coding UTF-8;        // Specifies character encoding to prevent text corruption
import Math;         // Library for math functions
import GUI;          // Library for building GUI components
import tool.Graph2D; // Library for rendering 2D graphs


// Parameters of the sine wave
double amplitude = 1.0;   // Amplitude (A)
double wavelength = 1.0;  // Wavelength (λ)
double period = 1.0;      // Period (T)

// Graph range, number of points, and time settings
const int N = 1024;          // Number of points (higher = smoother)
const double X_MIN = 0.0;    // Minimum value of X range
const double X_MAX = 4.0;    // Maximum value of X range
const double Y_MIN = -1.0;   // Minimum value of Y range
const double Y_MAX = 1.0;    // Maximum value of Y range
const double DT = 0.05;      // Time increment per loop (at speed = 1.0)
const double DX = (X_MAX - X_MIN) / N; // Spacing between X values

// Arrays for graph data
double waveX[ N ];  // X values
double waveY[ N ];  // Y values

// Variables for GUI components
int window;
int periodSlider;
int wavelengthSlider;
int amplitudeSlider;
int speedSlider;
int infoLabel;
int timeLabel;
int resetButton;

// Animation and state variables
float speed = 1.0;
int graph;
bool continuesLoop = true;
double t;


// ================================================================================
// Main Routine - executed automatically on startup
// ================================================================================

void main( ){

	// Ask whether to input wave parameters manually
	inputParameters();

	// Launch graph window
	createGraphWindow();

	// Build settings (GUI) window
	createSettingWindow();

	// The main loop.
	t = 0.0;
	while( continuesLoop ) {

		// Display current time
		string roundedTime = round(t, 1, HALF_UP);  // Round time to 1 decimal place
		setGraph2DTitle(graph, "t = " + roundedTime);

		// Compute coordinates to be plotted on the graph.
		for( int i=0; i<N; i++ ) {
			double x = X_MIN + i * DX; // The x coord of the i-th point.
			waveX[ i ] = x;
			waveY[ i ] = amplitude * sin( 2.0 * PI * ( t/period - x/wavelength ) );
		}

		// Update graph
		setGraph2DData( graph, waveX, waveY );

		// Advance time
		t += DT * speed;

		// Animation delay (30 ms)
		sleep( 30 );
	}

	// Exit this program.
	exit();
}


// ================================================================================
// Ask for wave parameters on startup
// ================================================================================

void inputParameters() {
	if ( confirm("Do you want to enter wave parameters manually?") ) {
		amplitude = input("Amplitude =", amplitude);
		wavelength = input("Wavelength =", wavelength);
		period = input("Period =", period);
	}
}


// ================================================================================
// Launch the graph software and configure it
// ================================================================================

void createGraphWindow() {

	// Launch the 2D graph software (RINEARN Graph 2D).
	graph = newGraph2D( 0, 0, 800, 500, "Graph Window" );

	// Disable the feature for adjusting x/y ranges automatically, 
	// and set the ranges explicitly.
	setGraph2DAutoRange( graph, false, false );
	setGraph2DRange( graph, X_MIN, X_MAX, Y_MIN, Y_MAX );

	// Enable/disable some plotting options.
	setGraph2DOption(graph, "WITH_POINTS", false);
	setGraph2DOption(graph, "WITH_LINES", true);

	// Set the graph title and the labels of x/y axes.
	setGraph2DLabel( graph, "x", "A sin 2π( t / T - x / λ )" );
}


// ================================================================================
// Build the settings (GUI) window
// ================================================================================

void createSettingWindow() {

	// Create a window.
	window = newWindow( 0, 500, 800, 230, "Setting Window" );

	// Create a label for displaying the value of the time variable t.
	timeLabel = newTextLabel( 10, 10, 200, 20, "" );
	mountComponent( timeLabel, window );

	// Create a slider (range: 0.0 to 1.0) for controlling the value of the amplitude.
	amplitudeSlider = newHorizontalSlider( 230, 40, 500, 20, amplitude, 0.0, 1.0 );
	mountComponent( amplitudeSlider, window );
	int amplitudeLabel = newTextLabel( 45, 40, 180, 15, " Amplitude: A (0-1)" );
	mountComponent( amplitudeLabel, window );

	// Create a slider (range: 0.2 to 10.0) for controlling the value of the period.
	periodSlider = newHorizontalSlider( 230, 60, 500, 20, period, 0.2, 10.0 );
	mountComponent( periodSlider, window );
	int periodLabel = newTextLabel( 45, 60, 180, 15, "Period: T (0.2-10)" );
	mountComponent( periodLabel, window );

	// Create a slider (range: 0.5 to 8.0) for controlling the value of the wavelength.
	wavelengthSlider = newHorizontalSlider( 230, 80, 500, 20, wavelength, 0.5, 8.0 );
	mountComponent( wavelengthSlider, window );
	int wavelengthLabel = newTextLabel( 45, 80, 180, 15, "Wavelength: λ (0.5-8)" );
	mountComponent( wavelengthLabel, window );

	// Create a label for displaying the current values of A, λ, and T.
	infoLabel = newTextLabel( 230, 100, 400, 20, "" );	
	mountComponent( infoLabel, window );
	updateInfoLabel();

	// Create a slider for controlling the animation speed.
	speedSlider = newHorizontalSlider( 230, 140, 300, 20, speed, 0.0, 1.0 );
	mountComponent( speedSlider, window );
	int speedLabel = newTextLabel( 45, 140, 180, 15, "Animation Speed" );
	mountComponent( speedLabel, window );

	// Create a button for resetting the time variable.
	resetButton = newButton(600, 125, 150, 40, "Reset Time");
	mountComponent( resetButton, window );

	// Update the contents of the window after placing the components.
	paintComponent( window );
}


// ================================================================================
// Update the label showing the current slider values
// ================================================================================

void updateInfoLabel() {
	string infoText
		= "( A="
		+ round(amplitude, 2, HALF_UP)
		+ ", λ="
		+ round(wavelength, 2, HALF_UP)
		+ ", T="
		+ round(period, 2, HALF_UP)
		+ ")";

	setComponentString(infoLabel, infoText);
	paintComponent(infoLabel);
	paintComponent(window);
}


// ================================================================================
// Event handler: called when any slider is moved
// ================================================================================

void onSliderMove(int id, float value) {

	// Update the appropriate global variable according to which slider was moved.
	if(id == amplitudeSlider) {
		amplitude = value;
	}
	if(id == periodSlider) {
		period = value;
	}
	if(id == wavelengthSlider) {
		wavelength = value;
	}
	if (id == speedSlider) {
		speed = value;
	}

	// Update the label displaying A, λ, and T.
	updateInfoLabel();
}


// ================================================================================
// Event handler: called when a button is clicked
// ================================================================================

void onButtonClick(int id) {

	// If the reset button was clicked, reset the time variable t to 0.
	if (id == resetButton) {
		t = 0.0;
	}
}


// ================================================================================
// Event handler: called when the window is closed
// ================================================================================

void onWindowClose(int id) {

	// Exit the main animation loop to terminate the program.
	continuesLoop = false;
}


// ================================================================================
// Event handler: called when the graph window is closed
// ================================================================================

void onGraph2DClose(int id) {

	// Exit the main animation loop to terminate the program.
	continuesLoop = false;
}