Workshop › Tetris-style Blocks › Step 3 of 32

Draw one cell

What we are doing

drawCell(col, row, color) paints the cell at a column and row. It is drawn one pixel smaller on every side, so stacked blocks show a thin dark line between them. We try it on the bottom-left cell.

```js
function drawCell(col, row, color) {
  ctx.fillStyle = color
  ctx.fillRect(col * CELL + 1, row * CELL + 1, CELL - 2, CELL - 2)
}

drawCell(0, 19, '#94a3b8')
```

What it means

• The three parameters are the column, the row and the color.
• col * CELL + 1 is 1 pixel right of the cell's left edge; CELL - 2 is 22, so there is a 1-pixel gap on each side.
• The last line is a test call: column 0, row 19, grey.

Your turn

1. Under the let board line write drawCell.
2. At the very end, leave an empty line and write the test call.

Skills: Drawing on a canvas, Functions

← The board as rows of numbers Draw the whole board →

All steps

1. The well
2. The board as rows of numbers
3. Draw one cell
4. Draw the whole board
5. The number is the color
6. A piece is a small grid
7. A list of shapes
8. All seven pieces
9. Does it fit inside the well?
10. Blocks are in the way
11. Try, then move
12. Move with the arrows
13. Turn a matrix
14. Turn with Up
15. Wall kicks
16. Falling by itself
17. A random piece at the top
18. Land and lock
19. One function starts a game
20. When the pile reaches the top
21. Game Over on screen
22. Play again
23. Clear full rows
24. Points for lines
25. The side panel
26. Levels
27. Faster every level
28. A fair bag of pieces
29. The next piece
30. Drop it
31. The ghost piece
32. Build it yourself: hold a piece