adjust material size for melting for armor parts, weapons, trap components and tools...

docs/changelog.txt

@@ -54,6 +54,7 @@ Template for new versions:
 ## New Tools
 
 ## New Features
+- `tweak`: ``material-size-for-melting``: change melting return for inorganic armor parts, shields, weapons, trap components and tools to stop smelters from creating metal, bring melt return for adamantine in line with other metals to ~95% of forging cost. wear reduces melt return by 10% per level
 
 ## Fixes
 

docs/plugins/tweak.rst

@@ -53,6 +53,17 @@ Commands
     Names filled waterskins, flasks, and vials according to their contents,
     the same way other containers such as barrels, bins, and cages are named.
     (:bug:`4914`)
+``material-size-for-melting``
+    Changes how item size for melting is calculated. Affects weapons, shields,
+    armor parts, tools, trap components including items made from adamantine.
+    As result base return for melting is equal to 95% of production cost.
+    Each level of wear decreases melt return by further 10%.
+    Limitation of melting return being handled by game in 0,3 bar increments is
+    solved by adding random component to material size. E.g. for cap with item
+    size 1 melting return will be equal to 0,9 bar base return with 16,(6)%
+    chance for additional 0,3 bar. As result average return for melting cap
+    will be ~0,95 bar.
+    (:bug:`6027`).
 ``named-codices``
     Displays titles for books instead of the default material description.
 ``partial-items``

plugins/tweak/tweak.cpp

@@ -17,6 +17,7 @@ using namespace DFHack;
 #include "tweaks/eggs-fertile.h"
 #include "tweaks/fast-heat.h"
 #include "tweaks/flask-contents.h"
+#include "tweaks/material-size-for-melting.h"
 #include "tweaks/named-codices.h"
 #include "tweaks/partial-items.h"
 #include "tweaks/reaction-gloves.h"
@@ -74,6 +75,16 @@ DFhackCExport command_result plugin_init(color_ostream &out, vector<PluginComman
 
     TWEAK_HOOK("reaction-gloves", reaction_gloves_hook, produce);
 
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_armor_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_gloves_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_shoes_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_helm_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_pants_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_weapon_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_trapcomp_hook, getMaterialSizeForMelting);
+    TWEAK_HOOK("material-size-for-melting", material_size_for_melting_tool_hook, getMaterialSizeForMelting);
+    rng.init();
+
     return CR_OK;
 }
 

plugins/tweak/tweaks/material-size-for-melting.h

@@ -0,0 +1,65 @@
+#include <cmath>
+
+#include "modules/Materials.h"
+#include "modules/Random.h"
+
+#include "df/inorganic_raw.h"
+#include "df/item_armorst.h"
+#include "df/item_constructed.h"
+#include "df/item_glovesst.h"
+#include "df/item_helmst.h"
+#include "df/item_pantsst.h"
+#include "df/item_shieldst.h"
+#include "df/item_shoesst.h"
+#include "df/item_toolst.h"
+#include "df/item_trapcompst.h"
+#include "df/item_weaponst.h"
+
+static Random::MersenneRNG rng;
+static float get_random() {
+    return static_cast <float> (rng.drandom1());
+}
+
+static int32_t get_material_size_for_melting(df::item_constructed *item, int32_t base_material_size, float production_stack_size) {
+    const float melt_return_per_material_size = 0.3f, base_melt_recovery = 0.95f, loss_per_wear_level = 0.1f;
+
+    if (item->mat_type == 0) // INORGANIC only
+    {
+        float calculated_size, forging_cost_per_item;
+
+        auto inorganic = df::inorganic_raw::find(item->mat_index);
+        if (inorganic && inorganic->flags.is_set(df::inorganic_flags::DEEP_SPECIAL)){
+            //adamantine items
+            forging_cost_per_item = static_cast<float>(base_material_size) / production_stack_size;
+        }
+        else {
+            // non adamantine items
+            forging_cost_per_item = std::max(std::floor(static_cast<float>(base_material_size) / 3.0f), 1.0f);
+            forging_cost_per_item /= production_stack_size;
+        }
+        calculated_size = forging_cost_per_item / melt_return_per_material_size;
+        float melt_recovery = base_melt_recovery - static_cast<float>(item->wear) * loss_per_wear_level;
+        calculated_size *= melt_recovery;
+        int32_t random_part = ((modff(calculated_size, &calculated_size) > get_random()) ? 1 : 0);
+        return  static_cast<int32_t>(calculated_size) + random_part;
+    }
+    return base_material_size;
+}
+
+#define DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(TYPE, PRODUCTION_STACK_SIZE) \
+struct material_size_for_melting_##TYPE##_hook : df::item_##TYPE##st {\
+    typedef df::item_##TYPE##st interpose_base;\
+    DEFINE_VMETHOD_INTERPOSE(int32_t, getMaterialSizeForMelting, ()) {\
+        return get_material_size_for_melting(this, INTERPOSE_NEXT(getMaterialSizeForMelting)(),PRODUCTION_STACK_SIZE);\
+    }\
+};\
+IMPLEMENT_VMETHOD_INTERPOSE(material_size_for_melting_##TYPE##_hook, getMaterialSizeForMelting);
+
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(armor, 1.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(gloves, 2.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(shoes, 2.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(helm, 1.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(pants, 1.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(weapon, 1.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(trapcomp, 1.0f)
+DEFINE_MATERIAL_SIZE_FOR_MELTING_TWEAK(tool, 1.0f)