/*
* Camera.c
*
* This plugin registers a new view with the sim that orbits the aircraft. We do this by:
*
* 1. Registering a hotkey to engage the view.
* 2. Setting the view to external when we are engaged.
* 3. Registering a new camera control funcioin that ends when a new view is picked.
*
*/
#include <string.h>
#include "XPLMDisplay.h"
#include "XPLMUtilities.h"
#include "XPLMCamera.h"
#include "XPLMDataAccess.h"
#include "XPLMDisplay.h"
#include <stdio.h>
#include <math.h>
static XPLMHotKeyID gHotKey = NULL;
static XPLMDataRef gPlaneX = NULL;
static XPLMDataRef gPlaneY = NULL;
static XPLMDataRef gPlaneZ = NULL;
static void MyHotKeyCallback(void * inRefcon);
static int MyOrbitPlaneFunc(
XPLMCameraPosition_t * outCameraPosition,
int inIsLosingControl,
void * inRefcon);
PLUGIN_API int XPluginStart(
char * outName,
char * outSig,
char * outDesc)
{
strcpy(outName, "Camera");
strcpy(outSig, "xplanesdk.examples.camera");
strcpy(outDesc, "A plugin that adds a camera view.");
/* Prefetch the sim variables we will use. */
gPlaneX = XPLMFindDataRef("sim/flightmodel/position/local_x");
gPlaneY = XPLMFindDataRef("sim/flightmodel/position/local_y");
gPlaneZ = XPLMFindDataRef("sim/flightmodel/position/local_z");
/* Register our hot key for the new view. */
gHotKey = XPLMRegisterHotKey(XPLM_VK_F8, xplm_DownFlag,
"Circling External View",
MyHotKeyCallback,
NULL);
return 1;
}
PLUGIN_API void XPluginStop(void)
{
XPLMUnregisterHotKey(gHotKey);
}
PLUGIN_API void XPluginDisable(void)
{
}
PLUGIN_API int XPluginEnable(void)
{
return 1;
}
PLUGIN_API void XPluginReceiveMessage(
XPLMPluginID inFromWho,
int inMessage,
void * inParam)
{
}
void MyHotKeyCallback(void * inRefcon)
{
/* This is the hotkey callback. First we simulate a joystick press and
* release to put us in 'free view 1'. This guarantees that no panels
* are showing and we are an external view. */
XPLMCommandButtonPress(xplm_joy_v_fr1);
XPLMCommandButtonRelease(xplm_joy_v_fr1);
/* Now we control the camera until the view changes. */
XPLMControlCamera(xplm_ControlCameraUntilViewChanges, MyOrbitPlaneFunc, NULL);
}
/*
* MyOrbitPlaneFunc
*
* This is the actual camera control function, the real worker of the plugin. It is
* called each time X-Plane needs to draw a frame.
*
*/
int MyOrbitPlaneFunc(
XPLMCameraPosition_t * outCameraPosition,
int inIsLosingControl,
void * inRefcon)
{
if (outCameraPosition && !inIsLosingControl)
{
int w, h, x, y;
float dx, dz, dy, heading, pitch;
char buf[256];
/* First get the screen size and mouse location. We will use this to decide
* what part of the orbit we are in. The mouse will move us up-down and around. */
XPLMGetScreenSize(&w, &h);
XPLMGetMouseLocation(&x, &y);
heading = 360.0 * (float) x / (float) w;
pitch = 20.0 * (((float) y / (float) h) * 2.0 - 1.0);
/* Now calculate where the camera should be positioned to be 200
* meters from the plane and pointing at the plane at the pitch and
* heading we wanted above. */
dx = -200.0 * sin(heading * 3.1415 / 180.0);
dz = 200.0 * cos(heading * 3.1415 / 180.0);
dy = -200 * tan(pitch * 3.1415 / 180.0);
/* Fill out the camera position info. */
outCameraPosition->x = XPLMGetDataf(gPlaneX) + dx;
outCameraPosition->y = XPLMGetDataf(gPlaneY) + dy;
outCameraPosition->z = XPLMGetDataf(gPlaneZ) + dz;
outCameraPosition->pitch = pitch;
outCameraPosition->heading = heading;
outCameraPosition->roll = 0;
}
/* Return 1 to indicate we want to keep controlling the camera. */
return 1;
}
