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tomshanley

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matrix inside circle

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forked from tomshanley's block: matrix inside circle

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { 
      margin: 50;
    }
    circle {
      fill: none;
      stroke: black;
			stroke-width: 2px;
   	}
    rect {
      stroke: black;
			stroke-width: 1px;
   	}
  </style>
</head>

<body>
  
  <div id="chart"></div>
  <div id="count"></div>
  
  <script>
    
    console.clear()
    
    let radius = 200
    let diameter = radius * 2
    let margin = 20
    let squareWidth = 30
    let n = Math.floor(diameter / squareWidth)
    let offset = (diameter - (n * squareWidth)) / 2
    let width = diameter
    let height = width
    let numberOfSquaresInsideCircle = 0
    
    // let percent = 40

let svg = d3.select("#chart").append("svg")
    	.attr("width", width + (margin * 2))
    	.attr("height", height + (margin * 2))
    
    let g = svg.append("g")
    	.attr("transform", "translate(" + margin + ", " + margin + ")")
    
     let circle = g.append("circle")
    	.attr("cx", radius)
    	.attr("cy", radius)
    	.attr("r", radius)
    	.style("fill", "grey")
    
    for (var i = 0; i < n; i++) {
      for (var j = 0; j < n; j++) {
        
        let x = (j * squareWidth) + offset
        let y = (i * squareWidth) + offset
                
        if(isSquareOutsideCircle(x, y, squareWidth, radius)) {
          
        } else {
          numberOfSquaresInsideCircle = numberOfSquaresInsideCircle + 1
          g.append("rect")
            .attr("x", x)
            .attr("y", y)
            .attr("width", squareWidth)
            .attr("height", squareWidth)
            .style("fill", "white")
            .attr("id", "cell-" + i + "-" + j)
        }
        
    	}
    }
    
    /*let squares = d3.selectAll("rect")
    	.style("fill", function(d, i){
        return ((numberOfSquaresInsideCircle - i)/numberOfSquaresInsideCircle) * 100 < percent
        ? "orange"
        : "white"
      })*/
     
    d3.select("#count")
    	.text(numberOfSquaresInsideCircle)
     
    function isSquareOutsideCircle(squareX, squareY, squareW, circleR) {
      
      	if (isPointOutsideCircle(squareX, squareY, circleR)) {
          return true
        } else if (isPointOutsideCircle((squareX + squareW), squareY, circleR)) {
          return true
        } else if (isPointOutsideCircle(squareX, (squareY + squareW), circleR)) {
          return true
        } else if (isPointOutsideCircle((squareX + squareW), (squareY + squareW), circleR)) {
          return true
        } else {
          return false
        }
      
    }
    
    function isPointOutsideCircle(x, y, r) {
      return hypothenuese(Math.abs(r - x), Math.abs(r - y))	> r ? true : false
    }
    
    function hypothenuese(side1, side2) {
      return Math.sqrt((side1 * side1) + (side2 * side2))
    }

</script>
</body>

https://d3js.org/d3.v4.min.js