/* 
 * Touch sensitive keyboard
 */
#include "midiIO.h"
#include "glut.h"
#include <stdlib.h>

/* function defs */
void idle(void);
void handleKeys(unsigned char key, int, int);
int drawObjects(void);
double myRand(void);

/* globals */
int pad[4] = {0, 0, 0, 0};
int state[4] = {0, 0, 0, 0};
int note[4] = {50, 55, 60, 65};
double x0, y0, x1, y1, x2, y2, x3, y3;



/**********************************************************************/
void handleKeys(unsigned char key, int x, int y)
{
  if (key == 'q')
	{
	exit(0);
	}

} /* end handleKeys */


double myRand(void)
{
double sign;

if (rand() > 16384)
	{
	sign = -1.0;
	}
else
	{
	sign = 1.0;
	}
return ((double)rand() / 32767.0) * sign;
}


/**********************************************************************/
void idle(void)
{
MDevent event;
int channel = 1;
int index, noteOn = 0, noteOff = 0;

if (getMidiEvent(&event) > 0) /* retrieve most current event */
	{	
	switch (event.msg[1])
		{
		case 16:
			pad[0] = event.msg[2];
			if ((pad[0] > 0) && (state[0] == 0))
				{
				noteOn = 1;
				index = 0;
				}
			else if (pad[0] == 0)
				{
				state[0] = 0;
				noteOff = 1;
				index = 0;
				}
			break;
		case 17:
			pad[1] = event.msg[2];
			if ((pad[1] > 0) && (state[1] == 0))
				{
				noteOn = 1;
				index = 1;
				}
			else if (pad[1] == 0)
				{
				state[1] = 0;
				noteOff = 1;
				index = 1;
				}
			break;
		case 18:
			pad[2] = event.msg[2];
			if ((pad[2] > 0) && (state[2] == 0))
				{
				noteOn = 1;
				index = 2;
				}
			else if (pad[2] == 0)
				{
				state[2] = 0;
				noteOff = 1;
				index = 2;
				}
			break;
		case 19:
			pad[3] = event.msg[2];
			if ((pad[3] > 0) && (state[3] == 0))
				{
				noteOn = 1;
				index = 3;
				}
			else if (pad[3] == 0)
				{
				state[3] = 0;
				noteOff = 1;
				index = 3;
				}
			break;
		case 75:
			/* send instrument type */
			event.msg[0] = MD_PROGRAMCHANGE|channel;
			event.msg[1] = event.msg[2];
			sendMidiEvent(&event);
			break;
		default:
			break;
		} /* end switch */

	/* process note change */
	if (noteOn)
		{
		/* send note on */	
		event.msg[0] = MD_NOTEON|channel;
		event.msg[1] = note[index];
		event.msg[2] = 100;
		sendMidiEvent(&event);
		}

	if (noteOff)
		{
		/* Now send a note off */
		event.msg[0] = MD_NOTEOFF|channel;
		event.msg[1] = note[index];
		event.msg[2] = 0;
		sendMidiEvent(&event);
		}

	glutPostRedisplay();
	} /* end if */
} /* end idle */


/**********************************************************************/
int drawObjects(void)
{
double size;
int sign;

if (pad[0] > 0)
	{
	if (state[0] == 0)
		{
		x0 = myRand() * 3.0;
		y0 = myRand() * 2.0;
		state[0] = 1;
		}
	size = ((double)pad[0] / 127.0) * 2.0;
	glPushMatrix();
	glColor3f(1.0, 0.0, 0.0);
	glTranslatef(x0, y0, 0.0);
	glutSolidSphere(size, 8, 8);
	glPopMatrix();
	}

if (pad[1] > 0)
	{
	if (state[1] == 0)
		{
		x1 = myRand() * 3.0;
		y1 = myRand() * 2.0;
		state[1] = 1;
		}
	size = ((double)pad[1] / 127.0) * 2.0;
	glPushMatrix();
	glColor3f(0.0, 1.0, 1.0);
	glTranslatef(x1, y1, 0.0);
	glutSolidSphere(size, 8, 8);
	glPopMatrix();
	}

if (pad[2] > 0)
	{
	if (state[2] == 0)
		{
		x2 = myRand() * 3.0;
		y2 = myRand() * 2.0;
		state[2] = 1;
		}
	size = ((double)pad[2] / 127.0) * 2.0;
	glPushMatrix();
	glColor3f(0.0, 1.0, 0.0);
	glTranslatef(x2, y2, 0.0);
	glutSolidSphere(size, 8, 8);
	glPopMatrix();
	}

if (pad[3] > 0)
	{
	if (state[3] == 0)
		{
		x3 = myRand() * 3.0;
		y3 = myRand() * 2.0;
		state[3] = 1;
		}
	size = ((double)pad[3] / 127.0) * 2.0;
	glPushMatrix();
	glColor3f(0.0, 0.0, 1.0);
	glTranslatef(x3, y3, 0.0);
	glutSolidSphere(size, 8, 8);
	glPopMatrix();
	}

return 1;
} /* end drawObject */


/**********************************************************************/
void display(void)
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();

  gluPerspective(90, 1.33, 0.01, 1000);

  gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
  
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();

  drawObjects();

  glutSwapBuffers();
  glFlush();
} /* end display */


/**********************************************************************/
int main(int argc, char** argv)
{
printf("\nInitializing midi...\n");
initMidi("Serial Port 2\0", "Software Synth\0");

printf("Initializing graphics...\n");
  glutInit(&argc, argv);
  glutInitWindowSize(640, 480);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
  glutCreateWindow("demo");

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glShadeModel(GL_SMOOTH);
  glFlush(); 

  glutKeyboardFunc(handleKeys);
  glutIdleFunc(idle);
  glutDisplayFunc(display);

  glutMainLoop();

return 0;
} /* end main */