pixolith / fabricjs-async-web-worker-filters Goto Github PK

been playing with custom filters in Fabric JS. But I just don't know how to undo anything done. Seems the pixels get overwritten by the process, which is fine, but how do I go back to the original?

So, in the custom filter, the results are placed into the canvas as follows:

                    imageDataArray.forEach( function( data ) {
                        cacheCtx.putImageData( data.data, 0, data.blocks );
                    } );

That shows the processed image in the render. But I don't understand how to "get back" the original. I have tried this before the processing:

        var obj = canvas.getActiveObject();
        var originalSource = obj._originalElement.currentSrc; // restore the original since filters trash the canvas
        obj.filters[index] = filter;
        obj.applyFilters(canvas.renderAll.bind(canvas)); 

But it does not "get it back". I really don't wish to reload the image each time as they can be large at times. Any help appreciated.