Subversion Repositories gelsvn

// ----------------------------------------

// A simple OBJ viewer.

// 

// Controls:

// - left mouse down + mouse motion : rotate

// - Scroll button and +- buttons   : zoom

// - right mouse click              : centre trackball

// - esc                            : exits

// - x,y,z buttons                  : switch trackball up axis 

// ----------------------------------------

#if (_MSC_VER >= 1200)

#pragma warning (disable: 4786)

#endif

#include <list>

#include <vector>

#include <CGLA/Vec3f.h>

#include <CGLA/Mat4x4f.h>

#include "Graphics/gel_glut.h"

#include "Geometry/TriMesh.h"

#include "Graphics/SimpleTrackBall.h"

#include "Geometry/obj_load.h"

using namespace std;

using namespace CGLA;

using namespace Geometry;

using namespace Graphics;

namespace

{

	int win_size_x = 800;

	int win_size_y = 800;

	SimpleTrackBall* ball;

	int main_window; 

	bool depth_pick(int x, int y,Vec3f& wp)

	{

		// Enquire about the viewport dimensions

		GLint viewport[4];

		glGetIntegerv(GL_VIEWPORT, viewport);

		// Get the minimum and maximum depth values.

		float minmax_depth[2];

		glGetFloatv(GL_DEPTH_RANGE, minmax_depth);

		// Read a single pixel at the position of the mouse cursor.

		float depth;

		glReadPixels(x, viewport[3]-y, 1,1, GL_DEPTH_COMPONENT,

								 GL_FLOAT, (void*) &depth);

		// If the depth corresponds to the far plane, we clicked on the

		// background.

		if(depth == minmax_depth[1])

			return false;

		// The lines below copy the viewing transformation from OpenGL

		// to local variables. The call to gluLookAt must have exactly 

		// the same parameters as when the scene is drawn.

		glLoadIdentity();

		ball->gl_view();

		double mvmat[16];

		glGetDoublev(GL_MODELVIEW_MATRIX, mvmat);

		// Copy the projection matrix. We assume it is unchanged.

		double prjmat[16];

		glGetDoublev(GL_PROJECTION_MATRIX, prjmat);

		// Now unproject the point from screen to world coordinates.

		double ox, oy, oz;

		gluUnProject(x,viewport[3]-y,depth,

								 mvmat,prjmat,viewport,

								 &ox, &oy, &oz);

		wp = Vec3f(ox,oy,oz);

		return true;

	}

	TriMesh mesh;

	void mouse_motion(int x, int y)

	{

		ball->roll(x,y);

	}

	void mouse(int button, int state, int x, int y)

	{

		if(button==GLUT_RIGHT_BUTTON && state==GLUT_DOWN)

			{

				Vec3f p;

				if(depth_pick(x, y, p))

					ball->set_center(p);

			}

		else if(button==3) 

			ball->farther(); 

		else if(button==4)

			ball->closer();

	}

	void idle()

	{

		if ( glutGetWindow() != main_window ) 

			glutSetWindow(main_window);  

		glutPostRedisplay();

	}

	void display() 

	{

			static bool washere = false;

			static unsigned int l;

			if(!washere)

			{

					cout << "Creating display list" << endl;

					l = glGenLists(1);

					glNewList(l, GL_COMPILE);

					mesh.gl_draw();

					glEndList();

					washere = true;

			}

			glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

			glLoadIdentity();

			ball->gl_view();

			glCallList(l);

			glutSwapBuffers();

	}

	void keyboard(unsigned char key, int x, int y) 

	{	

		switch(key) 

			{

			case '\033': exit(0); break;

			case '+': ball->closer(); break;

			case '-': ball->farther(); break;

			default:

				ball->up_axis(key);

			}

	}

}

int main(int argc, char** argv)

{ 

	// GLUT INIT

	glutInitDisplayMode(GLUT_RGBA|GLUT_DOUBLE|GLUT_DEPTH);

	glutInitWindowSize(win_size_x, win_size_y);

	glutInit(&argc, argv);

	main_window = glutCreateWindow("OBJ Viewer");

	glutDisplayFunc(display);

	glutKeyboardFunc(keyboard);

	glutMotionFunc(mouse_motion);

	glutMouseFunc(mouse);

	glutIdleFunc(idle);

	// GL INIT

	glClearColor(.8f, 0.9f, 1.0f, 0.f);

	glEnable(GL_DEPTH_TEST);

	glEnable(GL_LIGHTING);

	glEnable(GL_LIGHT0);

	glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1);

	glShadeModel(GL_SMOOTH);

	// LOAD OBJ

	string fn;

	if(argc>1)

			fn = argv[1];

		else

			fn = "../../data/head.obj";

	cout << "Loading " << fn << endl;

	if(fn == "") exit(0);

	obj_load(fn, mesh);

	if(!mesh.has_normals())

		{

			cout << "Computing normals" << endl;

			mesh.compute_normals();

		}

	// Initialize textures

	mesh.gl_init_textures();

	// Initialize Trackball

	Vec3f c;

	float r;

	mesh.get_bsphere(c,r);

	r *= 1.5;

	ball = new SimpleTrackBall(c,r);

	// Setup projection

	glMatrixMode(GL_PROJECTION);

	glLoadIdentity();

	gluPerspective(53,1.0f,r/100,r*3);

	glMatrixMode(GL_MODELVIEW);

	// Pass control to GLUT

	glutMainLoop();

	return 0;

}