Fix for gifs that require datum to be u64

Also added visual preview file for testing

Author: Chi-EEE

.gitignore

@@ -1,4 +1,6 @@
 
+__visual_preview__/
+
 # Created by https://www.toptal.com/developers/gitignore/api/node
 # Edit at https://www.toptal.com/developers/gitignore?templates=node
 

__test__/index.spec.ts

@@ -40,6 +40,9 @@ test('Correct Frame Count', (t) => {
 
   gif = Decoder.decode('./gifs/BBoomer.gif') // Interlace Gif
   t.is(gif.frames.length, 13)
+
+  gif = Decoder.decode('./gifs/YESITHINKSO.gif') // 64 bit datum gif
+  t.is(gif.frames.length, 162)
 })
 
 test('Decoding Individual Frames', (t) => {
@@ -67,11 +70,14 @@ test('Decoding Individual Frames', (t) => {
   gif = Decoder.decode('./gifs/forsenEnter.gif')
   t.is(gif.decodeFrame(gif.frames[33]).length, 3136)
 
-  gif = Decoder.decode('./gifs/shadowchanHeart.0')
+  gif = Decoder.decode('./gifs/shadowchanHeart.0') // 0 file gif
   t.is(gif.decodeFrame(gif.frames[0]).length, 3136)
 
   gif = Decoder.decode('./gifs/BBoomer.gif') // Interlace Gif
   t.is(gif.decodeFrame(gif.frames[0]).length, 3136)
+
+  gif = Decoder.decode('./gifs/YESITHINKSO.gif') // 64 bit datum gif
+  t.is(gif.decodeFrame(gif.frames[0]).length, 3136)
 })
 
 test('sample_2_animation.gif: Frame 3: Top is 2', (t) => {

__test__/visual_preview.js

@@ -0,0 +1,25 @@
+const { Decoder } = require('../index');
+const { writeFileSync, existsSync, mkdirSync } = require('fs');
+const { createCanvas } = require('@napi-rs/canvas');
+const previewDirectory = './__visual_preview__'
+
+// Create preview
+if (!existsSync(previewDirectory)) {
+    mkdirSync(previewDirectory);
+}
+
+const gif = Decoder.decode('./gifs/YESITHINKSO.gif')
+let buffers = gif.decodeFrames()
+
+const canvas = createCanvas(gif.lsd.width, gif.lsd.height)
+const ctx = canvas.getContext("2d");
+
+for (let i = 1; i <= buffers.length; i++) {
+    const frame = gif.frames[i]
+    const buffer = buffers[i]
+    const image = ctx.createImageData(frame.im.width, frame.im.height)
+    image.data.set(buffer)
+    ctx.putImageData(image, frame.im.left, frame.im.top)
+    const canvasBuffer = canvas.toBuffer('image/png')
+    writeFileSync(`${previewDirectory}/${i}.png`, canvasBuffer)
+}

gifs/YESITHINKSO.gif

@@ -39,14 +39,14 @@ export class Gif {
   globalTable: Array<Color>
   frames: Array<Frame>
   /**
-  * This function goes through every index stream of the frames and makes a vector of buffers from them.
-  */
+   * This function goes through every index stream of the frames and makes a vector of buffers from them.
+   */
   decodeFrames(): Array<Buffer>
   /**
-  * This function individually decodes the frame inputted into the function
-  *
-  * Source: https://gist.github.com/devunwired/4479231#file-gifdecoder-java-L359
-  */
+   * This function individually decodes the frame inputted into the function
+   *
+   * Source: https://gist.github.com/devunwired/4479231#file-gifdecoder-java-L359
+   */
   decodeFrame(frame: Frame): Buffer
 }
 export class Frame {

index.d.ts

@@ -69,6 +69,7 @@
     "@napi-rs/package-template": "^1.0.0"
   },
   "devDependencies": {
+    "@napi-rs/canvas": "^0.1.28",
     "@napi-rs/cli": "^2.9.0",
     "@swc-node/register": "^1.5.1",
     "@types/node": "^18.7.6",