Java tutorial
/* * Copyright LWJGL. All rights reserved. * License terms: http://lwjgl.org/license.php */ package org.lwjgl.demo.opengl.textures; import org.lwjgl.BufferUtils; import org.lwjgl.PointerBuffer; import org.lwjgl.demo.opengl.util.WavefrontMeshLoader; import org.lwjgl.demo.opengl.util.WavefrontMeshLoader.Mesh; import org.lwjgl.glfw.*; 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; import java.io.IOException; import java.nio.ByteBuffer; import java.nio.FloatBuffer; import java.nio.IntBuffer; import static org.lwjgl.opengl.ARBShaderObjects.*; import static org.lwjgl.opengl.ARBVertexShader.*; import static org.lwjgl.opengl.ARBVertexBufferObject.*; import static org.lwjgl.opengl.ARBFragmentShader.*; import static org.lwjgl.demo.opengl.util.DemoUtils.*; import static org.lwjgl.glfw.GLFW.*; import static org.lwjgl.opengl.GL11.*; import static org.lwjgl.stb.STBImage.*; import static org.lwjgl.system.MemoryUtil.*; /** * Just like {@link EnvironmentDemo}, but also adds a reflective teapot. * * @author Kai Burjack */ public class EnvironmentTeapotDemo { long window; int width = 1024; int height = 768; float fov = 60, rotX, rotY; int environmentProgram; int teapotProgram; int invViewProjUniform; int viewProjUniform; int cameraPositionUniform; Matrix4f projectionMatrix = new Matrix4f(); Matrix4f viewMatrix = new Matrix4f(); Matrix4f viewProjMatrix = new Matrix4f(); Matrix4f invViewProjMatrix = new Matrix4f(); Vector3f cameraPosition = new Vector3f(); FloatBuffer matrixBuffer = BufferUtils.createFloatBuffer(16); Mesh mesh; int numVertices; long normalsOffset; int teapotVbo; int fullscreenVbo; GLCapabilities caps; GLFWKeyCallback keyCallback; GLFWFramebufferSizeCallback fbCallback; GLFWCursorPosCallback cpCallback; GLFWScrollCallback sCallback; Callback debugProc; void init() throws IOException { if (!glfwInit()) throw new IllegalStateException("Unable to initialize GLFW"); glfwDefaultWindowHints(); glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE); glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE); window = glfwCreateWindow(width, height, "Spherical environment mapping with teapot demo", NULL, NULL); if (window == NULL) throw new AssertionError("Failed to create the GLFW window"); System.out.println("Move the mouse to look around"); System.out.println("Zoom in/out with mouse wheel"); glfwSetFramebufferSizeCallback(window, fbCallback = new GLFWFramebufferSizeCallback() { @Override public void invoke(long window, int width, int height) { if (width > 0 && height > 0 && (EnvironmentTeapotDemo.this.width != width || EnvironmentTeapotDemo.this.height != height)) { EnvironmentTeapotDemo.this.width = width; EnvironmentTeapotDemo.this.height = height; } } }); 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); } } }); glfwSetCursorPosCallback(window, cpCallback = new GLFWCursorPosCallback() { @Override public void invoke(long window, double x, double y) { float nx = (float) x / width * 2.0f - 1.0f; float ny = (float) y / height * 2.0f - 1.0f; rotX = ny * (float) Math.PI * 0.5f; rotY = nx * (float) Math.PI; } }); glfwSetScrollCallback(window, sCallback = new GLFWScrollCallback() { @Override public void invoke(long window, double xoffset, double yoffset) { if (yoffset < 0) fov *= 1.05f; else fov *= 1f / 1.05f; if (fov < 10.0f) fov = 10.0f; else if (fov > 120.0f) fov = 120.0f; } }); GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor()); glfwSetWindowPos(window, (vidmode.width() - width) / 2, (vidmode.height() - height) / 