Strange output on Array3D(3) toArray()

## *What* is wrong?
When using a kernel to draw a CPU Array3D(3) into a texture and then converted back using toArray(), the resulting array is very strange and wrong, with some values being correct and others being either duplicated or entirely incorrect.

## *Where* does it happen?
In GPU.js, running on my Windows 7 PC, headlessgl in node.js v12.18.1.

## *How* do we replicate the issue?
Create a 3D array and assign each value set to its index in the array...
e.g.,
```
const gridSize = 8;
const buffer = [];
for (let x = 0; x < gridSize; x++) {
let currXArr = [];
buffer.push(currXArr);
for (let y = 0; y < gridSize; y++) {
let currYArr = [];
currXArr.push(currYArr);
for (let z = 0; z < gridSize; z++) {
currYArr.push(new Float32Array([x,y,z]));
}
}
}
```

Build the following kernel:
```
const pipelineFuncSettings = {
output: [gridSize, gridSize, gridSize],
pipeline: true,
returnType: 'Array(3)',
};
const copyFramebufferFuncImmutable = gpu.createKernel(function(framebufTex) {
const voxelColour = framebufTex[this.thread.x][this.thread.y][this.thread.z];
return [voxelColour[0], voxelColour[1], voxelColour[2]];
}, {...pipelineFuncSettings, immutable: true, argumentTypes: {framebufTex: 'Array3D(3)'}});
```

Draw the CPU buffer into a GPU texture and retrieve it as an array:
```
const bufferTex = copyFramebufferFuncImmutable(buffer);
const texArray = bufferTex.toArray();
```

Then look to see if what we did was properly copied from the CPU -> GPU -> CPU:
```
function debugPrint(arr) {
for (let x = 0; x < gridSize; x++) {
for (let y = 0; y < gridSize; y++) {
const temp = [];
for (let z = 0; z < gridSize; z++) {
const currColour = arr[x][y][z];
temp.push("("+currColour[0].toFixed(0)+","+currColour[1].toFixed(0)+","+currColour[2].toFixed(0)+")")
}
strArr.push(temp.join(", "));
}
}
console.log(strArr.join("\n"));
}
```

... and get this comparative abomination:

