private void evaluateInto(final float[] vars, final int offset) {
        evaluate();
        for (int vi = 0; vi < nBuildInVars; vi++) {
            final int idx = buildInVariableIdx[vi];
            vars[vi + offset] = idx == -1 ? 0.f : variableData[idx];
        }
    }
decode a byte-array into a lookup data array
main/src/main/java/cgeo/geocaching/brouter/expressions/BExpressionContext.java