XPLM Panel Graphics API

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The XPLMPanelGraphics API provides a 2-D drawing toolkit for avionics screens and instrument panels. You use these routines from within an avionics drawing callback (registered via XPLMRegisterAvionicsCallbacksEx or XPLMCreateAvionicsEx) to draw lines, polygons, text, and images onto the panel surface.

All drawing is expressed in panel coordinates: X increases to the right and Y increases upward. Drawing commands are buffered and rendered by X-Plane at the end of your callback; you do not manage OpenGL state directly.

Drawing State

Panel graphics functions modify a shared drawing state that includes a transformation matrix, a scissor (clip) rectangle, and a stencil mask. Each of these has a push/pop stack so you can save and restore state around localized drawing operations.

Drawing Order

Primitives are drawn in the order you submit them. Later drawing calls paint over earlier ones. Use the retained-drawing API to record a sequence of draw calls once and replay it efficiently on subsequent frames.