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HTML

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CSS

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CSS Base

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HTML
!

CSS 

              
                body {
  margin: 0;
  position: absolute;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
  background-color: #eee;
}

.block {
  box-sizing: border-box;
  position: absolute;
  transform: scale(0.85);
  border-radius: 6px;
}

.block--test {
  background-color: rgba(152, 152, 152, 0.514);
}

.block--block {
  animation-name: drop;
  animation-timing-function: linear;
  animation-iteration-count: 1;
  background: linear-gradient(#E6DADA, #FFB88C, #FFAFBD, #606c88);
  background-size: 100vw 100vh;
  background-position: 0 0;
  background-attachment: fixed;
}

.block--invalid {
  background-color:  #e538357e;
}

@keyframes drop {
  from {
    transform: translateY(-100vh) scale(0.85);
  }
  to {
    transform: translateY(0) scale(0.85);
  }
}
!

JS 

              
                const blockSize = 35
const stepSpeed = 110
const fallSpeed = 1500
const container = document.body

const viewWidth = window.innerWidth
const viewHeight = window.innerHeight

const xBlockCount = Math.ceil(viewWidth / blockSize)
const yBlockCount = Math.ceil(viewHeight / blockSize)
let currentYIndex = 0

const STATES = {
  EMPTY: 'empty',
  TEST: 'test',
  INVALID: 'invalid',
  BLOCK: 'block',
  DONE: 'done',
}

const SHAPES = [
  V_LINE,
  H_LINE,
  BOX,
  DOT,
  L_SHAPE_1,
  L_SHAPE_2,
  L_SHAPE_3,
  L_SHAPE_4,
  L_SHAPE_5,
  L_SHAPE_6,
  L_SHAPE_7,
  L_SHAPE_8,
  Z_SHAPE_1,
  Z_SHAPE_2,
  Z_SHAPE_3,
  Z_SHAPE_4,
  T_SHAPE_1,
  T_SHAPE_2,
  T_SHAPE_3,
  T_SHAPE_4,
]

let grid = Array.from({ length: yBlockCount }, () => {
  return Array.from({ length: xBlockCount}, () => {
    return STATES.EMPTY
  })
})

addPiece()

async function addPiece() {
  [x, y] = getCoordinates()
  await testShapes(x, y)
  let lastLineHasEmptyBlocks = currentYIndex < (yBlockCount - 1) || grid[yBlockCount - 1].some(x => x === STATES.EMPTY)

  if (lastLineHasEmptyBlocks) {
    addPiece()
  }
}

function getCoordinates() {
  const lineIsFull = !grid[currentYIndex].some(state => state === STATES.EMPTY)
  const lastLine = currentYIndex === (yBlockCount - 1)

  if (lineIsFull && !lastLine) {
    currentYIndex++
  }

  let randomX = Math.floor(Math.random() * xBlockCount)

  while (grid[currentYIndex][randomX] !== STATES.EMPTY) {
    // randomX = Math.floor(Math.random() * xBlockCount)
    if (randomX === (xBlockCount - 1)) {
      randomX = 0
    } else {
      randomX++
    }
  }
  
  return [randomX, currentYIndex]
}

async function testShapes(x, y) {
  const shapeFunction = getRandomShapeFunction()
  const shapeCoords = shapeFunction(x, y)
  if (invalidShapeCoords(shapeCoords)) {
    return
  }
  const previousShapeCoordsStates = []
  let invalid = false

  shapeCoords.forEach(([x, y]) => {
    if (!grid[y] || !grid[y][x]) {
      invalid = true
    }
    previousShapeCoordsStates.push(grid[y][x])
    grid[y][x] = STATES.TEST
  })

  await draw(stepSpeed)

  if (invalid || invalidPoints(shapeCoords, previousShapeCoordsStates)) {
    setPoints(shapeCoords, STATES.INVALID)

    await draw(stepSpeed)

    shapeCoords.forEach(([x, y], index) => {
      if (grid[y] && grid[y][x]) {
        grid[y][x] = previousShapeCoordsStates[index]
      }
    })

    await draw(stepSpeed)
  } else {
    setPoints(shapeCoords, STATES.BLOCK)

    await draw(fallSpeed)
  }
}

function invalidShapeCoords(shapeCoords) {
  return shapeCoords.some(([x, y]) => {
    if (!grid[y] || !grid[y][x]) {
      return true
    }
  })
}

function createBlock(type, x, y) {
  const blockElement = document.createElement('div')
  blockElement.classList.add('block', `block--${type}`)
  blockElement.style.height = blockElement.style.width = `${blockSize}px`
  blockElement.style.bottom = `${y * blockSize}px`
  blockElement.style.left = `${x * blockSize}px`
  if (type === STATES.BLOCK) {
    blockElement.style.animationDuration = `${fallSpeed}ms`
  }
  container.appendChild(blockElement)
  return blockElement
}

function hasAccessibleX(y) {
  return grid[y].some((state, x) => {
    let accessible = true
    if (state !== STATES.EMPTY) {
      accessible = false
    }
    
    grid.forEach((row, index) => {
      if (index > y && row[x] !== STATES.EMPTY) {
        accessible = false
      }
    })

    return accessible
  })
}

function invalidPoints(shapeCoords, previousShapeCoordsStates) {
  let invalid = false
  if (previousShapeCoordsStates.some(point => point !== STATES.EMPTY)) {
    invalid = true
  }

