mkjs/code/formats/2d/nclr.js

102 lines
3.1 KiB
JavaScript

//
// nclr.js
//--------------------
// Loads nclr files and provides a variety of functions for accessing and using the data.
// Palette information for nitro 2d graphics.
// by RHY3756547
//
window.nclr = function(input) {
var mainOff;
var t = this;
if (input != null) {
load(input);
}
this.load = load;
function load(input) {
var view = new DataView(input);
var header = null;
var offset = 0;
var tex;
//nitro 3d header
header = nitro.readHeader(view);
if (header.stamp != "RLCN") throw "NCLR invalid. Expected RLCN, found "+header.stamp;
if (header.numSections < 1 || header.numSections > 2) throw "NCLR invalid. Too many sections - should have 2.";
offset = header.sectionOffsets[0];
//end nitro
t.sectionOffsets = header.sectionOffsets;
t.sectionOffsets[0] = 0x18;
mainOff = offset;
t.pltt = loadPLTT(view);
if (header.numSections > 1) t.pcmp = loadPCMP(view);
}
function loadPLTT(view) {
var offset = t.sectionOffsets[0] - 8;
var pltt = {};
pltt.type = readChar(view, offset+0x0)+readChar(view, offset+0x1)+readChar(view, offset+0x2)+readChar(view, offset+0x3);
if (pltt.type != "TTLP") throw "NCLR invalid. Expected TTLP, found "+pltt.type;
pltt.blockSize = view.getUint32(offset+0x4, true);
t.sectionOffsets[1] = t.sectionOffsets[0] + pltt.blockSize;
pltt.bitDepth = view.getUint32(offset+0x8, true); //3 -> 4bit, 4 -> 8bit
pltt.padding = view.getUint32(offset+0xC, true);
pltt.palEntries = view.getUint32(offset+0x10, true) / 2; //stored in bytes, 2 bytes per col. seems to be wrong sometimes? (8bit mode, padding as 1)
pltt.colorsPerPal = view.getUint32(offset+0x14, true); //usually 16
//16-bit pallete data
//XBBBBBGGGGGRRRRR
var colsPerPal = (pltt.bitDepth == 4)?256:16;
var realPalCount = (pltt.blockSize - 0x18) / 2;
offset += 0x18;
pltt.palettes = [];
var curPal = [];
for (var i=0; i<realPalCount; i++) {
curPal.push(readPalColour(view, offset));
if (curPal.length >= colsPerPal) {
pltt.palettes.push(curPal);
curPal = [];
}
offset += 2;
}
if (curPal.length > 0) pltt.palettes.push(curPal);
return pltt;
}
function loadPCMP(view) { //palette count map, supposedly. maps each palette to an ID
var offset = t.sectionOffsets[1] - 8;
var pcmp = {};
pcmp.type = readChar(view, offset+0x0)+readChar(view, offset+0x1)+readChar(view, offset+0x2)+readChar(view, offset+0x3);
if (pcmp.type != "PMCP") throw "NCLR invalid. Expected PMCP, found "+stamp;
pcmp.blockSize = view.getUint32(offset+0x4, true);
pcmp.palCount = view.getUint16(offset+0x8, true);
//unknown 16: 0?
pcmp.unknown = view.getUint32(offset+0xC, true);
offset += 0x10;
var palIDs = [];
for (var i=0; i<pcmp.palCount; i++) {
palIDs.push(view.getUint16(offset, true));
offset += 2;
}
return pcmp;
}
function readPalColour(view, ind) {
var col = view.getUint16(ind, true);
var f = 255/31;
return [Math.round((col&31)*f), Math.round(((col>>5)&31)*f), Math.round(((col>>10)&31)*f), 255];
}
function readChar(view, offset) {
return String.fromCharCode(view.getUint8(offset));
}
}