OpenGL--恒星，卫星，行星系统

为了方便，先用金字塔，正方体，小正方体代替恒星，卫星，行星。
并用矩阵堆栈的形式实现。

#include <GL\glew.h>
#include <GLFW\glfw3.h>
#include <string>
#include <iostream>
#include <fstream>
#include <cmath>
#include <stack>
#include <glm\glm.hpp>
#include <glm\gtc\type_ptr.hpp> // glm::value_ptr
#include <glm\gtc\matrix_transform.hpp> // glm::translate, glm::rotate, glm::scale, glm::perspective
#include "Utils.h"
using namespace std;#define numVAOs 1
#define numVBOs 2float cameraX, cameraY, cameraZ;//视图矩阵，相机位置
GLuint renderingProgram;
GLuint vao[numVAOs];
GLuint vbo[numVBOs];// 分配在display()函数中使用的变量空间，这样它们就不必在渲染过程中分配
GLuint mvLoc, projLoc;
int width, height;
float aspect;
glm::mat4 pMat, vMat, mMat, mvMat;stack<glm::mat4>mvStack;void setupVertices(void) {//正方体//36个顶点，12个三角形，组成了放置在原点处的2×2×2立方体float vertexPositions[108] = {-1.0f,  1.0f, -1.0f, -1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f,1.0f, -1.0f, -1.0f, 1.0f,  1.0f, -1.0f, -1.0f,  1.0f, -1.0f,1.0f, -1.0f, -1.0f, 1.0f, -1.0f,  1.0f, 1.0f,  1.0f, -1.0f,1.0f, -1.0f,  1.0f, 1.0f,  1.0f,  1.0f, 1.0f,  1.0f, -1.0f,1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f, 1.0f,  1.0f,  1.0f,-1.0f, -1.0f,  1.0f, -1.0f,  1.0f,  1.0f, 1.0f,  1.0f,  1.0f,-1.0f, -1.0f,  1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f,  1.0f,-1.0f, -1.0f, -1.0f, -1.0f,  1.0f, -1.0f, -1.0f,  1.0f,  1.0f,-1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f,  1.0f, -1.0f, -1.0f,1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f,  1.0f,-1.0f,  1.0f, -1.0f, 1.0f,  1.0f, -1.0f, 1.0f,  1.0f,  1.0f,1.0f,  1.0f,  1.0f, -1.0f,  1.0f,  1.0f, -1.0f,  1.0f, -1.0f};//金字塔//18个顶点，6个三角形float pyramidPositions[54] ={ -1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 0.0f, 1.0f, 0.0f,    //front1.0f, -1.0f, 1.0f, 1.0f, -1.0f, -1.0f, 0.0f, 1.0f, 0.0f,    //right1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, 0.0f, 1.0f, 0.0f,  //back-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, 1.0f, 0.0f, 1.0f, 0.0f,  //left-1.0f, -1.0f, -1.0f, 1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, //LF1.0f, -1.0f, 1.0f, -1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f  //RR};glGenVertexArrays(1, vao);//创建顶点数组对象VAO,      //数据集发送给管线时，是以缓冲区形式发送的glBindVertexArray(vao[0]);//将指定的VAO标记为活跃，生成的缓冲区和这个VAO关联glGenBuffers(numVBOs, vbo);//创建VBO.//参数1，创建多少个ID，参数2，保存返回的ID的数组glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);//将缓冲区【0】标记为活跃glBufferData(GL_ARRAY_BUFFER, sizeof(vertexPositions), vertexPositions, GL_STATIC_DRAW);//将包含顶点数据的数组复制进活跃缓冲区glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);glBufferData(GL_ARRAY_BUFFER, sizeof(pyramidPositions), pyramidPositions, GL_STATIC_DRAW);
}//init()函数负责执行只需要一次的任务
void init(GLFWwindow* window) {renderingProgram = Utils::createShaderProgram("vertShader.glsl", "fragShader.glsl");//获取GL程序的ID，该程序创建着色器glfwGetFramebufferSize(window, &width, &height);aspect = (float)width / (float)height;//屏幕纵横比.透视矩阵需要的参数//构建透视矩阵//根据所需的视锥提供3D效果，这里放在了init里，因为只需要构建一次pMat = glm::perspective(1.0472f, aspect, 0.1f, 1000.0f);//构建透视矩阵//参数 1. 指定视场角(这里是60°，对应弧度是1.0472）//，2. 屏幕纵横比 ，3.近裁剪平面，4.远裁剪平面cameraX = 0.0f; cameraY = 0.0f; cameraZ = 12.0f;//相机放在z轴的下方setupVertices();//将顶点数据复制进缓冲区
}//调用display函数的速率被称为帧率
void display(GLFWwindow* window, double currentTime) {
