// Keyboard demo. Shows how to use more than one key on the keyboard
// at a time. Demo has a red box on a black background and user can
// use arrow keys or the 'w', 'a', 's', 'd' keys to move the box
// around the screen, the point being that you can hold more than
// one key down at a time and the box will move accordingly (ie.
// diagonally).


//#include <windows.h>
#include <gl/glut.h>
#include <stdio.h>

// Initial square position and size
float xPos = 320.0;
float yPos = 240.0;
GLsizei rsize = 25;

#define FALSE 0
#define TRUE 1

int up = FALSE;
int down = FALSE;
int left = FALSE;
int right = FALSE;


void moveObject(void)
{
    if(left)
    {
	xPos -= 4.0;
	
	// Keep it inside of the box
	if(xPos-rsize < 0.0)
	    xPos = 0.0+rsize;
    }
    
    if(right)
    {
	xPos += 4.0;
	
	// Keep it inside of the box
	if(xPos+rsize > 640.0)
	    xPos = 640.0-rsize;
	
    }
    
    if(up)
    {
	yPos += 4.0;
	
	// Keep it inside of the box
	if(yPos+rsize > 480.0)
	    yPos = 480.0-rsize;
	
    }
    
    if(down)
    {
	yPos -= 4.0;
	// Keep it inside of the box
	if(yPos-rsize < 0.0)
	    yPos = 0.0+rsize;
    }
}


void myDisplay(void)
{
    glClear(GL_COLOR_BUFFER_BIT);
    
    glColor3f(1.0f, 0.0f, 0.0f);
    
    moveObject();

    glRectf(xPos-rsize, yPos-rsize, xPos+rsize, yPos+rsize);
    
    glutSwapBuffers();
}


void TimerFunc(int value)
{
    myDisplay();
    glutPostRedisplay();
    glutTimerFunc(33,TimerFunc, 1);
}


void myInit(void)
{
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glColor3f(0.0f, 0.0f, 0.0f);
    glPointSize(1.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0, 640.0, 0.0, 480.0);
}


void pressKey(unsigned char key, int x, int y)
{
    switch (key)
	{
	case 'a':
	    left = TRUE;
	    break;
	case 'd':
	    right = TRUE;
	    break;
	case 'w':
	    up = TRUE;
	    break;
	case 's':
	    down = TRUE;
	    break;
	}
}


void releaseKey(unsigned char key, int x, int y)
{
    switch (key)
    {
    case 'a':
	left = FALSE;
	break;
    case 'd':
	right = FALSE;
	break;
    case 'w':
	up = FALSE;
	break;
    case 's':
	down = FALSE;
	break;
    }
}


void pressKeySpecial(int key, int x, int y)
{
    switch (key)
    {
    case GLUT_KEY_LEFT :
	left = TRUE;
	break;
    case GLUT_KEY_RIGHT :
	right = TRUE;
	break;
    case GLUT_KEY_UP :
	up = TRUE;
	break;
    case GLUT_KEY_DOWN :
	down = TRUE;
	break;
    }
}


void releaseKeySpecial(int key, int x, int y)
{
    switch (key)
    {
    case GLUT_KEY_LEFT :
	left = FALSE;
	break;
    case GLUT_KEY_RIGHT :
	right = FALSE;
	break;
    case GLUT_KEY_UP :
	up = FALSE;
	break;
    case GLUT_KEY_DOWN :
	down = FALSE;
	break;
    }
}


int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
    glutInitWindowSize(640, 480);
    glutInitWindowPosition(50, 50);
    glutCreateWindow("KeyBoard Test");
    glutDisplayFunc(myDisplay);
    glutTimerFunc(33, TimerFunc, 1);
    glutSpecialFunc(pressKeySpecial);
    glutSpecialUpFunc(releaseKeySpecial);
    glutKeyboardFunc(pressKey);
    glutKeyboardUpFunc(releaseKey);
    myInit();
    glutMainLoop();
    
    return 1;
}