import { FileLoader } from './FileLoader.js';
import { DefaultLoadingManager } from './LoadingManager.js';
import { WEBGL_PIXEL_TYPE, WEBGL_PIXEL_FORMAT } from '../const.js';
/**
* A loader for loading a .hdr Image.
* @constructor
* @memberof zen3d
* @param {zen3d.LoadingManager} manager — The loadingManager for the loader to use. Default is zen3d.DefaultLoadingManager.
*/
function RGBELoader(manager) {
this.manager = (manager !== undefined) ? manager : DefaultLoadingManager;
this.type = WEBGL_PIXEL_TYPE.UNSIGNED_BYTE;
}
Object.assign(RGBELoader.prototype, /** @lends zen3d.RGBELoader.prototype */{
/**
* Load the URL and pass the response to the onLoad function.
* @param {string} url — the path or URL to the file. This can also be a Data URI.
* @param {Function} [onLoad=] — Will be called when loading completes. The argument will be the loaded image ( draw to an canvas element ).
* @param {Function} [onProgress=] — Will be called while load progresses. The argument will be the XMLHttpRequest instance, which contains .total and .loaded bytes.
* @param {Function} [onError=] — Will be called if an error occurs.
*/
load: function(url, onLoad, onProgress, onError) {
var that = this;
var loader = new FileLoader(this.manager);
loader.setResponseType('arraybuffer');
loader.load(url, function(buffer) {
if (onLoad !== undefined) {
onLoad(that.parse(buffer));
}
}, onProgress, onError);
},
// adapted from http://www.graphics.cornell.edu/~bjw/rgbe.html
parse: function(buffer) {
var
/* return codes for rgbe routines */
// RGBE_RETURN_SUCCESS = 0,
RGBE_RETURN_FAILURE = -1,
/* default error routine. change this to change error handling */
rgbe_read_error = 1,
rgbe_write_error = 2,
rgbe_format_error = 3,
rgbe_memory_error = 4,
rgbe_error = function (rgbe_error_code, msg) {
switch (rgbe_error_code) {
case rgbe_read_error: console.error("zen3d.RGBELoader Read Error: " + (msg || ''));
break;
case rgbe_write_error: console.error("zen3d.RGBELoader Write Error: " + (msg || ''));
break;
case rgbe_format_error: console.error("zen3d.RGBELoader Bad File Format: " + (msg || ''));
break;
default:
case rgbe_memory_error: console.error("zen3d.RGBELoader: Error: " + (msg || ''));
}
return RGBE_RETURN_FAILURE;
},
/* offsets to red, green, and blue components in a data (float) pixel */
// RGBE_DATA_RED = 0,
// RGBE_DATA_GREEN = 1,
// RGBE_DATA_BLUE = 2,
/* number of floats per pixel, use 4 since stored in rgba image format */
// RGBE_DATA_SIZE = 4,
/* flags indicating which fields in an rgbe_header_info are valid */
RGBE_VALID_PROGRAMTYPE = 1,
RGBE_VALID_FORMAT = 2,
RGBE_VALID_DIMENSIONS = 4,
NEWLINE = "\n",
fgets = function (buffer, lineLimit, consume) {
lineLimit = !lineLimit ? 1024 : lineLimit;
var p = buffer.pos,
i = -1, len = 0, s = '', chunkSize = 128,
chunk = String.fromCharCode.apply(null, new Uint16Array(buffer.subarray(p, p + chunkSize)));
while ((0 > (i = chunk.indexOf(NEWLINE))) && (len < lineLimit) && (p < buffer.byteLength)) {
s += chunk; len += chunk.length;
p += chunkSize;
chunk += String.fromCharCode.apply(null, new Uint16Array(buffer.subarray(p, p + chunkSize)));
}
if (-1 < i) {
/* for (i=l-1; i>=0; i--) {
byteCode = m.charCodeAt(i);
if (byteCode > 0x7f && byteCode <= 0x7ff) byteLen++;
else if (byteCode > 0x7ff && byteCode <= 0xffff) byteLen += 2;