CPU (Original/Control) i.e., `debugPrint(buffer);`:
```
(0,0,0), (0,0,1), (0,0,2), (0,0,3), (0,0,4), (0,0,5), (0,0,6), (0,0,7)
(0,1,0), (0,1,1), (0,1,2), (0,1,3), (0,1,4), (0,1,5), (0,1,6), (0,1,7)
(0,2,0), (0,2,1), (0,2,2), (0,2,3), (0,2,4), (0,2,5), (0,2,6), (0,2,7)
(0,3,0), (0,3,1), (0,3,2), (0,3,3), (0,3,4), (0,3,5), (0,3,6), (0,3,7)
(0,4,0), (0,4,1), (0,4,2), (0,4,3), (0,4,4), (0,4,5), (0,4,6), (0,4,7)
(0,5,0), (0,5,1), (0,5,2), (0,5,3), (0,5,4), (0,5,5), (0,5,6), (0,5,7)
(0,6,0), (0,6,1), (0,6,2), (0,6,3), (0,6,4), (0,6,5), (0,6,6), (0,6,7)
(0,7,0), (0,7,1), (0,7,2), (0,7,3), (0,7,4), (0,7,5), (0,7,6), (0,7,7)
(1,0,0), (1,0,1), (1,0,2), (1,0,3), (1,0,4), (1,0,5), (1,0,6), (1,0,7)
(1,1,0), (1,1,1), (1,1,2), (1,1,3), (1,1,4), (1,1,5), (1,1,6), (1,1,7)
(1,2,0), (1,2,1), (1,2,2), (1,2,3), (1,2,4), (1,2,5), (1,2,6), (1,2,7)
(1,3,0), (1,3,1), (1,3,2), (1,3,3), (1,3,4), (1,3,5), (1,3,6), (1,3,7)
(1,4,0), (1,4,1), (1,4,2), (1,4,3), (1,4,4), (1,4,5), (1,4,6), (1,4,7)
(1,5,0), (1,5,1), (1,5,2), (1,5,3), (1,5,4), (1,5,5), (1,5,6), (1,5,7)
(1,6,0), (1,6,1), (1,6,2), (1,6,3), (1,6,4), (1,6,5), (1,6,6), (1,6,7)
(1,7,0), (1,7,1), (1,7,2), (1,7,3), (1,7,4), (1,7,5), (1,7,6), (1,7,7)
(2,0,0), (2,0,1), (2,0,2), (2,0,3), (2,0,4), (2,0,5), (2,0,6), (2,0,7)
(2,1,0), (2,1,1), (2,1,2), (2,1,3), (2,1,4), (2,1,5), (2,1,6), (2,1,7)
(2,2,0), (2,2,1), (2,2,2), (2,2,3), (2,2,4), (2,2,5), (2,2,6), (2,2,7)
(2,3,0), (2,3,1), (2,3,2), (2,3,3), (2,3,4), (2,3,5), (2,3,6), (2,3,7)
(2,4,0), (2,4,1), (2,4,2), (2,4,3), (2,4,4), (2,4,5), (2,4,6), (2,4,7)
(2,5,0), (2,5,1), (2,5,2), (2,5,3), (2,5,4), (2,5,5), (2,5,6), (2,5,7)
(2,6,0), (2,6,1), (2,6,2), (2,6,3), (2,6,4), (2,6,5), (2,6,6), (2,6,7)
(2,7,0), (2,7,1), (2,7,2), (2,7,3), (2,7,4), (2,7,5), (2,7,6), (2,7,7)
(3,0,0), (3,0,1), (3,0,2), (3,0,3), (3,0,4), (3,0,5), (3,0,6), (3,0,7)
(3,1,0), (3,1,1), (3,1,2), (3,1,3), (3,1,4), (3,1,5), (3,1,6), (3,1,7)
(3,2,0), (3,2,1), (3,2,2), (3,2,3), (3,2,4), (3,2,5), (3,2,6), (3,2,7)
(3,3,0), (3,3,1), (3,3,2), (3,3,3), (3,3,4), (3,3,5), (3,3,6), (3,3,7)
(3,4,0), (3,4,1), (3,4,2), (3,4,3), (3,4,4), (3,4,5), (3,4,6), (3,4,7)
(3,5,0), (3,5,1), (3,5,2), (3,5,3), (3,5,4), (3,5,5), (3,5,6), (3,5,7)
(3,6,0), (3,6,1), (3,6,2), (3,6,3), (3,6,4), (3,6,5), (3,6,6), (3,6,7)
(3,7,0), (3,7,1), (3,7,2), (3,7,3), (3,7,4), (3,7,5), (3,7,6), (3,7,7)
