movement in a 3D terrain using GLUT and OOP

OpenGL OpenGL: Basic Coding
1

I’m programming a fun little scene that consists of 4 quads, one being the terrain and than 3 walls enclosing it. I want to create an object, for now something simple like a cube, and be able to move it around the terrain via the arrow keys.

I am implementing this using GLUT 3.7 and using an classes and C++ OOP design for all of my objects.

I am able to draw a cube in the middle of the terrain, but i can not move it. Any suggestions? code for the terrain, robot and main are posted below.

  /*
GLTerrain.cpp

  GLTerrain class implementation

  Author: Michael Le
  Date Created: 3.4.04
  Dependencies: openGL libraries

*/
#include "GLTerrain.h"
#include "textureLoader.h"

GLTerrain::GLTerrain(){
	_terrainBmp = "";
	_wallBmp = "";
}

GLTerrain::GLTerrain(char* terrainBmp, char* wallBmp){
	_terrainBmp = terrainBmp;
	_wallBmp = wallBmp;
}

GLTerrain::~GLTerrain(){
	delete _terrainBmp;
	delete _wallBmp;
}

void GLTerrain::initTex(char * terrainBmp, char* wallBmp){
	setTerrainBmp(terrainBmp);
	setWallBmp(wallBmp);
}

void GLTerrain::setTerrainBmp(char* terrainBmp){
	_terrainBmp = terrainBmp;
}

void GLTerrain::setWallBmp(char* wallBmp){
	_wallBmp = wallBmp;
}

void GLTerrain::setupTextures(){
	textureLoader* texLoader = new textureLoader();
	_terrainTex = texLoader->LoadGLTexture(_terrainBmp);
	_wallTex = texLoader->LoadGLTexture(_wallBmp);
	delete texLoader;
}

void GLTerrain::drawTerrain(){
	setupTextures();
	glEnable(GL_TEXTURE_2D);
	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
	glBindTexture(GL_TEXTURE_2D, _terrainTex);
	// terrain
	glBegin(GL_QUADS);
		glTexCoord2f(0.0f, 0.0f);	glVertex3f(0.0f, 0.0f, 600.0f);
		glTexCoord2f(1.0f, 0.0f);	glVertex3f(800.0f, 0.0f, 600.0f);
		glTexCoord2f(1.0f, 0.75f);	glVertex3f(800.0f, 0.0f, 0.0f);
		glTexCoord2f(0.0f, 0.75f);	glVertex3f(0.0f, 0.0f, 0.0f);
	glEnd();
	glBindTexture(GL_TEXTURE_2D, _wallTex);
	glBegin(GL_QUADS);
		// left wall
		glTexCoord2f(0.0f, 0.0f);	glVertex3f(0.0f, 0.0f, 600.0f);
		glTexCoord2f(1.0f, 0.0f);	glVertex3f(0.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 0.5f);	glVertex3f(0.0f, 300.0f, 0.0f);
		glTexCoord2f(0.0f, 0.5f);	glVertex3f(0.0f, 300.0f, 600.0f);
		glEdgeFlag(GL_TRUE);
	
		// back wall
		glTexCoord2f(0.0f, 0.0f);	glVertex3f(0.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 0.0f);	glVertex3f(800.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 0.375f);	glVertex3f(800.0f, 300.0f, 0.0f);
		glTexCoord2f(0.0f, 0.375f);	glVertex3f(0.0f, 300.0f, 0.0f);
		glEdgeFlag(GL_TRUE);
	
		// right wall
		glTexCoord2f(0.0f, 0.0f);	glVertex3f(800.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 0.0f);	glVertex3f(800.0f, 0.0f, 600.0f);
		glTexCoord2f(1.0f, 0.5f);	glVertex3f(800.0f, 300.0f, 600.0f);
		glTexCoord2f(0.0f, 0.5f);	glVertex3f(800.0f, 300.0f, 0.0f);
	glEnd();
	glFlush();
	glDisable(GL_TEXTURE_2D);
}

