lwjgl: basic window

src/main/java/de/bixilon/minosoft/gui/rendering/DummyRender.java

@@ -0,0 +1,16 @@
+package de.bixilon.minosoft.gui.rendering;
+
+import org.lwjgl.Version;
+
+public class DummyRender {
+    public static void main(String[] args) {
+
+        System.out.println("Hello LWJGL " + Version.getVersion() + "!");
+
+        RenderWindow renderWindow = new RenderWindow();
+        renderWindow.init();
+        renderWindow.startLoop();
+        renderWindow.exit();
+
+    }
+}

src/main/java/de/bixilon/minosoft/gui/rendering/RenderWindow.java

@@ -0,0 +1,128 @@
+package de.bixilon.minosoft.gui.rendering;
+
+import org.lwjgl.glfw.GLFWErrorCallback;
+import org.lwjgl.glfw.GLFWVidMode;
+import org.lwjgl.glfw.GLFWWindowSizeCallback;
+import org.lwjgl.opengl.GL;
+import org.lwjgl.system.MemoryStack;
+
+import java.nio.IntBuffer;
+
+import static org.lwjgl.glfw.Callbacks.glfwFreeCallbacks;
+import static org.lwjgl.glfw.GLFW.*;
+import static org.lwjgl.opengl.GL11.*;
+import static org.lwjgl.system.MemoryStack.stackPush;
+import static org.lwjgl.system.MemoryUtil.NULL;
+
+
+public class RenderWindow {
+    private long window;
+
+    public void init() {
+        // Setup an error callback. The default implementation
+        // will print the error message in System.err.
+        GLFWErrorCallback.createPrint(System.err).set();
+
+        // Initialize GLFW. Most GLFW functions will not work before doing this.
+        if (!glfwInit()) {
+            throw new IllegalStateException("Unable to initialize GLFW");
+        }
+
+        // Configure GLFW
+        glfwDefaultWindowHints(); // optional, the current window hints are already the default
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+        glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); // the window will stay hidden after creation
+        glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); // the window will be resizable
+
+        // Create the window
+        this.window = glfwCreateWindow(800, 600, "Hello World!", NULL, NULL);
+        if (this.window == NULL) {
+            glfwTerminate();
+            throw new RuntimeException("Failed to create the GLFW window");
+        }
+
+
+        glfwSetWindowSizeCallback(this.window, new GLFWWindowSizeCallback() {
+            @Override
+            public void invoke(long window, int width, int height) {
+                glViewport(0, 0, width, height);
+            }
+        });
+
+
+        // Setup a key callback. It will be called every time a key is pressed, repeated or released.
+        glfwSetKeyCallback(this.window, (window, key, scancode, action, mods) -> {
+            if (key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE) {
+                glfwSetWindowShouldClose(window, true); // We will detect this in the rendering loop
+            }
+        });
+
+
+        // Get the thread stack and push a new frame
+        try (MemoryStack stack = stackPush()) {
+            IntBuffer pWidth = stack.mallocInt(1); // int*
+            IntBuffer pHeight = stack.mallocInt(1); // int*
+
+            // Get the window size passed to glfwCreateWindow
+            glfwGetWindowSize(this.window, pWidth, pHeight);
+
+            // Get the resolution of the primary monitor
+            GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());
+
+            // Center the window
+            glfwSetWindowPos(
+                    this.window,
+                    (vidmode.width() - pWidth.get(0)) / 2,
+                    (vidmode.height() - pHeight.get(0)) / 2
+            );
+        } // the stack frame is popped automatically
+
+        // Make the OpenGL context current
+        glfwMakeContextCurrent(this.window);
+        // Enable v-sync
+        glfwSwapInterval(1);
+
+
+        // Make the window visible
+        glfwShowWindow(this.window);
+
+        GL.createCapabilities();
+        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
+    }
+
+
+    public void startLoop() {
+        // This line is critical for LWJGL's interoperation with GLFW's
+        // OpenGL context, or any context that is managed externally.
+        // LWJGL detects the context that is current in the current thread,
+        // creates the GLCapabilities instance and makes the OpenGL
+        // bindings available for use.
+        // Run the rendering loop until the user has attempted to close
+        // the window or has pressed the ESCAPE key.
+        while (!glfwWindowShouldClose(this.window)) {
+            loop();
+        }
+    }
+
+    private void loop() {
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // clear the framebuffer
+
+        glfwSwapBuffers(this.window); // swap the color buffers
+
+        // Poll for window events. The key callback above will only be
+        // invoked during this call.
+        glfwPollEvents();
+    }
+
+    public void exit() {
+        // Free the window callbacks and destroy the window
+        glfwFreeCallbacks(this.window);
+        glfwDestroyWindow(this.window);
+
+        // Terminate GLFW and free the error callback
+        glfwTerminate();
+        glfwSetErrorCallback(null).free();
+    }
+}