Java tutorial
/* * Copyright LWJGL. All rights reserved. * License terms: http://lwjgl.org/license.php */ package org.lwjgl.demo.opengl.raytracing; import org.lwjgl.BufferUtils; import org.lwjgl.glfw.*; import org.lwjgl.opengl.GL; import org.lwjgl.opengl.GLUtil; import org.lwjgl.system.Callback; import org.lwjgl.demo.opengl.util.DemoUtils; import org.joml.Matrix4f; import org.joml.Vector3f; import java.io.IOException; import java.nio.ByteBuffer; import java.nio.FloatBuffer; import java.nio.IntBuffer; import static java.lang.Math.*; import static org.lwjgl.glfw.GLFW.*; import static org.lwjgl.opengl.GL11.*; import static org.lwjgl.opengl.GL15.*; import static org.lwjgl.opengl.GL20.*; import static org.lwjgl.opengl.GL30.*; import static org.lwjgl.opengl.GL31.*; import static org.lwjgl.opengl.GL33.*; import static org.lwjgl.system.MemoryUtil.*; /** * Raytracing demo. * <p/> * Same as {@link Demo33} but with using a Uniform Buffer Object to transfer the * camera parameters to the shader. * * @author Kai Burjack */ public class Demo33Ubo { private long window; private int width = 1024; private int height = 768; private boolean resetFramebuffer = true; private int tex; private int vao; private int fbo; private int rayTracingProgram; private int quadProgram; private int sampler; private int cameraSettingsUbo; private ByteBuffer cameraSettingsUboData = BufferUtils.createByteBuffer(4 * 4 * 5); private FloatBuffer cameraSettingsUboDataFb = cameraSettingsUboData.asFloatBuffer(); /** * The UBO binding point that we assign manually. In OpenGL 4.3 this can be * queried from the linked program via glGetProgramResource. */ private int cameraSettingsUboBinding = 1; private int timeUniform; private int blendFactorUniform; private int framebufferUniform; private int widthUniform; private int heightUniform; private int bounceCountUniform; private float mouseDownX; private float mouseX; private boolean mouseDown; private float currRotationAboutY = 0.0f; private float rotationAboutY = 0.8f; private long firstTime; private int frameNumber; private int bounceCount = 1; private Matrix4f projMatrix = new Matrix4f(); private Matrix4f viewMatrix = new Matrix4f(); private Matrix4f invViewProjMatrix = new Matrix4f(); private Vector3f tmpVector = new Vector3f(); private Vector3f cameraPosition = new Vector3f(); private Vector3f cameraLookAt = new Vector3f(0.0f, 0.5f, 0.0f); private Vector3f cameraUp = new Vector3f(0.0f, 1.0f, 0.0f); GLFWErrorCallback errCallback; GLFWKeyCallback keyCallback; GLFWFramebufferSizeCallback fbCallback; GLFWCursorPosCallback cpCallback; GLFWMouseButtonCallback mbCallback; Callback debugProc; static { /* * Tell LWJGL that we only want 3.3 functionality. */ System.setProperty("org.lwjgl.opengl.maxVersion", "3.3"); } private void init() throws IOException { glfwSetErrorCallback(errCallback = new GLFWErrorCallback() { private GLFWErrorCallback delegate = GLFWErrorCallback.createPrint(System.err); @Override public void invoke(int error, long description) { if (error == GLFW_VERSION_UNAVAILABLE) System.err.println("This demo requires OpenGL 3.3 or higher."); delegate.invoke(error, description); } @Override public void free() { delegate.free(); } }); if (!glfwInit()) throw new IllegalStateException("Unable to initialize GLFW"); glfwDefaultWindowHints(); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); window = glfwCreateWindow(width, height, "Raytracing Demo (fragment shader)", NULL, NULL); if (window == NULL) { throw new AssertionError("Failed to create the GLFW window"); } System.out.println("Press keypad '+' or 'page up' to increase the number of bounces."); System.out.println("Press keypad '-' or 'page down' to decrease the number of bounces."); glfwSetKeyCallback(window, keyCallback = new GLFWKeyCallback() { @Override public void invoke(long window, int key, int scancode, int action, int mods) { if (action != GLFW_RELEASE) { return; } if (key == GLFW_KEY_ESCAPE) { glfwSetWindowShouldClose(window, true); } else if (key == GLFW_KEY_KP_ADD || key == GLFW_KEY_PAGE_UP) { int newBounceCount = Math.min(4, Demo33Ubo.this.bounceCount + 1); if (newBounceCount != Demo33Ubo.this.bounceCount) { Demo33Ubo.this.bounceCount = newBounceCount; System.out.println("Ray bounce count is now: " + Demo33Ubo.this.bounceCount); Demo33Ubo.this.frameNumber = 0; } } else if (key == GLFW_KEY_KP_SUBTRACT || key == GLFW_KEY_PAGE_DOWN) { int newBounceCount = Math.max(1, Demo33Ubo.this.bounceCount - 1); if (newBounceCount != Demo33Ubo.this.bounceCount) { Demo33Ubo.this.bounceCount = newBounceCount; System.out.println("Ray bounce count is now: " + Demo33Ubo.this.bounceCount); Demo33Ubo.this.frameNumber = 0; } } } }); glfwSetFramebufferSizeCallback(window, fbCallback = new GLFWFramebufferSizeCallback() { @Override public void invoke(long window, int width, int height) { if (width > 0 && height > 0 && (Demo33Ubo.this.width != width || Demo33Ubo.this.height != height)) { Demo33Ubo.this.width = width; Demo33Ubo.this.height = height; Demo33Ubo.this.resetFramebuffer = true; Demo33Ubo.this.frameNumber = 0; } } }); glfwSetCursorPosCallback(window, cpCallback = new GLFWCursorPosCallback() { @Override public void invoke(long window, double x, double y) { Demo33Ubo.this.mouseX = (float) x; if (mouseDown) { Demo33Ubo.this.frameNumber = 0; } } }); glfwSetMouseButtonCallback(window, mbCallback = new GLFWMouseButtonCallback() { @Override public void invoke(long window, int button, int action, int mods) { if (action == GLFW_PRESS) { Demo33Ubo.this.mouseDownX = Demo33Ubo.this.mouseX; Demo33Ubo.this.mouseDown = true; } else if (action == GLFW_RELEASE) { Demo33Ubo.this.mouseDown = false; Demo33Ubo.this.rotationAboutY = Demo33Ubo.this.currRotationAboutY; } } }); GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor()); glfwSetWindowPos(window, (vidmode.width() - width) / 2, (vidmode.height() - height) / 2); glfwMakeContextCurrent(window); glfwSwapInterval(0); glfwShowWindow(window); IntBuffer framebufferSize = BufferUtils.createIntBuffer(2); nglfwGetFramebufferSize(window, memAddress(framebufferSize), memAddress(framebufferSize) + 4); width = framebufferSize.get(0); height = framebufferSize.get(1); GL.createCapabilities(); debugProc = GLUtil.setupDebugMessageCallback(); /* Create all needed GL resources */ createFramebufferTexture(); createSampler(); createFrameBufferObject(); createCameraSettingsUbo(); quadFullScreenVao(); createRayTracingProgram(); initRayTracingProgram(); createQuadProgram(); initQuadProgram(); firstTime = System.nanoTime(); } /** * Create a VAO with a full-screen quad VBO. */ private void quadFullScreenVao() { this.vao = glGenVertexArrays(); int vbo = glGenBuffers(); glBindVertexArray(vao); glBindBuffer(GL_ARRAY_BUFFER, vbo); ByteBuffer bb = BufferUtils.createByteBuffer(4 * 2 * 6); FloatBuffer fv = bb.asFloatBuffer(); fv.put(-1.0f).put(-1.0f); fv.put(1.0f).put(-1.0f); fv.put(1.0f).put(1.0f); fv.put(1.0f).put(1.0f); fv.put(-1.0f).put(1.0f); fv.put(-1.0f).put(-1.0f); glBufferData(GL_ARRAY_BUFFER, bb, GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 2, GL_FLOAT, false, 0, 0L); glBindBuffer(GL_ARRAY_BUFFER, 0); glBindVertexArray(0); } /** * Create the full-scren quad shader. * * @throws IOException */ private void createQuadProgram() throws IOException { int program = glCreateProgram(); int vshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/quad.vs", GL_VERTEX_SHADER, "330"); int fshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/quad.fs", GL_FRAGMENT_SHADER, "330"); glAttachShader(program, vshader); glAttachShader(program, fshader); glBindAttribLocation(program, 0, "vertex"); glBindFragDataLocation(program, 0, "color"); glLinkProgram(program); int linked = glGetProgrami(program, GL_LINK_STATUS); String programLog = glGetProgramInfoLog(program); if (programLog.trim().length() > 0) { System.err.println(programLog); } if (linked == 0) { throw new AssertionError("Could not link program"); } this.quadProgram = program; } /** * Create the ray tracing shader program. * * @return that program id * * @throws IOException */ private void createRayTracingProgram() throws IOException { int program = glCreateProgram(); int vshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/quad.vs", GL_VERTEX_SHADER, "330"); int fshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/raytracingUbo.fs", GL_FRAGMENT_SHADER); int random = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/random.glsl", GL_FRAGMENT_SHADER); int randomCommon = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/randomCommon.glsl", GL_FRAGMENT_SHADER, "330"); glAttachShader(program, vshader); glAttachShader(program, fshader); glAttachShader(program, random); glAttachShader(program, randomCommon); glBindAttribLocation(program, 0, "vertex"); glBindFragDataLocation(program, 0, "color"); glLinkProgram(program); int linked = glGetProgrami(program, GL_LINK_STATUS); String programLog = glGetProgramInfoLog(program); if (programLog.trim().length() > 0) { System.err.println(programLog); } if (linked == 0) { throw new AssertionError("Could not link program"); } this.rayTracingProgram = program; } /** * Initialize the full-screen-quad program. */ private void initQuadProgram() { glUseProgram(quadProgram); int texUniform = glGetUniformLocation(quadProgram, "tex"); glUniform1i(texUniform, 0); glUseProgram(0); } /** * Initialize the ray tracing shader. */ private void initRayTracingProgram() { glUseProgram(rayTracingProgram); timeUniform = glGetUniformLocation(rayTracingProgram, "time"); blendFactorUniform = glGetUniformLocation(rayTracingProgram, "blendFactor"); framebufferUniform = glGetUniformLocation(rayTracingProgram, "framebuffer"); widthUniform = glGetUniformLocation(rayTracingProgram, "width"); heightUniform = glGetUniformLocation(rayTracingProgram, "height"); bounceCountUniform = glGetUniformLocation(rayTracingProgram, "bounceCount"); glUniform1i(framebufferUniform, 0); int cameraSettingsIndex = glGetUniformBlockIndex(rayTracingProgram, "CameraSettings"); glUniformBlockBinding(rayTracingProgram, cameraSettingsIndex, this.cameraSettingsUboBinding); glUseProgram(0); } /** * Create the texture that will serve as our framebuffer. */ private void createFramebufferTexture() { this.tex = glGenTextures(); glBindTexture(GL_TEXTURE_2D, tex); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, width, height, 0, GL_RGBA, GL_FLOAT, (ByteBuffer) null); glBindTexture(GL_TEXTURE_2D, 0); } /** * Create the sampler to sample the framebuffer texture within the shader. */ private void createSampler() { this.sampler = glGenSamplers(); glSamplerParameteri(this.sampler, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glSamplerParameteri(this.sampler, GL_TEXTURE_MAG_FILTER, GL_NEAREST); } private void resizeFramebufferTexture() { glDeleteTextures(tex); glDeleteFramebuffers(fbo); createFramebufferTexture(); createFrameBufferObject(); } /** * Create the frame buffer object that our ray tracing shader uses to render * into the framebuffer texture. */ private int createFrameBufferObject() { this.fbo = glGenFramebuffers(); glBindFramebuffer(GL_FRAMEBUFFER, fbo); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, this.tex, 0); int fboStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (fboStatus != GL_FRAMEBUFFER_COMPLETE) { throw new AssertionError("Could not create FBO: " + fboStatus); } glBindFramebuffer(GL_FRAMEBUFFER, 0); return fbo; } private void createCameraSettingsUbo() { this.cameraSettingsUbo = glGenBuffers(); glBindBuffer(GL_UNIFORM_BUFFER, cameraSettingsUbo); glBufferData(GL_UNIFORM_BUFFER, 4 * 4 * 5, GL_STATIC_DRAW); glBindBuffer(GL_UNIFORM_BUFFER, 0); } private void updateCameraSettingsUbo() { FloatBuffer fv = cameraSettingsUboDataFb; /* Set viewing frustum corner rays in shader */ fv.put(cameraPosition.x).put(cameraPosition.y).put(cameraPosition.z).put(0.0f); invViewProjMatrix.transformProject(tmpVector.set(-1, -1, 0)).sub(cameraPosition); fv.put(tmpVector.x).put(tmpVector.y).put(tmpVector.z).put(0.0f); invViewProjMatrix.transformProject(tmpVector.set(-1, 1, 0)).sub(cameraPosition); fv.put(tmpVector.x).put(tmpVector.y).put(tmpVector.z).put(0.0f); invViewProjMatrix.transformProject(tmpVector.set(1, -1, 0)).sub(cameraPosition); fv.put(tmpVector.x).put(tmpVector.y).put(tmpVector.z).put(0.0f); invViewProjMatrix.transformProject(tmpVector.set(1, 1, 0)).sub(cameraPosition); fv.put(tmpVector.x).put(tmpVector.y).put(tmpVector.z).put(0.0f); fv.rewind(); glBindBuffer(GL_UNIFORM_BUFFER, this.cameraSettingsUbo); glBufferSubData(GL_UNIFORM_BUFFER, 0, this.cameraSettingsUboData); glBindBuffer(GL_UNIFORM_BUFFER, 0); } /** * Compute one frame by tracing the scene using our ray tracing shader and * presenting that image on the screen. */ private void trace() { glUseProgram(rayTracingProgram); if (mouseDown) { /* * If mouse is down, compute the camera rotation based on mouse * cursor location. */ currRotationAboutY = rotationAboutY + (mouseX - mouseDownX) * 0.01f; } else { currRotationAboutY = rotationAboutY; } /* Rotate camera about Y axis. */ cameraPosition.set((float) sin(-currRotationAboutY) * 3.0f, 2.0f, (float) cos(-currRotationAboutY) * 3.0f); viewMatrix.setLookAt(cameraPosition, cameraLookAt, cameraUp); if (resetFramebuffer) { projMatrix.setPerspective((float) Math.toRadians(60.0f), (float) width / height, 1f, 2f); resizeFramebufferTexture(); resetFramebuffer = false; } projMatrix.invertPerspectiveView(viewMatrix, invViewProjMatrix); /* Update cameraSettings UBO */ updateCameraSettingsUbo(); long thisTime = System.nanoTime(); float elapsedSeconds = (thisTime - firstTime) / 1E9f; glUniform1f(timeUniform, elapsedSeconds); /* * We are going to average multiple successive frames, so here we * compute the blend factor between old frame and new frame. 0.0 - use * only the new frame > 0.0 - blend between old frame and new frame */ float blendFactor = frameNumber / (frameNumber + 1.0f); glUniform1f(blendFactorUniform, blendFactor); glUniform1i(bounceCountUniform, bounceCount); glUniform1f(widthUniform, width); glUniform1f(heightUniform, height); /* Bind UBO for rendering */ glBindBufferBase(GL_UNIFORM_BUFFER, this.cameraSettingsUboBinding, this.cameraSettingsUbo); /* * Draw full-screen quad to generate frame with our tracing shader * program. */ glBindFramebuffer(GL_FRAMEBUFFER, fbo); glBindVertexArray(vao); glBindTexture(GL_TEXTURE_2D, tex); glBindSampler(0, this.sampler); glDrawArrays(GL_TRIANGLES, 0, 6); glBindSampler(0, 0); glBindTexture(GL_TEXTURE_2D, 0); glBindVertexArray(0); glBindFramebuffer(GL_FRAMEBUFFER, 0); glUseProgram(0); /* Unbind UBO */ glBindBufferBase(GL_UNIFORM_BUFFER, this.cameraSettingsUboBinding, 0); frameNumber++; } /** * Present the final image on the screen/viewport. */ private void present() { /* * Draw the rendered image on the screen using textured full-screen * quad. */ glUseProgram(quadProgram); glBindVertexArray(vao); glBindTexture(GL_TEXTURE_2D, tex); glBindSampler(0, this.sampler); glDrawArrays(GL_TRIANGLES, 0, 6); glBindSampler(0, 0); glBindTexture(GL_TEXTURE_2D, 0); glBindVertexArray(0); glUseProgram(0); } private void loop() { while (!glfwWindowShouldClose(window)) { glfwPollEvents(); glViewport(0, 0, width, height); trace(); present(); glfwSwapBuffers(window); } } private void run() { try { init(); loop(); if (debugProc != null) debugProc.free(); errCallback.free(); keyCallback.free(); fbCallback.free(); cpCallback.free(); mbCallback.free(); glfwDestroyWindow(window); } catch (Throwable t) { t.printStackTrace(); } finally { glfwTerminate(); } } public static void main(String[] args) { new Demo33Ubo().run(); } }