#include <GL/glew.h>
#include <GL/gl.h>
#include <GL/glext.h>
#include <GL/GLUT.h>

#include <math.h>

#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <fstream>
#include <assert.h>

#include "heightfield.h"

#pragma comment(lib,"glew32.lib")

float xpos = 851.078, ypos = 351.594, zpos = 281.033, xrot = 758, yrot = 238, angle=0.0;
float lastx, lasty;

float bounce;
float cScale = 1.0;

SwiftHeightField hField;

void camera (void) {
	int posX = (int)xpos;
	int posZ = (int)zpos;

	glRotatef(xrot,1.0,0.0,0.0);
	glRotatef(yrot,0.0,1.0,0.0); 
	glTranslated(-xpos,-ypos,-zpos);
}

void display (void) {
	glClearColor (0.0,0.0,0.0,1.0);
    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();  
	camera();

	glPushMatrix();
	hField.Render();
	glPopMatrix();

	glutSwapBuffers();
}

void Init (void) {
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LEQUAL);

	hField.Create("heightField.raw", 1024, 1024);
}

void mouseMovement(int x, int y) {
	int diffx=x-lastx; 
	int diffy=y-lasty; 
	lastx=x; 
	lasty=y; 
	xrot += (float) diffy; 
	yrot += (float) diffx;
}

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

	if (key == 'w')
	{
	float xrotrad, yrotrad;
	yrotrad = (yrot / 180 * 3.141592654f);
	xrotrad = (xrot / 180 * 3.141592654f); 
	xpos += float(sin(yrotrad)) * cScale;
	zpos -= float(cos(yrotrad)) * cScale;
	ypos -= float(sin(xrotrad)) ;
	bounce += 0.04;
	}

	if (key == 's')
	{
	float xrotrad, yrotrad;
	yrotrad = (yrot / 180 * 3.141592654f);
	xrotrad = (xrot / 180 * 3.141592654f); 
	xpos -= float(sin(yrotrad)) * cScale;
	zpos += float(cos(yrotrad)) * cScale;
	ypos += float(sin(xrotrad));
	bounce += 0.04;
	}

	if (key == 'd')
	{
    float yrotrad;
	yrotrad = (yrot / 180 * 3.141592654f);
	xpos += float(cos(yrotrad)) * cScale;
	zpos += float(sin(yrotrad)) * cScale;
	}

	if (key == 'a')
	{
	float yrotrad;
	yrotrad = (yrot / 180 * 3.141592654f);
	xpos -= float(cos(yrotrad)) * cScale;
	zpos -= float(sin(yrotrad)) * cScale;
	}

}

void reshape (int w, int h) {
	glViewport (0, 0, (GLsizei)w, (GLsizei)h);
	glMatrixMode (GL_PROJECTION);
	glLoadIdentity ();
	gluPerspective (60, (GLfloat)w / (GLfloat)h, 1.0, 1000.0);
	glMatrixMode (GL_MODELVIEW);
}

int main (int argc, char **argv) {
    glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH | GLUT_RGBA);
	glutInitWindowSize(500, 500);
	glutInitWindowPosition(100, 100);
    glutCreateWindow("A basic OpenGL Window");
	Init();
    glutDisplayFunc(display);
	glutIdleFunc(display);
	glutReshapeFunc(reshape);
	glutKeyboardFunc(keyboard);
	glutPassiveMotionFunc(mouseMovement);
    glutMainLoop ();
    return 0;
}