engine/rr: build the Ray Reconstruction models from nvngx_dlssd.dll alone, without a capture

Models built from nvngx_dlssd.dll 310.9.1 are byte-identical to the capture-built ones (every file, plus
d4r-rr's outputs on capF, capF4K, capF900, capFXparticles and capDT). 310.9.1 contains 310.7's D/E kernels
and weights.

engine/rr/rr_templates.py

@@ -0,0 +1,103 @@
+#!/usr/bin/env python3
+"""The two argument-block templates of a preset D / E model (enc0.args, hkpn.args) without a capture.
+
+usage: rr_templates.py NVNGX_DLSSD_DLL D|E OUT_DIR
+       rr_templates.py NVNGX_DLSSD_DLL D|E --check MODEL_DIR...   (compare with templates compile_rr.py took from captures)
+
+engine/runtime_rr.inc fills every field of the two blocks that depends on the frame, the geometry or the bound inputs.
+Across captures of different sizes, inputs and frames (2026-10-14: capD, capDT, capD4K, capDX*, capE, capE3) what is
+left is the same few constants for both presets, plus two floats of encoder 0 (bytes 540 and 544) that differ between
+the presets. NGX sets those two in code: `sub ecx, 4; je D; cmp ecx, 1; jne ...; mov [rbx + X], E0; mov [rbx + X + 4],
+E1; jmp ...; D: mov [rbx + X], D0; mov [rbx + X + 4], D1` (ecx = the preset), which find_floats() looks up in the DLL.
+The templates are written on the user's machine and are never packaged.
+"""
+import re
+import struct
+import sys
+from pathlib import Path
+
+ENC0_BYTES, HKPN_BYTES = 1032, 480
+# (offset, packed value) of the constants the runtime keeps
+ENC0_CONST = [(360, struct.pack('<f', 1.0)), (532, struct.pack('<I', 2)), (988, struct.pack('<I', 1))]
+HKPN_CONST = [(148, struct.pack('<f', 1.0)), (436, struct.pack('<f', 0.25)), (456, struct.pack('<I', 1))]
+# the byte ranges engine/runtime_rr.inc writes every frame (setFrame), for --check
+ENC0_WRITTEN = [(0, 8), (48, 64), (80, 84), (136, 160), (312, 352), (364, 368), (432, 440), (472, 480), (528, 532),
+                (536, 537), (539, 540), (596, 980), (980, 981), (984, 988), (1024, 1032)]
+HKPN_WRITTEN = [(0, 48), (56, 64), (140, 148), (152, 156), (160, 161), (256, 264), (336, 344), (432, 433), (440, 444)]
+
+# mov [rbx + disp32], imm32 is c7 83 disp32 imm32
+PATTERN = re.compile(rb'\x83\xe9\x04\x74.\x83\xf9\x01\x75.'
+                     rb'\xc7\x83(....)(....)\xc7\x83(....)(....)\xeb.'
+                     rb'\xc7\x83(....)(....)\xc7\x83(....)(....)', re.S)
+
+
+def find_floats(dll):
+    """{'D': (f0, f1), 'E': (f0, f1)}: encoder 0's bytes 540 / 544 as NGX's code sets them"""
+    found = set()
+    for m in PATTERN.finditer(dll):
+        e0, e0v, e1, e1v, d0, d0v, d1, d1v = m.groups()
+        x = struct.unpack('<I', e0)[0]
+        if struct.unpack('<I', e1)[0] == x + 4 and e0 == d0 and e1 == d1:
+            found.add((d0v + d1v, e0v + e1v))
+    if len(found) != 1:
+        raise SystemExit(f'found {len(found)} candidates for the preset constants of encoder 0 (expected one): '
+                         'not a DLL layout this builder knows')
+    d, e = found.pop()
+    return {'D': d, 'E': e}
+
+
+def templates(dll, preset):
+    enc0, hkpn = bytearray(ENC0_BYTES), bytearray(HKPN_BYTES)
+    for off, v in ENC0_CONST:
+        enc0[off:off + len(v)] = v
+    for off, v in HKPN_CONST:
+        hkpn[off:off + len(v)] = v
+    enc0[540:548] = find_floats(dll)[preset]
+    return bytes(enc0), bytes(hkpn)
+
+
+def masked(b, written, handles):
+    b = bytearray(b)
+    for lo, hi in written:
+        b[lo:hi] = bytes(hi - lo)
+    for off in handles:
+        b[off:off + 8] = bytes(8)
+    return bytes(b)
+
+
+def handles(rr_txt, stage):
+    for line in Path(rr_txt).read_text().splitlines():
+        f = line.split()
+        if f[:2] == ['stage', stage]:
+            tex = [] if f[5] == '-' else [int(x) for x in f[5].split(',')]
+            surf = [] if f[6] == '-' else [int(x.split(':')[0]) for x in f[6].split(',')]
+            return tex + surf
+    return []
+
+
+def main():
+    if len(sys.argv) < 4:
+        raise SystemExit(__doc__)
+    dll, preset = Path(sys.argv[1]).read_bytes(), sys.argv[2].upper()
+    if preset not in ('D', 'E'):
+        raise SystemExit('preset D or E')
+    enc0, hkpn = templates(dll, preset)
+    if sys.argv[3] == '--check':
+        bad = 0
+        for model in sys.argv[4:]:
+            for name, ours, written in (('enc0', enc0, ENC0_WRITTEN), ('hkpn', hkpn, HKPN_WRITTEN)):
+                theirs = (Path(model) / f'{name}.args').read_bytes()
+                h = handles(Path(model) / 'rr.txt', name)
+                a, b = masked(ours, written, h), masked(theirs, written, h)
+                diff = [i for i in range(len(a)) if a[i] != b[i]]
+                bad += bool(diff)
+                print(f'{model} {name}: ' + ('same' if not diff else f'{len(diff)} bytes differ, first at {diff[:8]}'))
+        sys.exit(1 if bad else 0)
+    out = Path(sys.argv[3])
+    out.mkdir(parents=True, exist_ok=True)
+    (out / 'enc0.args').write_bytes(enc0)
+    (out / 'hkpn.args').write_bytes(hkpn)
+
+
+if __name__ == '__main__':
+    main()