  let checkedXPoints = []

  const bottomPoints = shapeCoords.filter(([x, y]) => {
    let bottom = true
    shapeCoords.forEach(([xCompare, yCompare]) => {
      if (x === xCompare && y > yCompare) {
        bottom = false
      }
    })

    return bottom
  })

  bottomPoints.find(([x, y]) => {
    if (checkedXPoints.includes(x)) {
      return
    }

    for (let i = (y - 1); i >= 0;i--) {
      if (grid[i] && grid[i][x] === STATES.EMPTY) {
        invalid = true
        break
      }
    }
    checkedXPoints.push(x)
  })

  return invalid
}

function getRandomShapeFunction() {
  const index = Math.floor(Math.random() * SHAPES.length)
  return SHAPES[index]
}

function setPoints(points, state) {
  points.forEach(([x, y]) => {
    if (grid[y] && grid[y][x]) {
      grid[y][x] = state
    }
  })
}

async function draw(showFor) {
  Array.from(container.children).forEach(child => {
    if (child.classList.contains(`block--${STATES.INVALID}`) || child.classList.contains(`block--${STATES.TEST}`)) {
      child.remove()
    }
  })

  const tempBlocks = []
  grid = grid.map((y, yIndex) => {
    return y.map((x, xIndex) => {
      if (![STATES.EMPTY, STATES.DONE].includes(x)) {
        createBlock(x, xIndex, yIndex)

        if (x === STATES.BLOCK) {
          tempBlocks.push(createBlock(STATES.TEST, xIndex, yIndex))
        }
      }

      if (x === STATES.BLOCK) {
        return STATES.DONE
      } else {
        return x
      }
    })
  })

  if (showFor) {
    await sleep(showFor)
  }

  tempBlocks.forEach(block => block.remove())
}

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

/*
  1
  2
  3
  4
*/
function V_LINE(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x, y + 2],
    [x, y + 3],
  ]
}

/*
  1 2 3 4
*/
function H_LINE(x, y) {
  return [
    [x, y],
    [x + 1, y],
    [x + 2, y],
    [x + 3, y],
  ]
}

/*
  1 2
  3 4
*/
function BOX(x, y) {
  return [
    [x, y],
    [x + 1, y],
    [x, y + 1],
    [x + 1, y + 1],
  ]
}

/*
  1
*/
function DOT(x, y) {
  return [
    [x, y]
  ]
}

/*
  1
  2
  3 4
*/
function L_SHAPE_1(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x, y + 2],
    [x + 1, y + 2],
  ]
}

/*
      1
  4 3 2
*/
function L_SHAPE_2(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x - 1, y + 1],
    [x - 2, y + 1],
  ]
}

/*
  1 2
    3
    4
*/
function L_SHAPE_3(x, y) {
  return [
    [x, y],
    [x + 1, y],
    [x + 1, y + 1],
    [x + 1, y + 2]
  ]
}

/*
  3 2 1
  4
*/
function L_SHAPE_4(x, y) {
  return [
    [x, y],
    [x - 1, y],
    [x - 2, y],
    [x - 2, y + 1]
  ]
}

/*
    1
    2
  4 3
*/
function L_SHAPE_5(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x, y + 2],
    [x - 1, y + 2]
  ]
}

/*
  1
  2 3 4
*/
function L_SHAPE_6(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x + 1, y + 1],
    [x + 2, y + 1]
  ]
}

/*
  2 1
  3
  4
*/
function L_SHAPE_7(x, y) {
  return [
    [x, y],
    [x - 1, y],
    [x - 1, y + 1],
    [x - 1, y + 2]
  ]
}

/*
  1 2 3
      4
*/
function L_SHAPE_8(x, y) {
  return [
    [x, y],
    [x + 1, y],
    [x + 2, y],
    [x + 2, y + 1]
  ]
}

/*
  1 2
    3 4
*/
function Z_SHAPE_1(x, y) {
  return [
    [x, y],
    [x + 1, y],
    [x + 1, y + 1],
    [x + 2, y + 1]
  ]
}

/*
  1 
  2 3
    4
*/
function Z_SHAPE_2(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x + 1, y + 1],
    [x + 1, y + 2]
  ]
}

/*
    2 1
  4 3
*/
function Z_SHAPE_3(x, y) {
  return [
    [x, y],
    [x - 1, y],
    [x - 1, y + 1],
    [x - 2, y + 1]
  ]
}

/*
    1
  3 2
  4
*/
function Z_SHAPE_4(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x - 1, y + 1],
    [x - 1, y + 2]
  ]
}

/*
    1
  2 3 4
*/
function T_SHAPE_1(x, y) {
  return [
    [x, y],
    [x - 1, y + 1],
    [x, y + 1],
    [x + 1, y + 1]
  ]
}

/*
    1
  3 2
    4
*/
function T_SHAPE_2(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x - 1, y + 1],
    [x, y + 2]
  ]
}

/*
  1 2 3
    4
*/
function T_SHAPE_3(x, y) {
  return [
    [x, y],
    [x + 1, y],
    [x + 2, y],
    [x + 1, y + 1]
  ]
}

/*
  1
  2 3
  4
*/
function T_SHAPE_4(x, y) {
  return [
    [x, y],
    [x, y + 1],
    [x + 1, y + 1],
    [x, y + 2]
  ]
}
!
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