哪里网站建设公司比较好,揭阳网页制作,自己用笔记本做网站,网站怎么建设好看OpenGL笔记十四之GLM数学库的配置与使用 —— 2024-07-20 中午
bilibili赵新政老师的教程看后笔记
code review! 文章目录 OpenGL笔记十四之GLM数学库的配置与使用1.旋转变换运行效果2.平移变换运行效果3.缩放变换运行效果4.复合变换#xff1a;先旋转 再平移运行效果5.复合…OpenGL笔记十四之GLM数学库的配置与使用 —— 2024-07-20 中午
bilibili赵新政老师的教程看后笔记
code review! 文章目录 OpenGL笔记十四之GLM数学库的配置与使用1.旋转变换运行效果2.平移变换运行效果3.缩放变换运行效果4.复合变换先旋转 再平移运行效果5.复合变换先平移 后旋转运行效果6.每一帧都旋转运行效果7.关键代码7.1.vs7.2.fs7.3.main.cpp关键片段7.4.shader.h关键片段7.5.shader.cpp关键片段7.6.core.h中要把代码包含进来 把GLM文件夹拷贝thirdParty/include文件夹下 1.旋转变换运行效果 2.平移变换运行效果 3.缩放变换运行效果 4.复合变换先旋转 再平移运行效果 5.复合变换先平移 后旋转运行效果 6.每一帧都旋转运行效果
注意每一帧都是从起始位姿旋转而至
7.关键代码
7.1.vs 代码
#version 330 core
layout (location 0) in vec3 aPos;
layout (location 1) in vec3 aColor;
layout (location 2) in vec2 aUV;out vec3 color;
out vec2 uv;uniform mat4 transform;//aPos作为attribute属性传入shader
//不允许更改的
void main()
{vec4 position vec4(aPos, 1.0);position transform * position;gl_Position position;color aColor;uv aUV;
}7.2.fs 代码
#version 330 core
out vec4 FragColor;in vec3 color;
in vec2 uv;uniform sampler2D sampler;void main()
{FragColor texture(sampler, uv);
}7.3.main.cpp关键片段 main.cpp完整代码
#include iostream#include glframework/core.h
#include glframework/shader.h
#include string
#include assert.h//断言
#include wrapper/checkError.h
#include application/Application.h
#include glframework/texture.h/*
*┌────────────────────────────────────────────────┐
*│ 目 标 初步学习GLM库的平移/旋转/缩放
*│ 讲 师 赵新政(Carma Zhao)
*│ 拆分目标
* -1 引入GLM的头文件
* -2 更改vertexShader加入uniform变量mat4 transform
* -3 使用传入的transform给我们的顶点坐标进行变换
* -4 为shader类增加uniform矩阵传输的功能
* -5 使用矩阵做复合变换
* -6 连续转动三角形动画
*└────────────────────────────────────────────────┘
*/GLuint vao;
Shader* shader nullptr;
Texture* texture nullptr;
glm::mat4 transform(1.0f);void OnResize(int width, int height) {GL_CALL(glViewport(0, 0, width, height));std::cout OnResize std::endl;
}void OnKey(int key, int action, int mods) {std::cout key std::endl;
}void doRotationTransform() {//构建一个旋转矩阵绕着z轴旋转45度角//rotate函数用于生成旋转矩阵//bug1:rotate必须得到一个float类型的角度c的template//bug2:rotate函数接受的不是角度degree接收的弧度radians//注意点radians函数也是模板函数切记要传入float类型数据加f后缀transform glm::rotate(glm::mat4(1.0f),glm::radians(90.0f), glm::vec3(0.0, 0.0, 1.0));
}//平移变换
void doTranslationTransform() {transform glm::translate(glm::mat4(1.0f), glm::vec3(0.5f, 0.0f, 0.0f));
}//缩放变换
void doScaleTransform() {transform glm::scale(glm::mat4(1.0f), glm::vec3(0.1f, 0.5f, 1.0f));
}//复合变换
void doTransform() {glm::mat4 rotateMat glm::rotate(glm::mat4(1.0f), glm::radians(90.0f), glm::vec3(0.0, 0.0, 1.0));glm::mat4 translateMat glm::translate(glm::mat4(1.0f), glm::vec3(0.5f, 0.0f, 0.0f));//先旋转 再平移// transform translateMat * rotateMat;//先平移 后旋转transform rotateMat * translateMat;
}float angle 0.0f;
void doRotation() {angle 2.0f;//每一帧都会“重新”构建一个旋转矩阵transform glm::rotate(glm::mat4(1.0f), glm::radians(angle), glm::vec3(0.0, 0.0, 1.0));
