/*
 * Copyright © 2004 David Reveman, Peter Nilsson
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without
 * fee, provided that the above copyright notice appear in all copies
 * and that both that copyright notice and this permission notice
 * appear in supporting documentation, and that the names of
 * David Reveman and Peter Nilsson not be used in advertising or
 * publicity pertaining to distribution of the software without
 * specific, written prior permission. David Reveman and Peter Nilsson
 * makes no representations about the suitability of this software for
 * any purpose. It is provided "as is" without express or implied warranty.
 *
 * DAVID REVEMAN AND PETER NILSSON DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL DAVID REVEMAN AND
 * PETER NILSSON BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA
 * OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 *
 * Authors: David Reveman <c99drn@cs.umu.se>
 *          Peter Nilsson <c99pnn@cs.umu.se>
 */

#include <cairo.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <math.h>

#include "demo.h"

#define NUMPTS 6

static double animpts[NUMPTS * 2];
static double deltas[NUMPTS * 2];
static double theta;

static void
setup(cairo_surface_t *target, int w, int h)
{
	int i;

	//cairo_scale (cr, 3.0, 1.0);

	for (i = 0; i < (NUMPTS * 2); i += 2) {
		animpts[i + 0] = (float) (drand48 () * w);
		animpts[i + 1] = (float) (drand48 () * h);
		deltas[i + 0] = (float) (drand48 () * 6.0 + 4.0);
		deltas[i + 1] = (float) (drand48 () * 6.0 + 4.0);

		if (animpts[i + 0] > w / 2.0)
			deltas[i + 0] = -deltas[i + 0];
		if (animpts[i + 1] > h / 2.0)
			deltas[i + 1] = -deltas[i + 1];
	}
}

static void
animate (double *pts, double *deltas, int index, int limit)
{
	double newpt = pts[index] + deltas[index];

	if (newpt <= 0) {
		newpt = -newpt;
		deltas[index] = (double) (drand48 () * 4.0 + 2.0);
	} else if (newpt >= (double) limit) {
		newpt = 2.0 * limit - newpt;
		deltas[index] = - (double) (drand48 () * 4.0 + 2.0);
	}
	pts[index] = newpt;
}

static void
step (int w, int h)
{
	int i;

	for (i = 0; i < (NUMPTS * 2); i += 2) {
		animate (animpts, deltas, i + 0, w);
		animate (animpts, deltas, i + 1, h);
	}

	theta += M_PI / 360;
}

static void
draw (cairo_t *cr, int w, int h)
{
	double *ctrlpts = animpts;
	int len = (NUMPTS * 2);
	double prevx = ctrlpts[len - 2];
	double prevy = ctrlpts[len - 1];
	double curx = ctrlpts[0];
	double cury = ctrlpts[1];
	double midx = (curx + prevx) / 2.0;
	double midy = (cury + prevy) / 2.0;
	double x1, y1, x2, y2;
	double mx, my, ww, hh;
	cairo_pattern_t *pattern;
	int i;

	cairo_set_source_rgba (cr, 0.75, 0.75, 0.75, 1.0);
	cairo_set_line_width (cr, 1.0);

	step (w, h);

	cairo_new_path (cr);
	cairo_move_to (cr, midx, midy);

	for (i = 2; i <= (NUMPTS * 2); i += 2) {
		double x2, x1 = (midx + curx) / 2.0;
		double y2, y1 = (midy + cury) / 2.0;

		prevx = curx;
		prevy = cury;
		if (i < (NUMPTS * 2)) {
			curx = ctrlpts[i + 0];
			cury = ctrlpts[i + 1];
		} else {
			curx = ctrlpts[0];
			cury = ctrlpts[1];
		}
		midx = (curx + prevx) / 2.0;
		midy = (cury + prevy) / 2.0;
		x2 = (prevx + midx) / 2.0;
		y2 = (prevy + midy) / 2.0;
		cairo_curve_to (cr, x1, y1, x2, y2, midx, midy);
	}
	cairo_close_path (cr);

	cairo_path_extents (cr, &x1, &y1, &x2, &y2);

