Take a look at the parseParameters Object params function in the various classes in MissionHandlers. This should give a good idea about what it is we are about to do. The code we will add for the parseParameters function is given below. Note that we remove the code already within parseParameters which simply calls a superclass method. This is not really what we would like.
We want to override the superclass method and change the return values. The first thing we do is check if the params object is null or is not of the Schema type we are expect, i. If either is the case, we return false presumably telling the caller of this function that the Schmea given is not something the Implementation was designed for.
On the other hand, if the params object is indeed of type RewardForStructureCopying , we perform a cast from Object , Java's only class that has no superclass and from which all other classes inherit, to RewardForStructureCopying and set the instance to a variance named rscparams following the convention of the other Reward Handlers rsc stands for Reward, Structure and copying resp.
Once we have a RewardForStructureCopying instance, we can query it for the variables we'd like to store. Firstly, we get four BlockPos instances. This is the first Minecraft type we are seeing! BlockPos is essentially an object that contains information about a block's position or in other words contains data similar to a 3-tuple or 3-dimensional vector. Note the use of the method blockPosFromPos which is given below:. It turns out that Pos comprises of BigDecimal s since Pos uses xs:decimal s.
This is a nice type for performing accurate and exact arithmetic operations; however, for comparing two grids of the same volume, we will be comparing the blocks within the grid themselves and we don't really care for decimals or floating point arithmetic. We can make do with integers. We use these to immediately perform a simple check: do the player structure and goal structure intersect?
