Workshop › Klondike Solitaire › Step 1 of 40

Klondike Solitaire: The green table

The classic card game, built from piles. Thirteen piles in one object, overlapping columns, the rules as pure functions, tap to move, drag and drop with a grab offset, a win check after every move, and undo with a stack of snapshots.

What we are doing

Every card game needs a table. We find the canvas, take its 2D context (the pen), and start a loop that paints the whole canvas green about 60 times a second.

```js
const canvas = document.getElementById('game')
const ctx = canvas.getContext('2d')

function draw() {
  ctx.fillStyle = '#166534'
  ctx.fillRect(0, 0, canvas.width, canvas.height)
}

function loop() {
  draw()
  requestAnimationFrame(loop)
}

requestAnimationFrame(loop)
```

What it means

• getElementById('game') finds the 480×560 canvas; getContext('2d') gives the pen, ctx.
• draw fills a rectangle as big as the canvas with dark green, starting at the top-left corner (0, 0).
• loop draws and books itself for the next screen refresh with requestAnimationFrame; the last line starts it.

Your turn

Write the code under the three comment lines, then press Run.

Skills: Drawing on a canvas, The game loop

Draw one card →

All steps

1. The green table
2. Draw one card
3. The face of a card
4. Red and black
5. A deck of 52
6. Shuffle
7. Piles in one object
8. Deal the seven columns
9. A place for every pile
10. Put the piles on the table
11. Fan out the columns
12. Outlines for empty places
13. Turn over a card
14. Space turns a card
15. Go through the stock again
16. What is under the pointer?
17. Hitting a card in a column
18. Tap the stock
19. Rule 1: building a column
20. Rule 2: building a foundation
21. Move cards by the rules
22. Turn over the uncovered card
23. Find where a card goes
24. Pick up a card
25. Tap to move
26. A move counter
27. Count the moves
28. Where did you grab it?
29. Follow the pointer
30. Draw the held cards at the pointer
31. Drop it where you want
32. Drop a king into an empty column
33. A clock
34. Winning
35. You won!
36. A new game
37. The best time
38. Snapshots of the table
39. Undo
40. Build it yourself: finish by itself