//配置背景，深度缓冲区，渲染程序，以及和原来一样的投影矩阵/////清除深度缓冲区glClear(GL_DEPTH_BUFFER_BIT);//隐藏面消除需要同时用到颜色缓冲区和深度缓冲区glClearColor(1.0, 1.0, 1.0, 1.0);						//这里只清楚了深度缓冲区，不然可能会导致黑屏glClear(GL_COLOR_BUFFER_BIT);glEnable(GL_CULL_FACE);//背面剔除//启用着色器glUseProgram(renderingProgram);//将含有两个已编译着色器的程序载入OpenGL管线阶段（在GPU上！）//glUseProgram没有运行着色器，它只是将着色器加载进硬件//着色器需要视图矩阵的统一变量//获取V矩阵和投影矩阵的统一变量// m/模型矩阵在世界坐标空间中表示对象的位置和朝向mvLoc = glGetUniformLocation(renderingProgram, "mv_matrix");//获取着色器程序中MV矩阵统一变量的位置projLoc = glGetUniformLocation(renderingProgram, "proj_matrix");//获取着色器程序中投影矩阵统一变量的位置
//将视图矩阵推入堆栈vMat = glm::translate(glm::mat4(1.0f), glm::vec3(-cameraX, -cameraY, -cameraZ));//v，视图，相机，变换矩阵mvStack.push(vMat);//摄像机glUniformMatrix4fv(projLoc, 1, GL_FALSE, glm::value_ptr(pMat));//将矩阵数据发送到统一变量中//--------------------pyramid == sunmvStack.push(mvStack.top());//将新矩阵推入堆栈，对第一个对象来说，直接复制一份视图矩阵mvStack.top() *= glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, -0.0f));//太阳的位置//将父对象的模型矩阵和复制的的视图矩阵结合mvStack.push(mvStack.top());//生成完整的MV矩阵，包括它的自转mvStack.top() *= rotate(glm::mat4(1.0f), (float)currentTime, glm::vec3(1.0f, 0.0f, 0.0f));//稍后会弹出不会影响子对象glUniformMatrix4fv(mvLoc, 1, GL_FALSE, glm::value_ptr(mvStack.top()));//将矩阵数据发送到统一变量中，value_ptr返回的是对矩阵数据的引用glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);//将VBO关联给顶点着色器中相应的顶点属性glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(0);glEnable(GL_DEPTH_TEST);	//调整OpenGL设置，绘制模型glDepthFunc(GL_LEQUAL);glFrontFace(GL_CW);glDrawArrays(GL_TRIANGLES, 0, 18);mvStack.pop();//---------------------cube == planetmvStack.push(mvStack.top());mvStack.top() *= glm::translate(glm::mat4(1.0f), glm::vec3(sin((float)currentTime) * 4.0, 0.0f, cos((float)currentTime) * 4.0));mvStack.push(mvStack.top());mvStack.top() *= rotate(glm::mat4(1.0f), (float)currentTime, glm::vec3(0.0, 1.0, 0.0));//稍后会弹出不会影响子对象glUniformMatrix4fv(mvLoc, 1, GL_FALSE, glm::value_ptr(mvStack.top()));//将矩阵数据发送到统一变量中，value_ptr返回的是对矩阵数据的引用glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);//将VBO关联给顶点着色器中相应的顶点属性glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(0);glEnable(GL_DEPTH_TEST);	//调整OpenGL设置，绘制模型glDepthFunc(GL_LEQUAL);glDrawArrays(GL_TRIANGLES, 0, 36);mvStack.pop();//-----------------------smaller cube == moonmvStack.push(mvStack.top());mvStack.top() *= glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, sin((float)currentTime) * 2.0, cos((float)currentTime) * 2.0));mvStack.top() *= rotate(glm::mat4(1.0f), (float)currentTime, glm::vec3(0.0, 0.0, 1.0));mvStack.top() *= scale(glm::mat4(1.0f), glm::vec3(0.25, 0.25, 0.25));glUniformMatrix4fv(mvLoc, 1, GL_FALSE, glm::value_ptr(mvStack.top()));//将矩阵数据发送到统一变量中，value_ptr返回的是对矩阵数据的引用glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);//将VBO关联给顶点着色器中相应的顶点属性glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(0);glEnable(GL_DEPTH_TEST);	//调整OpenGL设置，绘制模型glDepthFunc(GL_LEQUAL);glDrawArrays(GL_TRIANGLES, 0, 36);mvStack.pop(); mvStack.pop(); mvStack.pop();mvStack.pop();//最后一个是视图矩阵
}
void window_size_callback(GLFWwindow* win, int newWidth, int newHeight) {aspect = (float)newWidth / (float)newHeight;glViewport(0, 0, newWidth, newHeight);pMat = glm::perspective(1.0472f, aspect, 0.1f, 1000.0f);
}
