base

2026-10-14 11:04:08 +00:00
commit 46b03f16c0
120 changed files with 8871 additions and 0 deletions
@@ -0,0 +1,56 @@
+"""Generate a tiny unlocked classic Garmin IMG with one RGN vector feature.
+Only for exercising the converter's control flow, NOT a real-world compatibility test.
+"""
+from pathlib import Path
+import struct
+import sys
+
+def u24(n): return (n & 0xffffff).to_bytes(3,'little')
+def coord(deg):return round(deg*(1<<24)/360)
+def bitstream(values):
+    bits = [1,0,1,0]  # x same-sign+, y same-sign+
+    for x,y in values:
+        for value in (x,y):
+            bits += [(value >> i)&1 for i in range(11)]
+    return bytes(sum(bits[i+j]<<j for j in range(min(8,len(bits)-i))) for i in range(0,len(bits),8))
+
+def gen(dest):
+    blocksize=512
+    blob=bytearray(512*20)
+    blob[0x10:0x17]=b'DSKIMG\0'
+    blob[0x41:0x48]=b'GARMIN\0'
+    blob[0x61]=9;blob[0x62]=0
+    blob[0x40c:0x410]=(512*8).to_bytes(4,'little')
+    for j,(ext,block,length) in enumerate([('TRE',8,0xe0),('RGN',9,0xd0)]):
+        at=0x600+j*512
+        blob[at]=1;blob[at+1:at+9]=b'TESTMAP '
+        blob[at+9:at+12]=ext.encode()
+        struct.pack_into('<IHH',blob,at+12,length,0,0)
+        struct.pack_into('<H',blob,at+32,block)
+        struct.pack_into('<H',blob,at+34,0xffff)
+    tre=bytearray(0xe0)
+    struct.pack_into('<H',tre,0,0xc0)
+    tre[2:12]=b'GARMIN TRE'
+    for at,value in [(0x15,42.35),(0x18,25.05),(0x1b,41.85),(0x1e,24.45)]:
+        tre[at:at+3]=u24(coord(value))
+    struct.pack_into('<IIII',tre,0x21,0xc0,4,0xc4,14)
+    # level with bits=20 and 1 subdivision
+    tre[0xc0:0xc4]=bytes([0,20,1,0])
+    sub=bytearray(14)
+    sub[0:3]=u24(0);sub[3]=0x40
+    sub[4:7]=u24(coord(24.75))
+    sub[7:10]=u24(coord(42.1))
+    struct.pack_into('<HH',sub,10,1200,1200)
+    tre[0xc4:0xd2]=sub
+    blob[8*512:8*512+len(tre)]=tre
+    rgn=bytearray(0xd0)
+    struct.pack_into('<H',rgn,0,0x7d)
+    rgn[2:12]=b'GARMIN RGN'
+    path=bitstream([(2000,2000)]*4)
+    geom=bytes([0x03,0,0,0])+struct.pack('<hh',0,0)+bytes([len(path),0x99])+path
+    struct.pack_into('<II',rgn,0x15,0x7d,len(geom))
+    rgn[0x7d:0x7d+len(geom)]=geom
+    blob[9*512:9*512+len(rgn)]=rgn
+    Path(dest).write_bytes(blob)
+
+if __name__=='__main__':gen(sys.argv[1])