Files
qelectrotech-source-mirror/cmake/developer_options.cmake
T
ispyisail 2e4bb486bb Add 3D mouse (SpaceMouse/SpacePilot) pan/zoom support via libspnav
Implements discussion #599's phase 1 (Linux, libspnav): a 3Dconnexion
6-DOF device pans and zooms the active diagram view, via spacenavd.

## Off by default, zero cost when off

QET_ENABLE_SPACEMOUSE (cmake/developer_options.cmake) is OFF. Verified in
two separate build directories from a clean configure: with it off, the
new cmake/find_spacemouse.cmake step runs and does nothing (no library
lookup, no definition, no new source files compiled), and qetapp.cpp/.h
produce zero new object code -- both are entirely #ifdef'd out. The
default build is byte-for-byte the same shape as before this commit.

With it on, libspnav is located via its pkg-config file (spnav.pc, shipped
by libspnav-dev on Debian/Ubuntu and equivalent packages elsewhere). If the
option is on but the library isn't found, this does not hard-fail
configure: it downgrades back to off with a warning, so an opt-in feature
never blocks a developer who doesn't have the library installed.

## No new navigation logic -- a new input source for the existing one

DiagramView::wheelEvent() already turns a physical wheel's delta into
horizontalScrollBar()/verticalScrollBar() calls for pan and a
zoom(1 + value/1000) call for zoom -- see diagramview.cpp:661-687.
SpaceMouseListener calls exactly those same primitives from spnav motion
events instead of wheel events. It does not reimplement panning or
zooming.

## Safe by construction even when compiled in

The overwhelming majority of users of a build with the option on still
won't have spacenavd running or a device attached -- that must never
surface as an error dialog or a startup warning. SpaceMouseListener::
isAvailable() reflects this: spnav_open() failing is treated as the
ordinary case, not an error, and the object then does nothing at all.
Verified for real in this environment, which genuinely has no spacenavd
running: built with the option on, ran the resulting binary to completion,
and confirmed zero crashes and zero spnav-related output of any kind --
the silence is the point.

Motion is read via a QSocketNotifier on spnav_fd() (event-driven, no
polling loop, no idle cost) and applied to whichever DiagramView is
currently active, found via qApp->activeWindow() -> QETDiagramEditor ->
currentProjectView() -> currentDiagram(): a 6-DOF device is one ambient
input source for the whole application, not something tied to a
particular window, so there is exactly one listener, owned by QETApp.

## What could not be verified without hardware

The Z-axis-to-zoom-factor mapping (SpaceMouseListener::zoomFactorForZAxis)
is a pure function specifically so it could be tested without a live
device: confirmed a centered device (z=0) yields exactly 1.0 (an exact
no-op, not an epsilon-off value that could trip DiagramView::zoom()'s
>=1 branch), and that push/pull produce symmetric zoom-in/out factors.

What genuinely cannot be checked in this environment: which physical axis
is "left/right" vs "up/down" vs "push/forward", their sign, and whether
the ZOOM_DIVISOR/PAN_SCALE constants feel right on real hardware. Both are
named constants specifically so recalibrating them is a one-line change
once someone with a device tries it -- flagged plainly in the PR rather
than presented as verified.

## Not in this commit

Windows/macOS (proprietary 3DxWare SDK, materially bigger lift) and
device button mapping are both explicitly out of scope for this phase per
the discussion.
2026-08-02 21:04:57 +12:00

41 lines
1.7 KiB
CMake

# Copyright 2006 The QElectroTech Team
# This file is part of QElectroTech.
#
# QElectroTech is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# QElectroTech is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
message(" - developer_options")
# warn on *any* usage of deprecated APIs
add_definitions(-DQT_DEPRECATED_WARNINGS)
# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# disables all the APIs deprecated before Qt 6.0.0
#add_definitions(-DQT_DISABLE_DEPRECATED_BEFORE=0x060000)
# to enable function names and line numbers even for release builds
add_definitions(-DQT_MESSAGELOGCONTEXT)
# You can make your code warn on compile time for the TODO's
# In order to do so, uncomment the following line.
#add_definitions(-DTODO_LIST)
# Build with KF5
option(BUILD_WITH_KF5 "Build with KF5" ON)
# Phase 1 (Linux, libspnav) of discussion #599: 3Dconnexion SpaceMouse/
# SpacePilot pan/zoom support. Off by default -- see cmake/find_spacemouse.cmake
# for what happens when it is on but libspnav isn't found.
option(QET_ENABLE_SPACEMOUSE "Build with 3Dconnexion/libspnav 3D mouse support for pan/zoom (Linux, requires libspnav-dev and spacenavd)" OFF)