monkey v66: dataview compatibility

Monkey Forums/Monkey Bug Reports/monkey v66: dataview compatibility

AdamRedwoods

(Posted 2012) [#1]

Just a note on DataView (HTML5), since it isn't widely accepted yet.

Thought you could do an undefined check on it and if undefined, use backward compatibility:

backwards check example:
	if (typeof DataView !== 'undefined') {
		this.dataView=new DataView( buffer );
	} else {
		//compatibility
		this.dataView=new DataView__( buffer );
	}


function DataView__(buffer) {
	//this.buffer = buffer;
	this.byteArray=new Int8Array( buffer );
	this.shortArray=new Int16Array( buffer );
	this.intArray=new Int32Array( buffer );
	this.floatArray=new Float32Array( buffer );
}

DataView__.prototype.setInt8 = function(addr,value) {
	this.byteArray[addr]=value;
}
DataView__.prototype.setInt16 = function(addr,value) {
	this.shortArray[addr>>1]=value;
}
DataView__.prototype.setInt32 = function(addr,value) {
	this.intArray[addr>>2]=value;
}
DataView__.prototype.setFloat32 = function(addr,value) {
	this.floatArray[addr>>2]=value;
}

DataView__.prototype.getInt8 = function(addr,value) {
	return this.byteArray[addr];
}
DataView__.prototype.getInt16 = function(addr,value) {
	return this.shortArray[addr>>1];
}
DataView__.prototype.getInt32 = function(addr,value) {
	return this.intArray[addr>>2];
}
DataView__.prototype.getFloat32 = function(addr,value) {
	return this.floatArray[addr>>2];
}

otherwise this breaks quite a few browsers.

marksibly

(Posted 2012) [#2]

Hi,

Here's a DataView-less version that handles misaligned data I was working on a while back.

If it works OK for you I'll include it in next release...


function BBDataBuffer(){
	this.arrayBuffer=null;
	this.length=0;
}

BBDataBuffer.tbuf=new ArrayBuffer(4);
BBDataBuffer.tbytes=new Int8Array( BBDataBuffer.tbuf );
BBDataBuffer.tshorts=new Int16Array( BBDataBuffer.tbuf );
BBDataBuffer.tints=new Int32Array( BBDataBuffer.tbuf );
BBDataBuffer.tfloats=new Float32Array( BBDataBuffer.tbuf );

BBDataBuffer.prototype._Init=function( buffer ){
	this.arrayBuffer=buffer;
	this.length=buffer.byteLength;
	this.bytes=new Int8Array( buffer );	
	this.shorts=new Int16Array( buffer,0,this.length/2 );	
	this.ints=new Int32Array( buffer,0,this.length/4 );	
	this.floats=new Float32Array( buffer,0,this.length/4 );
}

BBDataBuffer.prototype._New=function( length ){
	if( this.arrayBuffer ) return false;
	
	var buf=new ArrayBuffer( length );
	if( !buf ) return false;
	
	this._Init( buf );
	return true;
}

BBDataBuffer.prototype._Load=function( path ){
	if( this.arrayBuffer ) return false;
	
	var buf=loadArrayBuffer( path );
	if( !buf ) return false;
	
	this._Init( buf );
	return true;
}

BBDataBuffer.prototype.Length=function(){
	return this.length;
}

BBDataBuffer.prototype.Discard=function(){
	if( this.arrayBuffer ){
		this.arrayBuffer=null;
		this.length=0;
	}
}

BBDataBuffer.prototype.PokeByte=function( addr,value ){
	this.bytes[addr]=value;
}

BBDataBuffer.prototype.PokeShort=function( addr,value ){
	if( addr&1 ){
		BBDataBuffer.tshorts[0]=value;
		this.bytes[addr]=BBDataBuffer.tbytes[0];
		this.bytes[addr+1]=BBDataBuffer.tbytes[1];
		return;
	}
	this.shorts[addr>>1]=value;
}

BBDataBuffer.prototype.PokeInt=function( addr,value ){
	if( addr&3 ){
		BBDataBuffer.tints[0]=value;
		this.bytes[addr]=BBDataBuffer.tbytes[0];
		this.bytes[addr+1]=BBDataBuffer.tbytes[1];
		this.bytes[addr+2]=BBDataBuffer.tbytes[2];
		this.bytes[addr+3]=BBDataBuffer.tbytes[3];
		return;
	}
	this.ints[addr>>2]=value;
}

BBDataBuffer.prototype.PokeFloat=function( addr,value ){
	if( addr&3 ){
		BBDataBuffer.tfloats[0]=value;
		this.bytes[addr]=BBDataBuffer.tbytes[0];
		this.bytes[addr+1]=BBDataBuffer.tbytes[1];
		this.bytes[addr+2]=BBDataBuffer.tbytes[2];
		this.bytes[addr+3]=BBDataBuffer.tbytes[3];
		return;
	}
	this.floats[addr>>2]=value;
}

BBDataBuffer.prototype.PeekByte=function( addr ){
	return this.bytes[addr];
}

BBDataBuffer.prototype.PeekShort=function( addr ){
	if( addr&1 ){
		BBDataBuffer.tbytes[0]=this.bytes[addr];
		BBDataBuffer.tbytes[1]=this.bytes[addr+1];
		return BBDataBuffer.tshorts[0];
	}
	return this.shorts[addr>>1];
}

BBDataBuffer.prototype.PeekInt=function( addr ){
	if( addr&3 ){
		BBDataBuffer.tbytes[0]=this.bytes[addr];
		BBDataBuffer.tbytes[1]=this.bytes[addr+1];
		BBDataBuffer.tbytes[2]=this.bytes[addr+2];
		BBDataBuffer.tbytes[3]=this.bytes[addr+3];
		return BBDataBuffer.tints[0];
	}
	return this.ints[addr>>2];
}

BBDataBuffer.prototype.PeekFloat=function( addr ){
	if( addr&3 ){
		BBDataBuffer.tbytes[0]=this.bytes[addr];
		BBDataBuffer.tbytes[1]=this.bytes[addr+1];
		BBDataBuffer.tbytes[2]=this.bytes[addr+2];
		BBDataBuffer.tbytes[3]=this.bytes[addr+3];
		return BBDataBuffer.tfloats[0];
	}
	return this.floats[addr>>2];
}

AdamRedwoods

(Posted 2012) [#3]

works, thanks.

but ~~the asyncdataloader in html5 is corrupting or truncating data~~ (was my code/can't load images through arraybuffer in js yet), and in main.js (from trans targets) the loadDataBuffer() still uses DataView... so, those are still things to think about.

skid	(Posted 2012) [#4]

IE9 doesn't seem to support ArrayBuffers.

AdamRedwoods

(Posted 2012) [#5]

True, but it is in IE10, and IE9 doesn't have dataview either.
http://msdn.microsoft.com/en-us/library/s4esdbwz(v=vs.94).aspx

(and FWIW, no webgl on IE either...)

skid	(Posted 2012) [#6]

I mistook them for banks and went with them for some audio stuff, my bad, have replaced with int[] based bindings for now.