int main(void) {if (!glfwInit()) { exit(EXIT_FAILURE); }glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);//设置窗口选项glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);GLFWwindow* window = glfwCreateWindow(600, 600, "Chapter 4 - program 2", NULL, NULL);glfwMakeContextCurrent(window);//让当前窗口的环境在当前线程上成为当前环境if (glewInit() != GLEW_OK) { exit(EXIT_FAILURE); }glfwSwapInterval(1);glfwSetWindowSizeCallback(window, window_size_callback);init(window);while (!glfwWindowShouldClose(window)) {display(window, glfwGetTime());glfwSwapBuffers(window);glfwPollEvents();}glfwDestroyWindow(window);glfwTerminate();exit(EXIT_SUCCESS);
}

#include <GL\glew.h>
#include <GLFW\glfw3.h>
#include <SOIL2\soil2.h>
#include <string>
#include <iostream>
#include <fstream>
#include <cmath>
#include <glm\glm.hpp>
#include <glm\gtc\type_ptr.hpp> // glm::value_ptr
#include <glm\gtc\matrix_transform.hpp> // glm::translate, glm::rotate, glm::scale, glm::perspective
#include "Utils.h"
using namespace std;Utils::Utils() {}string Utils::readShaderFile(const char *filePath) {string content;ifstream fileStream(filePath, ios::in);string line = " ";while (!fileStream.eof()) {getline(fileStream, line);content.append(line + "\n");}fileStream.close();return content;
}bool Utils::checkOpenGLError() {bool foundError = false;int glErr = glGetError();while (glErr != GL_NO_ERROR) {cout << "glError: " << glErr << endl;foundError = true;glErr = glGetError();}return foundError;
}void Utils::printShaderLog(GLuint shader) {int len = 0;int chWrittn = 0;char *log;glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &len);if (len > 0) {log = (char *)malloc(len);glGetShaderInfoLog(shader, len, &chWrittn, log);cout << "Shader Info Log: " << log << endl;free(log);}
}GLuint Utils::prepareShader(int shaderTYPE, const char *shaderPath)
{	GLint shaderCompiled;string shaderStr = readShaderFile(shaderPath);const char *shaderSrc = shaderStr.c_str();//获取着色器信息的字符串GLuint shaderRef = glCreateShader(shaderTYPE);//创建着色器glShaderSource(shaderRef, 1, &shaderSrc, NULL);//将字符串复制进着色器中glCompileShader(shaderRef);//编译着色器checkOpenGLError();glGetShaderiv(shaderRef, GL_COMPILE_STATUS, &shaderCompiled);if (shaderCompiled != 1){	if (shaderTYPE == 35633) cout << "Vertex ";if (shaderTYPE == 36488) cout << "Tess Control ";if (shaderTYPE == 36487) cout << "Tess Eval ";if (shaderTYPE == 36313) cout << "Geometry ";if (shaderTYPE == 35632) cout << "Fragment ";cout << "shader compilation error." << endl;printShaderLog(shaderRef);}return shaderRef;//返回程序的ID
}void Utils::printProgramLog(int prog) {int len = 0;int chWrittn = 0;char *log;glGetProgramiv(prog, GL_INFO_LOG_LENGTH, &len);if (len > 0) {log = (char *)malloc(len);glGetProgramInfoLog(prog, len, &chWrittn, log);cout << "Program Info Log: " << log << endl;free(log);}
}int Utils::finalizeShaderProgram(GLuint sprogram)
{	GLint linked;glLinkProgram(sprogram); //请求GLSL编译器确保他们的兼容性checkOpenGLError();glGetProgramiv(sprogram, GL_LINK_STATUS, &linked);if (linked != 1){	cout << "linking failed" << endl;printProgramLog(sprogram);}return sprogram;
}GLuint Utils::createShaderProgram(const char *vp, const char *fp) {GLuint vShader = prepareShader(GL_VERTEX_SHADER, vp);//获取编译着色器后得到的着色器对象GLuint fShader = prepareShader(GL_FRAGMENT_SHADER, fp);GLuint vfprogram = glCreateProgram();//创建程序对象glAttachShader(vfprogram, vShader);//将着色器对象载入程序对象中glAttachShader(vfprogram, fShader);finalizeShaderProgram(vfprogram); //请求GLSL编译器确保他们的兼容性return vfprogram;
