Start decompressing data (to do: implement a compressor)

9 files changed, 48 insertions, 10 deletions

diff --git a/gfx/copyright/copyright.bin.xor b/gfx/copyright/copyright.bin.xor
new file mode 100644
index 0000000..463037b
--- /dev/null
+++ b/gfx/copyright/copyright.bin.xor
diff --git a/gfx/copyright/copyright.png b/gfx/copyright/copyright.png
new file mode 100644
index 0000000..d18739b
--- /dev/null
+++ b/gfx/copyright/copyright.png
diff --git a/gfx/copyright/copyright.tilemap b/gfx/copyright/copyright.tilemap
new file mode 100644
index 0000000..4e41767
--- /dev/null
+++ b/gfx/copyright/copyright.tilemap
diff --git a/gfx/copyright/copyright.tilemap.xor b/gfx/copyright/copyright.tilemap.xor
new file mode 100644
index 0000000..1156fd6
--- /dev/null
+++ b/gfx/copyright/copyright.tilemap.xor
diff --git a/shim.sym b/shim.sym
index 57a56fd..3d3c4cb 100644
--- a/shim.sym
+++ b/shim.sym
@@ -59,10 +59,6 @@
 
 3c:4377 function_3c_4377
 
-6c:7eec compressed_tilemap_6c_7eec
-
-75:7d35 compressed_gfx_75_7d35
-
 7b:41e0 gfx_blank_char
 
 00:a03e s_a03e
diff --git a/source/bank_28.asm b/source/bank_28.asm
index d798744..e5d96fe 100644
--- a/source/bank_28.asm
+++ b/source/bank_28.asm
@@ -6,15 +6,15 @@ SECTION "function_28_426a", ROMX[$426a], BANK[$28]
 function_28_426a::
     ld a, $01
     ld [w_d6b5], a
-    ld a, BANK(compressed_gfx_75_7d35)
-    ld hl, compressed_gfx_75_7d35
+    ld a, BANK(compressed_gfx_copyright)
+    ld hl, compressed_gfx_copyright
     ld de, _VRAM8800
-    ld bc, 182
+    ld bc, $b6
     call decompress
-    ld a, BANK(compressed_tilemap_6c_7eec)
-    ld hl, compressed_tilemap_6c_7eec
+    ld a, BANK(compressed_tilemap_copyright)
+    ld hl, compressed_tilemap_copyright
     ld de, _SCRN0
-    ld bc, 82
+    ld bc, $52
     call decompress
     call function_00_1085
     ; TBC
diff --git a/source/bank_6c.asm b/source/bank_6c.asm
new file mode 100644
index 0000000..d6f5816
--- /dev/null
+++ b/source/bank_6c.asm
@@ -0,0 +1,4 @@
+SECTION "compressed_tilemap_copyright", ROMX[$7eec], BANK[$6c]
+compressed_tilemap_copyright::
+INCBIN "gfx/copyright/copyright.tilemap.xor"
+.end::
diff --git a/source/bank_75.asm b/source/bank_75.asm
index 0862024..a23a85e 100644
--- a/source/bank_75.asm
+++ b/source/bank_75.asm
@@ -23,3 +23,8 @@ INCBIN "gfx/levels/lv_5_pokemon_tower_sgb.bin"
 gfx_lv_5_pokemon_tower_duplicate::
 INCBIN "gfx/levels/lv_5_pokemon_tower.bin"
 .end::
+
+SECTION "compressed_gfx_copyright", ROMX[$7d35], BANK[$75]
+compressed_gfx_copyright::
+INCBIN "gfx/copyright/copyright.bin.xor"
+.end::
diff --git a/tools/dump_decompress.py b/tools/dump_decompress.py
new file mode 100644
index 0000000..2776c2b
--- /dev/null
+++ b/tools/dump_decompress.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python3
+
+# Usage: ./dump_decompress.py 75:7d35 00b6 >compressed.bin 2>decompressed.bin
+
+from sys import argv, stdout, stderr
+
+file = open("DMGAKVJ0.1", "rb").read()
+
+bank_addr = argv[1].split(':')
+bank = int(bank_addr[0], 16)
+addr = int(bank_addr[1], 16)
+length = int(argv[2], 16)
+offset = bank * 0x4000 + addr - (0x4000 if bank else 0)
+
+output = []
+i = offset
+v = 0x00
+for _1 in range(length):
+    byte = file[i]
+    i += 1
+    if byte < 0x80:
+        for _2 in range(byte + 1):
+            v ^= file[i]
+            output.append(v)
+            i += 1
+    else:
+        for _2 in range(byte - 0x7e):
+            v ^= file[i]
+            output.append(v)
+        i += 1
+
+stdout.buffer.write(bytes(file[offset:i])) # compressed
+stderr.buffer.write(bytes(output)) # decompressed