137 lines
5.1 KiB
C

#ifndef _XPLMInstance_h_
#define _XPLMInstance_h_
/*
* Copyright 2005-2012 Sandy Barbour and Ben Supnik All rights reserved. See
* license.txt for usage. X-Plane SDK Version: 2.1.1
*
*/
/***************************************************************************
* XPLMInstance
***************************************************************************/
/*
* This API provides instanced drawing of X-Plane objects (.obj files). In
* contrast to old drawing APIs, which required you to draw your own objects
* per-frame, the instancing API allows you to simply register an OBJ for
* drawing, then move or manipulate it later (as needed).
*
* This provides one tremendous benefit: it keeps all dataref operations for
* your object in one place. Because datarefs are main thread only, allowing
* dataref access anywhere is a serious performance bottleneck for the
* simulator---the whole simulator has to pause and wait for each dataref
* access. This performance penalty will only grow worse as X-Plane moves
* toward an ever more heavily multithreaded engine.
*
* The instancing API allows X-Plane to isolate all dataref manipulations for
* all plugin object drawing to one place, potentially providing huge
* performance gains.
*
* Here's how it works:
*
* When an instance is created, it provides a list of all datarefs you want to
* manipulate in for the OBJ in the future. This list of datarefs replaces the
* ad-hoc collections of dataref objects previously used by art assets. Then,
* per-frame, you can manipulate the instance by passing in a "block" of
* packed floats representing the current values of the datarefs for your
* instance. (Note that the ordering of this set of packed floats must exactly
* match the ordering of the datarefs when you created your instance.)
*
*/
#include "XPLMDefs.h"
#include "XPLMScenery.h"
#ifdef __cplusplus
extern "C" {
#endif
/***************************************************************************
* Instance Creation and Destruction
***************************************************************************/
/*
* Registers and unregisters instances.
*
*/
/*
* XPLMInstanceRef
*
* An opaque handle to an instance.
*
*/
typedef void * XPLMInstanceRef;
/*
* XPLMCreateInstance
*
* XPLMCreateInstance creates a new instance, managed by your plug-in, and
* returns a handle to the instance. A few important requirements:
*
* * The object passed in must be fully loaded and returned from the XPLM
* before you can create your instance; you cannot pass a null obj ref, nor
* can you change the ref later.
*
* * If you use any custom datarefs in your object, they must be registered
* before the object is loaded. This is true even if their data will be
* provided via the instance dataref list.
*
* * The instance dataref array must be a valid ptr to an array of at least
* one item that is null terminated. That is, if you do not want any
* datarefs, you must passa ptr to an array with a null item. You cannot
* pass null for this.
*
*/
XPLM_API XPLMInstanceRef XPLMCreateInstance(
XPLMObjectRef obj,
const char ** datarefs);
/*
* XPLMDestroyInstance
*
* XPLMDestroyInstance destroys and deallocates your instance; once called,
* you are still responsible for releasing the OBJ ref.
*
* Tip: you can release your OBJ ref after you call XPLMCreateInstance as long
* as you never use it again; the instance will maintain its own reference to
* the OBJ and the object OBJ be deallocated when the instance is destroyed.
*
*/
XPLM_API void XPLMDestroyInstance(
XPLMInstanceRef instance);
/***************************************************************************
* Instance Manipulation
***************************************************************************/
/*
* XPLMInstanceSetPosition
*
* Updates both the position of the instance and all datarefs you registered
* for it. Call this from a flight loop callback or UI callback.
*
* __DO NOT__ call XPLMInstanceSetPosition from a drawing callback; the whole
* point of instancing is that you do not need any drawing callbacks. Setting
* instance data from a drawing callback may have undefined consequences, and
* the drawing callback hurts FPS unnecessarily.
*
* The memory pointed to by the data pointer must be large enough to hold one
* float for every data ref you have registered, and must contain valid
* floating point data.
*
* BUG: before X-Plane 11.50, if you have no dataref registered, you must
* still pass a valid pointer for data and not null.
*
*/
XPLM_API void XPLMInstanceSetPosition(
XPLMInstanceRef instance,
const XPLMDrawInfo_t * new_position,
const float * data);
#ifdef __cplusplus
}
#endif
#endif