/*
glRobot.cpp

  Implementation of glRobot class

  Author: Michael Le
  Date Created: 3.4.04
  Dependencies: openGL libraries
*/

#include "glRobot.h"
#include "textureLoader.h"

//GLUquadricObj *robot;

glRobot::glRobot(){
	_x = 0.0f;
	_y = 0.0f;
	_z = 0.0f;
	_spin = 0.0f;
	_robotBmp = "";
}

glRobot::glRobot(GLfloat x, GLfloat y, GLfloat z, GLfloat spin, char * robotBmp, char* robot2Bmp){
	_x = x;
	_y = y;
	_z = z;
	_spin = spin;
	_robotBmp = robotBmp;
	_robot2Bmp = robot2Bmp;
}

glRobot::~glRobot(){
	delete _robotBmp;
	delete _robot2Bmp;
}

void glRobot::setupTexture(){
	textureLoader* texLoader = new textureLoader();
	_robotTex = texLoader->LoadGLTexture(_robotBmp);
	_robot2Tex = texLoader->LoadGLTexture(_robot2Bmp);
	delete texLoader;
}

void glRobot::drawRobot(){
	setupTexture();
	glTranslatef(_x, _y, _z);
	glRotatef(_spin, 0.0f, 1.0f, 0.0f);
	glEnable(GL_TEXTURE_2D);
	glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
	glBindTexture(GL_TEXTURE_2D, _robotTex);
	/*
	robot = gluNewQuadric();
	gluQuadricTexture(robot, GL_TRUE);
	gluQuadricDrawStyle(robot, GLU_FILL);
	gluQuadricNormals(robot, GLU_SMOOTH);
	gluCylinder(robot, 16.0, 16.0, 48.0, 0, 1);
	glDisable(GL_TEXTURE_2D);
	gluDisk(robot, 0.0, 16.0, 0, 1);
	glPushMatrix();
	glShadeModel(GL_SMOOTH);
	glRotatef(90.0, -1.0, 0.0, 0.0);
	glTranslatef(_x, _y, _z);
	glRotatef(_spin, 0.0, 1.0, 0.0);
	glPopMatrix();
	*/
	
	glBegin(GL_QUADS);
		glTexCoord2f(0.0f, 0.0f); glVertex3f(0.0f, 0.0f, 32.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(32.0f, 0.0f, 32.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(32.0f, 32.0f, 32.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(0.0f, 32.0f, 32.0f);
	glEnd();
	glBindTexture(GL_TEXTURE_2D, _robot2Tex);
	glBegin(GL_QUADS);
		// left side
		glTexCoord2f(0.0f, 0.0f); glVertex3f(0.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(0.0f, 0.0f, 32.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(0.0f, 32.0f, 32.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(0.0f, 32.0f, 0.0f);
		// backside
		glTexCoord2f(0.0f, 0.0f); glVertex3f(32.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(0.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(0.0f, 32.0f, 0.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(32.0f, 32.0f, 0.0f);
		// right side
		glTexCoord2f(0.0f, 0.0f); glVertex3f(32.0f, 0.0f, 32.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(32.0f, 0.0f, 0.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(32.0f, 32.0f, 0.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(32.0f, 32.0f, 32.0f);
		// top
		glTexCoord2f(0.0f, 0.0f); glVertex3f(0.0f, 32.0f, 32.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(32.0f, 32.0f, 32.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(32.0f, 32.0f, 0.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(0.0f, 32.0f, 0.0f);
	glEnd();
	glFlush();
	glDisable(GL_TEXTURE_2D);
}

void glRobot::moveForward(){
	_z = _z + 5.0f;
	//glutPostRedisplay();
}

void glRobot::moveBack(){
	_z = _z - 5.0f;
	//glutPostRedisplay();
}

void glRobot::rotateLeft(){
	_spin = _spin + 10.0f;
	if (_spin > 360.0f)
		_spin = _spin - 360.0f;
	//glutPostRedisplay();
}

void glRobot::rotateRight(){
	_spin = _spin - 10.0f;
	if (_spin < 0.0f)
		_spin = _spin + 360.0f;
	//glutPostRedisplay();
}



/*  
TCT.cpp

    This is the main program.  it is relatively simple.  
  
