Mitre support

DrawMitre.hx

public inline
    function mitreDraw( ax_: Float, ay_: Float, bx_: Float, by_: Float, width_: Float, clockWise: Bool ){
        // bx_, by_ currently not required... but incase.
        // work out the opposite point to j, ie the mitre corner.
        //   calculate the difference from centre
        var deltaX = ax_ - jx;
        var deltaY = ay_ - jy;
        //   reflect j in relation to a
        var mitreCornerX = ax_ + deltaX;
        var mitreCornerY = ay_ + deltaY;
        // calculate distance between mitreCorner and centre a.
        var distXY = Math.sqrt(deltaX*deltaX + deltaY*deltaY);
        // calculate the miter cut off distance.
        var mitreVal = mitreLimit*width_/2;
        // see if it is applicable
        var mitreLimited = distXY > mitreVal;
        // find the ratio for extending the lines to the mitre cut off. 
        var mitreRatio = mitreVal/distXY; 
        if( clockWise ){
            if( !mitreLimited ) { // simple case no mitre cropped
                triangle2DFill( dxOld, dyOld, mitreCornerX, mitreCornerY, exPrev, eyPrev );
            } else {
                var deltaX1 = dxOld  + mitreRatio*( mitreCornerX - dxOld );
                var deltaY1 = dyOld  + mitreRatio*( mitreCornerY - dyOld );
                var deltaX2 = exPrev + mitreRatio*( mitreCornerX - exPrev );
                var deltaY2 = eyPrev + mitreRatio*( mitreCornerY - eyPrev );
                trace( 'delta ' + deltaX1 + ' ' + deltaX2 + ' ' + deltaY1 + ' ' + deltaY2 );
                // split mitre cropped into two triangle from the first line to the crop 
                triangle2DFill( dxOld, dyOld, deltaX1, deltaY1, deltaX2, deltaY2 );
                // from the first line to second crop point and then to second line
                triangle2DFill( dxOld, dyOld, deltaX2, deltaY2, exPrev, eyPrev );
            }
            // draw normal triangle corner 
            triangle2DFill( dxOld, dyOld, exPrev, eyPrev, jx, jy );
        } else {
            if( !mitreLimited ) { // see notes above
                triangle2DFill( exOld, eyOld, mitreCornerX, mitreCornerY, dxPrev, dyPrev );
            } else {
                var deltaX1 = exOld  + mitreRatio*( mitreCornerX - exOld );
                var deltaY1 = eyOld  + mitreRatio*( mitreCornerY - eyOld );
                var deltaX2 = dxPrev + mitreRatio*( mitreCornerX - dxPrev );
                var deltaY2 = dyPrev + mitreRatio*( mitreCornerY - dyPrev );
                trace( 'delta ' + deltaX1 + ' ' + deltaX2 + ' ' + deltaY1 + ' ' + deltaY2 );
                triangle2DFill( exOld, eyOld, deltaX1, deltaY1, deltaX2, deltaY2 );
                triangle2DFill( exOld, eyOld, deltaX2, deltaY2, dxPrev, dyPrev );
            }
            triangle2DFill( exOld, eyOld, dxPrev, dyPrev, jx, jy );
        }