<!doctype html>
<script src="code/chapter/19_paint.js"></script>

<div></div>
<script>
  function drawLine(from, to, color) {
    let points = [];
    if (Math.abs(from.x - to.x) > Math.abs(from.y - to.y)) {
      if (from.x > to.x) [from, to] = [to, from];
      let slope = (to.y - from.y) / (to.x - from.x);
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        y += slope;
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  function draw(pos, state, dispatch) {
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    return connect;
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    tools: {draw, line, fill, rectangle, pick}
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