info) {
-  let img = await bitmap.toImage()
+async function createPuzzleTileBitmaps(img, tiles, info) {
   var tileSize = info.tileSize
   var tileMarginWidth = info.tileMarginWidth
   var tileDrawSize = info.tileDrawSize
@@ -105,7 +127,6 @@ async function createPuzzleTileBitmaps(bitmap, tiles, info) {
     const srcRect = srcRectByIdx(info, tile.idx)
     const path = pathForShape(info.shapes[tile.idx])
 
-
     const c = Graphics.createCanvas(tileDrawSize, tileDrawSize)
     const ctx = c.getContext('2d')
     // -----------------------------------------------------------
@@ -118,8 +139,8 @@ async function createPuzzleTileBitmaps(bitmap, tiles, info) {
     ctx.clip(path)
     ctx.drawImage(
       img,
-      srcRect.x0 - tileMarginWidth,
-      srcRect.y0 - tileMarginWidth,
+      srcRect.x - tileMarginWidth,
+      srcRect.y - tileMarginWidth,
       tileDrawSize,
       tileDrawSize,
       0,
@@ -130,9 +151,7 @@ async function createPuzzleTileBitmaps(bitmap, tiles, info) {
     ctx.stroke(path)
     ctx.restore();
 
-    const bitmap = Graphics.canvasToBitmap(c, ctx)
-
-    bitmaps[tile.idx] = bitmap
+    bitmaps[tile.idx] = await createImageBitmap(c)
   }
 
   return bitmaps
@@ -142,12 +161,12 @@ function srcRectByIdx(puzzleInfo, idx) {
   let c = puzzleInfo.coords[idx]
   let cx = c.x * puzzleInfo.tileSize
   let cy = c.y * puzzleInfo.tileSize
-  return new BoundingRectangle(
-    cx,
-    cx + puzzleInfo.tileSize,
-    cy,
-    cy + puzzleInfo.tileSize
-  )
+  return {
+    x: cx,
+    y: cy,
+    w: puzzleInfo.tileSize,
+    h: puzzleInfo.tileSize,
+  }
 }
 
 const pointSub = (a, b) => ({ x: a.x - b.x, y: a.y - b.y })
@@ -165,12 +184,12 @@ const unfinishedTileByPos = (puzzle, pos) => {
       continue
     }
 
-    const collisionRect = new BoundingRectangle(
-      tile.pos.x,
-      tile.pos.x + puzzle.info.tileSize - 1,
-      tile.pos.y,
-      tile.pos.y + puzzle.info.tileSize - 1,
-    )
+    const collisionRect = {
+      x: tile.pos.x,
+      y: tile.pos.y,
+      w: puzzle.info.tileSize,
+      h: puzzle.info.tileSize,
+    }
     if (pointInBounds(pos, collisionRect)) {
       if (maxZ === -1 || tile.z > maxZ) {
         maxZ = tile.z
@@ -215,7 +234,7 @@ async function loadPuzzleBitmaps(puzzle) {
   // creation of tile bitmaps
   // then create the final puzzle bitmap
   // NOTE: this can decrease OR increase in size!
-  const bmpResized = Graphics.resizeBitmap(bmp, puzzle.info.width, puzzle.info.height)
+  const bmpResized = await Graphics.resizeBitmap(bmp, puzzle.info.width, puzzle.info.height)
   return await createPuzzleTileBitmaps(bmpResized, puzzle.tiles, puzzle.info)
 }
 
@@ -274,7 +293,7 @@ async function main () {
 
   // Create a dom and attach adapters to it so we can work with it
   const canvas = addCanvasToDom(Graphics.createCanvas())
-  const adapter = new CanvasAdapter(canvas)
+  const ctx = canvas.getContext('2d')
   const evts = new EventAdapter(canvas)
 
   // initialize some view data
@@ -314,8 +333,8 @@ async function main () {
   // The actual place for the puzzle. The tiles may
   // not be moved around infinitely, just on the (invisible)
   // puzzle table. however, the camera may move away from the table
-  const puzzleTableColor = [40, 40, 40, 0]
-  const puzzleTable = new Bitmap(
+  const puzzleTableColor = '#222'
+  const puzzleTable = await Graphics.createBitmap(
     puzzle.info.table.width,
     puzzle.info.table.height,
     puzzleTableColor
@@ -323,8 +342,8 @@ async function main () {
 
