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Observing Gamepad State (PadOverlay)

The SDL3 build of the engine includes a debug overlay that shows the gamepad state ( on/off for 16 buttons and analog values for 6 axes ) in real time in the upper-left corner of the screen. It is useful when checking controller behavior on actual hardware ( for example, the Switch ).

For the detailed display specification and internals, see the guides in src/core:

Example display

+--------------------------------+
| Pad: Xbox Series X Controller  |
| [A ][B ][X ][Y ]               |
| [L1][R1][L2][R2]               |
| [BK][ST][LS][RS]               |
| [Lf][Up][Rt][Dn]               |
| LX +0.45 LY -0.32              |
| RX +0.00 RY +0.00              |
| LT +0.00 RT +0.80              |
+--------------------------------+
  • Header: SDL gamepad name ( (none) when nothing is connected )
  • Cells: green while pressed, dark gray otherwise
  • Axes: stick axes range -1.00 〜 +1.00, trigger axes 0.00 〜 +1.00

The WINVER build has no gamepad abstraction API, so when shown through the OGLDrawDevice path, every button is off and every axis reads +0.00.

Enabling the overlay

It works independently of -memoverlay=1 ( upper-right corner ), and both can be shown at the same time.

Reading axes directly from TJS2

The overlay is for observation; to read analog axis values from a script, use System.getPadAxis.

var v = System.getPadAxis(0, System.padAxisLeftX);
// v は -1.0 〜 +1.0 の実数 (未接続/無効値で 0.0)

Six axis ID constants are provided, such as System.padAxisLeftX.

Use System.rumblePad / System.stopRumblePad for vibration. To check the number of connected gamepads or whether one is present, use System.getJoypadCount / System.hasJoypad.