(4,0,0), (4,0,1), (4,0,2), (4,0,3), (4,0,4), (4,0,5), (4,0,6), (4,0,7)
(4,1,0), (4,1,1), (4,1,2), (4,1,3), (4,1,4), (4,1,5), (4,1,6), (4,1,7)
(4,2,0), (4,2,1), (4,2,2), (4,2,3), (4,2,4), (4,2,5), (4,2,6), (4,2,7)
(4,3,0), (4,3,1), (4,3,2), (4,3,3), (4,3,4), (4,3,5), (4,3,6), (4,3,7)
(4,4,0), (4,4,1), (4,4,2), (4,4,3), (4,4,4), (4,4,5), (4,4,6), (4,4,7)
(4,5,0), (4,5,1), (4,5,2), (4,5,3), (4,5,4), (4,5,5), (4,5,6), (4,5,7)
(4,6,0), (4,6,1), (4,6,2), (4,6,3), (4,6,4), (4,6,5), (4,6,6), (4,6,7)
(4,7,0), (4,7,1), (4,7,2), (4,7,3), (4,7,4), (4,7,5), (4,7,6), (4,7,7)
(5,0,0), (5,0,1), (5,0,2), (5,0,3), (5,0,4), (5,0,5), (5,0,6), (5,0,7)
(5,1,0), (5,1,1), (5,1,2), (5,1,3), (5,1,4), (5,1,5), (5,1,6), (5,1,7)
(5,2,0), (5,2,1), (5,2,2), (5,2,3), (5,2,4), (5,2,5), (5,2,6), (5,2,7)
(5,3,0), (5,3,1), (5,3,2), (5,3,3), (5,3,4), (5,3,5), (5,3,6), (5,3,7)
(5,4,0), (5,4,1), (5,4,2), (5,4,3), (5,4,4), (5,4,5), (5,4,6), (5,4,7)
(5,5,0), (5,5,1), (5,5,2), (5,5,3), (5,5,4), (5,5,5), (5,5,6), (5,5,7)
(5,6,0), (5,6,1), (5,6,2), (5,6,3), (5,6,4), (5,6,5), (5,6,6), (5,6,7)
(5,7,0), (5,7,1), (5,7,2), (5,7,3), (5,7,4), (5,7,5), (5,7,6), (5,7,7)
(6,0,0), (6,0,1), (6,0,2), (6,0,3), (6,0,4), (6,0,5), (6,0,6), (6,0,7)
(6,1,0), (6,1,1), (6,1,2), (6,1,3), (6,1,4), (6,1,5), (6,1,6), (6,1,7)
(6,2,0), (6,2,1), (6,2,2), (6,2,3), (6,2,4), (6,2,5), (6,2,6), (6,2,7)
(6,3,0), (6,3,1), (6,3,2), (6,3,3), (6,3,4), (6,3,5), (6,3,6), (6,3,7)
(6,4,0), (6,4,1), (6,4,2), (6,4,3), (6,4,4), (6,4,5), (6,4,6), (6,4,7)
(6,5,0), (6,5,1), (6,5,2), (6,5,3), (6,5,4), (6,5,5), (6,5,6), (6,5,7)
(6,6,0), (6,6,1), (6,6,2), (6,6,3), (6,6,4), (6,6,5), (6,6,6), (6,6,7)
(6,7,0), (6,7,1), (6,7,2), (6,7,3), (6,7,4), (6,7,5), (6,7,6), (6,7,7)
(7,0,0), (7,0,1), (7,0,2), (7,0,3), (7,0,4), (7,0,5), (7,0,6), (7,0,7)
(7,1,0), (7,1,1), (7,1,2), (7,1,3), (7,1,4), (7,1,5), (7,1,6), (7,1,7)
(7,2,0), (7,2,1), (7,2,2), (7,2,3), (7,2,4), (7,2,5), (7,2,6), (7,2,7)
(7,3,0), (7,3,1), (7,3,2), (7,3,3), (7,3,4), (7,3,5), (7,3,6), (7,3,7)
(7,4,0), (7,4,1), (7,4,2), (7,4,3), (7,4,4), (7,4,5), (7,4,6), (7,4,7)
(7,5,0), (7,5,1), (7,5,2), (7,5,3), (7,5,4), (7,5,5), (7,5,6), (7,5,7)
(7,6,0), (7,6,1), (7,6,2), (7,6,3), (7,6,4), (7,6,5), (7,6,6), (7,6,7)
(7,7,0), (7,7,1), (7,7,2), (7,7,3), (7,7,4), (7,7,5), (7,7,6), (7,7,7)
```

