/*
        OpenLase - a realtime laser graphics toolkit

Copyright (C) 2009-2011 Hector Martin "marcan" <hector@marcansoft.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 or version 3.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <jack/jack.h>

#include <GL/glut.h>
#include <GL/gl.h>
#include <GL/glu.h>

int window;

jack_client_t *client;

typedef jack_default_audio_sample_t sample_t;
typedef jack_nframes_t nframes_t;

jack_port_t *in_x;
jack_port_t *in_y;
jack_port_t *in_g;

nframes_t rate;

#define HIST_SAMPLES (48 * 50)
#define BUF_SAMPLES (HIST_SAMPLES+48000)

typedef struct {
	float x, y, g;
} bufsample_t;

bufsample_t buffer[BUF_SAMPLES];

int buf_widx = 0;

float psize = 2;

static int process (nframes_t nframes, void *arg)
{
	sample_t *i_x = (sample_t *) jack_port_get_buffer (in_x, nframes);
	sample_t *i_y = (sample_t *) jack_port_get_buffer (in_y, nframes);
	sample_t *i_g = (sample_t *) jack_port_get_buffer (in_g, nframes);

	nframes_t frm;
	for (frm = 0; frm < nframes; frm++) {
		buffer[buf_widx].x = *i_x++;
		buffer[buf_widx].y = *i_y++;
		buffer[buf_widx].g = *i_g++;

		buf_widx++;
		if (buf_widx >= BUF_SAMPLES)
			buf_widx = 0;
	}

	return 0;
}

static int bufsize (nframes_t nframes, void *arg)
{
	printf ("the maximum buffer size is now %u\n", nframes);
	return 0;
}

static int srate (nframes_t nframes, void *arg)
{
	rate = nframes;
	if(rate % 1000) {
		printf("error: the sample rate should be a multiple of 1000\n");
		exit(1);
	}
	printf ("Sample rate: %u/sec\n", nframes);
	return 0;
}

static void jack_shutdown (void *arg)
{
	exit (1);
}

static inline void laser_color(float g, float ascale)
{
	float r, b;
	r = b = 0;
	if (g < 0)
		g = 0;
	if (g > 2.0)
		g = 2.0;
	if (g > 1.0) {
		r = b = g - 1.0;
		g = 1.0;
	}
	glColor4f(r, 1, b, g*ascale);
}

void draw_gl(void)
{
	int i, ridx;

	static int fno=0;
	fno++;
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	glLineWidth(psize);
	glPointSize(psize);

	// horrid workaround for recordmydesktop/libtheora brokenness
#if 0
	glBegin(GL_POINTS);
	glColor4f((fno&1) * (64/256.0), (fno&2) * (32/256.0), (fno&4)  * (16/256.0), 1);
	//glColor4f(1,1,1,1);
	glVertex3f(-0.99, -0.74, 0);
	glVertex3f(0.99, 0.74, 0);
	glVertex3f(-0.99, 0.74, 0);
	glVertex3f(0.99, -0.74, 0);
	glEnd();
#endif

	ridx = (buf_widx - HIST_SAMPLES + BUF_SAMPLES) % BUF_SAMPLES;

	float lx, ly, lg;
	lx = ly = lg = 0;

	float gdelay[2] = {0,0};

	for (i = 0; i<HIST_SAMPLES; i++)
	{
		float g;

		bufsample_t s = buffer[ridx];
		// lowpass
		s.x = lx * 0.65 + s.x * 0.35;
		s.y = ly * 0.65 + s.y * 0.35;
		// delay brightness
		gdelay[i%2] = s.g;
		s.g = gdelay[(i+1)%2];

		float d = sqrtf((s.x-lx)*(s.x-lx) + (s.y-ly)*(s.y-ly));
		if (d == 0)
			d = 0.0001;
		float dfactor = 0.01/d;
		if (dfactor > 1.5)
			dfactor = 1.5;

		int age = HIST_SAMPLES-i;
		float factor;

		factor = (HIST_SAMPLES-age)/(float)HIST_SAMPLES;

		factor = factor*factor;

		if (fabsf(s.x-lx) < 0.001 && fabsf(s.y-ly) < 0.001) {
			g = (s.g-0.2) * factor * 1.4;
			glBegin(GL_POINTS);
			laser_color(g, 0.08);
			glVertex3f(s.x, s.y, 0);
			glEnd();
		} else {
			g = (s.g-0.2) * factor * dfactor * 1.8;
			glBegin(GL_LINES);
			laser_color(lg, 0.8);
			glVertex3f(lx, ly, 0);
			laser_color(g, 0.8);
			glVertex3f(s.x, s.y, 0);
			glEnd();
		}

		lx = s.x;
		ly = s.y;
		lg = g;

		ridx++;
		if (ridx >= BUF_SAMPLES)
			ridx = 0;
	}
	glEnd();
	glutSwapBuffers();
}

void key_gl(unsigned char key, int x, int y)
{
	if (key == 27) {
		jack_client_close (client);
		glutDestroyWindow(window);
		exit(0);
	}
}

void resize_gl(int width, int height)
{
	int min = width > height ? height : width;
	glViewport((width-min)/2, (height-min)/2, min, min);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho (-1, 1, -1, 1, -1, 1);
	glMatrixMode(GL_MODELVIEW);
	psize = min/350.0;
}

void init_gl(int width, int height)
{
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0);
	glDepthFunc(GL_LESS);
	glDisable(GL_DEPTH_TEST);
	glEnable(GL_BLEND);
	glBlendFunc (GL_SRC_ALPHA, GL_ONE);
	glEnable(GL_POINT_SMOOTH);
	glEnable(GL_LINE_SMOOTH);
	resize_gl(width, height);
}

int main (int argc, char *argv[])
{
	if ((client = jack_client_new ("simulator")) == 0) {
		fprintf (stderr, "jack server not running?\n");
		return 1;
	}

	jack_set_process_callback (client, process, 0);
	jack_set_buffer_size_callback (client, bufsize, 0);
	jack_set_sample_rate_callback (client, srate, 0);
	jack_on_shutdown (client, jack_shutdown, 0);

	in_x = jack_port_register (client, "in_x", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
	in_y = jack_port_register (client, "in_y", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
	in_g = jack_port_register (client, "in_g", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);

	glutInit(&argc, argv);

	glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_ALPHA | GLUT_DEPTH);
	glutInitWindowSize(640, 640);
	glutInitWindowPosition(0, 0);

	window = glutCreateWindow("OpenLase Simulator");

	glutDisplayFunc(&draw_gl);
	glutIdleFunc(&draw_gl);
	glutReshapeFunc(&resize_gl);
	glutKeyboardFunc(&key_gl);
	init_gl(640, 640);

	if (jack_activate (client)) {
		fprintf (stderr, "cannot activate client");
		return 1;
	}

	glutMainLoop();
	return 0;
}