From 5a3346900ef7d54859740caf57678e79f1d6ce7c Mon Sep 17 00:00:00 2001
From: Andinus <andinus@nand.sh>
Date: Tue, 12 Oct 2021 15:00:22 +0530
Subject: Add code for translation

This is much better than what I wrote for scaling.
---
 .../2d-transformations/Translation.svelte          | 122 +++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 src/algorithms/2d-transformations/Translation.svelte

diff --git a/src/algorithms/2d-transformations/Translation.svelte b/src/algorithms/2d-transformations/Translation.svelte
new file mode 100644
index 0000000..9ce71da
--- /dev/null
+++ b/src/algorithms/2d-transformations/Translation.svelte
@@ -0,0 +1,122 @@
+<script>
+  import { onMount } from "svelte";
+  import Plotly from "plotly.js-basic-dist-min";
+
+  let points = [];
+  let newPoint = {x: 0, y: 0};
+
+  let translate = {x: 0, y: 0};
+
+  function addPoint() {
+    // Append to the list.
+    points = [
+      ...points, {
+        x: newPoint.x,
+        y: newPoint.y,
+        id: Date.now(),
+      }
+    ];
+    newPoint = {x: 0, y: 0}
+  }
+
+  function deletePoint(id) {
+    points = points.filter(item => item.id !== Number(id));
+  }
+
+  let pointsArray = {x: [], y: []};
+  let translatedPointsArray = {x: [], y: []};
+
+  function translatePoints() {
+    // Reset values.
+    pointsArray = {x: [], y: []};
+    translatedPointsArray = {x: [], y: []}
+
+    // Store the points in a matrix like array.
+    for (const point of points) {
+      pointsArray.x = [...pointsArray.x, point.x];
+      pointsArray.y = [...pointsArray.y, point.y];
+    }
+
+    // Translate the points.
+    for (const x of pointsArray.x)
+      translatedPointsArray.x.push(x + translate.x);
+
+    for (const y of pointsArray.y)
+      translatedPointsArray.y.push(y + translate.y);
+
+    // Plot graphs.
+    Plotly.newPlot('algoChart', [{
+      x: pointsArray.x,
+      y: pointsArray.y,
+      mode: 'markers',
+      marker: { size: 6 },
+      name: 'Original Points'
+    }, {
+      x: translatedPointsArray.x,
+      y: translatedPointsArray.y,
+      mode: 'markers',
+      marker: { size: 12 },
+      name: 'Translated Points'
+    }]);
+  }
+
+</script>
+
+<h2>Translation</h2>
+
+<form>
+  <input type="number" aria-label="x co-ordinate" placeholder="0"
+         bind:value={newPoint.x}>
+  <input type="number" aria-label="y co-ordinate" placeholder="0"
+         bind:value={newPoint.y}>
+  <button type="button" on:click={addPoint}>Add Point</button>
+</form>
+
+<h4>Translation co-ordinates</h4>
+<form>
+  <input type="number" aria-label="x co-ordinate" placeholder="0"
+         bind:value={translate.x}>
+  <input type="number" aria-label="y co-ordinate" placeholder="0"
+         bind:value={translate.y}>
+</form>
+
+{#if points.length > 0}
+  <button id="translatePoints" type="button"
+          on:click={translatePoints}>Translate Points</button>
+{/if}
+<hr>
+{#if points.length > 0}
+  <h4>Original Points</h4>
+  <table>
+    <thead>
+      <tr>
+        <th style="width: 2em;">Delete</th>
+        <th>x</th>
+        <th>y</th>
+      </tr>
+    </thead>
+    <tbody>
+      {#each points as point (point.id)}
+        <tr>
+          <td>
+            <button type="button"
+                    on:click={deletePoint(point.id)}>&nbsp;X&nbsp;</button>
+          </td>
+          <td>{point.x}</td>
+          <td>{point.y}</td>
+        </tr>
+      {/each}
+    </tbody>
+  </table>
+{/if}
+
+<div id="algoChart"></div>
+
+<style>
+  #translatePoints {
+    margin: .8em;
+    padding: 0.4em 1.2em;
+    width: 100%;
+  }
+  hr { color: var(--bg-hl-alt-intense); }
+</style>
-- 
cgit 1.4.1-2-gfad0