2); glfwMakeContextCurrent(window); glfwSwapInterval(0); glfwShowWindow(window); glfwSetCursorPos(window, width / 2, height / 2); 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_ARB_shader_objects) throw new AssertionError("This demo requires the ARB_shader_objects extension."); if (!caps.GL_ARB_vertex_shader) throw new AssertionError("This demo requires the ARB_vertex_shader extension."); if (!caps.GL_ARB_fragment_shader) throw new AssertionError("This demo requires the ARB_fragment_shader extension."); debugProc = GLUtil.setupDebugMessageCallback(); /* Create all needed GL resources */ loadMesh(); createTexture(); createFullScreenQuad(); createTeapotProgram(); createEnvironmentProgram(); } void loadMesh() throws IOException { mesh = new WavefrontMeshLoader().loadMesh("org/lwjgl/demo/opengl/models/teapot.obj.zip"); this.numVertices = mesh.numVertices; long bufferSize = 4 * (3 + 3) * mesh.numVertices; this.normalsOffset = 4L * 3 * mesh.numVertices; this.teapotVbo = glGenBuffersARB(); glBindBufferARB(GL_ARRAY_BUFFER_ARB, this.teapotVbo); glBufferDataARB(GL_ARRAY_BUFFER_ARB, bufferSize, GL_STATIC_DRAW_ARB); glBufferSubDataARB(GL_ARRAY_BUFFER_ARB, 0L, mesh.positions); glBufferSubDataARB(GL_ARRAY_BUFFER_ARB, normalsOffset, mesh.normals); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); } void createFullScreenQuad() { ByteBuffer vertices = BufferUtils.createByteBuffer(4 * 2 * 6); FloatBuffer fv = vertices.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); this.fullscreenVbo = glGenBuffersARB(); glBindBufferARB(GL_ARRAY_BUFFER_ARB, this.fullscreenVbo); glBufferDataARB(GL_ARRAY_BUFFER_ARB, vertices, GL_STATIC_DRAW_ARB); glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0); } static int createShader(String resource, int type) throws IOException { int shader = glCreateShaderObjectARB(type); ByteBuffer source = ioResourceToByteBuffer(resource, 1024); PointerBuffer strings = BufferUtils.createPointerBuffer(1); IntBuffer lengths = BufferUtils.createIntBuffer(1); strings.put(0, source); lengths.put(0, source.remaining()); glShaderSourceARB(shader, strings, lengths); glCompileShaderARB(shader); int compiled = glGetObjectParameteriARB(shader, GL_OBJECT_COMPILE_STATUS_ARB); String shaderLog = glGetInfoLogARB(shader); if (shaderLog.trim().length() > 0) { System.err.println(shaderLog); } if (compiled == 0) { throw new AssertionError("Could not compile shader"); } return shader; } void createEnvironmentProgram() throws IOException { int program = glCreateProgramObjectARB(); int vshader = createShader("org/lwjgl/demo/opengl/textures/environment.vs", GL_VERTEX_SHADER_ARB); int fshader = createShader("org/lwjgl/demo/opengl/textures/environment.fs", GL_FRAGMENT_SHADER_ARB); glAttachObjectARB(program, vshader); glAttachObjectARB(program, fshader); glLinkProgramARB(program); int linked = glGetObjectParameteriARB(program, GL_OBJECT_LINK_STATUS_ARB); String programLog = glGetInfoLogARB(program); if (programLog.trim().length() > 0) { System.err.println(programLog); } if (linked == 0) { throw new AssertionError("Could not link program"); } glUseProgramObjectARB(program); int texLocation = glGetUniformLocationARB(program, "tex"); glUniform1iARB(texLocation, 0); invViewProjUniform = glGetUniformLocationARB(program, "invViewProj"); this.environmentProgram = program; } void createTeapotProgram() throws IOException { int program = glCreateProgramObjectARB(); int vshader = createShader("org/lwjgl/demo/opengl/textures/teapot.vs", GL_VERTEX_SHADER_ARB); int