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.demo.opengl.util.DemoUtils; import org.lwjgl.glfw.*; import org.lwjgl.opengl.GL; import org.lwjgl.opengl.GLUtil; import org.lwjgl.system.Callback; 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.GL33.*; import static org.lwjgl.opengl.GL42.*; import static org.lwjgl.opengl.GL43.*; import static org.lwjgl.system.MathUtil.*; import static org.lwjgl.system.MemoryUtil.*; /** * This demo is used to showcase hybrid rasterization and ray tracing to make * the first bounce faster. * <p> * It works like the {@link HybridDemo}, but uses a Shader Storage Buffer Object * (SSBO) to let the host program dynamically specify the boxes via a memory * buffer that is read by the shader. * * @author Kai Burjack */ public class HybridDemoSsbo { /** * The boxes for both rasterization and ray tracing. */ private static Vector3f[] boxes = Scene.boxes; private long window; private int width = 1024; private int height = 768; private boolean resetFramebuffer = true; private int raytraceTexture; private int vao; private int computeProgram; private int quadProgram; private int rasterProgram; private int fbo; private int depthBuffer; private int vaoScene; private int positionTexture; private int normalTexture; private int ssbo; private int sampler; private int timeUniform; private int blendFactorUniform; private int bounceCountUniform; private int boxesSsboBinding; private int framebufferImageBinding; private int worldPositionImageBinding; private int worldNormalImageBinding; private int viewMatrixUniform; private int projectionMatrixUniform; private int workGroupSizeX; private int workGroupSizeY; 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 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); private FloatBuffer matrixBuffer = BufferUtils.createFloatBuffer(16); GLFWErrorCallback errCallback; GLFWKeyCallback keyCallback; GLFWFramebufferSizeCallback fbCallback; GLFWCursorPosCallback cpCallback; GLFWMouseButtonCallback mbCallback; Callback debugProc; static { /* * Tell LWJGL that we only want 4.3 functionality. */ System.setProperty("org.lwjgl.opengl.maxVersion", "4.3"); } 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 4.3 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, 4); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); window = glfwCreateWindow(width, height, "Raytracing Demo (compute shader (with SSBO) + raster)", 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, HybridDemoSsbo.this.bounceCount + 1); if (newBounceCount != HybridDemoSsbo.this.bounceCount) { HybridDemoSsbo.this.bounceCount = newBounceCount; System.out.println("Ray bounce count is now: " + HybridDemoSsbo.this.bounceCount); HybridDemoSsbo.this.frameNumber = 0; } } else if (key == GLFW_KEY_KP_SUBTRACT || key == GLFW_KEY_PAGE_DOWN) { int newBounceCount = Math.max(1, HybridDemoSsbo.this.bounceCount - 1); if (newBounceCount != HybridDemoSsbo.this.bounceCount) { HybridDemoSsbo.this.bounceCount = newBounceCount; System.out.println("Ray bounce count is now: " + HybridDemoSsbo.this.bounceCount); HybridDemoSsbo.this.frameNumber = 0; } } } }); glfwSetFramebufferSizeCallback(window, fbCallback = new GLFWFramebufferSizeCallback() { @Override public void invoke(long window, int width, int height) { if (width > 0 && height > 0 && (HybridDemoSsbo.this.width != width || HybridDemoSsbo.this.height != height)) { HybridDemoSsbo.this.width = width; HybridDemoSsbo.this.height = height; HybridDemoSsbo.this.resetFramebuffer = true; HybridDemoSsbo.this.frameNumber = 0; } } }); glfwSetCursorPosCallback(window, cpCallback = new GLFWCursorPosCallback() { @Override public void invoke(long window, double x, double y) { HybridDemoSsbo.this.mouseX = (float) x; if (mouseDown) { HybridDemoSsbo.this.frameNumber = 0; } } }); glfwSetMouseButtonCallback(window, mbCallback = new GLFWMouseButtonCallback() { @Override public void invoke(long window, int button, int action, int mods) { if (action == GLFW_PRESS) { HybridDemoSsbo.this.mouseDownX = HybridDemoSsbo.this.mouseX; HybridDemoSsbo.this.mouseDown = true; } else if (action == GLFW_RELEASE) { HybridDemoSsbo.this.mouseDown = false; HybridDemoSsbo.this.rotationAboutY = HybridDemoSsbo.