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Tidied up TARGE extractor

This commit is contained in:
n1474335 2020-03-27 12:05:23 +00:00
parent 5e51ed0a5f
commit 45011de494
1 changed files with 3 additions and 8 deletions
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11
src/core/lib/FileSignatures.mjs
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@ -474,7 +474,7 @@ export const FILE_SIGNATURES = {
mime: "image/x-targa",
description: "",
signature: [
{
{ // This signature is not at the beginning of the file. The extractor works backwards.
0: 0x54,
1: 0x52,
2: 0x55,
@ -492,7 +492,6 @@ export const FILE_SIGNATURES = {
14: 0x4c,
15: 0x45,
16: 0x2e
}
],
extractor: extractTARGA
@ -3075,6 +3074,7 @@ export function extractICO(bytes, offset) {
return stream.carve();
}
/**
* TARGA extractor.
*
@ -3082,7 +3082,6 @@ export function extractICO(bytes, offset) {
* @param {number} offset
*/
export function extractTARGA(bytes, offset) {
// Need all the bytes since we do not know how far up the image goes.
const stream = new Stream(bytes);
stream.moveTo(offset - 8);
@ -3094,7 +3093,7 @@ export function extractTARGA(bytes, offset) {
stream.moveBackwardsBy(8);
/**
* Move's backwards in the stream until it meet bytes that are the same as the amount of bytes moved.
* Moves backwards in the stream until it meet bytes that are the same as the amount of bytes moved.
*
* @param {number} sizeOfSize
* @param {number} maxSize
@ -3115,7 +3114,6 @@ export function extractTARGA(bytes, offset) {
/**
* Moves backwards in the stream until we meet bytes(when calculated) that are the same as the amount of bytes moved.
*
*/
function moveBackwardsUntilImageSize() {
stream.moveBackwardsBy(5);
@ -3134,14 +3132,12 @@ export function extractTARGA(bytes, offset) {
if (extensionOffset || developerOffset) {
if (extensionOffset) {
// Size is stored in two bytes hence the maximum is 0xffff.
moveBackwardsUntilSize(0xffff, 2);
// Move to where we think the start of the file is.
stream.moveBackwardsBy(extensionOffset);
} else if (developerOffset) {
// Size is stored in 4 bytes hence the maxiumum is 0xffffffff.
moveBackwardsUntilSize(0xffffffff, 4);
@ -3152,7 +3148,6 @@ export function extractTARGA(bytes, offset) {
stream.moveBackwardsBy(developerOffset);
}
} else {
// Move backwards until size === number of bytes passed.
moveBackwardsUntilImageSize();