From 4d4c75d91a19e27b24677b153b0a20501eb5afc4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C5=A0pan=C4=9Bl?=
 <OndrejSpanel@users.noreply.github.com>
Date: Mon, 25 Nov 2019 15:51:43 +0100
Subject: [PATCH] Demonstrate how to use disposeCanvas override to implement a
 render thread.

---
 test/org/lwjgl/opengl/awt/AWTThreadTest.java | 96 ++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 test/org/lwjgl/opengl/awt/AWTThreadTest.java

diff --git a/test/org/lwjgl/opengl/awt/AWTThreadTest.java b/test/org/lwjgl/opengl/awt/AWTThreadTest.java
new file mode 100644
index 0000000..dca304f
--- /dev/null
+++ b/test/org/lwjgl/opengl/awt/AWTThreadTest.java
@@ -0,0 +1,96 @@
+package org.lwjgl.opengl.awt;
+
+import java.awt.BorderLayout;
+import java.awt.Dimension;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
+
+import static org.lwjgl.opengl.GL.*;
+import static org.lwjgl.opengl.GL11.*;
+
+import javax.swing.JFrame;
+
+public class AWTThreadTest {
+    abstract static class AWTGLCanvasExplicitDispose extends AWTGLCanvas {
+        public AWTGLCanvasExplicitDispose(GLData data) {
+            super(data);
+        }
+
+        @Override
+        public void disposeCanvas() {
+        }
+
+        public void doDisposeCanvas() {
+            super.disposeCanvas();
+        }
+    }
+    public static void main(String[] args) {
+        Semaphore signalTerminate = new Semaphore(0);
+        Semaphore signalTerminated = new Semaphore(0);
+        JFrame frame = new JFrame("AWT test") {
+            @Override
+            public void dispose() {
+                // request the cleanup
+                signalTerminate.release();
+                try {
+                    // wait until the thread is done with the cleanup
+                    signalTerminated.acquire();
+                } catch (InterruptedException ignored) {
+                }
+                super.dispose();
+            }
+        };
+        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
+        frame.setLayout(new BorderLayout());
+        frame.setPreferredSize(new Dimension(600, 600));
+        GLData data = new GLData();
+        data.samples = 4;
+        data.swapInterval = 0;
+        AWTGLCanvasExplicitDispose canvas;
+        frame.add(canvas = new AWTGLCanvasExplicitDispose(data) {
+            private static final long serialVersionUID = 1L;
+            public void initGL() {
+                System.out.println("OpenGL version: " + effective.majorVersion + "." + effective.minorVersion + " (Profile: " + effective.profile + ")");
+                createCapabilities();
+                glClearColor(0.3f, 0.4f, 0.5f, 1);
+            }
+            public void paintGL() {
+                int w = getWidth();
+                int h = getHeight();
+                float aspect = (float) w / h;
+                glClear(GL_COLOR_BUFFER_BIT);
+                glViewport(0, 0, w, h);
+                glBegin(GL_QUADS);
+                glColor3f(0.4f, 0.6f, 0.8f);
+                glVertex2f(-0.75f / aspect, 0.0f);
+                glVertex2f(0, -0.75f);
+                glVertex2f(+0.75f / aspect, 0);
+                glVertex2f(0, +0.75f);
+                glEnd();
+                swapBuffers();
+            }
+
+        }, BorderLayout.CENTER);
+        frame.pack();
+        frame.setVisible(true);
+        frame.transferFocus();
+
+        Runnable renderLoop = new Runnable() {
+            public void run() {
+                while (true) {
+                    canvas.render();
+                    try {
+                        if (signalTerminate.tryAcquire(10, TimeUnit.MILLISECONDS)) {
+                            canvas.doDisposeCanvas();
+                            signalTerminated.release();
+                            return;
+                        }
+                    } catch (InterruptedException ignored) {
+                    }
+                }
+            }
+        };
+        Thread renderThread = new Thread(renderLoop);
+        renderThread.start();
+    }
+}