OpenGL--恒星，卫星，行星系统
发布时间
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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 2
float 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,
0f, -1.0f, -1.0f, 1.0f, 1.0f, -1.0f, -1.0f, 1.0f, -1.0f,
0f, -1.0f, -1.0f, 1.0f, -1.0f, 1.0f, 1.0f, 1.0f, -1.0f,
0f, -1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f,
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,
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,
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, //front
0f, -1.0f, 1.0f, 1.0f, -1.0f, -1.0f, 0.0f, 1.0f, 0.0f, //right
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, //LF
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 == sun
mvStack.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 == planet
mvStack.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 == moon
mvStack.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);
}
AI生成项目cpp
 #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 section
glBindTexture(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 section
return 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; }
AI生成项目cpp
 #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();
};
AI生成项目cpp
vertShader.glsl
#version 430
layout (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);
}
AI生成项目cpp
fragShader.glsl
#version 430
in vec4 varyingColor;
out vec4 color;
uniform mat4 mv_matrix;
uniform mat4 proj_matrix;
void main(void)
{ color = varyingColor;
}
AI生成项目cpp
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