TJS2でBitmapファイル読み込みテスト

readbmp.tjs

Plugins.link("plugin/BinaryStream.dll");

const bsRead = 0;
const bsWrite = 1;
const bsAppend = 2;
const bsUpdate = 3;

const bsSeekSet = 0;
const bsSeekCur = 1;
const bsSeekEnd = 2;

var stream = new BinaryStream("sample.bmp",bsRead);
var bmpfileheader = stream.read(2+4+2+2+4);

var filesize = 0;
var offsetimage = 0;
if( bmpfileheader !== void ) {
	var header = bmpfileheader.unpack("CCLSSL");
	if( header !== null ) {
		if( header[0] == 0x42 && header[1] == 0x4d ) { // BM
			filesize = header[2];
			Debug.message( "file size: " + filesize );
			offsetimage = header[5];
			Debug.message( "image offset: " + offsetimage );
		}
	}
}
var width = 0;
var height = 0;
var bitcount = 0;
var imagesize = 0;
var bmpheader = stream.read(4+4+4+2+2+4+4+4+4+4+4); // 新しいバージョンは考えない
if( bmpheader !== void ) {
	var header = bmpheader.unpack("LllSSLLLLLL");
	if( header !== null && header[0] == 40 ) {
		width = header[1];
		Debug.message( "width: " + width );
		height = header[2];
		Debug.message( "height: " + height );
		var biPlanes = header[3];
		Debug.message( "planes: " + biPlanes );
		if( biPlanes != 1 ) throw new Exception("Not support format");
		bitcount = header[4];
		Debug.message( "bit count: " + bitcount );
		if( bitcount != 24 && bitcount != 32 ) throw new Exception("Not support format");
		var biCompression = header[5];
		Debug.message( "compression: " + biCompression );
		if( biCompression != 0 ) throw new Exception("Not support format");
		imagesize = header[6];
		var biXPixPerMeter = header[7];
		Debug.message( "xppm: " + biXPixPerMeter );
		var biYPixPerMeter = header[8];
		Debug.message( "yppm: " + biYPixPerMeter );
		var biClrUsed = header[9];
		Debug.message( "palette used: " + biClrUsed );
		var biClrImporant = header[10];
		Debug.message( "important palette: " + biClrImporant );
	}
}
if( width != 0 && height != 0 ) {
	stream.seek( offsetimage, bsSeekSet );
	var imagedata = stream.read(filesize-offsetimage);
	if( imagedata !== void ) {
		var img = imagedata.unpack("C*");
		if( img !== null ) {
			if( height < 0 ) height = -height;	// 逆さ無視
			var reverse = height-1;
			var line = (width * bitcount) / 8;
			if ((line % 4) != 0) {
				line = ((line \ 4) + 1) * 4;
			}
			var numcolorbyte = 3;
			var bitmap = new Bitmap(width,height);
			var index = 0;
			if( bitcount == 32 ) {
				numcolorbyte = 4;
			}
			for( var y = 0; y < height; y++ ) {
				var offset = index;
				for( var x = 0; x < width; x++ ) {
					var b = img[offset+0];
					var g = img[offset+1];
					var r = img[offset+2];
					var color = (r << 16) | (g << 8) | b;
					bitmap.setPixel( x, reverse-y, color );
					bitmap.setMaskPixel( x, reverse-y, 255 );
					offset+=numcolorbyte;
				}
				index += line;
			}
			bitmap.save( "sample.png", "png24" );
		}
	}
}

stream.close();