| 1 | <!DOCTYPE html> |
| 2 | <html lang="es"> |
| 3 | |
| 4 | <head> |
| 5 | <meta charset="UTF-8"> |
| 6 | <meta name="viewport" |
| 7 | content="width=device-width"> |
| 8 | <title>Mueve con Botones</title> |
| 9 | <style> |
| 10 | .sprite { |
| 11 | position: fixed; |
| 12 | font-size: 3rem; |
| 13 | } |
| 14 | </style> |
| 15 | </head> |
| 16 | |
| 17 | <body> |
| 18 | <h1>Mueve con Botones</h1> |
| 19 | <p> |
| 20 | <button onclick="retrocede()"> |
| 21 | ◀ |
| 22 | </button> |
| 23 | <button onclick="avanza()"> |
| 24 | ▶ |
| 25 | </button> |
| 26 | </p> |
| 27 | <output id="carita" |
| 28 | class="sprite"> |
| 29 | 😄 |
| 30 | </output> |
| 31 | <script> |
| 32 | let yBase |
| 33 | let xMenor |
| 34 | let xMayor |
| 35 | const VELOCIDAD = 30 |
| 36 | actualiza() |
| 37 | let x = xMenor |
| 38 | dibuja() |
| 39 | |
| 40 | function retrocede() { |
| 41 | actualiza() |
| 42 | if (x > xMenor) { |
| 43 | x -= VELOCIDAD |
| 44 | } |
| 45 | dibuja() |
| 46 | } |
| 47 | |
| 48 | function avanza() { |
| 49 | actualiza() |
| 50 | if (x < xMayor) { |
| 51 | x += VELOCIDAD |
| 52 | } |
| 53 | dibuja() |
| 54 | } |
| 55 | |
| 56 | function actualiza() { |
| 57 | yBase = innerHeight / 2 |
| 58 | xMenor = innerWidth / 5 |
| 59 | xMayor = 4 * innerWidth / 5 |
| 60 | } |
| 61 | |
| 62 | function dibuja() { |
| 63 | carita.style = `left: ${x}px; |
| 64 | bottom: ${yBase}px` |
| 65 | } |
| 66 | </script> |
| 67 | </body> |
| 68 | |
| 69 | </html> |