//
// Copyright 2008 Johannes Hofmann <Johannes.Hofmann@gmx.de>
//
// This software may be used and distributed according to the terms
// of the GNU General Public License, incorporated herein by reference.

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <FL/Fl.H>
#include <FL/fl_draw.H>

#include "CurveEditor.H"

CurveEditor::CurveEditor(int my_x, int my_y, int my_w, int my_h) :
	Fl_Widget(my_x, my_y, my_w, my_h) {

	marked_point = -1;

	n = 5;
	X = (double*) calloc(n, sizeof(double));
	Y = (double*) calloc(n, sizeof(double));


	for (int i = 0; i < n; i++) {
		X[i] = (double) i / (n - 1);
		Y[i] = (double) i / (n - 1);
	}

	acc = gsl_interp_accel_alloc ();
	spline = gsl_spline_alloc (gsl_interp_cspline, n);
	gsl_spline_init (spline, X, Y, n);
}

void
CurveEditor::draw() {
	fl_color(FL_BLACK);
	fl_rectf(x(), y(), w(), h());

	fl_color(FL_WHITE);
	fl_begin_line();	
	for (double _x = 0.0; _x < 1.0; _x = _x + 0.01) {
		double _y = gsl_spline_eval(spline, _x, acc);

		fl_vertex(x() + _x * w(), y() + h() - h() * _y);
	}
	fl_end_line();

	for (int i = 0; i < n; i++) {
		if (i == marked_point) {
			fl_color(FL_RED);
		} else {
			fl_color(FL_WHITE);
		}
		fl_rect(x() + w() * X[i] - 2, y() + h() - h() * Y[i] - 2, 4, 4);
	}
}


int
CurveEditor::handle(int event) {
	int	mark_x = Fl::event_x() - x();
	int	mark_y = Fl::event_y() - y();

	switch(event) {

		case FL_PUSH:    
			if (Fl::event_button() == 1) {
				for (int i = 0; i < n; i++) {
					int x_i = (int) rint(X[i] * w());
					int y_i = (int) rint(h() - Y[i] * h());

					if (mark_x >= x_i - 2 && mark_x <= x_i + 2 &&
						mark_y >= y_i - 2 && mark_y <= y_i + 2) {
						marked_point = i;
						redraw();
						break;
					}
				}
			}
			Fl::focus(this);
			return 1;
			break;
		case FL_DRAG:
			set(marked_point,  (double) mark_x / w(), 1.0 - (double) mark_y / h());

			return 1;
			break;
		case FL_RELEASE:
			marked_point = -1;
			return 1;
			break;
		case FL_FOCUS:
			return 1;
			break;
		case FL_UNFOCUS:
			return 0;
			break;
        }
	return 0;
}

void
CurveEditor::set(int i, double _x, double _y) {
	if (i >= n ||
		(_x < 0.0 || _x > 1.0 || _y < 0.0 || _y > 1.0) ||
		(i < n - 1 && _x >= X[i + 1]) ||
		(i > 0 && _x <= X[i - 1])) {
		return;
	}

	X[i] = _x;
	Y[i] = _y;
	gsl_spline_init (spline, X, Y, n);

	printf("%4f,%4f", X[0], Y[0]);	
	for (int i = 1; i < n; i++) {
		printf(";%4f,%4f", X[i], Y[i]);	
	}
	printf("\n");
	redraw();
}