block2.javascript

// create a DataView for obtaining a value from the binary pixel data
const tileDataView = new DataView(pixelData.buffer);

// To find the byte index:
// (1) get the index of the start of the row in which the pixel is located
//     (row index * number of columns)
// (2) add to that the column index
// (3) multiply by the number of bytes used for each pixel (4)
const byteIndex = (coordsInTile.y * tileSize + coordsInTile.x) * BYTES_PER_WORD;

// use the byte index and the machine's endianness to obtain the pixel value
const pixelValue = tileDataView.getFloat32(byteIndex, littleEndian);