}void prepareVAO() {//1 准备positions colorsfloat positions[] {-0.5f, -0.5f, 0.0f,0.5f, -0.5f, 0.0f,0.0f, 0.5f, 0.0f,};float colors[] {1.0f, 0.0f,0.0f,0.0f, 1.0f,0.0f,0.0f, 0.0f,1.0f,};float uvs[] {0.0f, 0.0f,1.0f, 0.0f,0.5f, 1.0f,};unsigned int indices[] {0, 1, 2,};//2 VBO创建GLuint posVbo, colorVbo, uvVbo;glGenBuffers(1, posVbo);glBindBuffer(GL_ARRAY_BUFFER, posVbo);glBufferData(GL_ARRAY_BUFFER, sizeof(positions), positions, GL_STATIC_DRAW);glGenBuffers(1, colorVbo);glBindBuffer(GL_ARRAY_BUFFER, colorVbo);glBufferData(GL_ARRAY_BUFFER, sizeof(colors), colors, GL_STATIC_DRAW);glGenBuffers(1, uvVbo);glBindBuffer(GL_ARRAY_BUFFER, uvVbo);glBufferData(GL_ARRAY_BUFFER, sizeof(uvs), uvs, GL_STATIC_DRAW);//3 EBO创建GLuint ebo;glGenBuffers(1, ebo);glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);//4 VAO创建glGenVertexArrays(1, vao);glBindVertexArray(vao);//5 绑定vbo ebo 加入属性描述信息//5.1 加入位置属性描述信息glBindBuffer(GL_ARRAY_BUFFER, posVbo);glEnableVertexAttribArray(0);glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 3, (void*)0);//5.2 加入颜色属性描述数据glBindBuffer(GL_ARRAY_BUFFER, colorVbo);glEnableVertexAttribArray(1);glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 3, (void*)0);//5.3 加入uv属性描述数据glBindBuffer(GL_ARRAY_BUFFER, uvVbo);glEnableVertexAttribArray(2);glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 2, (void*)0);//5.4 加入ebo到当前的vaoglBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);glBindVertexArray(0);
}void prepareShader() {shader new Shader(assets/shaders/vertex.glsl,assets/shaders/fragment.glsl);
}void prepareTexture() {texture new Texture(assets/textures/goku.jpg, 0);
}void render() {//执行opengl画布清理操作GL_CALL(glClear(GL_COLOR_BUFFER_BIT));//绑定当前的programshader-begin();shader-setInt(sampler, 0);shader-setMatrix4x4(transform, transform);//绑定当前的vaoGL_CALL(glBindVertexArray(vao));//发出绘制指令GL_CALL(glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0));GL_CALL(glBindVertexArray(0));shader-end();
}int main() {if (!app-init(800, 600)) {return -1;}app-setResizeCallback(OnResize);app-setKeyBoardCallback(OnKey);//设置opengl视口以及清理颜色GL_CALL(glViewport(0, 0, 800, 600));GL_CALL(glClearColor(0.2f, 0.3f, 0.3f, 1.0f));prepareShader();prepareVAO();prepareTexture();// doRotationTransform();// doTranslationTransform();// doScaleTransform();doTransform();while (app-update()) {// doRotation();render();}app-destroy();return 0;
}7.4.shader.h关键片段
void setMatrix4x4(const std::string name, glm::mat4 value);shader.h完整代码
#pragma once#include core.h
#includestringclass Shader {
public:Shader(const char* vertexPath, const char* fragmentPath);~Shader();void begin();//开始使用当前Shadervoid end();//结束使用当前Shadervoid setFloat(const std::string name, float value);void setVector3(const std::string name, float x, float y, float z);void setVector3(const std::string name, const float* values);void setInt(const std::string name, int value);void setMatrix4x4(const std::string name, glm::mat4 value);
private://shader program//type:COMPILE LINKvoid checkShaderErrors(GLuint target,std::string type);private:GLuint mProgram{ 0 };
};
7.5.shader.cpp关键片段
void Shader::setMatrix4x4(const std::string name, glm::mat4 value) {//1 通过名称拿到Uniform变量的位置LocationGLint location GL_CALL(glGetUniformLocation(mProgram, name.c_str()));//2 通过Location更新Uniform变量的值//transpose参数表示是否对传输进去的矩阵数据进行转置glUniformMatrix4fv(location, 1, GL_FALSE, glm::value_ptr(value));
}shader.cpp完整代码
#includeshader.h
#include../wrapper/checkError.h#includestring
#includefstream
#includesstream
