Workshop › Connect Four › Step 4 of 38

One hole

What we are doing

Holes and discs are both circles, only in different colors. One small function, disc(x, y, color), will draw them all. We try it on the top-left hole.

```js
function disc(x, y, color) {
  ctx.fillStyle = color
  ctx.beginPath()
  ctx.arc(x, y, CELL / 2 - 6, 0, Math.PI * 2)
  ctx.fill()
}

  disc(CELL / 2, TOP + CELL / 2, '#0f172a')
```

What it means

• x, y and color are parameters: the values given in the call.
• beginPath starts a shape, arc(x, y, radius, start, end) adds a circle around (x, y), from angle 0 to a full turn (Math.PI * 2), and fill paints it. The radius is 26, leaving a gap between holes.
• The call draws the hole in the middle of the top-left cell: (32, 128).

Your turn

1. Above function draw() { write disc, followed by an empty line.
2. In draw, under the blue rectangle, write the disc(...) call.

Skills: Drawing on a canvas, Functions

← The blue board A whole row →

All steps

1. A dark background
2. A drawing function
3. The blue board
4. One hole
5. A whole row
6. All 42 holes
7. The board in memory
8. Discs in their colors
9. Draw every frame
10. Where does the disc land?
11. Play a column
12. Taking turns
13. Click to play
14. The next disc
15. Whose turn?
16. Playing with the keyboard
17. Keys 1 to 7
18. A disc on its way
19. Gravity
20. Watch it fall
21. Inside the board?
22. Walking along a line
23. Four in a row?
24. We have a winner
25. Circle the four
26. Who won?
27. A draw
28. Play again
29. Try a move and take it back
30. Win, or block
31. Don't help the player
32. Prefer the middle
33. The computer's turn
34. Only on your turn
35. You and the computer
36. Counting wins
37. Show the score
38. Build it yourself: the loser starts