bugfix(mouse): Fix bad drag tolerances with high scroll speed factors

[xezon]

• Fixes Army gets deselected when moving camera with drag right click #2778

This change fixes the bad drag tolerances with high scroll speed factors, which was introduced by #1501 and is especially pronounced in this Project because players are encouraged to set way higher scroll factors after #1026 when higher frame rates no longer increase the camera movement.

[greptile-apps]

Greptile Summary

This PR fixes click vs. drag misdetection that occurs when players use high keyboard scroll speed factors, which became more common after frame-rate-independent scrolling was introduced. The two-part fix scales down the drag tolerance in isClick() inversely proportional to the scroll speed factor and removes the 3D camera-position change check that was independently firing false "drag" signals whenever the camera moved between right-click-down and right-click-up.

• Adds Mouse::getDragToleranceAdjustedForScrollFactor(), which returns m_dragTolerance * (defaultScrollFactor / currentScrollFactor) so that a higher scroll factor yields a tighter pixel tolerance.
• Removes m_deselectDownCameraPosition and all associated camera-delta logic from SelectionTranslator, eliminating the third deselect-suppression condition that was overly sensitive to fast scrolling.

Confidence Score: 5/5

Safe to merge — the right-click deselect path is cleanly fixed and the removed camera-drift check had no other dependents.

Both changes are tightly scoped: the tolerance formula in getDragToleranceAdjustedForScrollFactor is mathematically straightforward, and stripping the camera-position delta from right-click deselect removes a known false-positive trigger without breaking any other behavior. No new state is introduced and the removed m_deselectDownCameraPosition member has no remaining references.

No files require special attention. The one open question — whether SelectionXlat.cpp:409 and MetaEvent.cpp:514 also need the scroll-factor-adjusted tolerance — is worth confirming but does not affect correctness of the changes in this PR.

Important Files Changed

Filename	Overview
Core/GameEngine/Source/GameClient/Input/Mouse.cpp	Adds getDragToleranceAdjustedForScrollFactor() and wires it into isClick(); formula is mathematically correct and the integer-to-float promotion for the comparison is safe.
Core/GameEngine/Include/GameClient/Mouse.h	Adds the getDragToleranceAdjustedForScrollFactor() declaration; no structural concerns.
Core/GameEngine/Source/GameClient/MessageStream/SelectionXlat.cpp	Removes the camera-position drift check from right-click deselect detection; correctly updates the comment to reflect only two remaining suppression conditions.
Core/GameEngine/Include/GameClient/SelectionXlat.h	Removes the m_deselectDownCameraPosition member now that the camera-drift check is gone; no remaining references.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[MSG_RAW_MOUSE_RIGHT_BUTTON_DOWN] --> B[Record anchor pixel position\nRecord timestamp]
    A --> C["~~Record 3D camera position~~\n(removed)"]
    style C stroke:#f66,stroke-dasharray:5 5,color:#f66

    D[MSG_RAW_MOUSE_RIGHT_BUTTON_UP] --> E[Read current pixel position\nRead current timestamp]
    E --> F["isClick(anchor, current, t0, t1)"]
    F --> G["dragTolerance =\nm_dragTolerance x (defaultScrollFactor / currentScrollFactor)"]
    G --> H{"abs(dx) > dragTolerance\nOR abs(dy) > dragTolerance\nOR elapsed > dragToleranceMS?"}
    H -- Yes --> I[Not a click - ignore deselect]
    H -- No --> J[Click detected - deselect / cancel GUI]

Loading

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flowchart TD
    A[MSG_RAW_MOUSE_RIGHT_BUTTON_DOWN] --> B[Record anchor pixel position\nRecord timestamp]
    A --> C["~~Record 3D camera position~~\n(removed)"]
    style C stroke:#f66,stroke-dasharray:5 5,color:#f66

    D[MSG_RAW_MOUSE_RIGHT_BUTTON_UP] --> E[Read current pixel position\nRead current timestamp]
    E --> F["isClick(anchor, current, t0, t1)"]
    F --> G["dragTolerance =\nm_dragTolerance x (defaultScrollFactor / currentScrollFactor)"]
    G --> H{"abs(dx) > dragTolerance\nOR abs(dy) > dragTolerance\nOR elapsed > dragToleranceMS?"}
    H -- Yes --> I[Not a click - ignore deselect]
    H -- No --> J[Click detected - deselect / cancel GUI]

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_{Reviews (2): Last reviewed commit: "Remove legacy m_deselectDownCameraPositi..." | Re-trigger Greptile}

[Caball009]

#1501 Seems related.

Maybe using DragTolerance3D (or the idea behind it: distance in the actual game world) makes more sense than accounting for scroll factor?

[xezon]

Maybe using DragTolerance3D (or the idea behind it: distance in the actual game world) makes more sense than accounting for scroll factor?

In principle yes, but that would require

DragTolerance3D = 30 ; How many feet in world space should we allow before it is a drag?

to be a reasonable value and the arguments of the isClick function to take in world positions instead of mouse positions.

#1501 Seems related.

It looks related yes.

[Skyaero42]

I think for now this is a sufficient fix.

[Caball009]

The GeneralsOnline devs are going to include this in a test build for the affected users to test. Let's wait a bit for the results.

[xezon]

#1501 Seems related.

Maybe using DragTolerance3D (or the idea behind it: distance in the actual game world) makes more sense than accounting for scroll factor?

Here is the fix using DragTolerance3D: #2826