GPU toArray() result i.e., `debugPrint(texBuffer);`:
```
(0,0,0), (1,0,0), (2,0,0), (3,0,0), (4,0,0), (5,0,0), (6,0,0), (7,0,0)
(0,1,0), (1,1,0), (2,1,0), (3,1,0), (4,1,0), (5,1,0), (6,1,0), (7,1,0)
(0,2,0), (1,2,0), (2,2,0), (3,2,0), (4,2,0), (5,2,0), (6,2,0), (7,2,0)
(0,3,0), (1,3,0), (2,3,0), (3,3,0), (4,3,0), (5,3,0), (6,3,0), (7,3,0)
(0,4,0), (1,4,0), (2,4,0), (3,4,0), (4,4,0), (5,4,0), (6,4,0), (7,4,0)
(0,5,0), (1,5,0), (2,5,0), (3,5,0), (4,5,0), (5,5,0), (6,5,0), (7,5,0)
(0,6,0), (1,6,0), (2,6,0), (3,6,0), (4,6,0), (5,6,0), (6,6,0), (7,6,0)
(0,7,0), (1,7,0), (2,7,0), (3,7,0), (4,7,0), (5,7,0), (6,7,0), (7,7,0)
(0,0,0), (1,0,4), (2,4,5), (3,2,4), (4,3,4), (5,4,4), (6,5,4), (7,6,4)
(0,0,1), (1,5,5), (2,1,5), (3,2,5), (4,3,5), (5,4,5), (6,5,5), (7,6,5)
(0,2,1), (1,0,6), (2,1,6), (3,2,6), (4,3,6), (5,4,6), (6,5,6), (7,6,5)
(0,0,3), (1,0,7), (2,1,7), (3,2,7), (4,3,7), (5,4,7), (6,7,5), (7,6,7)
(0,0,0), (1,1,0), (2,2,0), (3,3,0), (4,4,0), (5,0,5), (6,6,0), (7,7,0)
(0,0,1), (1,1,1), (2,2,1), (3,3,1), (4,1,5), (5,5,1), (6,6,1), (7,7,1)
(0,0,2), (1,1,2), (2,2,2), (3,2,5), (4,4,2), (5,5,2), (6,6,2), (7,7,2)
(0,0,3), (1,1,3), (2,3,5), (3,3,3), (4,4,3), (5,5,3), (6,6,3), (7,7,3)
(0,0,0), (1,0,4), (2,0,4), (3,0,4), (4,0,4), (5,0,4), (6,0,4), (7,0,4)
(0,1,1), (1,1,5), (2,1,5), (3,1,5), (4,1,5), (5,1,5), (6,1,5), (7,1,5)
(0,2,2), (1,2,6), (2,2,6), (3,2,6), (4,2,6), (5,2,6), (6,2,6), (7,2,6)
(0,3,3), (1,3,7), (2,3,7), (3,3,7), (4,3,7), (5,3,7), (6,3,7), (7,3,7)
(0,4,0), (1,4,0), (2,4,0), (3,4,0), (4,4,0), (5,4,0), (6,4,0), (7,4,0)
(0,5,1), (1,5,1), (2,5,1), (3,5,1), (4,5,1), (5,5,1), (6,5,1), (7,5,1)
(0,6,2), (1,6,2), (2,6,2), (3,6,2), (4,6,2), (5,6,2), (6,6,2), (7,6,2)
(0,7,3), (1,7,3), (2,7,3), (3,7,3), (4,7,3), (5,7,3), (6,7,3), (7,7,3)
(0,0,3), (1,0,3), (2,0,3), (3,0,3), (4,0,3), (5,0,3), (6,0,3), (7,0,3)
(0,1,3), (1,1,3), (2,1,3), (3,1,3), (4,1,3), (5,1,3), (6,1,3), (7,1,3)
(0,2,3), (1,2,3), (2,2,3), (3,2,3), (4,2,3), (5,2,3), (6,2,3), (7,2,3)
(0,3,3), (1,3,3), (2,3,3), (3,3,3), (4,3,3), (5,3,3), (6,3,3), (7,3,3)
(0,4,3), (1,4,3), (2,4,3), (3,4,3), (4,4,3), (5,4,3), (6,4,3), (7,4,3)
(0,5,3), (1,5,3), (2,5,3), (3,5,3), (4,5,3), (5,5,3), (6,5,3), (7,5,3)
(0,6,3), (1,6,3), (2,6,3), (3,6,3), (4,6,3), (5,6,3), (6,6,3), (7,6,3)
(0,7,3), (1,7,3), (2,7,3), (3,7,3), (4,7,3), (5,7,3), (6,7,3), (7,7,3)
(0,0,4), (1,0,4), (2,0,4), (3,0,4), (4,0,4), (5,0,4), (6,0,4), (7,0,4)
(0,1,4), (1,1,4), (2,1,4), (3,1,4), (4,1,4), (5,1,4), (6,1,4), (7,1,4)
(0,2,4), (1,2,4), (2,2,4), (3,2,4), (4,2,4), (5,2,4), (6,2,4), (7,2,4)
