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Tetris
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<canvas id="tetrisCanvas" width="200" height="400"></canvas> | |
<button onclick="moveShape(-1)">Left</button> | |
<button onclick="rotateShape()">Rotate</button> | |
<button onclick="moveShape(1)">Right</button> | |
<button onclick="dropShape()">Drop</button> | |
<script> | |
// remove complete row | |
var canvas = document.getElementById('tetrisCanvas'); | |
var ctx = canvas.getContext('2d'); | |
var shapes = [ | |
[ 0x4640, 0x0E40, 0x4C40, 0x4E00 ], // 'T' | |
[ 0x8C40, 0x6C00, 0x8C40, 0x6C00 ], // 'S' | |
[ 0x4C80, 0xC600, 0x4C80, 0xC600 ], // 'Z' | |
[ 0x4444, 0x0F00, 0x4444, 0x0F00 ], // 'I' | |
[ 0x44C0, 0x8E00, 0xC880, 0xE200 ], // 'J' | |
[ 0x88C0, 0xE800, 0xC440, 0x2E00 ], // 'L' | |
[ 0xCC00, 0xCC00, 0xCC00, 0xCC00 ] // 'O' | |
]; | |
function getNextShape() { | |
curShapeType = Math.floor((Math.random() * 7)); | |
curRotation = 0; | |
return shapes[curShapeType][curRotation] | |
} | |
var ROW_CNT = 20; | |
var COL_CNT = 10; | |
var curShapeType = 0, curRotation = 0, curShape = getNextShape() ; | |
var sPos = {x: (COL_CNT-4) / 2, y:0}; | |
var gamePanel = []; | |
for (var y = 0; y < ROW_CNT; y++) { | |
gamePanel[y] = []; | |
for (var x = 0; x < COL_CNT; x++) { | |
gamePanel[y][x] = 0; | |
} | |
} | |
var intervalHandler = setInterval(playingTetris, 400); | |
function playingTetris() { | |
if ( intersects(sPos.y + 1, sPos.x)) { | |
for (var i = 0; i < 4; i++) | |
for (var j = 0; j < 4; j++) | |
if ((curShape & (0x8000 >> (i * 4 + j))) && gamePanel[sPos.y+i]) { | |
gamePanel[sPos.y+i][sPos.x+j] = curShapeType+1; | |
} | |
curShape = getNextShape(); | |
sPos = {x: (COL_CNT-4) / 2, y:0}; | |
if (intersects(sPos.y, sPos.x)) { | |
clearInterval(intervalHandler); | |
alert("Game Over"); | |
} | |
gamePanel = removeRow(); | |
} else { | |
sPos.y++; | |
} | |
draw(); | |
} | |
function intersects(y, x) { | |
for (var i = 0; i < 4; i++) | |
for (var j = 0; j < 4; j++) | |
if (curShape & (0x8000 >> (i * 4 + j))) | |
if (y+i >= ROW_CNT || x+j < 0 || x+j >= 10 || gamePanel[y+i][x+j]) | |
return true; | |
return false; | |
} | |
function draw() { | |
ctx.fillStyle = 'white'; | |
ctx.fillRect(0, 0, 200, 400); | |
ctx.rect(0, 0, 200, 400); | |
ctx.strokeStyle="blue"; | |
ctx.stroke(); | |
ctx.fillStyle = 'black'; | |
for (var y = 0; y < gamePanel.length; y++) { | |
for (var x = 0; x < gamePanel[y].length; x++) { | |
if (gamePanel[y][x]) { | |
ctx.fillRect(x * 20, y * 20, 19, 19); | |
} | |
} | |
} | |
for (var y = 0; y < 4; y++) { | |
for (var x = 0; x < 4; x++) { | |
if (curShape & (0x8000 >> (y * 4 + x))) { | |
ctx.fillRect((sPos.x+x) * 20, (sPos.y+y) * 20, 19, 19); | |
} | |
} | |
} | |
} | |
function moveShape(value) { | |
if ( !intersects(sPos.y, sPos.x+value)) { | |
sPos.x += value; | |
draw(); | |
} | |
} | |
function dropShape() { | |
for (var y=sPos.y; y<ROW_CNT; y++) { | |
if ( !intersects(sPos.y+1, sPos.x)) { | |
sPos.y++; | |
draw(); | |
} else { | |
break; | |
} | |
} | |
} | |
function rotateShape() { | |
curRotation = (curRotation + 1) % 4;; | |
curShape = shapes[curShapeType][curRotation] | |
draw(); | |
} | |
function removeRow() { | |
var newRows = []; | |
var k = ROW_CNT; | |
for (var y = ROW_CNT-1; y>=0; y--) { | |
for (var x = 0; x < COL_CNT; x++) { | |
if (!gamePanel[y][x]) { | |
newRows[--k] = gamePanel[y].slice(); | |
break; | |
} | |
} | |
} | |
for (var y = 0; y < k; y++) { | |
newRows[y] = []; | |
for (var x = 0; x < COL_CNT; x++) | |
newRows[y][x] = 0; | |
} | |
return newRows; | |
} | |
</script> |
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