#51 Generalize fish bonus calculation to work for other goods

[abartels]

Right now, the calculation of fish bonus is a hard-coded special case, because fish bonus is the only one taking characteristics of adjacent tiles (land/!land, river) into account.

1.
Tile:getFishBonus() should be generalized into Tile:getGoodsBonus(GoodsType), to work for other types of goods as well.

2.
All necessary constraints&values should be loaded from specification.xml.

[Michael Vehrs]

Which "constraints&values" do you envisage?

[abartels]

"Condition" would have been the better term, not constraint...

For fish bonus, we have the following conditions:
A: More than 2 adjacent tiles are land (bonus_value=2)
B: At least 1 adjacent tile is a river (bonus_value=1)

[Where B is not completely Col1-compatible yet. For full compatibility, it should be:
B': At least one river adjacent in a possible river flow direction (NW, NE, SW, SE), which flows towards "this" tile.]

One could think of similar conditions for other resources:
Lumber: More than 3 adjacent tiles are forested (bonus for heavily forested areas)
Grain: More than 2 adjacent tiles are a river (bonus for fertile ground alongside a river)
Ore: If the tile has an ore bonus; then bonus_value=X, where X=number of adjacent mountain/hill tiles.

So generally, we'd need to encode the following to make the above possible:
1. Tile-condition: What tile-type? What bonus resource? Special cases like "hasRiver" or "isForested"
2. Adjacent-tiles-condition: as above, combined with Min/Max (number of tiles that need to fulfill that condition), Adjacency (what positions are considered adjacent for this rule)
3. the bonus modifier (=value), that is applied if all conditions are met.

A possible XML-structure for that might be (using fish bonus as example):

//fish bonus along coasts
<goods-modifier id="***">
<tile-condition condition="isWater"/>
<tile-adjacent-condition condition="isLand" min="3" max="8" adjacency="8-neighbourhood"/>
<modifier id="model.goods.fish" type="additive" value="2"/>
</goods-modifier>

//fish bonus in ocean near river mouths
<goods-modifier id="***">
<tile-condition condition="isOcean"/>
<tile-adjacent-condition condition="hasRiver" min="1" max="8" adjacency="4-neighbourhood-minor"/>
<modifier id="model.goods.fish" type="additive" value="1"/>
</goods-modifier>

[Mike Pope]

By 0.10.7 this is much more generalized as suggested. Closing.