}GLuint Utils::createShaderProgram(const char *vp, const char *gp, const char *fp) {GLuint vShader = prepareShader(GL_VERTEX_SHADER, vp);GLuint gShader = prepareShader(GL_GEOMETRY_SHADER, gp);GLuint fShader = prepareShader(GL_FRAGMENT_SHADER, fp);GLuint vgfprogram = glCreateProgram();glAttachShader(vgfprogram, vShader);glAttachShader(vgfprogram, gShader);glAttachShader(vgfprogram, fShader);finalizeShaderProgram(vgfprogram);return vgfprogram;
}GLuint Utils::createShaderProgram(const char *vp, const char *tCS, const char* tES, const char *fp) {GLuint vShader = prepareShader(GL_VERTEX_SHADER, vp);GLuint tcShader = prepareShader(GL_TESS_CONTROL_SHADER, tCS);GLuint teShader = prepareShader(GL_TESS_EVALUATION_SHADER, tES);GLuint fShader = prepareShader(GL_FRAGMENT_SHADER, fp);GLuint vtfprogram = glCreateProgram();glAttachShader(vtfprogram, vShader);glAttachShader(vtfprogram, tcShader);glAttachShader(vtfprogram, teShader);glAttachShader(vtfprogram, fShader);finalizeShaderProgram(vtfprogram);return vtfprogram;
}GLuint Utils::createShaderProgram(const char *vp, const char *tCS, const char* tES, char *gp, const char *fp) {GLuint vShader = prepareShader(GL_VERTEX_SHADER, vp);GLuint tcShader = prepareShader(GL_TESS_CONTROL_SHADER, tCS);GLuint teShader = prepareShader(GL_TESS_EVALUATION_SHADER, tES);GLuint gShader = prepareShader(GL_GEOMETRY_SHADER, gp);GLuint fShader = prepareShader(GL_FRAGMENT_SHADER, fp);GLuint vtgfprogram = glCreateProgram();glAttachShader(vtgfprogram, vShader);glAttachShader(vtgfprogram, tcShader);glAttachShader(vtgfprogram, teShader);glAttachShader(vtgfprogram, gShader);glAttachShader(vtgfprogram, fShader);finalizeShaderProgram(vtgfprogram);return vtgfprogram;
}GLuint Utils::loadCubeMap(const char *mapDir) {GLuint textureRef;string xp = mapDir; xp = xp + "/xp.jpg";string xn = mapDir; xn = xn + "/xn.jpg";string yp = mapDir; yp = yp + "/yp.jpg";string yn = mapDir; yn = yn + "/yn.jpg";string zp = mapDir; zp = zp + "/zp.jpg";string zn = mapDir; zn = zn + "/zn.jpg";textureRef = SOIL_load_OGL_cubemap(xp.c_str(), xn.c_str(), yp.c_str(), yn.c_str(), zp.c_str(), zn.c_str(),SOIL_LOAD_AUTO, SOIL_CREATE_NEW_ID, SOIL_FLAG_MIPMAPS);if (textureRef == 0) cout << "didnt find cube map image file" << endl;//	glBindTexture(GL_TEXTURE_CUBE_MAP, textureRef);// reduce seams//	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);//	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);//	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);return textureRef;
}GLuint Utils::loadTexture(const char *texImagePath)
{	GLuint textureRef;textureRef = SOIL_load_OGL_texture(texImagePath, SOIL_LOAD_AUTO, SOIL_CREATE_NEW_ID, SOIL_FLAG_INVERT_Y);if (textureRef == 0) cout << "didnt find texture file " << texImagePath << endl;// ----- mipmap/anisotropic sectionglBindTexture(GL_TEXTURE_2D, textureRef);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);glGenerateMipmap(GL_TEXTURE_2D);if (glewIsSupported("GL_EXT_texture_filter_anisotropic")) {GLfloat anisoset = 0.0f;glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &anisoset);glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, anisoset);}// ----- end of mipmap/anisotropic sectionreturn textureRef;
