Fix marker screen detection and click events (#2029 & #1853)

[MohabCodeX]

(#2029 & #1853)

Statement
Markers are not traditional GTA objects and don't integrate with the game's native collision system. Several approaches were evaluated, but integrating markers with onClientClick caused issues due to the fundamental difference between markers and world objects.

Why?
We couldn't use onClientClick for markers because if there's a world object behind a marker, the object would be detected with higher priority than the marker due to GTA's native collision system. Markers aren't like other world objects, they're client-side UI elements that don't participate in the game's standard collision detection, requiring a separate detection approach.

Solution
Implemented a specialized marker detection system, enhanced screen visibility detection (IsClientSideOnScreen) with proper viewport clipping, and a new onClientMarkerClick event with parameters (button, state, screenX, screenY, worldX, worldY, worldZ, distance).

Result :

• isElementOnScreen() now works properly with markers.
• onClientMarkerClick event provides marker interaction detection.

Notes: I also found that click detection isn’t perfectly equivalent to marker size or shape (tested with arrow type only). This might be fixed by someone else in another PR, since it’s the original behavior and not related to my edits. I could add a threshold to the detection, but I preferred to leave it as is for now.

Feedback is appreciated 👍🏻

Example Usage :

local marker = createMarker(0, 0, 5, "arrow", 2, 255, 0, 0, 255)

function onMarkerClicked(button, state, screenX, screenY, worldX, worldY, worldZ, distance)
    if button == "left" and state == "down" then
        if isElementOnScreen(marker) then
            outputChatBox(string.format("Clicked visible marker at: %.1f, %.1f, %.1f", worldX, worldY, worldZ))
            outputChatBox(string.format("Distance: %.1f units", distance))
            outputChatBox(string.format("Screen position: %d, %d", screenX, screenY))
        else
            outputChatBox("Clicked marker that's not visible on screen")
        end
    end
end
addEventHandler("onClientMarkerClick", marker, onMarkerClicked)

function checkMarkerVisibility()
    if isElementOnScreen(marker) then
        outputChatBox("Marker is visible - you can click it!")
    else
        outputChatBox("Marker is off-screen")
    end
end
setTimer(checkMarkerVisibility, 500, 0)

[Nico8340]

Solution
Implemented a specialized marker detection system, enhanced screen visibility detection (IsClientSideOnScreen) with proper viewport clipping, and a new onClientMarkerClick event with parameters (button, state, screenX, screenY, worldX, worldY, worldZ, distance).

There's no sign of the onClientMarkerClick event in your code. If you're still working on it, please mark this pull request as stale.

[MohabCodeX]

There's no sign of the onClientMarkerClick event in your code. If you're still working on it, please mark this pull request as stale.

Thanks , also onClientMarkerClick is already implemented

https://github.com/MohabCodeX/mtasa-blue/blob/fix/client-side-entity/Client/mods/deathmatch/logic/CClientGame.cpp#L2815

https://github.com/MohabCodeX/mtasa-blue/blob/fix/client-side-entity/Client/mods/deathmatch/logic/CClientGame.cpp#L2530