demostf/demo.js
1
0
Fork 0
mirror of https://github.com/demostf/demo.js synced 2026-06-04 00:54:14 +02:00
Code Issues Releases Wiki Activity

add encoders for variable length ints

Browse source
This commit is contained in:
Robin Appelman 2017-08-12 23:09:37 +02:00
commit 79cd277fed
9 changed files with 148 additions and 24 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/Parser/Packet/ClassInfo.ts
View file

@ -32,7 +32,7 @@ export function ParseClassInfo(stream: BitStream): ClassInfoPacket { // 10: clas
export function EncodeClassInfo(packet: ClassInfoPacket, stream: BitStream) {
stream.writeUint16(packet.number);
stream.writeBoolean(packet.create ? 1 : 0);
stream.writeBoolean(packet.create);
if (!packet.create) {
const bits = logBase2(packet.number) + 1;
for (const entry of packet.entries) {

19
src/Parser/Packet/ParserGenerator.ts
View file

@ -1,5 +1,6 @@
import {Packet} from '../../Data/Packet';
import {PacketHandler} from './Parser';
import {BitStream} from 'bit-buffer';
export function make(name: string, definition: string): PacketHandler {
const parts = definition.split('}');
@ -31,7 +32,7 @@ export function make(name: string, definition: string): PacketHandler {
};
}
function readItem(stream, description, data) {
function readItem(stream: BitStream, description: string, data) {
if (description[0] === 'b') {
return stream.readBoolean();
} else if (description[0] === 's') {
@ -54,25 +55,25 @@ function readItem(stream, description, data) {
}
}
function writeItem(stream, description, data, value) {
function writeItem(stream: BitStream, description: string, data, value: boolean | string | number) {
if (description[0] === 'b') {
return stream.writeBoolean(value);
return stream.writeBoolean(value as boolean);
} else if (description[0] === 's') {
if (description.length === 1) {
return stream.writeUTF8String(value);
return stream.writeUTF8String(value as string);
} else {
const length = parseInt(description.substr(1), 10);
return stream.writeUTF8String(value, length);
return stream.writeUTF8String(value as string, length);
}
} else if (description === 'f32') {
return stream.writeFloat32(value);
return stream.writeFloat32(value as number);
} else if (description[0] === 'u') {
const length = parseInt(description.substr(1), 10);
return stream.writeBits(value, length);
return stream.writeBits(value as number, length);
} else if (description[0] === '$') {
const variable = description.substr(1);
return stream.writeBits(value, data[variable]);
return stream.writeBits(value as number, data[variable]);
} else {
return stream.writeBits(value, parseInt(description, 10), true);
return stream.writeBits(value as number, parseInt(description, 10));
}
}

44
src/Parser/readBitVar.ts
View file

@ -1,4 +1,15 @@
import {BitStream} from 'bit-buffer';
import {logBase2} from '../Math';
function makeUnsigned(value: number, signed?: boolean) {
if (signed) {
const signBit = value < 0 ? 1 : 0;
return ((value ^ -signBit) << 1) + signBit;
} else {
return value;
}
}
export function readBitVar(stream: BitStream, signed?: boolean): number {
const type = stream.readBits(2);
switch (type) {
@ -14,6 +25,28 @@ export function readBitVar(stream: BitStream, signed?: boolean): number {
throw new Error('Invalid var bit');
}
export function writeBitVar(value: number, stream: BitStream, signed?: boolean) {
const bitsNeeded = (signed) ? logBase2(Math.abs(value)) + 2 : logBase2(value) + 1;
if (signed) {
const signBit = value < 0 ? 1 : 0;
value = value ^ (-signBit << (bitsNeeded - 1)) + (signBit << (bitsNeeded - 1));
}
if (bitsNeeded > 12) {
stream.writeBits(3, 2);
stream.writeBits(value, 32);
} else if (bitsNeeded > 8) {
stream.writeBits(2, 2);
stream.writeBits(value, 12);
} else if (bitsNeeded > 4) {
stream.writeBits(1, 2);
stream.writeBits(value, 8);
} else {
stream.writeBits(0, 2);
stream.writeBits(value, 4);
}
}
export const readUBitVar = readBitVar;
export function readVarInt(stream: BitStream, signed: boolean = false) {
@ -33,3 +66,14 @@ export function readVarInt(stream: BitStream, signed: boolean = false) {
return result;
}
}
export function writeVarInt(value: number, stream: BitStream, signed: boolean = false) {
value = makeUnsigned(value, signed);
do {
const byte = value & 0x7F;
const resumeBit = (value > 128) ? 0x80 : 0;
stream.writeUint8(byte | resumeBit);
value = value >> 7;
} while (value > 0);
}