}// GOLD material - ambient, diffuse, specular, and shininess
float* Utils::goldAmbient() { static float a[4] = { 0.2473f, 0.1995f, 0.0745f, 1 }; return (float*)a; }
float* Utils::goldDiffuse() { static float a[4] = { 0.7516f, 0.6065f, 0.2265f, 1 }; return (float*)a; }
float* Utils::goldSpecular() { static float a[4] = { 0.6283f, 0.5559f, 0.3661f, 1 }; return (float*)a; }
float Utils::goldShininess() { return 51.2f; }// SILVER material - ambient, diffuse, specular, and shininess
float* Utils::silverAmbient() { static float a[4] = { 0.1923f, 0.1923f, 0.1923f, 1 }; return (float*)a; }
float* Utils::silverDiffuse() { static float a[4] = { 0.5075f, 0.5075f, 0.5075f, 1 }; return (float*)a; }
float* Utils::silverSpecular() { static float a[4] = { 0.5083f, 0.5083f, 0.5083f, 1 }; return (float*)a; }
float Utils::silverShininess() { return 51.2f; }// BRONZE material - ambient, diffuse, specular, and shininess
float* Utils::bronzeAmbient() { static float a[4] = { 0.2125f, 0.1275f, 0.0540f, 1 }; return (float*)a; }
float* Utils::bronzeDiffuse() { static float a[4] = { 0.7140f, 0.4284f, 0.1814f, 1 }; return (float*)a; }
float* Utils::bronzeSpecular() { static float a[4] = { 0.3936f, 0.2719f, 0.1667f, 1 }; return (float*)a; }
float Utils::bronzeShininess() { return 25.6f; }

#include <GL\glew.h>
#include <GLFW\glfw3.h>
#include <SOIL2\soil2.h>
#include <string>
#include <iostream>
#include <fstream>
#include <cmath>
#include <vector>
#include <glm\glm.hpp>
#include <glm\gtc\type_ptr.hpp>
#include <glm\gtc\matrix_transform.hpp>class Utils
{
private:static std::string readShaderFile(const char *filePath);static void printShaderLog(GLuint shader);static void printProgramLog(int prog);static GLuint prepareShader(int shaderTYPE, const char *shaderPath);static int finalizeShaderProgram(GLuint sprogram);public:Utils();static bool checkOpenGLError();static GLuint createShaderProgram(const char *vp, const char *fp);static GLuint createShaderProgram(const char *vp, const char *gp, const char *fp);static GLuint createShaderProgram(const char *vp, const char *tCS, const char* tES, const char *fp);static GLuint createShaderProgram(const char *vp, const char *tCS, const char* tES, char *gp, const char *fp);static GLuint loadTexture(const char *texImagePath);static GLuint loadCubeMap(const char *mapDir);static float* goldAmbient();static float* goldDiffuse();static float* goldSpecular();static float goldShininess();static float* silverAmbient();static float* silverDiffuse();static float* silverSpecular();static float silverShininess();static float* bronzeAmbient();static float* bronzeDiffuse();static float* bronzeSpecular();static float bronzeShininess();
};

vertShader.glsl

#version 430layout (location=0) in vec3 position;uniform mat4 mv_matrix;
uniform mat4 proj_matrix;out vec4 varyingColor;void main(void)
{gl_Position = proj_matrix * mv_matrix * vec4(position,1.0);varyingColor = vec4(position,1.0)*0.5 + vec4(0.5, 0.5, 0.5, 0.5);
} 

fragShader.glsl

#version 430in vec4 varyingColor;
out vec4 color;uniform mat4 mv_matrix;
uniform mat4 proj_matrix;void main(void)
{	color = varyingColor;
}