基于OpenGL着色语言的地球模型

#include <iostream> #include <map> #include <gl/glew.h> #include <gl/glut.h> #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> #include "Sphere.h" #include "ScreenQuad.h" #include "textfile.h" #include "Shader.h" #include "Texture.h" #pragma comment(lib, "glew32.lib") using namespace glm; mat4 modelViewMatrix, viewMatrix, projectionMatrix, MVP; mat3 normalMatrix; mat4 transform; GLfloat lastPosition[3], axis[3] = {0.0, 0.0, -1.0}; GLuint width = 1000, height = 680; GLfloat angle = 23.6; GLfloat trans = 0.0; Shader sh; ScreenQuad *sq; Sphere *earth; const enum renderType{RENDERTOTEXTURE, RENDERTOBUFFER, ENUMCOUNT}; GLuint fb[ENUMCOUNT]; GLsizei samples = 16;//sample number GLuint pass1Index, pass2Index, pass3Index, pass4Index; void PointToVector(int x, int y, GLfloat *v) { GLfloat d, a; v[0] = (2.0 * x - width) / width; v[1] = (height - 2.0 * y) / height; d = sqrt(v[0] * v[0] + v[1] * v[1]); v[2] = cos((3.14159265 / 2.0) * ((d < 1.0) ? d : 1.0)); a = 1.0 / sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); v[0] *= a; v[1] *= a; v[2] *= a; } void changeSize(int w, int h) { if(h == 0) h = 1; glViewport(0, 0, w, h); projectionMatrix = perspective(45.0, (GLdouble)w / h, 1.0, 100.0); sh.SetUniformMatrix4fv("ProjectionMatrix", 1, &projectionMatrix[0][0]); width = w; height = h; } void setFBO() { GLuint rb[2]; glGenRenderbuffers(2, rb); glBindRenderbuffer(GL_RENDERBUFFER, rb[0]); glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, width, height); glBindRenderbuffer(GL_RENDERBUFFER, rb[1]); glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height); // Create the texture object GLuint renderTex, texColor; glGenTextures(1, &renderTex); glActiveTexture(GL_TEXTURE1); // Use texture unit 1 glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, renderTex); glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGBA, width, height, GL_TRUE); glGenTextures(1, &texColor); glActiveTexture(GL_TEXTURE2); glBindTexture(GL_TEXTURE_2D, texColor); //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width / 2, height / 2, 0, ) //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); GLuint texDep; glGenRenderbuffers(1, &texDep); glBindRenderbuffer(GL_RENDERBUFFER, texDep); glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples, GL_DEPTH_COMPONENT24, width, height); glGenFramebuffers(1, &fb[RENDERTOBUFFER]); glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb[RENDERTOBUFFER]); glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rb[0]); glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rb[1]); // Bind the texture to the FBO glGenFramebuffers(1, &fb[RENDERTOTEXTURE]); glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb[RENDERTOTEXTURE]); glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, renderTex, 0); glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, texDep); glBindFramebuffer(GL_FRAMEBUFFER, 0); } void setMatrices() { normalMatrix = mat3(vec3(modelViewMatrix[0]), vec3(modelViewMatrix[1]), vec3(modelViewMatrix[2])); MVP = projectionMatrix * modelViewMatrix; sh.SetUniformMatrix4fv("ProjectionMatrix", 1, &projectionMatrix[0][0]); sh.SetUniformMatrix4fv("ModelViewMatrix", 1, &modelViewMatrix[0][0]); sh.SetUniformMatrix3fv("NormalMatrix", 1, &normalMatrix[0][0]); sh.SetUniformMatrix4fv("MVP", 1, &MVP[0][0]); } void pass1()// render the scene to texture { //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb[RENDERTOTEXTURE]); glClearColor(0.0, 0.0, 0.0, 1.0); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glUniformSubroutinesuiv(GL_FRAGMENT_SHADER, 1, &pass1Index); /*rendering objects*/ projectionMatrix = perspective(45.0, (GLdouble)width / height, 1.0, 100.0); mat4 translatef = translate(mat4(1.0f), vec3(0.0, 0.0, trans)); mat4 rotatef = rotate(mat4(1.0f), angle, vec3(axis[0], axis[1], axis[2])); transform = rotatef * transform; modelViewMatrix = viewMatrix * translatef * transform; setMatrices(); earth->Render(); glBindFramebuffer(GL_FRAMEBUFFER, 0); } void pass2() { //glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); /*bind custom framebuffer and clear color and depth buffer*/ glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fb[RENDERTOBUFFER]); glClearColor(0.0, 0.0, 0.0, 1.0); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glUniformSubroutinesuiv(GL_FRAGMENT_SHADER, 1, &pass2Index); projectionMatrix = mat4(1.0); modelViewMatrix = mat4(1.0f); setMatrices(); sq->Render(); glBindFramebuffer(GL_FRAMEBUFFER, 0); } void pass3() { /*read custom framebuffer and draw to system framebuffer*/ glBindFramebuffer(GL_READ_FRAMEBUFFER, fb[RENDERTOBUFFER]); glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);//rendering to screen glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glClearColor(0.0, 0.0, 0.0, 1.0); glBlitFramebuffer(0, 0, width, height, 0, 0, width, height, GL_COLOR_BUFFER_BIT, GL_NEAREST); glutSwapBuffers(); glFinish(); } void renderScene(void) { pass1(); pass2(); pass3(); } void init() { glClearColor(0.0, 0.0, 0.0, 1.0); //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); earth = new Sphere(10.0, 1, 0, 360, 0, 180); sq = new ScreenQuad(); Texture tex; tex.CreateTexture("se", "earth.tga", GL_TEXTURE_2D); sh.SetUniform1i("EarthTex", tex.GetTextureIndex("se")); sh.SetUniform1i("screenTex", 1); sh.SetUniform4f("LightPosition", 20.0f, 0.0f, 0.0f, 0.0f); sh.SetUniform3f("LightIntensity", 1.0f, 1.0f, 1.0f); sh.SetUniform3f("Kd", 1.0f, 1.0f, 1.0f); sh.SetUniform3f("Ks", 0.9f, 0.9f, 0.9f); sh.SetUniform3f("Ka", 0.1f, 0.1f, 0.1f); sh.SetUniformf("Shininess", 1, 180.0f); sh.SetUniform1i("samples", samples); sh.SetUniform1i("width", width); sh.SetUniform1i("height", height); transform = mat4(1.0f); viewMatrix = lookAt(vec3(0.0, 0.0, 30.0), vec3(0.0, 0.0, 0.0), vec3(0.0, 1.0, 0.0)); setFBO(); GLuint programHandle = sh.GetProgram(); pass1Index = glGetSubroutineIndex(programHandle, GL_FRAGMENT_SHADER, "pass1"); pass2Index = glGetSubroutineIndex(programHandle, GL_FRAGMENT_SHADER, "pass2"); pass3Index = glGetSubroutineIndex(programHandle, GL_FRAGMENT_SHADER, "pass3"); pass4Index = glGetSubroutineIndex(programHandle, GL_FRAGMENT_SHADER, "pass4"); glEnable(GL_DEPTH_TEST); } void mouseClickEvent(int button, int state, int x, int y) { if(button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) { PointToVector(x, y, lastPosition); } } void mouseMotionEvent(int x, int y) { GLfloat currentPosition[3], dx, dy, dz; PointToVector(x, y, currentPosition); dx = currentPosition[0] - lastPosition[0]; dy = currentPosition[1] - lastPosition[1]; dz = currentPosition[2] - lastPosition[2]; angle = 90.0 * sqrt(dx * dx + dy * dy + dz * dz); axis[0] = lastPosition[1] * currentPosition[2] - lastPosition[2] * currentPosition[1]; axis[1] = lastPosition[2] * currentPosition[0] - lastPosition[0] * currentPosition[2]; axis[2] = lastPosition[0] * currentPosition[1] - lastPosition[1] * currentPosition[0]; lastPosition[0] = currentPosition[0]; lastPosition[1] = currentPosition[1]; lastPosition[2] = currentPosition[2]; glutPostRedisplay(); } void keyBoardEvent(unsigned char key, int x, int y) { switch(key) { case 'k': trans += 0.1; break; case 'l': trans -= 0.1; break; default: break; } glutPostRedisplay(); } void setShader() { sh.CreateProgram(); sh.CreateShader("vt", "earth.vs", GL_VERTEX_SHADER); sh.CreateShader("fm", "earth.fs", GL_FRAGMENT_SHADER); sh.LinkProgram(); sh.RunProgram(); } int main(int argc, char **argv) { glutInit(&argc, argv);