From 159b7067326535632a2d6491a6c9c9df853bb1ad Mon Sep 17 00:00:00 2001
From: Erik Abair <erik.abair@gmail.com>
Date: Wed, 9 Feb 2022 21:25:56 -0800
Subject: [PATCH] Read surfaces via AGP

---
 Texture.py    | 16 ++++++++++++----
 nv2a-trace.py |  3 ++-
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/Texture.py b/Texture.py
index 1a54999..daeda77 100644
--- a/Texture.py
+++ b/Texture.py
@@ -15,6 +15,11 @@
 import XboxHelper
 from xboxpy import nv2a
 
+# Value that may be added to contiguous memory addresses to access as ADDR_AGPMEM, which
+# is guaranteed to be linear (and thus may be slower than tiled ADDR_FBMEM but can be
+# manipulated directly).
+AGP_MEMORY_BASE = 0xF0000000
+
 TextureParameters = namedtuple(
     "TextureParameters",
     [
@@ -75,6 +80,9 @@ def get_bits(bits, offset, length):
 
     img = Image.new(mode, (width, height))
 
+    # TODO: Is unswizzling actually necessary if textures are read via AGP?
+    # Need to set up a swizzled test case and verify behavior.
+
     # FIXME: Unswizzle data on the fly instead
     if swizzled:
         data = nv2a.Unswizzle(data, bits_per_pixel, (width, height), pitch)
@@ -251,13 +259,13 @@ def dump_texture(xbox, offset, pitch, fmt_color, width, height):
             "RGB", (width, height), (255, 0, 255, 255)
         )  # FIXME! Palette mode!
     elif fmt_color == 0xC:  # DXT1
-        data = xbox.read(0x80000000 | offset, width * height // 2)
+        data = xbox.read(AGP_MEMORY_BASE | offset, width * height // 2)
         img = Image.frombytes("RGBA", (width, height), data, "bcn", 1)  # DXT1
     elif fmt_color == 0xE:  # DXT3
-        data = xbox.read(0x80000000 | offset, width * height * 1)
+        data = xbox.read(AGP_MEMORY_BASE | offset, width * height * 1)
         img = Image.frombytes("RGBA", (width, height), data, "bcn", 2)  # DXT3
     elif fmt_color == 0xF:  # DXT5
-        data = xbox.read(0x80000000 | offset, width * height * 1)
+        data = xbox.read(AGP_MEMORY_BASE | offset, width * height * 1)
         img = Image.frombytes("RGBA", (width, height), data, "bcn", 3)  # DXT5
     elif fmt_color == 0x10:
         tex_info = (False, A1R5G5B5)
@@ -304,7 +312,7 @@ def dump_texture(xbox, offset, pitch, fmt_color, width, height):
             pitch = width * bits_per_pixel // 8
 
         # FIXME: Might want to skip the empty area if pitch and width diverge?
-        data = xbox.read(0x80000000 | offset, pitch * height)
+        data = xbox.read(AGP_MEMORY_BASE | offset, pitch * height)
         img = _decode_texture(
             data,
             (width, height),
diff --git a/nv2a-trace.py b/nv2a-trace.py
index ff360a4..2d66336 100755
--- a/nv2a-trace.py
+++ b/nv2a-trace.py
@@ -19,7 +19,8 @@
 import Trace
 
 # pylint: disable=invalid-name
-_enable_experimental_disable_z_compression_and_tiling = True
+# TODO: Remove tiling suppression once AGP read in Texture.py is fully proven.
+_enable_experimental_disable_z_compression_and_tiling = False
 # pylint: enable=invalid-name