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 */ createRaytracingTexture(); createSampler(); createRasterizerTextures(); createRasterFrameBufferObject(); createSceneSSBO(); createFullScreenVao(); createSceneVao(); createRasterProgram(); initRasterProgram(); createComputeProgram(); initComputeProgram(); createQuadProgram(); initQuadProgram(); glEnable(GL_DEPTH_TEST); glEnable(GL_CULL_FACE); firstTime = System.nanoTime(); } /** * Create a Shader Storage Buffer Object which will hold our boxes to be * read by our Compute Shader. */ private void createSceneSSBO() { this.ssbo = glGenBuffers(); glBindBuffer(GL_ARRAY_BUFFER, ssbo); ByteBuffer ssboData = BufferUtils.createByteBuffer(4 * (4 + 4) * boxes.length / 2); FloatBuffer fv = ssboData.asFloatBuffer(); for (int i = 0; i < boxes.length; i += 2) { Vector3f min = boxes[i]; Vector3f max = boxes[i + 1]; /* * NOTE: We need to write vec4 here, because SSBOs have specific * alignment requirements for struct members (vec3 is always treated * as vec4 in memory!) * * See: * "https://www.safaribooksonline.com/library/view/opengl-programming-guide/9780132748445/app09lev1sec3.html" */ fv.put(min.x).put(min.y).put(min.z).put(0.0f); fv.put(max.x).put(max.y).put(max.z).put(0.0f); } glBufferData(GL_ARRAY_BUFFER, ssboData, GL_STATIC_DRAW); glBindBuffer(GL_ARRAY_BUFFER, 0); } /** * Creates a VAO with a full-screen quad VBO. */ private void createFullScreenVao() { 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); } /** * Creates a VAO for the scene. */ private void createSceneVao() { int vao = glGenVertexArrays(); int vbo = glGenBuffers(); glBindVertexArray(vao); glBindBuffer(GL_ARRAY_BUFFER, vbo); ByteBuffer bb = BufferUtils.createByteBuffer(boxes.length * 4 * (3 + 3) * 6 * 6); FloatBuffer fv = bb.asFloatBuffer(); for (int i = 0; i < boxes.length; i += 2) { DemoUtils.triangulateBox(boxes[i], boxes[i + 1], fv); } glBufferData(GL_ARRAY_BUFFER, bb, GL_STATIC_DRAW); glEnableVertexAttribArray(0); glVertexAttribPointer(0, 3, GL_FLOAT, false, 4 * (3 + 3), 0L); glEnableVertexAttribArray(1); glVertexAttribPointer(1, 3, GL_FLOAT, false, 4 * (3 + 3), 4 * 3); glBindBuffer(GL_ARRAY_BUFFER, 0); glBindVertexArray(0); this.vaoScene = vao; } /** * Create the frame buffer object that our rasterizer uses to render the * view-space position and normal into the textures. */ private void createRasterFrameBufferObject() { this.fbo = glGenFramebuffers(); this.depthBuffer = glGenRenderbuffers(); glBindFramebuffer(GL_FRAMEBUFFER, fbo); IntBuffer renderBuffers = BufferUtils.createIntBuffer(2).put(GL_COLOR_ATTACHMENT0) .put(GL_COLOR_ATTACHMENT1); renderBuffers.flip(); glDrawBuffers(renderBuffers); glBindRenderbuffer(GL_RENDERBUFFER, depthBuffer); glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, width, height); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, positionTexture, 0); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, normalTexture, 0); glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuffer); int fboStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER); if (fboStatus != GL_FRAMEBUFFER_COMPLETE) { throw new AssertionError("Could not create FBO: " + fboStatus); } glBindFramebuffer(GL_FRAMEBUFFER, 