Java tutorial
/* * Copyright LWJGL. All rights reserved. * License terms: http://lwjgl.org/license.php */ package org.lwjgl.demo.opengl.shadow; import static org.lwjgl.demo.opengl.util.DemoUtils.*; import static org.lwjgl.glfw.GLFW.*; import static org.lwjgl.opengl.GL11.*; import static org.lwjgl.opengl.GL12.*; import static org.lwjgl.opengl.GL15.*; import static org.lwjgl.opengl.GL20.*; import static org.lwjgl.opengl.EXTFramebufferObject.*; import static org.lwjgl.system.MemoryUtil.NULL; import static org.lwjgl.system.MemoryUtil.memAddress; import java.io.IOException; import java.nio.ByteBuffer; import java.nio.FloatBuffer; import java.nio.IntBuffer; import org.lwjgl.BufferUtils; import org.lwjgl.demo.opengl.raytracing.Scene; import org.lwjgl.demo.opengl.util.DemoUtils; import org.lwjgl.glfw.GLFWErrorCallback; import org.lwjgl.glfw.GLFWFramebufferSizeCallback; import org.lwjgl.glfw.GLFWKeyCallback; import org.lwjgl.glfw.GLFWVidMode; import org.lwjgl.opengl.GL; import org.lwjgl.opengl.GLCapabilities; import org.lwjgl.opengl.GLUtil; import org.lwjgl.system.Callback; import org.joml.Matrix4f; import org.joml.Vector3f; /** * Simple demo to showcase shadow mapping with a custom shader doing perspective * divide and depth test (i.e. no sampler2DShadow). * * @author Kai Burjack */ public class ShadowMappingDemo20 { private static Vector3f[] boxes = Scene.boxes2; private static Vector3f UP = new Vector3f(0.0f, 1.0f, 0.0f); static int shadowMapSize = 1024; static Vector3f lightPosition = new Vector3f(6.0f, 3.0f, 0.0f); static Vector3f lightLookAt = new Vector3f(0.0f, 1.0f, 0.0f); static Vector3f cameraPosition = new Vector3f(-3.0f, 6.0f, 6.0f); static Vector3f cameraLookAt = new Vector3f(0.0f, 0.0f, 0.0f); static float lightDistance = 10.0f; static float lightHeight = 4.0f; long window; int width = 1200; int height = 800; int vbo; int shadowProgram; int shadowProgramVPUniform; int normalProgram; int normalProgramBiasUniform; int normalProgramVPUniform; int normalProgramLVPUniform; int normalProgramLightPosition; int normalProgramLightLookAt; int fbo; int depthTexture; int samplerLocation; FloatBuffer matrixBuffer = BufferUtils.createFloatBuffer(16); Matrix4f light = new Matrix4f(); Matrix4f camera = new Matrix4f(); Matrix4f biasMatrix = new Matrix4f(0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 0.0f, 0.5f, 0.0f, 0.5f, 0.5f, 0.5f, 1.0f); GLCapabilities caps; GLFWErrorCallback errCallback; GLFWKeyCallback keyCallback; GLFWFramebufferSizeCallback fbCallback; Callback debugProc; void init() throws IOException { glfwSetErrorCallback(errCallback = new GLFWErrorCallback() { GLFWErrorCallback delegate = GLFWErrorCallback.createPrint(System.err); public void invoke(int error, long description) { if (error == GLFW_VERSION_UNAVAILABLE) System.err.println("This demo requires OpenGL 2.0 or higher."); delegate.invoke(error, description); } @Override public void free() { delegate.free(); } }); if (!glfwInit()) throw new IllegalStateException("Unable to initialize GLFW"); glfwDefaultWindowHints(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0); glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); window = glfwCreateWindow(width, height, "Shadow Mapping Demo", NULL, NULL); if (window == NULL) { throw new AssertionError("Failed to create the GLFW window"); } 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); } } }); glfwSetFramebufferSizeCallback(window, fbCallback = new GLFWFramebufferSizeCallback() { public void invoke(long window, int width, int height) { if (width > 0 && height > 0 && (ShadowMappingDemo20.this.width != width || ShadowMappingDemo20.this.height != height)) { ShadowMappingDemo20.this.width = width; ShadowMappingDemo20.this.height = height; } } }); 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); caps = GL.createCapabilities(); if (!caps.GL_EXT_framebuffer_object) { throw new AssertionError("This demo requires the EXT_framebuffer_object extension"); } debugProc = GLUtil.setupDebugMessageCallback(); /* Set some GL states */ glEnable(GL_CULL_FACE); glEnable(GL_DEPTH_TEST); glClearColor(0.2f, 0.3f, 0.4f, 1.0f); /* Create all needed GL resources */ createVbo(); createShadowProgram(); initShadowProgram(); createNormalProgram(); initNormalProgram(); createDepthTexture(); createFbo(); } /** * Create the texture storing the depth values of the light-render. */ void createDepthTexture() { depthTexture = glGenTextures(); glBindTexture(GL_TEXTURE_2D, depthTexture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, shadowMapSize, shadowMapSize, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, (ByteBuffer) null); glBindTexture(GL_TEXTURE_2D, 0); } /** * Create the FBO to render the depth values of the light-render into the * depth texture. */ void createFbo() { fbo = glGenFramebuffersEXT(); glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); glBindTexture(GL_TEXTURE_2D, depthTexture); glDrawBuffer(GL_NONE); glReadBuffer(GL_NONE); glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_2D, depthTexture, 0); int fboStatus = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT); if (fboStatus != GL_FRAMEBUFFER_COMPLETE_EXT) { throw new AssertionError("Could not