m_random_field OK (#241)

* 25 functions OK

* 10 functions OK

* Add block type and block kind enums/defines

* Formatting/style pass

* Move `FieldMakeBlockType` to `m_field_make`

* Remove unused/duplicate defines

* Split data out for `m_quest` and `m_random_field`; rename data symbols

* Generate `m_random_field.c` and rename function symbols.

* mRF_BlockTypeDirect2GateType, mRF_BlockTypeDirect2GateData OK

* mRF_Type2BlockInfo, mRF_Info2BlockType, mRF_GateType2GateCount, mRF_SearchPond, mRF_Attr2BeastRoadAttr, mRF_CheckBeastRoad OK

* mFI_GetUnitCol OK; mRF_PrintDebug and mRF_BlockInf2CheckBeastRoad OK (pending data import).

* Fix `m_random_field` code split; all newly included functions OK

* Fix mRF_Malloc return type; formatting pass

* Name m_random_field_ovl

* Rename data symbols (m_random_field_ovl).

* Rename symbols (all functions named)

* Import data

* Declare overlay segment; rename symbols

* mRF_MakeRandomField OK (all functions matching).

* Extract asset `data_combi_table`

* Clean up mRF_MakeRandomField; document m_field_make.h

* Rename mCoBG_unkStruct->unk6 as unitAttribute

* Misc cleanup and formatting.

* Rename additional data symbols (m_random_field_ovl).

* Formatting pass

* Improve documentation of BackgroundAttribute enum.

* Formatting pass; add omitted attribute.

1 files changed, 52 insertions, 0 deletions

diff --git a/tools/splat_ext/combi.py b/tools/splat_ext/combi.py
new file mode 100644
index 0000000..c243b04
--- /dev/null
+++ b/tools/splat_ext/combi.py
@@ -0,0 +1,52 @@
+import math
+import struct
+from typing import Optional
+from splat.util import options, log
+from splat.segtypes.common.codesubsegment import CommonSegCodeSubsegment
+
+class N64SegCombi(CommonSegCodeSubsegment):
+    def __init__(self, rom_start, rom_end, type, name, vram_start, args, yaml):
+        super().__init__(rom_start, rom_end, type, name, vram_start, args=args, yaml=yaml),
+
+        self.file_text: Optional[str] = None
+        self.data_only = isinstance(yaml, dict) and yaml.get("data_only", False)
+
+    def scan(self, rom_bytes: bytes):
+        data = rom_bytes[self.rom_start : self.rom_end]
+        symbol = self.create_symbol(addr=self.vram_start, in_segment=True, type="data", define=True)
+        entry_len = 6
+        count = len(data) // entry_len
+        lines = []
+
+        if (len(data)) % entry_len != 0:
+            log.error(f"Error: combi segment {self.name} length ({len(data)}) is not a multiple of {entry_len}!")
+
+        if not self.data_only:
+            lines.append(options.opts.generated_c_preamble)
+            lines.append("")
+            lines.append("// Combination types are used as indices into this table.")
+            lines.append("// Combination type can be derived from an acre ID by (acreID >> 2)")
+            lines.append("// (the two least significant bits of an acre ID store its height)")
+            lines.append(f"FieldMakeComboInfo {symbol.name}[{count}] = {{")
+
+        index_digits = math.ceil(math.log(count, 16))
+
+        for index, FieldMakeComboInfo in enumerate(struct.iter_unpack(">HHBB", data)):
+            bgId, fgId, blockType, pad = FieldMakeComboInfo
+            lines.append(f"  /* 0x{index:0{index_digits}X} */ {{ 0x{bgId:04X}, 0x{fgId:04X}, 0x{blockType:02X} }},")
+
+        if not self.data_only:
+            lines.append(f"}}; // size = 0x{count * 6:X}")
+            # lines.append("")
+            # lines.append(f"s32 {symbol.name}_number = {count};")
+
+        lines.append("")
+        self.file_text = "\n".join(lines)
+
+    def split(self, rom_bytes: bytes):
+        path = options.opts.asset_path / self.dir / f"{self.name}.inc.c"
+
+        if self.file_text and path:
+            path.parent.mkdir(parents=True, exist_ok=True)
+            with open(path, "w", newline="\n") as f:
+                f.write(self.file_text)