fshader = createShader("org/lwjgl/demo/opengl/textures/teapot.fs", GL_FRAGMENT_SHADER_ARB); glAttachObjectARB(program, vshader); glAttachObjectARB(program, fshader); glLinkProgramARB(program); int linked = glGetObjectParameteriARB(program, GL_OBJECT_LINK_STATUS_ARB); String programLog = glGetInfoLogARB(program); if (programLog.trim().length() > 0) { System.err.println(programLog); } if (linked == 0) { throw new AssertionError("Could not link program"); } glUseProgramObjectARB(program); viewProjUniform = glGetUniformLocationARB(program, "viewProj"); cameraPositionUniform = glGetUniformLocationARB(program, "cameraPosition"); this.teapotProgram = program; } static void createTexture() throws IOException { int tex = glGenTextures(); glBindTexture(GL_TEXTURE_2D, tex); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); ByteBuffer imageBuffer; IntBuffer w = BufferUtils.createIntBuffer(1); IntBuffer h = BufferUtils.createIntBuffer(1); IntBuffer comp = BufferUtils.createIntBuffer(1); ByteBuffer image; imageBuffer = ioResourceToByteBuffer("org/lwjgl/demo/opengl/textures/environment.jpg", 8 * 1024); if (!stbi_info_from_memory(imageBuffer, w, h, comp)) throw new IOException("Failed to read image information: " + stbi_failure_reason()); image = stbi_load_from_memory(imageBuffer, w, h, comp, 3); if (image == null) throw new IOException("Failed to load image: " + stbi_failure_reason()); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, w.get(0), h.get(0), 0, GL_RGB, GL_UNSIGNED_BYTE, image); stbi_image_free(image); } void update() { projectionMatrix.setPerspective((float) Math.toRadians(fov), (float) width / height, 0.01f, 100.0f); viewMatrix.translation(0, 0, -10.0f).rotateX(rotX).rotateY(rotY); viewMatrix.originAffine(cameraPosition); projectionMatrix.mulPerspectiveAffine(viewMatrix, viewProjMatrix).invert(invViewProjMatrix); glUseProgramObjectARB(environmentProgram); glUniformMatrix4fvARB(invViewProjUniform, false, invViewProjMatrix.get(matrixBuffer)); glUseProgramObjectARB(teapotProgram); glUniformMatrix4fvARB(viewProjUniform, false, viewProjMatrix.get(matrixBuffer)); glUniform3fARB(cameraPositionUniform, cameraPosition.x, cameraPosition.y, cameraPosition.z); } void render() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); /* Render environment map */ glDisable(GL_DEPTH_TEST); glUseProgramObjectARB(environmentProgram); glBindBufferARB(GL_ARRAY_BUFFER_ARB, this.fullscreenVbo); glEnableClientState(GL_VERTEX_ARRAY); glVertexPointer(2, GL_FLOAT, 0, 0L); glDrawArrays(GL_TRIANGLES, 0, 6); glDisableClientState(GL_VERTEX_ARRAY); /* Render teapot */ glEnable(GL_DEPTH_TEST); glUseProgramObjectARB(teapotProgram); glBindBufferARB(GL_ARRAY_BUFFER_ARB, this.teapotProgram); glEnableClientState(GL_NORMAL_ARRAY); glEnableClientState(GL_VERTEX_ARRAY); glVertexPointer(3, GL_FLOAT, 3 * 4, 0L); glNormalPointer(GL_FLOAT, 3 * 4, normalsOffset); glDrawArrays(GL_TRIANGLES, 0, numVertices); glDisableClientState(GL_VERTEX_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); } void loop() { while (!glfwWindowShouldClose(window)) { glfwPollEvents(); glViewport(0, 0, width, height); update(); render(); glfwSwapBuffers(window); } } void run() { try { init(); loop(); if (debugProc != null) { debugProc.free(); } cpCallback.free(); keyCallback.free(); fbCallback.free(); glfwDestroyWindow(window); } catch (Throwable t) { t.printStackTrace(); } finally { glfwTerminate(); } } public static void main(String[] args) { new EnvironmentTeapotDemo().run(); } }