   // In the middle of the table, there is a board. this is to
   // tell the player where to place the final puzzle
-  const boardColor = [80, 80, 80, 255]
-  const board = new Bitmap(
+  const boardColor = '#505050'
+  const board = await Graphics.createBitmap(
     puzzle.info.width,
     puzzle.info.height,
     boardColor
@@ -391,18 +410,19 @@ async function main () {
 
   // get the center position of a tile
   const tileCenterPos = (tile) => {
-    return tileRectByTile(tile).center()
+
+    return rectCenter(tileRectByTile(tile))
   }
 
   // get the would-be visible bounding rect if a tile was
   // in given position
   const tileRectByPos = (pos) => {
-    return new BoundingRectangle(
-      pos.x,
-      pos.x + puzzle.info.tileSize,
-      pos.y,
-      pos.y + puzzle.info.tileSize
-    )
+    return {
+      x: pos.x,
+      y: pos.y,
+      w: puzzle.info.tileSize,
+      h: puzzle.info.tileSize,
+    }
   }
 
   // get the current visible bounding rect for a tile
@@ -540,11 +560,11 @@ async function main () {
           let pt = pointSub(tile.pos, boardPos)
           let dst = tileRectByPos(pt)
           let srcRect = srcRectByIdx(puzzle.info, grabbingTileIdx)
-          if (srcRect.centerDistance(dst) < puzzle.info.snapDistance) {
+          if (rectCenterDistance(srcRect, dst) < puzzle.info.snapDistance) {
             // Snap the tile to the final destination
             moveGroupedTiles(tile, {
-              x: srcRect.x0 + boardPos.x,
-              y: srcRect.y0 + boardPos.y,
+              x: srcRect.x + boardPos.x,
+              y: srcRect.y + boardPos.y,
             })
             finishGroupedTiles(tile)
             rectTable.add(tp, puzzle.info.tileDrawSize)
@@ -554,13 +574,14 @@ async function main () {
               if (!other || (other.owner === -1) || areGrouped(t, other)) {
                 return false
               }
-              let trec_ = tileRectByTile(t)
-              let otrec = tileRectByTile(other).moved(
+              const trec_ = tileRectByTile(t)
+              const otrec = rectMoved(
+                tileRectByTile(other),
                 off[0] * puzzle.info.tileSize,
                 off[1] * puzzle.info.tileSize
               )
-              if (trec_.centerDistance(otrec) < puzzle.info.snapDistance) {
-                moveGroupedTiles(t, { x: otrec.x0, y: otrec.y0 })
+              if (rectCenterDistance(trec_, otrec) < puzzle.info.snapDistance) {
+                moveGroupedTiles(t, { x: otrec.x, y: otrec.y })
                 groupTiles(t, other)
                 setGroupedZIndex(t, t.z)
                 rectTable.add(tileCenterPos(t), puzzle.info.tileDrawSize)
@@ -614,7 +635,7 @@ async function main () {
   // if it improves performance:
   //   1. background
   //   2. tiles
-  //   3. (moving tiles)
+  //   3. (moving tiles
   //   4. (players)
   // (currently, if a player moves, everthing needs to be
   //  rerendered at that position manually, maybe it is faster
@@ -624,103 +645,57 @@ async function main () {
       return
     }
 
-    if (DEBUG) Debug.checkpoint_start(20)
+    let pos
+    let dim
 
-    // draw the puzzle table
-    if (rerenderTable) {
+    if (DEBUG) Debug.checkpoint_start(0)
 
-      Graphics.fillBitmapCapped(puzzleTable, puzzleTableColor, rectTable.get())
+    ctx.fillStyle = puzzleTableColor
+    ctx.fillRect(0, 0, canvas.width, canvas.height)
+    if (DEBUG) Debug.checkpoint('clear done')
 
-      if (DEBUG) Debug.checkpoint('after fill')
+    // DRAW BOARD
+    // ---------------------------------------------------------------
+    pos = viewport.worldToViewport(boardPos)
+    dim = viewport.worldDimToViewport({w: board.width, h: board.height})
+    ctx.drawImage(board,
+      0, 0, board.width, board.height,
+      pos.x, pos.y, dim.w, dim.h
+    )
+    if (DEBUG) Debug.checkpoint('board done')
 
