Map Drawing

These APIs are only valid from within a map drawing callback (one of XPLMIconDrawingCallback_t or XPLMMapLabelDrawingCallback_f). Your drawing callbacks are registered when you create a new map layer as part of your XPLMCreateMapLayer_t. The functions here hook into X-Plane's built-in map drawing functionality for icons and labels, so that you get a consistent style with the rest of the X-Plane map.

Note that the X-Plane 11 map introduces a strict ordering: layers of type xplm_MapLayer_Fill get drawn beneath all xplm_MapLayer_Markings layers. Likewise, all OpenGL drawing (performed in your layer's XPLMMapDrawingCallback_f) will appear beneath any icons and labels you draw.

XPLMMapOrientation

enum

Indicates whether a map element should be match its rotation to the map itself, or to the user interface. For instance, the map itself may be rotated such that "up" matches the user's aircraft, but you may want to draw a text label such that it is always rotated zero degrees relative to the user's perspective. In that case, you would have it draw with UI orientation.

Name	Value	Description
xplm_MapOrientation_Map	0	Orient such that a 0 degree rotation matches the map's north
xplm_MapOrientation_UI	1	Orient such that a 0 degree rotation is "up" relative to the user interface

XPLMDrawMapIconFromSheet

function

Enables plugin-created map layers to draw PNG icons using X-Plane's built-in icon drawing functionality. Only valid from within an XPLMIconDrawingCallback_t (but you can request an arbitrary number of icons to be drawn from within your callback).

X-Plane will automatically manage the memory for your texture so that it only has to be loaded from disk once as long as you continue drawing it per-frame. (When you stop drawing it, the memory may purged in a "garbage collection" pass, require a load from disk in the future.)

Instead of having X-Plane draw a full PNG, this method allows you to use UV coordinates to request a portion of the image to be drawn. This allows you to use a single texture load (of an icon sheet, for example) to draw many icons. Doing so is much more efficient than drawing a dozen different small PNGs.

The UV coordinates used here treat the texture you load as being comprised of a number of identically sized "cells". You specify the width and height in cells (ds and dt, respectively), as well as the coordinates within the cell grid for the sub-image you'd like to draw.

Note that you can use different ds and dt values in subsequent calls with the same texture sheet. This enables you to use icons of different sizes in the same sheet if you arrange them properly in the PNG.

This function is only valid from within an XPLMIconDrawingCallback_t (but you can request an arbitrary number of icons to be drawn from within your callback).

XPLM_API void       XPLMDrawMapIconFromSheet(
                         XPLMMapLayerID       layer,
                         const char *         inPngPath,
                         int                  s,
                         int                  t,
                         int                  ds,
                         int                  dt,
                         float                mapX,
                         float                mapY,
                         XPLMMapOrientation   orientation,
                         float                rotationDegrees,
                         float                mapWidth
                    );

XPLMDrawMapLabel

function

Enables plugin-created map layers to draw text labels using X-Plane's built-in labeling functionality. Only valid from within an XPLMMapLabelDrawingCallback_f (but you can request an arbitrary number of text labels to be drawn from within your callback).

XPLM_API void       XPLMDrawMapLabel(
                         XPLMMapLayerID       layer,
                         const char *         inText,
                         float                mapX,
                         float                mapY,
                         XPLMMapOrientation   orientation,
                         float                rotationDegrees
                    );