Investigating a field report that the cameraship secondary armor/score/map
screen showed its background BMP but no overlay graphics "on certain video
cards". The video card was a red herring: the machine was launched with
-ctcltype 2 (game pod) instead of 3 (cameraship), and the overlay block in
hudchat.cpp is gated on CTCL_GetType()==_ECTCL_CameraShip, so it never ran.
This is hard to spot because the two gates are independent. HSH_EnterFullScreen2
and CMR_Device open the screen and paint its background based purely on whether
a spare secondary monitor exists, and never consult the CTCL role. A wrong
-ctcltype therefore yields a screen that lights up, shows the correct artwork
and renders nothing, which is visually identical to a DirectDraw failure. The
same background-only screen also appears on a game pod when an MFD mode finds no
dual-head span and falls through to the single-secondary mr_device path.
Diagnostics added:
- render.cpp: log the CTCL type in gos-displays.txt from HSH_EnterFullScreen2,
via the existing g_pfnCTCL_GetType hook so GameOS gains no game-code
dependency. Always logged, and states in words whether overlays will be drawn.
- render.cpp/.hpp: CHSH_Device::m_nDrawCalls, incremented in DrawQuad,
DrawThickFrame and DrawTexture, reset in CMR_Device::BeginScene and reported
for the first 5 frames from CMR_Device::EndScene when -tmr is active. Zero
draws proves the overlay code never ran; non-zero with a blank screen would
mean it ran and drew invisibly. This distinction is what settled the case.
- render.cpp: log CMR_Device surface creation plus the overlay texture's
dimensions, depth and channel masks.
- New -tmr <0-3> switch (MW4Application.cpp, documented in -help): 0 normal,
1 background blit with DDBLTFAST_WAIT|DDBLTFAST_NOCOLORKEY, 2 Clear instead of
the background blit, 3 as 2 plus alpha blending off and an untextured magenta
DrawQuad.
Mode 3 drew magenta and mode 2 was pure black, which cleared the 3D device, the
flip and the background blit in two runs; the draw counter then reported 0 and
pointed straight at the gate. Documented as STEP 11 in CLAUDE.md, including the
field triage rule: read "CTCL type =" in gos-displays.txt before suspecting
drivers.
Co-authored-by: Claude Opus 5 (Anthropic) <noreply@anthropic.com>
Co-authored-by: GitHub Copilot <copilot@github.com>
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