block by nitaku 8905722

Coloring of three intersecting regions

Full Screen

Same as this example, but supporting the intersection of three regions. The code could be easily generalized to more regions.

index.js


/* get a D3 reference of the SVG
*/

(function() {
  var A, B, C, c, defs, hatches, new_patterns, svg, vis;

  svg = d3.select('svg');

  vis = svg.append('g').attr('transform', 'translate(350,45) scale(0.8)');

  /* define three colors
  */

  c = 40;

  A = d3.hcl(60, c, 80);

  B = d3.hcl(180, c, 70);

  C = d3.hcl(300, c, 60);

  /* create hatch patterns
  */

  hatches = [
    {
      size: 40,
      c: [A, B],
      id: 'AB'
    }, {
      size: 40,
      c: [B, C],
      id: 'BC'
    }, {
      size: 40,
      c: [A, C],
      id: 'AC'
    }, {
      size: 60,
      c: [A, B, C],
      id: 'ABC'
    }
  ];

  defs = svg.append('defs');

  new_patterns = defs.selectAll('.hatch').data(hatches).enter().append('pattern').attr('class', 'hatch').attr('id', function(d) {
    return d.id;
  }).attr('patternUnits', 'userSpaceOnUse').attr('width', function(d) {
    return d.size;
  }).attr('height', function(d) {
    return d.size;
  });

  new_patterns.append('rect').attr('x', 0).attr('y', 0).attr('width', function(d) {
    return d.size;
  }).attr('height', function(d) {
    return d.size;
  }).attr('fill', function(d) {
    return d.c[0];
  });

  new_patterns.append('path').attr('d', function(d) {
    return "M0 0 L" + (d.size / d.c.length) + " 0 L0 " + (d.size / d.c.length) + " z\nM" + d.size + " 0 L" + d.size + " " + (d.size / d.c.length) + " L" + (d.size / d.c.length) + " " + d.size + " L0 " + d.size + " z";
  }).attr('fill', function(d) {
    return d.c[1];
  });

  new_patterns.filter(function(d) {
    return d.c.length === 3;
  }).append('path').attr('d', function(d) {
    return "M" + (d.size / 3) + " 0 L" + (2 * d.size / 3) + " 0 L0 " + (2 * d.size / 3) + " L0 " + (d.size / 3) + " z\nM" + d.size + " " + (d.size / 3) + " L" + d.size + " " + (2 * d.size / 3) + " L" + (2 * d.size / 3) + " " + d.size + " L" + (d.size / 3) + " " + d.size + " z";
  }).attr('fill', function(d) {
    return d.c[2];
  });

  /* create a fake intersection of two squares
  */

  vis.append('path').attr('d', 'M0 0 l300 0 l0 100 l-200 0 l0 100 l-100 0 z').attr('fill', A);

  vis.append('path').attr('d', 'M300 100 l100 0 l0 300 l-200 0 l0 -100 l100 0 z').attr('fill', B);

  vis.append('path').attr('d', 'M-100 200 l100 0 l0 100 l100 0 l0 100 l100 0 l0 100 l-300 0 z').attr('fill', C);

  vis.append('path').attr('d', 'M100 100 l200 0 l0 200 l-100 0 l0 -100 l-100 0 z').attr('fill', 'url(#AB)');

  vis.append('rect').attr('x', 0).attr('y', 200).attr('width', 100).attr('height', 100).attr('fill', 'url(#AC)');

  vis.append('rect').attr('x', 100).attr('y', 200).attr('width', 100).attr('height', 100).attr('fill', 'url(#ABC)');

  vis.append('rect').attr('x', 100).attr('y', 300).attr('width', 100).attr('height', 100).attr('fill', 'url(#BC)');

}).call(this);

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="description" content="Coloring of intersecting regions"/>
    <title>Coloring of intersecting regions</title>
    <script src="//d3js.org/d3.v3.min.js"></script>
  </head>
  <body>
    <svg width="960" height="500">
    </svg>
  <script src="index.js"></script>
</html>

index.coffee

### get a D3 reference of the SVG ###
svg = d3.select('svg')
vis = svg.append('g')
    .attr('transform', 'translate(350,45) scale(0.8)')

### define three colors ###
c = 40
A = d3.hcl(60,c,80)
B = d3.hcl(180,c,70)
C = d3.hcl(300,c,60)

### create hatch patterns ###
hatches = [
    {size:40,c:[A,B],id:'AB'},
    {size:40,c:[B,C],id:'BC'},
    {size:40,c:[A,C],id:'AC'},
    {size:60,c:[A,B,C],id:'ABC'}
]

defs = svg.append('defs')

new_patterns = defs.selectAll('.hatch')
    .data(hatches)
  .enter().append('pattern')
    .attr('class', 'hatch')
    .attr('id', (d)->d.id)
    .attr('patternUnits', 'userSpaceOnUse')
    .attr('width', (d)->d.size)
    .attr('height', (d)->d.size)
    
new_patterns.append('rect')
    .attr('x',0)
    .attr('y',0)
    .attr('width', (d)->d.size)
    .attr('height', (d)->d.size)
    .attr('fill', (d)->d.c[0])
    
new_patterns.append('path')
    .attr('d', (d) -> """
        M0 0 L#{d.size/d.c.length} 0 L0 #{d.size/d.c.length} z
        M#{d.size} 0 L#{d.size} #{d.size/d.c.length} L#{d.size/d.c.length} #{d.size} L0 #{d.size} z
     """)
     .attr('fill', (d)->d.c[1])
    
new_patterns.filter((d)->d.c.length is 3).append('path')
    .attr('d', (d) -> """
        M#{d.size/3} 0 L#{2*d.size/3} 0 L0 #{2*d.size/3} L0 #{d.size/3} z
        M#{d.size} #{d.size/3} L#{d.size} #{2*d.size/3} L#{2*d.size/3} #{d.size} L#{d.size/3} #{d.size} z
     """)
     .attr('fill', (d)->d.c[2])
    
### create a fake intersection of two squares ###
vis.append('path')
    .attr('d', 'M0 0 l300 0 l0 100 l-200 0 l0 100 l-100 0 z')
    .attr('fill', A)
     
vis.append('path')
    .attr('d', 'M300 100 l100 0 l0 300 l-200 0 l0 -100 l100 0 z')
    .attr('fill', B)
    
vis.append('path')
    .attr('d', 'M-100 200 l100 0 l0 100 l100 0 l0 100 l100 0 l0 100 l-300 0 z')
    .attr('fill', C)
    
vis.append('path')
    .attr('d', 'M100 100 l200 0 l0 200 l-100 0 l0 -100 l-100 0 z')
    .attr('fill', 'url(#AB)')
    
vis.append('rect')
    .attr('x', 0)
    .attr('y', 200)
    .attr('width', 100)
    .attr('height', 100)
    .attr('fill', 'url(#AC)')
    
vis.append('rect')
    .attr('x', 100)
    .attr('y', 200)
    .attr('width', 100)
    .attr('height', 100)
    .attr('fill', 'url(#ABC)')
    
vis.append('rect')
    .attr('x', 100)
    .attr('y', 300)
    .attr('width', 100)
    .attr('height', 100)
    .attr('fill', 'url(#BC)')