Difference between revisions of "Flags with Polygons"

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Line 1: Line 1:
<pre id='shellbody'>
<pre id='shellbody' data-qtp='canvas'></pre>
<div style='background:silver;padding:5px'>
You can dive into the code, or you can watch these worked examples [[Flags of Russia]]
<canvas id='usr' width=--snippet-w-- height=--snippet-h--></canvas>
<canvas id='ans' width=--snippet-w-- height=--snippet-h-- style='display:none'></canvas>
</div>
</pre>
 
<pre id='shelljs'>
--snippet-usr--
drawFlag(document.getElementById('usr').getContext('2d'));
(()=>{
  --snippet-ans--
  drawFlag(document.getElementById('ans').getContext('2d'));
})();
let [a,b] = ['usr','ans']
    .map(id=>document.getElementById(id))
    .map(elem=>elem.getContext('2d').getImageData(0,0,elem.width,elem.height))
let diff = a.data.map((v,i) => v===b.data[i]?1:0).reduce((acc,v)=>acc+v,0)*100/a.data.length;
let fb = document.createElement('div');
fb.innerText = `Score: ${diff.toFixed(1)}`;
document.body.appendChild(fb);
fetch(`/reportProgress.php?uid=--snippet-uid--&qid=--snippet-qid--&score=${diff}`);
</pre>
==Napier==
==Napier==
<div class=qu data-height="150" data-width="150">
<div class=qu data-height="150" data-width="150">
[[Image:flagnapier.png]]
[[Image:flagnapier.png|left|frame|Napier University]]
 
<pre class=usr>
<pre class=usr>
function drawFlag(ctx)
function drawFlag(ctx)
Line 47: Line 27:
   ctx.fillStyle = "red";
   ctx.fillStyle = "red";
   ctx.fill();
   ctx.fill();
}
</pre>
</div>
==The Czech Republic==
<div class=qu data-width="300" data-height="200">
* 300 by 200
* The point of intersection is the centre of the rectangle
[[Image:flagczech.png|left|frame|Flag of Czech Republic]]
<pre class=usr>
function drawFlag(ctx)
{
}
</pre>
<pre class=ans>
function drawFlag(ctx)
{
  ctx.fillStyle = 'blue';
  ctx.moveTo(0,0);
  ctx.lineTo(150,100);
  ctx.lineTo(0,200);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'white';
  ctx.moveTo(0,0);
  ctx.lineTo(150,100);
  ctx.lineTo(300,100);
  ctx.lineTo(300,0);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'red';
  ctx.moveTo(0,200);
  ctx.lineTo(150,100);
  ctx.lineTo(300,100);
  ctx.lineTo(300,200);
  ctx.fill(); 
}
}
</pre>
</pre>
Line 53: Line 70:
==The Bahamas==
==The Bahamas==
<div class=qu data-height="150" data-width="300" data-cols='40'>
<div class=qu data-height="150" data-width="300" data-cols='40'>
[[Image:flagbahamas.png]]
[[Image:flagbahamas.png|left|frame|Flag Bahamas]]
 
<pre class=usr>
<pre class=usr>
function drawFlag(ctx)
function drawFlag(ctx)
Line 78: Line 96:
<div class=qu data-width="300" data-height="150">
<div class=qu data-width="300" data-height="150">


[[Image:flagjamaica.png|border]]
[[Image:flagjamaica.png|left|frame|Flag of Jamaica]]


<pre class=usr>
<pre class=usr>
Line 117: Line 135:
==Seychelles==
==Seychelles==
<div class=qu data-height="150" data-width="300">
<div class=qu data-height="150" data-width="300">
[[Image:flagseychelles.png]]
[[Image:flagseychelles.png|left|frame|Flag of Seychelles]]


<pre class=usr>
<pre class=usr>

Latest revision as of 15:06, 20 August 2021


You can dive into the code, or you can watch these worked examples Flags of Russia

Napier

Napier University
function drawFlag(ctx)
{
  ctx.fillStyle = 'white';
  ctx.fillRect(0,0,150,150);
  ctx.fillStyle = 'red';
  ctx.moveTo(0,0);
  ctx.lineTo(150,0);
  ctx.lineTo(150,150);
  ctx.fill();
}
function drawFlag(ctx)
{
  ctx.fillStyle = 'white';
  ctx.fillRect(0,0,150,150);
  ctx.moveTo(0,0);
  ctx.lineTo(150,150);
  ctx.lineTo(0,150);
  ctx.fillStyle = "red";
  ctx.fill();
}

The Czech Republic

  • 300 by 200
  • The point of intersection is the centre of the rectangle
Flag of Czech Republic
function drawFlag(ctx)
{
}
function drawFlag(ctx)
{
  ctx.fillStyle = 'blue';
  ctx.moveTo(0,0);
  ctx.lineTo(150,100);
  ctx.lineTo(0,200);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'white';
  ctx.moveTo(0,0);
  ctx.lineTo(150,100);
  ctx.lineTo(300,100);
  ctx.lineTo(300,0);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'red';
  ctx.moveTo(0,200);
  ctx.lineTo(150,100);
  ctx.lineTo(300,100);
  ctx.lineTo(300,200);
  ctx.fill();  
}

The Bahamas

Flag Bahamas
function drawFlag(ctx)
{
}
function drawFlag(ctx)
{
  ctx.fillStyle = 'rgb(127,192,255)';
  ctx.fillRect(0,0,300,150);
  ctx.fillStyle = 'rgb(255,255,0)';
  ctx.fillRect(0,50,300,50);
  ctx.fillStyle = 'black';
  ctx.moveTo(0,0);
  ctx.lineTo(112,75);
  ctx.lineTo(0,150);
  ctx.fill();
}

Jamaica

Flag of Jamaica
function drawFlag(ctx)
{
  ctx.fillStyle = 'yellow';
  ctx.fillRect(0,0,300,150);
}
function drawFlag(ctx)
{
  ctx.fillStyle = 'yellow';
  ctx.fillRect(0,0,300,150);
  ctx.fillStyle = 'green';
  ctx.moveTo(30,0);
  ctx.lineTo(150,60);
  ctx.lineTo(270,0);
  ctx.fill();
  ctx.moveTo(30,150);
  ctx.lineTo(150,90);
  ctx.lineTo(270,150);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'black';
  ctx.moveTo(0,15);
  ctx.lineTo(120,75);
  ctx.lineTo(0,135);
  ctx.fill();
  ctx.moveTo(300,15);
  ctx.lineTo(180,75);
  ctx.lineTo(300,135);
  ctx.fill();
}

Seychelles

Flag of Seychelles
function drawFlag(ctx)
{
}
function drawFlag(ctx)
{
  ctx.fillStyle = 'blue';
  ctx.moveTo(0,150);
  ctx.lineTo(0,0);
  ctx.lineTo(100,0);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'yellow';
  ctx.moveTo(0,150);
  ctx.lineTo(100,0);
  ctx.lineTo(200,0);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'red';
  ctx.moveTo(0,150);
  ctx.lineTo(200,0);
  ctx.lineTo(300,0);
  ctx.lineTo(300,50);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'white';
  ctx.moveTo(0,150);
  ctx.lineTo(300,50);
  ctx.lineTo(300,100);
  ctx.fill();
  ctx.beginPath();
  ctx.fillStyle = 'green';
  ctx.moveTo(0,150);
  ctx.lineTo(300,150);
  ctx.lineTo(300,100);
  ctx.fill();
}