if (byteCode >= 0xDC00 && byteCode <= 0xDFFF) i--; //trail surrogate
} */
if (false !== consume) buffer.pos += len + i + 1;
return s + chunk.slice(0, i);
}
return false;
},
/* minimal header reading. modify if you want to parse more information */
RGBE_ReadHeader = function (buffer) {
var line, match,
// regexes to parse header info fields
magic_token_re = /^#\?(\S+)$/,
gamma_re = /^\s*GAMMA\s*=\s*(\d+(\.\d+)?)\s*$/,
exposure_re = /^\s*EXPOSURE\s*=\s*(\d+(\.\d+)?)\s*$/,
format_re = /^\s*FORMAT=(\S+)\s*$/,
dimensions_re = /^\s*\-Y\s+(\d+)\s+\+X\s+(\d+)\s*$/,
// RGBE format header struct
header = {
valid: 0, /* indicate which fields are valid */
string: '', /* the actual header string */
comments: '', /* comments found in header */
programtype: 'RGBE', /* listed at beginning of file to identify it after "#?". defaults to "RGBE" */
format: '', /* RGBE format, default 32-bit_rle_rgbe */
gamma: 1.0, /* image has already been gamma corrected with given gamma. defaults to 1.0 (no correction) */
exposure: 1.0, /* a value of 1.0 in an image corresponds to <exposure> watts/steradian/m^2. defaults to 1.0 */
width: 0, height: 0 /* image dimensions, width/height */
};
if (buffer.pos >= buffer.byteLength || !(line = fgets(buffer))) {
return rgbe_error(rgbe_read_error, "no header found");
}
/* if you want to require the magic token then uncomment the next line */
if (!(match = line.match(magic_token_re))) {
return rgbe_error(rgbe_format_error, "bad initial token");
}
header.valid |= RGBE_VALID_PROGRAMTYPE;
header.programtype = match[1];
header.string += line + "\n";
while (true) {
line = fgets(buffer);
if (false === line) break;
header.string += line + "\n";
if ('#' === line.charAt(0)) {
header.comments += line + "\n";
continue; // comment line
}
if (match = line.match(gamma_re)) {
header.gamma = parseFloat(match[1]);
}
if (match = line.match(exposure_re)) {
header.exposure = parseFloat(match[1]);
}
if (match = line.match(format_re)) {
header.valid |= RGBE_VALID_FORMAT;
header.format = match[1];// '32-bit_rle_rgbe';
}
if (match = line.match(dimensions_re)) {
header.valid |= RGBE_VALID_DIMENSIONS;
header.height = parseInt(match[1], 10);
header.width = parseInt(match[2], 10);
}
if ((header.valid & RGBE_VALID_FORMAT) && (header.valid & RGBE_VALID_DIMENSIONS)) break;
}
if (!(header.valid & RGBE_VALID_FORMAT)) {
return rgbe_error(rgbe_format_error, "missing format specifier");
}
if (!(header.valid & RGBE_VALID_DIMENSIONS)) {
return rgbe_error(rgbe_format_error, "missing image size specifier");
}
return header;
},
RGBE_ReadPixels_RLE = function (buffer, w, h) {
var data_rgba, offset, pos, count, byteValue,
scanline_buffer, ptr, ptr_end, i, l, off, isEncodedRun,
scanline_width = w, num_scanlines = h, rgbeStart;
if (
// run length encoding is not allowed so read flat
((scanline_width < 8) || (scanline_width > 0x7fff)) ||
// this file is not run length encoded
((2 !== buffer[0]) || (2 !== buffer[1]) || (buffer[2] & 0x80))
) {
// return the flat buffer
return new Uint8Array(buffer);
}
if (scanline_width !== ((buffer[2] << 8) | buffer[3])) {
return rgbe_error(rgbe_format_error, "wrong scanline width");
}
data_rgba = new Uint8Array(4 * w * h);
if (!data_rgba.length) {
return rgbe_error(rgbe_memory_error, "unable to allocate buffer space");
}
offset = 0; pos = 0; ptr_end = 4 * scanline_width;
rgbeStart = new Uint8Array(4);
