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glViewerExercise.C File Reference

Detailed Description

Script showing how to use the GL viewer API to animate a picture.

#include "TGLViewer.h"
#include "TGLOrthoCamera.h"
#include "TTimer.h"
#include "TRandom.h"
#include "TVirtualPad.h"
TTimer timer(25);
TRandom randGen(0);
Int_t moveCount = 0;
void AnimateCamera()
{
// initialization
static Double_t fov = 30;
static Double_t zoom = 0.78;
static Double_t dolly = 1500.0;
static Double_t center[3] = {-164.0, -164.0, -180.0};
static Double_t hRotate = 0.0;
static Double_t vRotate = 0.0;
// steps
static Double_t fovStep = randGen.Rndm() * 3.0 - 0.5;
static Double_t zoomStep = (20 - randGen.Rndm()) / 1000.;
static Double_t dollyStep = randGen.Rndm() * 5.0 - 1.0;
static Double_t centerStep[3] = {randGen.Rndm() * 4, randGen.Rndm() * 4, randGen.Rndm() * 4};
static Double_t hRotateStep = randGen.Rndm() * 0.025;
static Double_t vRotateStep = randGen.Rndm() * 0.05;
// move center
center[0] += centerStep[0];
center[1] += centerStep[1];
center[2] += centerStep[2];
Double_t mag = TMath::Sqrt(center[0] * center[0] + center[1] * center[1] + center[2] * center[2]);
if (mag > 500) {
centerStep[0] = -centerStep[0];
centerStep[1] = -centerStep[1];
centerStep[2] = -centerStep[2];
}
// rotate
hRotate += hRotateStep;
vRotate += vRotateStep;
if (vRotate >= TMath::TwoPi() || vRotate <= 0.0)
vRotateStep = -vRotateStep;
if (hRotate >= (TMath::PiOver2() - 0.02f) || hRotate <= (0.07f - TMath::PiOver2())) {
hRotateStep = -hRotateStep;
}
// dolly
dolly += dollyStep;
if (dolly >= 2000.0 || dolly <= 1500.0)
dollyStep = -dollyStep;
// modify frustum
TGLViewer *v = (TGLViewer *)gPad->GetViewer3D();
if (camera < 3) {
fov += fovStep;
if (fov > 130.0 || fov < 5.0)
fovStep = -fovStep;
} else {
zoom += zoomStep;
if (zoom > 4.0 || zoom < 0.25)
zoomStep = -zoomStep;
}
// apply
if (camera < 3)
v->SetPerspectiveCamera(camera, fov, dollyStep, center, hRotateStep, vRotateStep);
else
v->SetOrthoCamera(camera, zoom, dollyStep, center, hRotateStep, vRotateStep);
if (++moveCount % 10 == 0)
v->RefreshPadEditor(v);
}
void glViewerExercise()
{
gROOT->ProcessLine(".x nucleus.C");
TGLViewer *v = (TGLViewer *)gPad->GetViewer3D();
// Random draw style
Int_t style = randGen.Integer(3);
switch (style) {
case 0: v->SetStyle(TGLRnrCtx::kFill); break;
case 1: v->SetStyle(TGLRnrCtx::kOutline); break;
case 2: v->SetStyle(TGLRnrCtx::kWireFrame); break;
}
// Lights - turn some off randomly
TGLLightSet *ls = v->GetLightSet();
if (randGen.Integer(2) == 0)
if (randGen.Integer(2) == 0)
if (randGen.Integer(2) == 0)
if (randGen.Integer(2) == 0)
// Random camera type
Int_t id = randGen.Integer(6);
camera = (TGLViewer::ECameraType)id;
v->SetCurrentCamera(camera);
v->CurrentCamera().SetExternalCenter(kTRUE);
if (id > 2) {
// 0, 1, and 2 - are different 'perspective' camers.
TGLOrthoCamera &o = static_cast<TGLOrthoCamera &>(v->CurrentCamera());
}
// Now animate the camera
TGLSAViewer *sav = dynamic_cast<TGLSAViewer *>(v);
if (sav)
sav->GetFrame()->Connect("CloseWindow()", "TTimer", &timer, "TurnOff()");
timer.SetCommand("AnimateCamera()");
timer.TurnOn();
}
int Int_t
Definition RtypesCore.h:45
constexpr Bool_t kFALSE
Definition RtypesCore.h:94
double Double_t
Definition RtypesCore.h:59
constexpr Bool_t kTRUE
Definition RtypesCore.h:93
Option_t Option_t style
#define gROOT
Definition TROOT.h:406
#define gPad
Encapsulates a set of lights for OpenGL.
Definition TGLLightSet.h:22
void SetLight(ELight light, Bool_t on)
Set a light on/off.
Orthographic projection camera.
void SetEnableRotate(Bool_t x)
The top level standalone GL-viewer - created via plugin manager.
Definition TGLSAViewer.h:38
TGCompositeFrame * GetFrame() const
Return the main-frame.
void SetStyle(Short_t st)
Base GL viewer object - used by both standalone and embedded (in pad) GL.
Definition TGLViewer.h:55
void SetPerspectiveCamera(ECameraType camera, Double_t fov, Double_t dolly, Double_t center[3], Double_t hRotate, Double_t vRotate)
Set a perspective camera to supplied configuration - note this does not need to be the current camera...
Bool_t Connect(const char *signal, const char *receiver_class, void *receiver, const char *slot)
Non-static method is used to connect from the signal of this object to the receiver slot.
Definition TQObject.cxx:869
This is the base class for the ROOT Random number generators.
Definition TRandom.h:27
Handles synchronous and a-synchronous timer events.
Definition TTimer.h:51
constexpr Double_t PiOver2()
Definition TMath.h:51
Double_t Sqrt(Double_t x)
Returns the square root of x.
Definition TMath.h:666
constexpr Double_t TwoPi()
Definition TMath.h:44
Author
Richard Maunder

Definition in file glViewerExercise.C.