0); glBindRenderbuffer(GL_RENDERBUFFER, 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 raster shader. * * @throws IOException */ private void createRasterProgram() throws IOException { int program = glCreateProgram(); int vshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/raster.vs", GL_VERTEX_SHADER); int fshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/raster.fs", GL_FRAGMENT_SHADER); glAttachShader(program, vshader); glAttachShader(program, fshader); glBindAttribLocation(program, 0, "vertexPosition"); glBindAttribLocation(program, 1, "vertexNormal"); glBindFragDataLocation(program, 0, "worldPosition_out"); glBindFragDataLocation(program, 1, "worldNormal_out"); 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.rasterProgram = program; } /** * Create the tracing compute shader program. * * @throws IOException */ private void createComputeProgram() throws IOException { int program = glCreateProgram(); int cshader = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/hybridSsbo.glsl", GL_COMPUTE_SHADER); int random = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/random.glsl", GL_COMPUTE_SHADER); int randomCommon = DemoUtils.createShader("org/lwjgl/demo/opengl/raytracing/randomCommon.glsl", GL_COMPUTE_SHADER, "330"); glAttachShader(program, cshader); glAttachShader(program, random); glAttachShader(program, randomCommon); 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.computeProgram = program; } /** * Initialize the full-screen-quad program. */ private void initQuadProgram() { glUseProgram(quadProgram); int texUniform = glGetUniformLocation(quadProgram, "tex"); glUniform1i(texUniform, 0); glUseProgram(0); } /** * Initialize the raster program. */ private void initRasterProgram() { glUseProgram(rasterProgram); viewMatrixUniform = glGetUniformLocation(rasterProgram, "viewMatrix"); projectionMatrixUniform = glGetUniformLocation(rasterProgram, "projectionMatrix"); glUseProgram(0); } /** * Initialize the compute shader. */ private void initComputeProgram() { glUseProgram(computeProgram); IntBuffer workGroupSize = BufferUtils.createIntBuffer(3); glGetProgramiv(computeProgram, GL_COMPUTE_WORK_GROUP_SIZE, workGroupSize); workGroupSizeX = workGroupSize.get(0); workGroupSizeY = workGroupSize.get(1); timeUniform = glGetUniformLocation(computeProgram, "time"); blendFactorUniform = glGetUniformLocation(computeProgram, "blendFactor"); bounceCountUniform = glGetUniformLocation(computeProgram, "bounceCount"); /* Query the binding point of the SSBO */ /* * First, obtain the "resource index" used for further queries on that * resource. */ int boxesResourceIndex = glGetProgramResourceIndex(computeProgram, GL_SHADER_STORAGE_BLOCK, "Boxes"); IntBuffer props = BufferUtils.createIntBuffer(1); IntBuffer params = BufferUtils.createIntBuffer(1); props.put(0, GL_BUFFER_BINDING); /* Now query the "BUFFER_BINDING" of that resource */ glGetProgramResourceiv(computeProgram, GL_SHADER_STORAGE_BLOCK, boxesResourceIndex, props, null, params); boxesSsboBinding = params.get(0); /* Query the "image binding point" of the image uniforms */ int loc = glGetUniformLocation(computeProgram, "framebufferImage"); glGetUniformiv(computeProgram, loc, params); framebufferImageBinding = params.get(0); loc = glGetUniformLocation(computeProgram, "worldPositionImage"); glGetUniformiv(computeProgram, loc, params); worldPositionImageBinding = params.get(0); loc = glGetUniformLocation(computeProgram, "worldNormalImage"); glGetUniformiv(computeProgram, loc, params); worldNormalImageBinding = params.get(0); glUseProgram(0); } /** * Create the texture that will serve as our framebuffer for the ray tracer. */ private void