scanline_buffer = new Uint8Array(ptr_end);
// read in each successive scanline
while ((num_scanlines > 0) && (pos < buffer.byteLength)) {
if (pos + 4 > buffer.byteLength) {
return rgbe_error(rgbe_read_error);
}
rgbeStart[0] = buffer[pos++];
rgbeStart[1] = buffer[pos++];
rgbeStart[2] = buffer[pos++];
rgbeStart[3] = buffer[pos++];
if ((2 != rgbeStart[0]) || (2 != rgbeStart[1]) || (((rgbeStart[2] << 8) | rgbeStart[3]) != scanline_width)) {
return rgbe_error(rgbe_format_error, "bad rgbe scanline format");
}
// read each of the four channels for the scanline into the buffer
// first red, then green, then blue, then exponent
ptr = 0;
while ((ptr < ptr_end) && (pos < buffer.byteLength)) {
count = buffer[pos++];
isEncodedRun = count > 128;
if (isEncodedRun) count -= 128;
if ((0 === count) || (ptr + count > ptr_end)) {
return rgbe_error(rgbe_format_error, "bad scanline data");
}
if (isEncodedRun) {
// a (encoded) run of the same value
byteValue = buffer[pos++];
for (i = 0; i < count; i++) {
scanline_buffer[ptr++] = byteValue;
}
// ptr += count;
} else {
// a literal-run
scanline_buffer.set(buffer.subarray(pos, pos + count), ptr);
ptr += count; pos += count;
}
}
// now convert data from buffer into rgba
// first red, then green, then blue, then exponent (alpha)
l = scanline_width; // scanline_buffer.byteLength;
for (i = 0; i < l; i++) {
off = 0;
data_rgba[offset] = scanline_buffer[i + off];
off += scanline_width; // 1;
data_rgba[offset + 1] = scanline_buffer[i + off];
off += scanline_width; // 1;
data_rgba[offset + 2] = scanline_buffer[i + off];
off += scanline_width; // 1;
data_rgba[offset + 3] = scanline_buffer[i + off];
offset += 4;
}
num_scanlines--;
}
return data_rgba;
};
var byteArray = new Uint8Array(buffer);
// var byteLength = byteArray.byteLength;
byteArray.pos = 0;
var rgbe_header_info = RGBE_ReadHeader(byteArray);
if (RGBE_RETURN_FAILURE !== rgbe_header_info) {
var w = rgbe_header_info.width,
h = rgbe_header_info.height,
image_rgba_data = RGBE_ReadPixels_RLE(byteArray.subarray(byteArray.pos), w, h);
if (RGBE_RETURN_FAILURE !== image_rgba_data) {
if (this.type === WEBGL_PIXEL_TYPE.UNSIGNED_BYTE) {
var data = image_rgba_data;
var format = WEBGL_PIXEL_FORMAT.RGBA; // RGBE handled as RGBA in shaders
var type = WEBGL_PIXEL_TYPE.UNSIGNED_BYTE;
} else if (this.type === WEBGL_PIXEL_TYPE.FLOAT) {
var RGBEByteToRGBFloat = function (sourceArray, sourceOffset, destArray, destOffset) {
var e = sourceArray[sourceOffset + 3];
var scale = Math.pow(2.0, e - 128.0) / 255.0;
destArray[destOffset + 0] = sourceArray[sourceOffset + 0] * scale;
destArray[destOffset + 1] = sourceArray[sourceOffset + 1] * scale;
destArray[destOffset + 2] = sourceArray[sourceOffset + 2] * scale;
};
var numElements = (image_rgba_data.length / 4) * 3;
var floatArray = new Float32Array(numElements);
for (var j = 0; j < numElements; j++) {
RGBEByteToRGBFloat(image_rgba_data, j * 4, floatArray, j * 3);
}
var data = floatArray;
var format = WEBGL_PIXEL_FORMAT.RGB;
var type = WEBGL_PIXEL_TYPE.FLOAT;
} else {
console.error('zen3d.RGBELoader: unsupported type: ', this.type);
}
return {
width: w, height: h,
data: data,
header: rgbe_header_info.string,
gamma: rgbe_header_info.gamma,
exposure: rgbe_header_info.exposure,
format: format,
type: type
};
}
}
return null;
}
});
export { RGBELoader };