	This file creates a GLUT handler so that we can interface with glut through the C++
  wrapper.  It then creates a demo window and makes that window the current
  idle window and begins the GLUT main loop.
*/

// this first line takes care of windows complaining about a win32 MAIN API crap...
#pragma comment( linker, "/entry:\"mainCRTStartup\"" ) 

#include <GL/glut.h>
#include <GL/glaux.h>
#include "GLTerrain.h"
#include "glRobot.h"
#include <windows.h>
#include <iostream>

#pragma comment( lib, "opengl32.lib" )								// Search For OpenGL32.lib While Linking ( NEW )
#pragma comment( lib, "glu32.lib" )									// Search For GLu32.lib While Linking    ( NEW )
#pragma comment( lib, "glaux.lib" )	

GLTerrain _terrain = GLTerrain("data/grass2.bmp", "data/sky.bmp");
//glRobot _robot = glRobot(400.0f, 0.0f, 300.0f, 180.0f, "data/robot.bmp", "data/robot2.bmp");

void initialize(){
	glEnable(GL_TEXTURE_2D);
	glShadeModel(GL_SMOOTH);
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0f);
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LEQUAL);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
}

void drawScene(){
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glPushMatrix();
	_terrain.drawTerrain();
	//_robot.drawRobot();
	//glRotatef(_robot.getSpin(), 0.0, 1.0, 0.0);
	//glTranslatef(_robot.getX(), _robot.getY(), _robot.getZ());
	//glColor3f(1.0,1.0,1.0);
	//glBegin(GL_QUADS);
	//	glVertex3f(0.0f, 0.0f, 32.0f);
	//	glVertex3f(32.0f, 0.0f, 32.0f);
	//	glVertex3f(32.0f, 0.0f, 0.0f);
	//	glVertex3f(0.0f, 0.0f, 0.0f);
	//glEnd();
	glPopMatrix();
	glutSwapBuffers();
}

void reshape(int w, int h){
	glViewport(0, 0, (GLsizei) w, (GLsizei) h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(90.0f, (GLfloat) w/ (GLfloat) h, 1.0f, 750.0f);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(400.0f, 343.0f, 605.0f, 400.0f, 0.0f, 300.0f, 0.0f, 1.0f, -1.0f);
}

void keyboard(unsigned char key, int x, int y){
	switch(key){
	case 27:
		glutLeaveGameMode();
		exit(0);
		break;
	default:
		break;
	}
}

void rotateRight(){
	//_robot.rotateRight();
	glutPostRedisplay();
}

void rotateLeft(){
//	_robot.rotateLeft();
	glutPostRedisplay();
}

void moveForward(){
//	_robot.moveForward();
	glutPostRedisplay();
}

void moveBack(){
//	_robot.moveBack();
	glutPostRedisplay();
}

void arrowKeys(int key, int x, int y){
	switch(key){
	case GLUT_KEY_RIGHT:
		glutIdleFunc(rotateRight);
		break;
	case GLUT_KEY_LEFT:
		glutIdleFunc(rotateLeft);
		break;
	case GLUT_KEY_UP:
		glutIdleFunc(moveForward);
		break;
	case GLUT_KEY_DOWN:
		glutIdleFunc(moveBack);
	default:
		break;
	}
}


int main(int argc, char** argv){
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
	glutGameModeString("800x600:16");
	if(glutGameModeGet(GLUT_GAME_MODE_POSSIBLE))
		glutEnterGameMode();
	else{
		MessageBox(NULL,"Can not enter gamemode.","Error",MB_ICONSTOP);
		return -1;
	}
	initialize();

	glutDisplayFunc(drawScene);
	glutReshapeFunc(reshape);
	glutKeyboardFunc(keyboard);
	//glutSpecialFunc();
	//glutIdleFunc(drawScene);
	glutMainLoop();
	return 0;
}

Thanks, any help is greatly appreciated!!!