create FBO: " + fboStatus); } glBindTexture(GL_TEXTURE_2D, 0); glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); } /** * Creates a VBO for the scene with some boxes. */ static void createVbo() { int vbo = glGenBuffers(); 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); } void createShadowProgram() throws IOException { shadowProgram = glCreateProgram(); int vshader = createShader("org/lwjgl/demo/opengl/shadow/shadowMapping-vs.glsl", GL_VERTEX_SHADER); int fshader = createShader("org/lwjgl/demo/opengl/shadow/shadowMapping-fs.glsl", GL_FRAGMENT_SHADER); glAttachShader(shadowProgram, vshader); glAttachShader(shadowProgram, fshader); glBindAttribLocation(shadowProgram, 0, "position"); glLinkProgram(shadowProgram); int linked = glGetProgrami(shadowProgram, GL_LINK_STATUS); String programLog = glGetProgramInfoLog(shadowProgram); if (programLog.trim().length() > 0) { System.err.println(programLog); } if (linked == 0) { throw new AssertionError("Could not link program"); } } void initShadowProgram() { glUseProgram(shadowProgram); shadowProgramVPUniform = glGetUniformLocation(shadowProgram, "viewProjectionMatrix"); glUseProgram(0); } void createNormalProgram() throws IOException { normalProgram = glCreateProgram(); int vshader = createShader("org/lwjgl/demo/opengl/shadow/shadowMappingShade-vs.glsl", GL_VERTEX_SHADER); int fshader = createShader("org/lwjgl/demo/opengl/shadow/shadowMappingShade-fs.glsl", GL_FRAGMENT_SHADER); glAttachShader(normalProgram, vshader); glAttachShader(normalProgram, fshader); glBindAttribLocation(normalProgram, 0, "position"); glBindAttribLocation(normalProgram, 1, "normal"); glLinkProgram(normalProgram); int linked = glGetProgrami(normalProgram, GL_LINK_STATUS); String programLog = glGetProgramInfoLog(normalProgram); if (programLog.trim().length() > 0) { System.err.println(programLog); } if (linked == 0) { throw new AssertionError("Could not link program"); } } void initNormalProgram() { glUseProgram(normalProgram); samplerLocation = glGetUniformLocation(normalProgram, "depthTexture"); normalProgramBiasUniform = glGetUniformLocation(normalProgram, "biasMatrix"); normalProgramVPUniform = glGetUniformLocation(normalProgram, "viewProjectionMatrix"); normalProgramLVPUniform = glGetUniformLocation(normalProgram, "lightViewProjectionMatrix"); normalProgramLightPosition = glGetUniformLocation(normalProgram, "lightPosition"); normalProgramLightLookAt = glGetUniformLocation(normalProgram, "lightLookAt"); glUniform1i(samplerLocation, 0); glUseProgram(0); } /** * Update the camera MVP matrix. */ void update() { /* Update light */ double alpha = System.currentTimeMillis() / 1000.0 * 0.5; float x = (float) Math.sin(alpha); float z = (float) Math.cos(alpha); lightPosition.set(lightDistance * x, 3 + (float) Math.sin(alpha), lightDistance * z); light.setPerspective((float) Math.toRadians(45.0f), 1.0f, 0.1f, 60.0f).lookAt(lightPosition, lightLookAt, UP); /* Update camera */ camera.setPerspective((float) Math.toRadians(45.0f), (float) width / height, 0.1f, 30.0f) .lookAt(cameraPosition, cameraLookAt, UP); } /** * Render the shadow map into a depth texture. */ void renderShadowMap() { glUseProgram(shadowProgram); /* Set MVP matrix of the "light camera" */ glUniformMatrix4fv(shadowProgramVPUniform, false, light.get(matrixBuffer)); glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); glViewport(0, 0, shadowMapSize, shadowMapSize); /* Only clear depth buffer, since we don't have a color draw buffer */ glClear(GL_DEPTH_BUFFER_BIT); glDrawArrays(GL_TRIANGLES, 0, 6 * 6 * boxes.length); glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); glUseProgram(0); } /** * Render the scene normally, with sampling the previously rendered depth * texture. */ void renderNormal() { glUseProgram(normalProgram); /* Set MVP matrix of camera */ glUniformMatrix4fv(normalProgramVPUniform, false, camera.get(matrixBuffer)); /* Set MVP matrix that was used when doing the light-render */ glUniformMatrix4fv(normalProgramLVPUniform, false, light.get(matrixBuffer)); /* The bias-matrix used to convert to NDC coordinates */ glUniformMatrix4fv(normalProgramBiasUniform, false, biasMatrix.get(matrixBuffer)); /* Light position and lookat for normal lambertian computation */ glUniform3f(normalProgramLightPosition, lightPosition.x, lightPosition.y, lightPosition.z); glUniform3f(normalProgramLightLookAt, lightLookAt.x, lightLookAt.y, lightLookAt.z); glViewport(0, 0, width, height); /* Must clear both color and depth, since we are re-rendering the scene */ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glBindTexture(GL_TEXTURE_2D, depthTexture); glDrawArrays(GL_TRIANGLES, 0, 6 * 6 * boxes.length); glBindTexture(GL_TEXTURE_2D, 0); glUseProgram(0); } void loop() { while (!glfwWindowShouldClose(window)) { glfwPollEvents(); update(); renderShadowMap(); renderNormal(); glfwSwapBuffers(window); } } void run() { try { init(); loop(); if (debugProc != null) debugProc.free(); errCallback.free(); keyCallback.free(); fbCallback.free(); glfwDestroyWindow(window); } catch (Throwable t) { t.printStackTrace(); } finally { glfwTerminate(); } } public static void main(String[] args) { new ShadowMappingDemo20().run(); } }