-      // draw the puzzle board on the table
-      Graphics.mapBitmapToBitmapCapped(
-        board,
-        board.getBoundingRect(),
-        puzzleTable,
-        new BoundingRectangle(
-          boardPos.x,
-          boardPos.x + board.width - 1,
-          boardPos.y,
-          boardPos.y + board.height - 1,
-        ),
-        rectTable.get()
+    // DRAW TILES
+    // ---------------------------------------------------------------
+    for (let tile of tilesSortedByZIndex()) {
+      let bmp = bitmaps[tile.idx]
+      pos = viewport.worldToViewport({
+        x: puzzle.info.tileDrawOffset + tile.pos.x,
+        y: puzzle.info.tileDrawOffset + tile.pos.y,
+      })
+      dim = viewport.worldDimToViewport({
+        w: puzzle.info.tileDrawSize,
+        h: puzzle.info.tileDrawSize,
+      })
+      ctx.drawImage(bmp,
+        0, 0, bmp.width, bmp.height,
+        pos.x, pos.y, dim.w, dim.h
       )
-
-      if (DEBUG) Debug.checkpoint('imgtoimg')
-
-      // draw all the tiles on the table
-
-      for (let tile of tilesSortedByZIndex()) {
-        let rect = new BoundingRectangle(
-          puzzle.info.tileDrawOffset + tile.pos.x,
-          puzzle.info.tileDrawOffset + tile.pos.x + puzzle.info.tileDrawSize,
-          puzzle.info.tileDrawOffset + tile.pos.y,
-          puzzle.info.tileDrawOffset + tile.pos.y + puzzle.info.tileDrawSize,
-        )
-        let bmp = bitmaps[tile.idx]
-        Graphics.mapBitmapToBitmapCapped(
-          bmp,
-          bmp.getBoundingRect(),
-          puzzleTable,
-          rect,
-          rectTable.get()
-        )
-      }
-
-      if (DEBUG) Debug.checkpoint('tiles')
     }
+    if (DEBUG) Debug.checkpoint('tiles done')
 
-    if (rerenderTable || rerender) {
-      // finally draw the finished table onto the canvas
-      // only part of the table may be visible, depending on the
-      // camera
-      adapter.clear()
-      adapter.apply()
-
-      if (DEBUG) Debug.checkpoint('afterclear_1')
-
-      // TODO: improve the rendering
-      // atm it is pretty slow (~40-50ms)
-      Graphics.mapBitmapToAdapter(
-        puzzleTable,
-        viewport.rect(),
-        adapter,
-        adapter.getBoundingRect()
-      )
-
-      if (DEBUG) Debug.checkpoint('to_adapter_1')
-
-    } else if (rerenderPlayer) {
-      adapter.clearRect(rectPlayer.get())
-
-      if (DEBUG) Debug.checkpoint('afterclear_2')
-
-      Graphics.mapBitmapToAdapterCapped(
-        puzzleTable,
-        viewport.rect(),
-        adapter,
-        adapter.getBoundingRect(),
-        rectPlayer.get()
-      )
-
-      if (DEBUG) Debug.checkpoint('to_adapter_2')
+    // DRAW PLAYERS
+    // ---------------------------------------------------------------
+    for (let id of Object.keys(players)) {
+      const p = players[id]
+      const cursor = p.down ? cursorGrab : cursorHand
+      const pos = viewport.worldToViewport(p)
+      ctx.drawImage(cursor, pos.x, pos.y)
     }
+    //
+    if (DEBUG) Debug.checkpoint('players done')
 
-    if (rerenderPlayer) {
-      for (let id of Object.keys(players)) {
-        const p = players[id]
-        const cursor = p.down ? cursorGrab : cursorHand
-        const pos = viewport.worldToViewport(p)
-        Graphics.drawBitmap(adapter, cursor, pos)
-      }
 
-      if (DEBUG) Debug.checkpoint('after_players')
-    }
-
-    adapter.apply()
-
-    if (DEBUG) Debug.checkpoint('finals')
+    if (DEBUG) Debug.checkpoint('all done')
 
     rerenderTable = false
     rerenderPlayer = false