feat: display module — brightness and power control over DDC/CI - #18
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adds `smctl display list | brightness | power` for external displays on Apple Silicon, via the private IOAVService I2C interface. The DDC layer is vendored from m1ddc (MIT, waydabber) and converted from Objective-C to plain C/CoreFoundation so SwiftPM builds it without ARC bridging. `power off` uses VCP 0xD6 (soft off): the panel powers down and drops signal, but stays in the macOS layout, so windows are not rearranged and it can be woken back over DDC. A true layout disconnect (CGSConfigureDisplayEnabled) was tested and rejected: it is a one-way door that survives replug and sleep, recoverable only by resetting the WindowServer display plists and rebooting. main.swift is renamed to SMCtl.swift because @main cannot coexist with a file named main.swift once the target has more than one source file.
🤖 LeoCode Review⏳ 等待审查... 最后更新: 2026-07-03 18:17 |
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Summary
smctl displaycommand group for external displays on Apple Silicon:list [--json],brightness [0-100] [--display <index|uuid>] [--json],power on|off [--display …]DisplayDDCC target: DDC/CI over the private IOAVService I2C interface, vendored from m1ddc (MIT) and converted from Objective-C to plain C/CoreFoundationpower off= VCP 0xD6 soft-off: panel drops signal but stays in the macOS layout (no window rearrangement) and wakes back over DDCmain.swift→SMCtl.swiftrename (Swift forbids@mainalongside amain.swiftin a multi-file target)Why not a true layout disconnect
CGSConfigureDisplayEnabled(displayplacer route) was tested on this machine and is a one-way door: the disabled display disappears from every layer (CG, IOKit, BetterDisplay), survives replug and full sleep, and only comes back after deleting the WindowServer display plists and rebooting. Documented in project memory; deliberately not shipped.Test plan