createRaytracingTexture() { this.raytraceTexture = glGenTextures(); glBindTexture(GL_TEXTURE_2D, raytraceTexture); glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA32F, width, height); 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); } /** * Create the textures that the rasterizer renders into. */ private void createRasterizerTextures() { this.positionTexture = glGenTextures(); glBindTexture(GL_TEXTURE_2D, positionTexture); glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA32F, width, height); glBindTexture(GL_TEXTURE_2D, 0); this.normalTexture = glGenTextures(); glBindTexture(GL_TEXTURE_2D, normalTexture); glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA16F, width, height); glBindTexture(GL_TEXTURE_2D, 0); } /** * Resize the framebuffer textures for both rasterization and ray tracing. */ private void resizeFramebufferTexture() { glDeleteTextures(raytraceTexture); glDeleteTextures(positionTexture); glDeleteTextures(normalTexture); glDeleteRenderbuffers(depthBuffer); glDeleteFramebuffers(fbo); createRaytracingTexture(); createRasterizerTextures(); createRasterFrameBufferObject(); } private void update() { 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, 0.01f, 100.0f); resizeFramebufferTexture(); resetFramebuffer = false; } } /** * Rasterize the scene and write depth and position data into framebuffer * textures. */ private void raster() { glEnable(GL_DEPTH_TEST); glUseProgram(rasterProgram); /* Update matrices in shader */ glUniformMatrix4fv(viewMatrixUniform, false, viewMatrix.get(matrixBuffer)); glUniformMatrix4fv(projectionMatrixUniform, false, projMatrix.get(matrixBuffer)); /* Rasterize the boxes into the FBO */ glBindFramebuffer(GL_FRAMEBUFFER, fbo); glClear(GL_DEPTH_BUFFER_BIT); glBindVertexArray(vaoScene); glDrawArrays(GL_TRIANGLES, 0, 6 * 6 * boxes.length / 2); glBindVertexArray(0); glBindFramebuffer(GL_FRAMEBUFFER, 0); glUseProgram(0); } /** * Compute one frame by tracing the scene using our compute shader. */ private void trace() { glUseProgram(computeProgram); glDisable(GL_DEPTH_TEST); 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); /* Bind level 0 of framebuffer texture as writable image in the shader. */ glBindImageTexture(framebufferImageBinding, raytraceTexture, 0, false, 0, GL_READ_WRITE, GL_RGBA32F); /* Bind level 1 and 2 to our rasterized images */ glBindImageTexture(worldPositionImageBinding, positionTexture, 0, false, 0, GL_READ_ONLY, GL_RGBA32F); glBindImageTexture(worldNormalImageBinding, normalTexture, 0, false, 0, GL_READ_ONLY, GL_RGBA16F); /* Bind the SSBO containing our boxes */ glBindBufferBase(GL_SHADER_STORAGE_BUFFER, boxesSsboBinding, ssbo); /* Compute appropriate invocation dimension. */ int worksizeX = mathRoundPoT(width); int worksizeY = mathRoundPoT(height); /* Invoke the compute shader. */ glDispatchCompute(worksizeX / workGroupSizeX, worksizeY / workGroupSizeY, 1); /* * Synchronize all writes to the framebuffer image before we let OpenGL * source texels from it afterwards when rendering the final image with * the full-screen quad. */ glMemoryBarrier(GL_SHADER_IMAGE_ACCESS_BARRIER_BIT); /* Reset bindings. */ glBindBufferBase(GL_SHADER_STORAGE_BUFFER, boxesSsboBinding, 0); glBindImageTexture(framebufferImageBinding, 0, 0, false, 0, GL_READ_WRITE, GL_RGBA32F); glBindImageTexture(worldPositionImageBinding, 0, 0, false, 0, GL_READ_ONLY, GL_RGBA32F); glBindImageTexture(worldNormalImageBinding, 0, 0, false, 0, GL_READ_ONLY, GL_RGBA16F); glUseProgram(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, raytraceTexture); 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); update(); raster(); 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 HybridDemoSsbo().run(); } }