/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.opengl.examples;


import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.opengl.*;
import org.eclipse.swt.widgets.*;

class BitmapTextTab extends OpenGLTab {
	private Text messageText;
	private FontData fontData;
	private float[] textColor = { 1.0f, 0.0f, 0.0f };
	private float xPos = -130.0f, yPos = 0.0f;
	private int listIndexBase;
	private final static int LIST_INDEX_SIZE = 256;
	private final static int DEFAULT_FONT_SIZE = 24;
	private final static String DEFAULT_FONT_NAME = "Courier";

	/**
	 * @see OpenGLTab#createControls(Composite)
	 */
	void createControls(Composite composite) {
		Group movementGroup = new Group(composite, SWT.NONE);
		movementGroup.setText("Translation");
		movementGroup.setLayout(new GridLayout(2, false));

		new Label(movementGroup, SWT.NONE).setText("X:");
		final Slider xMove = new Slider(movementGroup, SWT.NONE);
		xMove.setIncrement(1);
		xMove.setMaximum(42);
		xMove.setMinimum(0);
		xMove.setThumb(2);
		xMove.setPageIncrement(2);
		xMove.setSelection(7);
		xMove.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				xPos = (xMove.getSelection() * 10) - 200;
			}
		});

		new Label(movementGroup, SWT.NONE).setText("Y:");
		final Slider yMove = new Slider(movementGroup, SWT.NONE);
		yMove.setIncrement(1);
		yMove.setMaximum(42);
		yMove.setMinimum(0);
		yMove.setThumb(2);
		yMove.setPageIncrement(2);
		yMove.setSelection(20);
		yMove.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				yPos = (yMove.getSelection() * 10) - 200;
			}
		});

		Composite textGroup = new Composite(composite,SWT.NONE);
		GridLayout layout = new GridLayout(2,false);
		layout.marginHeight = 0;
		layout.marginWidth = 0;
		textGroup.setLayout(layout);
		textGroup.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL));
		
		new Label(textGroup, SWT.NONE).setText("Text:");
		messageText = new Text(textGroup, SWT.BORDER);
		GridData data = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
		data.grabExcessHorizontalSpace = true;
		messageText.setLayoutData(data);
		messageText.setText("OpenGL - SWT");

		final Button fontSelectButton = new Button(composite, SWT.NONE);
		fontSelectButton.setText("Set Font");
		
		final ColorSelectionGroup colorGroup =
			new ColorSelectionGroup(composite, SWT.NONE);
		colorGroup.setText("Text color");
		colorGroup.addColorSelectionListener(new IColorSelectionListener() {
			public void handleColorSelection(RGB rgb) {
				GL.glColor3ub((byte) rgb.red, (byte) rgb.green, (byte) rgb.blue);
			}
		});
		
		fontSelectButton.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event e) {
				FontDialog fontDialog = new FontDialog(fontSelectButton.getShell());
				fontDialog.setText("Choose Font Options");
				double[] currentColor = new double[4];
				GL.glGetDoublev(GL.GL_CURRENT_COLOR, currentColor);
				fontDialog.setRGB(
					new RGB(
						(int) currentColor[0] * 255,
						(int) currentColor[1] * 255,
						(int) currentColor[2] * 255));
				fontDialog.setFontData(fontData);
				FontData result = fontDialog.open();
				if (result != null) {
					fontData = result;
					RGB rgb = fontDialog.getRGB();
					GL.glColor3ub((byte) rgb.red, (byte) rgb.green, (byte) rgb.blue);
					colorGroup.setRGB(rgb);
					getContext().loadBitmapFont(fontData, null, listIndexBase, 32, 96);
				}
			}
		});
	}

	/**
	 * @see OpenGLTab#dispose()
	 */
	void dispose() {
		super.dispose();
		GL.glDeleteLists(listIndexBase, LIST_INDEX_SIZE);
	}

	/**
	 * Draws the text to the screen
	 * 
	 * @param string the text to draw
	 */
	void drawText(String string) {
		char[] stringChars = string.toCharArray();
		int[] text = new int[stringChars.length];
		for (int i = 0; i < text.length; i++) {
			text[i] = (int) stringChars[i];
		}
		// pushes the display list bits
		GL.glPushAttrib(GL.GL_LIST_BIT);
		// sets the base character to 32
		GL.glListBase(listIndexBase - 32);
		GL.glCallLists(text.length, GL.GL_UNSIGNED_INT, text);
		// pops the display list bits
		GL.glPopAttrib();
	}
	
	/**
	 * @see OpenGLTab#getTabText()
	 */
	String getTabText() {
		return "Bitmap Text";
	}

	/**
	 * @see OpenGLTab#init()
	 */
	void init() {
		GL.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
		GL.glColor3fv(textColor);
		GL.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
		GL.glEnable(GL.GL_DEPTH_TEST);
		GL.glEnable(GL.GL_BLEND);
		// build the initial font
		listIndexBase = GL.glGenLists(LIST_INDEX_SIZE);
		fontData = new FontData();
		fontData.setHeight(DEFAULT_FONT_SIZE);
		fontData.setName(DEFAULT_FONT_NAME);
		getContext().loadBitmapFont(fontData, null, listIndexBase, 32, LIST_INDEX_SIZE);
	}

	/**
	 * @see OpenGLTab#renderScene()
	 */
	void renderScene() {
		GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
		GL.glLoadIdentity();
		GL.glRasterPos2f(xPos, yPos);
		drawText(messageText.getText());
	}

	/**
	 * @see OpenGLTab#setupViewingArea()
	 */
	void setupViewingArea() {
		// use ortho view since this tab does not need any depth
		Rectangle rect = getGlCanvas().getClientArea();
		int width = rect.width;
		int height = rect.height;
		width = Math.max(width, 1);
		GL.glViewport(0, 0, width, height);
		float nRange = 200.0f;
		GL.glMatrixMode(GL.GL_PROJECTION);
		GL.glLoadIdentity();
		if (width <= height) {
			GL.glOrtho(
				-nRange, nRange, -nRange * height / width,
				nRange * height / width, -nRange, nRange);
		} else {
			GL.glOrtho(
				-nRange * height / width, nRange * height / width, -nRange,
				nRange, -nRange, nRange);
		}
		GL.glMatrixMode(GL.GL_MODELVIEW);
		GL.glLoadIdentity();
	}
}