yard.cpp

//  ========================================================================
//  COSC363: Computer Graphics (2018);  University of Canterbury.
//
//  FILE NAME: Yard.cpp
//  See Lab03.pdf for details.
//  ========================================================================

#include <iostream>
#include <cmath> 
#include <GL/glut.h>
#include "loadTGA.h"
using namespace std;

GLuint txId[2];   //Texture ids
float angle = 0, look_x, look_z = -1., eye_x, eye_z;  //Camera parameters

													  //--------------------------------------------------------------------------------
void loadTexture()
{
	glGenTextures(2, txId); 	// Create 2 texture ids

	glBindTexture(GL_TEXTURE_2D, txId[0]);  //Use this texture
	loadTGA("Wall.tga");
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	//Set texture parameters
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glBindTexture(GL_TEXTURE_2D, txId[1]);  //Use this texture
	loadTGA("Floor.tga");
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	//Set texture parameters
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);


	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
}

//--------------------------------------------------------------------------------
void special(int key, int x, int y)
{
	if (key == GLUT_KEY_LEFT) angle -= 0.1;  //Change direction
	else if (key == GLUT_KEY_RIGHT) angle += 0.1;
	else if (key == GLUT_KEY_DOWN)
	{  //Move backward
		eye_x -= 0.1*sin(angle);
		eye_z += 0.1*cos(angle);
	}
	else if (key == GLUT_KEY_UP)
	{ //Move forward
		eye_x += 0.1*sin(angle);
		eye_z -= 0.1*cos(angle);
	}

	look_x = eye_x + 100 * sin(angle);
	look_z = eye_z - 100 * cos(angle);
	glutPostRedisplay();
}

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

void initialise()
{
	//	loadTexture();	
	//	glEnable(GL_TEXTURE_2D);
	glClearColor(0., 1., 1., 1.);    //Background colour 		
}

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

void walls()
{
	glColor3f(0.8, 0.7, 0.3);   //replace with a texture

	glBegin(GL_QUADS);

	////////////////////// BACK WALL ///////////////////////

	glVertex3f(-15, 1, -15);
	glVertex3f(-15, -1, -15);
	glVertex3f(15, -1, -15);
	glVertex3f(15, 1, -15);

	////////////////////// FRONT WALL ///////////////////////

	glVertex3f(-15, 1, 15);
	glVertex3f(-15, -1, 15);
	glVertex3f(15, -1, 15);
	glVertex3f(15, 1, 15);

	////////////////////// LEFT WALL ///////////////////////

	glVertex3f(-15, 1, -15);
	glVertex3f(-15, -1, -15);
	glVertex3f(-15, -1, 15);
	glVertex3f(-15, 1, 15);


	////////////////////// RIGHT WALL ///////////////////////

	glVertex3f(15, 1, -15);
	glVertex3f(15, -1, -15);
	glVertex3f(15, -1, 15);
	glVertex3f(15, 1, 15);

	glEnd();
}
//--------------------------------------------------------------------------------

void floor()
{
	glColor3d(0.6, 0.25, 0.25);  //replace with a texture

	glBegin(GL_QUADS);
	glVertex3f(-15, -1, -15);
	glVertex3f(-15, -1, 15);
	glVertex3f(15, -1, 15);
	glVertex3f(15, -1, -15);
	glEnd();
}

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

void display()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(45., 1., 1., 100.);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(eye_x, 0, eye_z, look_x, 0, look_z, 0, 1, 0);

	walls();
	floor();

	glutSwapBuffers();
}

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

int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
	glutInitWindowSize(600, 600);
	glutInitWindowPosition(10, 10);
	glutCreateWindow("The Yard");
	initialise();

	glutDisplayFunc(display);
	glutSpecialFunc(special);
	glutMainLoop();
	return 0;
}