File name
Commit message
Commit date
File name
Commit message
Commit date
File name
Commit message
Commit date
File name
Commit message
Commit date
File name
Commit message
Commit date
File name
Commit message
Commit date
const FLOAT_EOF = 0xf;
const FLOAT_LOOKUP = [
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', '.', 'E', 'E-', null, '-'
];
const FLOAT_ENCODE_LOOKUP = {
'.': 10,
'E': 11,
'E-': 12,
'-': 14
};
export default class CFFOperand {
static decode(stream, value) {
if (32 <= value && value <= 246) {
return value - 139;
}
if (247 <= value && value <= 250) {
return (value - 247) * 256 + stream.readUInt8() + 108;
}
if (251 <= value && value <= 254) {
return -(value - 251) * 256 - stream.readUInt8() - 108;
}
if (value === 28) {
return stream.readInt16BE();
}
if (value === 29) {
return stream.readInt32BE();
}
if (value === 30) {
let str = '';
while (true) {
let b = stream.readUInt8();
let n1 = b >> 4;
if (n1 === FLOAT_EOF) { break; }
str += FLOAT_LOOKUP[n1];
let n2 = b & 15;
if (n2 === FLOAT_EOF) { break; }
str += FLOAT_LOOKUP[n2];
}
return parseFloat(str);
}
return null;
}
static size(value) {
// if the value needs to be forced to the largest size (32 bit)
// e.g. for unknown pointers, set to 32768
if (value.forceLarge) {
value = 32768;
}
if ((value | 0) !== value) { // floating point
let str = '' + value;
return 1 + Math.ceil((str.length + 1) / 2);
} else if (-107 <= value && value <= 107) {
return 1;
} else if (108 <= value && value <= 1131 || -1131 <= value && value <= -108) {
return 2;
} else if (-32768 <= value && value <= 32767) {
return 3;
} else {
return 5;
}
}
static encode(stream, value) {
// if the value needs to be forced to the largest size (32 bit)
// e.g. for unknown pointers, save the old value and set to 32768
let val = Number(value);
if (value.forceLarge) {
stream.writeUInt8(29);
return stream.writeInt32BE(val);
} else if ((val | 0) !== val) { // floating point
stream.writeUInt8(30);
let str = '' + val;
for (let i = 0; i < str.length; i += 2) {
let c1 = str[i];
let n1 = FLOAT_ENCODE_LOOKUP[c1] || +c1;
if (i === str.length - 1) {
var n2 = FLOAT_EOF;
} else {
let c2 = str[i + 1];
var n2 = FLOAT_ENCODE_LOOKUP[c2] || +c2;
}
stream.writeUInt8((n1 << 4) | (n2 & 15));
}
if (n2 !== FLOAT_EOF) {
return stream.writeUInt8((FLOAT_EOF << 4));
}
} else if (-107 <= val && val <= 107) {
return stream.writeUInt8(val + 139);
} else if (108 <= val && val <= 1131) {
val -= 108;
stream.writeUInt8((val >> 8) + 247);
return stream.writeUInt8(val & 0xff);
} else if (-1131 <= val && val <= -108) {
val = -val - 108;
stream.writeUInt8((val >> 8) + 251);
return stream.writeUInt8(val & 0xff);
} else if (-32768 <= val && val <= 32767) {
stream.writeUInt8(28);
return stream.writeInt16BE(val);
} else {
stream.writeUInt8(29);
return stream.writeInt32BE(val);
}
}
}