Re-balancing costs.

[Darkhax]

The current enchantment cost calculation system can be pretty messy. One of the biggest issues was the cost from level to level was not linear. Some of the calculations such as calculating the cost of increasing an enchantment from level 3 to level 5 expect it to be, and perform best when that is the case. There are also more factors that need to be included in the cost, such as treasure enchantments, and curses. While those could be retrofitted into the older method, the new one is much more straight forward. Included in this issue are the new code methods, and a table of the results.

The old method

    public static int calculateEnchantmentCost (Enchantment enchantment, int level) {

        int cost = (int) Math.floor(Math.max(1F, 1F + 2F * level * ((float) level / enchantment.getMaxLevel()) + (10 - enchantment.getRarity().getWeight()) * 0.2F));
        cost = cost + (int) (cost * 1.5f);
        cost = cost + (enchantment.getRarity() == Rarity.COMMON ? 1 : enchantment.getRarity() == Rarity.UNCOMMON ? 5 : enchantment.getRarity() == Rarity.RARE ? 10 : 20);
        return cost;
    }

The new method

    // New
    public static int calculateNewEnchCost(Enchantment enchantment, int level) {

        // Base cost is equal to roughly 2.5 levels of EXP.
        int cost = 25;

        // Cost is multiplied up to 10, based on rarity of the enchant.
        // Rarer the enchant, higher the cost.
        cost *= Math.max(11 - enchantment.getRarity().getWeight(), 1);

        // Linear cost increase based on level.
        cost *= level;

        // The cost factor is applied. Default is 1.5.
        // TODO make configurable
        cost *= 1.5f;

        // Curses cost even more to apply
        if (enchantment.isCurse()) {

            // TODO make configurable
            cost *= 1.5f;
        }

        // Treasures cost more to apply
        if (enchantment.isTreasureEnchantment()) {

            // TODO make configurable
            cost *= 1.5f;
        }

        return cost;
    }

Enchantment costs

Enchantment	Old Cost	New Cost
Protection I	3	2
Protection II	8	4
Protection III	13	6
Protection IV	23	8
Fire Protection I	10	13
Fire Protection II	15	22
Fire Protection III	20	27
Fire Protection IV	30	31
Feather Falling I	10	13
Feather Falling II	15	22
Feather Falling III	20	27
Feather Falling IV	30	31
Blast Protection I	17	18
Blast Protection II	20	27
Blast Protection III	27	32
Blast Protection IV	35	36
Projectile Protection I	10	13
Projectile Protection II	15	22
Projectile Protection III	20	27
Projectile Protection IV	30	31
Respiration I	17	18
Respiration II	22	27
Respiration III	30	32
Aqua Affinity	20	18
Thorns I	27	20
Thorns II	32	28
Thorns III	40	34
Depth Strider I	17	18
Depth Strider II	22	27
Depth Strider III	30	32
Frost Walker I	17	23
Frost Walker II	25	32
§cCurse of Binding	30	30
Sharpness I	3	2
Sharpness II	6	4
Sharpness III	11	6
Sharpness IV	18	8
Sharpness V	28	11
Smite I	10	13
Smite II	12	22
Smite III	17	27
Smite IV	25	31
Smite V	35	34
Bane of Arthropods I	10	13
Bane of Arthropods II	12	22
Bane of Arthropods III	17	27
Bane of Arthropods IV	25	31
Bane of Arthropods V	35	34
Knockback I	12	13
Knockback II	20	22
Fire Aspect I	17	18
Fire Aspect II	25	27
Looting I	17	18
Looting II	22	27
Looting III	30	32
Sweeping Edge I	17	18
Sweeping Edge II	22	27
Sweeping Edge III	30	32
Efficiency I	3	2
Efficiency II	6	4
Efficiency III	11	6
Efficiency IV	18	8
Efficiency V	28	11
Silk Touch	30	20
Unbreaking I	10	13
Unbreaking II	15	22
Unbreaking III	25	27
Fortune I	17	18
Fortune II	22	27
Fortune III	30	32
Power I	3	2
Power II	6	4
Power III	11	6
Power IV	18	8
Power V	28	11
Punch I	17	18
Punch II	25	27
Flame	20	18
Infinity	30	20
Luck of the Sea I	17	18
Luck of the Sea II	22	27
Luck of the Sea III	30	32
Lure I	17	18
Lure II	22	27
Lure III	30	32
Mending	20	23
§cCurse of Vanishing	30	30