(0,3,4), (1,3,4), (2,3,4), (3,3,4), (4,3,4), (5,3,4), (6,3,4), (7,3,4)
(0,4,4), (1,4,4), (2,4,4), (3,4,4), (4,4,4), (5,4,4), (6,4,4), (7,4,4)
(0,5,4), (1,5,4), (2,5,4), (3,5,4), (4,5,4), (5,5,4), (6,5,4), (7,5,4)
(0,6,4), (1,6,4), (2,6,4), (3,6,4), (4,6,4), (5,6,4), (6,6,4), (7,6,4)
(0,7,4), (1,7,4), (2,7,4), (3,7,4), (4,7,4), (5,7,4), (6,7,4), (7,7,4)
(0,0,0), (1,0,5), (2,1,5), (3,2,5), (4,3,5), (5,5,1), (6,5,5), (7,6,5)
(0,0,1), (1,0,6), (2,1,6), (3,2,6), (4,6,1), (5,4,6), (6,5,6), (7,6,6)
(0,0,2), (1,0,7), (2,1,7), (3,7,1), (4,3,7), (5,4,7), (6,5,7), (7,6,7)
(0,0,0), (1,1,0), (2,0,1), (3,3,0), (4,4,0), (5,5,0), (6,6,0), (7,7,0)
(0,0,1), (1,1,1), (2,2,1), (3,3,1), (4,4,1), (5,5,1), (6,6,1), (7,7,1)
(0,2,1), (1,1,2), (2,2,2), (3,3,2), (4,4,2), (5,5,2), (6,6,2), (7,2,1)
(0,0,3), (1,1,3), (2,2,3), (3,3,3), (4,4,3), (5,5,3), (6,3,1), (7,7,3)
(0,0,4), (1,1,4), (2,2,4), (3,3,4), (4,4,4), (5,4,1), (6,6,4), (7,7,4)
(0,0,0), (1,0,5), (2,0,5), (3,0,5), (4,0,5), (5,0,5), (6,0,5), (7,0,5)
(0,1,1), (1,1,6), (2,1,6), (3,1,6), (4,1,6), (5,1,6), (6,1,6), (7,1,6)
(0,2,2), (1,2,7), (2,2,7), (3,2,7), (4,2,7), (5,2,7), (6,2,7), (7,2,7)
(0,3,0), (1,3,0), (2,3,0), (3,3,0), (4,3,0), (5,3,0), (6,3,0), (7,3,0)
(0,4,1), (1,4,1), (2,4,1), (3,4,1), (4,4,1), (5,4,1), (6,4,1), (7,4,1)
(0,5,2), (1,5,2), (2,5,2), (3,5,2), (4,5,2), (5,5,2), (6,5,2), (7,5,2)
(0,6,3), (1,6,3), (2,6,3), (3,6,3), (4,6,3), (5,6,3), (6,6,3), (7,6,3)
(0,7,4), (1,7,4), (2,7,4), (3,7,4), (4,7,4), (5,7,4), (6,7,4), (7,7,4)
(0,0,7), (1,0,7), (2,0,7), (3,0,7), (4,0,7), (5,0,7), (6,0,7), (7,0,7)
(0,1,7), (1,1,7), (2,1,7), (3,1,7), (4,1,7), (5,1,7), (6,1,7), (7,1,7)
(0,2,7), (1,2,7), (2,2,7), (3,2,7), (4,2,7), (5,2,7), (6,2,7), (7,2,7)
(0,3,7), (1,3,7), (2,3,7), (3,3,7), (4,3,7), (5,3,7), (6,3,7), (7,3,7)
(0,4,7), (1,4,7), (2,4,7), (3,4,7), (4,4,7), (5,4,7), (6,4,7), (7,4,7)
(0,5,7), (1,5,7), (2,5,7), (3,5,7), (4,5,7), (5,5,7), (6,5,7), (7,5,7)
(0,6,7), (1,6,7), (2,6,7), (3,6,7), (4,6,7), (5,6,7), (6,6,7), (7,6,7)
(0,7,7), (1,7,7), (2,7,7), (3,7,7), (4,7,7), (5,7,7), (6,7,7), (7,7,7)
```

## *How* important is this (1-5)?
Strikes me as a pretty integral issue since there appears to be a non-identical transformation between CPU and GPU buffers.

## Expected behavior (i.e. solution)
Those two arrays should be the same (or at least differ by an obvious matrix transform/mapping), instead the toArray() buffer is filled with duplicate data and errors that don't map *at all* to the original CPU buffer.