	mx = (x1 + x2) / 2.;
	my = (y1 + y2) / 2.;
	ww = x2 - mx;
	hh = y2 - my;

	x1 = cos(theta) * ww + sin(theta) * hh + mx;
	y1 = -sin(theta) * ww + cos(theta) * hh + my;
	x2 = cos(M_PI+theta) * ww + sin(M_PI+theta) * hh + mx;
	y2 = -sin(M_PI+theta) * ww + cos(M_PI+theta) * hh + my;

	pattern = cairo_pattern_create_linear (x1, y1, x2, y2);
	cairo_pattern_add_color_stop_rgba (pattern, 0.0, 1.0, 0.0, 0.0, 0.6);
	cairo_pattern_add_color_stop_rgba (pattern, 1.0, 0.0, 0.0, 1.0, 0.3);
	cairo_pattern_set_filter (pattern, CAIRO_FILTER_BILINEAR);

	cairo_move_to (cr, 0, 0);
	cairo_set_source (cr, pattern);
	cairo_pattern_destroy (pattern);

	cairo_set_antialias (cr, CAIRO_ANTIALIAS_NONE);
	cairo_fill_preserve (cr);
	cairo_set_source_rgba (cr, .1, .75, .1, .9);
	cairo_set_line_width (cr, 3.);
	cairo_set_antialias (cr, CAIRO_ANTIALIAS_DEFAULT);
	cairo_stroke (cr);
}

static int done;
static void signal_handler(int sig)
{
	done = sig;
}

int main (int argc, char **argv)
{
	struct device *device;
	struct timeval start, last_tty, last_fps, now;

	double delta;
	int frame = 0;
	int frames = 0;
	int benchmark;
	enum clip clip;
	const char *version;

	device = device_open(argc, argv);
	version = device_show_version(argc, argv);
	clip = device_get_clip(argc,argv);
	benchmark = device_get_benchmark(argc, argv);
	if (benchmark == 0)
		benchmark = 20;

	setup(device->scanout, device->width, device->height);

	signal(SIGHUP, signal_handler);
	gettimeofday(&start, 0); now = last_tty = last_fps = start;
	do {
		struct framebuffer *fb = device->get_framebuffer (device);
		cairo_t *cr;

		cr = cairo_create(fb->surface);

		cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
		cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
		cairo_paint (cr);
		cairo_set_operator (cr, CAIRO_OPERATOR_OVER);

		cairo_save(cr);
		device_apply_clip(device, cr, clip);
		draw(cr, device->width, device->height);
		cairo_restore(cr);

		gettimeofday(&now, NULL);
		if (benchmark < 0 && last_fps.tv_sec)
			fps_draw(cr, device->name, version, &last_fps, &now);
		last_fps = now;

		cairo_destroy(cr);

		fb->show (fb);
		fb->destroy (fb);

		if (benchmark < 0 && 0) {
			delta = now.tv_sec - last_tty.tv_sec;
			delta += (now.tv_usec - last_tty.tv_usec)*1e-6;
			frames++;
			if (delta >  5) {
				printf("%.2f fps\n", frames/delta);
				last_tty = now;
				frames = 0;
			}
		}

		frame++;
		if (benchmark > 0) {
			delta = now.tv_sec - start.tv_sec;
			delta += (now.tv_usec - start.tv_usec)*1e-6;
			if (delta > benchmark) {
				printf("gradient: %.2f fps\n", frame / delta);
				break;
			}
		}
	} while (!done);

	if (benchmark < 0) {
		struct framebuffer *fb = device->get_framebuffer (device);
		cairo_t *cr = cairo_create(fb->surface);

		cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
		cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
		cairo_paint (cr);
		cairo_set_operator (cr, CAIRO_OPERATOR_OVER);

		device_apply_clip(device, cr, clip);
		draw(cr, device->width, device->height);
		cairo_destroy(cr);

		fps_finish(fb, device->name, version, "gradient");
		fb->show (fb);
		fb->destroy (fb);
		pause();
	}

	return 0;
}