armorpaint/base/Sources/parser_exr.ts

// Based on miniexr.cpp - public domain - 2013 Aras Pranckevicius / Unity Technologies
// https://github.com/aras-p/miniexr
// https://www.openexr.com/documentation/openexrfilelayout.pdf

function parser_exr_write_string(out: i32[], str: string) {
	for (let i: i32 = 0; i < str.length; ++i) {
		out.push(str.charCodeAt(i));
	}
}

function parser_exr_run(width: i32, height: i32, src: ArrayBuffer, bits: i32 = 16, type: i32 = 1, off: i32 = 0): ArrayBuffer {
	let out: u8[] = [];
	out.push(0x76); // magic
	out.push(0x2f);
	out.push(0x31);
	out.push(0x01);
	out.push(2); // version, scanline
	out.push(0);
	out.push(0);
	out.push(0);
	parser_exr_write_string(out, "channels");
	out.push(0);
	parser_exr_write_string(out, "chlist");
	out.push(0);

	out.push(55);
	out.push(0);
	out.push(0);
	out.push(0);

	let attrib: i32 = bits == 16 ? 1 : 2; // half, float

	out.push("B".charCodeAt(0)); // B
	out.push(0);

	out.push(attrib);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push("G".charCodeAt(0)); // G
	out.push(0);

	out.push(attrib);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push("R".charCodeAt(0)); // R
	out.push(0);

	out.push(attrib);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);

	parser_exr_write_string(out, "compression");
	out.push(0);
	parser_exr_write_string(out, "compression");
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0); // no compression

	parser_exr_write_string(out, "dataWindow");
	out.push(0);
	parser_exr_write_string(out, "box2i");
	out.push(0);

	out.push(16);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	let ww: i32 = width - 1;
	let hh: i32 = height - 1;

	out.push(ww & 0xff);
	out.push((ww >> 8) & 0xff);
	out.push((ww >> 16) & 0xff);
	out.push((ww >> 24) & 0xff);

	out.push(hh & 0xff);
	out.push((hh >> 8) & 0xff);
	out.push((hh >> 16) & 0xff);
	out.push((hh >> 24) & 0xff);

	parser_exr_write_string(out, "displayWindow");
	out.push(0);
	parser_exr_write_string(out, "box2i");
	out.push(0);

	out.push(16);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(ww & 0xff);
	out.push((ww >> 8) & 0xff);
	out.push((ww >> 16) & 0xff);
	out.push((ww >> 24) & 0xff);

	out.push(hh & 0xff);
	out.push((hh >> 8) & 0xff);
	out.push((hh >> 16) & 0xff);
	out.push((hh >> 24) & 0xff);

	parser_exr_write_string(out, "lineOrder");
	out.push(0);
	parser_exr_write_string(out, "lineOrder");
	out.push(0);

	out.push(1);
	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0); // increasing Y

	parser_exr_write_string(out, "pixelAspectRatio");
	out.push(0);
	parser_exr_write_string(out, "float");
	out.push(0);

	out.push(4);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0); // 1.0f
	out.push(0);
	out.push(0x80);
	out.push(0x3f);

	parser_exr_write_string(out, "screenWindowCenter");
	out.push(0);

	parser_exr_write_string(out, "v2f");
	out.push(0);

	out.push(8);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0);
	out.push(0);
	out.push(0);
	out.push(0);

	parser_exr_write_string(out, "screenWindowWidth");
	out.push(0);

	parser_exr_write_string(out, "float");
	out.push(0);

	out.push(4);
	out.push(0);
	out.push(0);
	out.push(0);

	out.push(0); // 1.0f
	out.push(0);
	out.push(0x80);
	out.push(0x3f);

	out.push(0); // end of header

	let channels: i32 = 4;
	let byte_size: i32 = bits == 16 ? 2 : 4;
	let k_header_size: i32 = out.length;
	let k_scanline_table_size: i32 = 8 * height;
	let pixel_row_size: i32 = width * 3 * byte_size;
	let full_row_size: i32 = pixel_row_size + 8;

	// line offset table
	let ofs: i32 = k_header_size + k_scanline_table_size;
	for (let y: i32 = 0; y < height; ++y) {
		out.push(ofs & 0xff);
		out.push((ofs >> 8) & 0xff);
		out.push((ofs >> 16) & 0xff);
		out.push((ofs >> 24) & 0xff);
		out.push(0);
		out.push(0);
		out.push(0);
		out.push(0);
		ofs += full_row_size;
	}

	// scanline data
	let stride: i32 = channels * byte_size;
	let pos: i32 = 0;
	let srcView: DataView = new DataView(src);

	let write_line16 = (bytePos: i32) => {
		for (let x: i32 = 0; x < width; ++x) {
			out.push(srcView.getUint8(bytePos    ));
			out.push(srcView.getUint8(bytePos + 1));
			bytePos += stride;
		}
	}

	let write_line32 = (bytePos: i32) => {
		for (let x: i32 = 0; x < width; ++x) {
			out.push(srcView.getUint8(bytePos    ));
			out.push(srcView.getUint8(bytePos + 1));
			out.push(srcView.getUint8(bytePos + 2));
			out.push(srcView.getUint8(bytePos + 3));
			bytePos += stride;
		}
	}

	let write_line = bits == 16 ? write_line16 : write_line32;

	let write_bgr = (off: i32) => {
		write_line(pos + byte_size * 2);
		write_line(pos + byte_size);
		write_line(pos);
	}

	let write_single = (off: i32) => {
		write_line(pos + off * byte_size);
		write_line(pos + off * byte_size);
		write_line(pos + off * byte_size);
	}

	let write_data = type == 1 ? write_bgr : write_single;

	for (let y: i32 = 0; y < height; ++y) {
		// coordinate
		out.push(y & 0xff);
		out.push((y >> 8) & 0xff);
		out.push((y >> 16) & 0xff);
		out.push((y >> 24) & 0xff);
		// data size
		out.push(pixel_row_size & 0xff);
		out.push((pixel_row_size >> 8) & 0xff);
		out.push((pixel_row_size >> 16) & 0xff);
		out.push((pixel_row_size >> 24) & 0xff);
		// data
		write_data(off);
		pos += width * stride;
	}

	return Uint8Array.from(out).buffer;
}