| /******************************************************************************* |
| * Copyright (c) 2000, 2016 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.swt.snippets; |
| |
| /* |
| * SWT OpenGL snippet: capture a LWJGL drawing to an SWT Image |
| * |
| * This example is essentially Snippet195 with the capture() method |
| * added. It should be easily adaptable to other OpenGL packages. |
| * |
| * For a list of all SWT example snippets see |
| * http://www.eclipse.org/swt/snippets/ |
| * |
| * @since 3.2 |
| */ |
| import java.nio.*; |
| |
| import org.eclipse.swt.*; |
| import org.eclipse.swt.graphics.*; |
| import org.eclipse.swt.layout.*; |
| import org.eclipse.swt.opengl.*; |
| import org.eclipse.swt.widgets.*; |
| import org.eclipse.swt.widgets.Display; |
| import org.lwjgl.*; |
| import org.lwjgl.opengl.*; |
| import org.lwjgl.util.glu.*; |
| |
| public class Snippet341 { |
| static void drawTorus(float r, float R, int nsides, int rings) { |
| float ringDelta = 2.0f * (float) Math.PI / rings; |
| float sideDelta = 2.0f * (float) Math.PI / nsides; |
| float theta = 0.0f, cosTheta = 1.0f, sinTheta = 0.0f; |
| for (int i = rings - 1; i >= 0; i--) { |
| float theta1 = theta + ringDelta; |
| float cosTheta1 = (float) Math.cos(theta1); |
| float sinTheta1 = (float) Math.sin(theta1); |
| GL11.glBegin(GL11.GL_QUAD_STRIP); |
| float phi = 0.0f; |
| for (int j = nsides; j >= 0; j--) { |
| phi += sideDelta; |
| float cosPhi = (float) Math.cos(phi); |
| float sinPhi = (float) Math.sin(phi); |
| float dist = R + r * cosPhi; |
| GL11.glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi); |
| GL11.glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, r * sinPhi); |
| GL11.glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi); |
| GL11.glVertex3f(cosTheta * dist, -sinTheta * dist, r * sinPhi); |
| } |
| GL11.glEnd(); |
| theta = theta1; |
| cosTheta = cosTheta1; |
| sinTheta = sinTheta1; |
| } |
| } |
| |
| public static void main(String [] args) { |
| final Display display = new Display(); |
| Shell shell = new Shell(display); |
| shell.setLayout(new GridLayout()); |
| GLData data = new GLData (); |
| data.doubleBuffer = true; |
| final GLCanvas canvas = new GLCanvas(shell, SWT.NONE, data); |
| canvas.setLayoutData(new GridData(640,480)); |
| |
| canvas.setCurrent(); |
| try { |
| GLContext.useContext(canvas); |
| } catch(LWJGLException e) { e.printStackTrace(); } |
| |
| canvas.addListener(SWT.Resize, event -> { |
| Rectangle bounds = canvas.getBounds(); |
| float fAspect = (float) bounds.width / (float) bounds.height; |
| canvas.setCurrent(); |
| try { |
| GLContext.useContext(canvas); |
| } catch(LWJGLException e) { e.printStackTrace(); } |
| GL11.glViewport(0, 0, bounds.width, bounds.height); |
| GL11.glMatrixMode(GL11.GL_PROJECTION); |
| GL11.glLoadIdentity(); |
| GLU.gluPerspective(45.0f, fAspect, 0.5f, 400.0f); |
| GL11.glMatrixMode(GL11.GL_MODELVIEW); |
| GL11.glLoadIdentity(); |
| }); |
| |
| GL11.glClearColor(1.0f, 1.0f, 1.0f, 1.0f); |
| GL11.glColor3f(1.0f, 0.0f, 0.0f); |
| GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST); |
| GL11.glClearDepth(1.0); |
| GL11.glLineWidth(2); |
| GL11.glEnable(GL11.GL_DEPTH_TEST); |
| |
| Button button = new Button(shell, SWT.PUSH); |
| button.setText("Capture"); |
| button.addListener(SWT.Selection, event -> capture(canvas)); |
| shell.pack(); |
| shell.open(); |
| |
| display.asyncExec(new Runnable() { |
| int rot = 0; |
| @Override |
| public void run() { |
| if (!canvas.isDisposed()) { |
| canvas.setCurrent(); |
| try { |
| GLContext.useContext(canvas); |
| } catch(LWJGLException e) { e.printStackTrace(); } |
| GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT); |
| GL11.glClearColor(.3f, .5f, .8f, 1.0f); |
| GL11.glLoadIdentity(); |
| GL11.glTranslatef(0.0f, 0.0f, -10.0f); |
| float frot = rot; |
| GL11.glRotatef(0.15f * rot, 2.0f * frot, 10.0f * frot, 1.0f); |
| GL11.glRotatef(0.3f * rot, 3.0f * frot, 1.0f * frot, 1.0f); |
| rot++; |
| GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_LINE); |
| GL11.glColor3f(0.9f, 0.9f, 0.9f); |
| drawTorus(1, 1.9f + ((float) Math.sin((0.004f * frot))), 15, 15); |
| canvas.swapBuffers(); |
| display.asyncExec(this); |
| } |
| } |
| }); |
| |
| while (!shell.isDisposed()) { |
| if (!display.readAndDispatch()) |
| display.sleep(); |
| } |
| display.dispose(); |
| } |
| |
| static void capture(GLCanvas glCanvas) { |
| final int PAD = 4; |
| Display display = glCanvas.getDisplay(); |
| Rectangle bounds = glCanvas.getBounds(); |
| int size = bounds.width * PAD * bounds.height; |
| |
| ByteBuffer buffer = ByteBuffer.allocateDirect(size); |
| GL11.glReadPixels(0, 0, bounds.width, bounds.height, GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buffer); |
| byte[] bytes = new byte[size]; |
| buffer.get(bytes); |
| /* |
| * In OpenGL (0,0) is at the bottom-left corner, and y values ascend in the upward |
| * direction. This is opposite to SWT which defines (0,0) to be at the top-left |
| * corner with y values ascendingin the downwards direction. Re-order the OpenGL- |
| * provided bytes to SWT's expected order so that the Image will not appear inverted. |
| */ |
| byte[] temp = new byte[bytes.length]; |
| for (int i = 0; i < bytes.length; i += bounds.width * PAD) { |
| System.arraycopy(bytes, bytes.length - i - bounds.width * PAD, temp, i, bounds.width * PAD); |
| } |
| bytes = temp; |
| ImageData data = new ImageData(bounds.width, bounds.height, 32, new PaletteData(0xFF000000, 0xFF0000, 0xFF00), PAD, bytes); |
| final Image image = new Image(display, data); |
| |
| Shell shell = new Shell(display); |
| shell.setLayout(new GridLayout()); |
| Canvas canvas = new Canvas(shell, SWT.NONE); |
| canvas.setLayoutData(new GridData(bounds.width, bounds.height)); |
| canvas.addListener(SWT.Paint, event -> event.gc.drawImage(image, 0, 0)); |
| shell.pack(); |
| shell.open(); |
| shell.addListener(SWT.Dispose, event -> image.dispose()); |
| } |
| } |