#includeiostreamShader::Shader(const char* vertexPath, const char* fragmentPath) {//声明装入shader代码字符串的两个stringstd::string vertexCode;std::string fragmentCode;//声明用于读取vs跟fs文件的inFileStreamstd::ifstream vShaderFile;std::ifstream fShaderFile;//保证ifstream遇到问题的时候可以抛出异常vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);try {//1 打开文件vShaderFile.open(vertexPath);fShaderFile.open(fragmentPath);//2 将文件输入流当中的字符串输入到stringStream里面std::stringstream vShaderStream, fShaderStream;vShaderStream vShaderFile.rdbuf();fShaderStream fShaderFile.rdbuf();//3 关闭文件vShaderFile.close();fShaderFile.close();//4 将字符串从stringStream当中读取出来转化到code String当中vertexCode vShaderStream.str();fragmentCode fShaderStream.str();}catch (std::ifstream::failure e) {std::cout ERROR: Shader File Error: e.what() std::endl;}const char* vertexShaderSource vertexCode.c_str();const char* fragmentShaderSource fragmentCode.c_str();//1 创建Shader程序vs、fsGLuint vertex, fragment;vertex glCreateShader(GL_VERTEX_SHADER);fragment glCreateShader(GL_FRAGMENT_SHADER);//2 为shader程序输入shader代码glShaderSource(vertex, 1, vertexShaderSource, NULL);glShaderSource(fragment, 1, fragmentShaderSource, NULL);//3 执行shader代码编译 glCompileShader(vertex);//检查vertex编译结果checkShaderErrors(vertex, COMPILE);glCompileShader(fragment);//检查fragment编译结果checkShaderErrors(fragment, COMPILE);//4 创建一个Program壳子mProgram glCreateProgram();//6 将vs与fs编译好的结果放到program这个壳子里glAttachShader(mProgram, vertex);glAttachShader(mProgram, fragment);//7 执行program的链接操作形成最终可执行shader程序glLinkProgram(mProgram);//检查链接错误checkShaderErrors(mProgram, LINK);//清理glDeleteShader(vertex);glDeleteShader(fragment);
}
Shader::~Shader() {}void Shader::begin() {GL_CALL(glUseProgram(mProgram));
}void Shader::end() {GL_CALL(glUseProgram(0));
}void Shader::setFloat(const std::string name, float value) {//1 通过名称拿到Uniform变量的位置LocationGLint location GL_CALL(glGetUniformLocation(mProgram, name.c_str()));//2 通过Location更新Uniform变量的值GL_CALL(glUniform1f(location, value));
}void Shader::setVector3(const std::string name, float x, float y, float z) {//1 通过名称拿到Uniform变量的位置LocationGLint location GL_CALL(glGetUniformLocation(mProgram, name.c_str()));//2 通过Location更新Uniform变量的值GL_CALL(glUniform3f(location, x, y, z));
}//重载 overload
void Shader::setVector3(const std::string name, const float* values) {//1 通过名称拿到Uniform变量的位置LocationGLint location GL_CALL(glGetUniformLocation(mProgram, name.c_str()));//2 通过Location更新Uniform变量的值//第二个参数你当前要更新的uniform变量如果是数组数组里面包括多少个向量vec3GL_CALL(glUniform3fv(location, 1, values));
}void Shader::setInt(const std::string name, int value) {//1 通过名称拿到Uniform变量的位置LocationGLint location GL_CALL(glGetUniformLocation(mProgram, name.c_str()));//2 通过Location更新Uniform变量的值glUniform1i(location, value);
}void Shader::setMatrix4x4(const std::string name, glm::mat4 value) {//1 通过名称拿到Uniform变量的位置LocationGLint location GL_CALL(glGetUniformLocation(mProgram, name.c_str()));//2 通过Location更新Uniform变量的值//transpose参数表示是否对传输进去的矩阵数据进行转置glUniformMatrix4fv(location, 1, GL_FALSE, glm::value_ptr(value));
}void Shader::checkShaderErrors(GLuint target, std::string type) {int success 0;char infoLog[1024];if (type COMPILE) {glGetShaderiv(target, GL_COMPILE_STATUS, success);if (!success) {glGetShaderInfoLog(target, 1024, NULL, infoLog);std::cout Error: SHADER COMPILE ERROR \n infoLog std::endl;}}else if (type LINK) {glGetProgramiv(target, GL_LINK_STATUS, success);if (!success) {glGetProgramInfoLog(target, 1024, NULL, infoLog);std::cout Error: SHADER LINK ERROR \n infoLog std::endl;}}else {std::cout Error: Check shader errors Type is wrong std::endl;}
}7.6.core.h中要把代码包含进来
core.h
#pragma once//注意glad头文件必须在glfw引用之前引用
#include glad/glad.h
#include GLFW/glfw3.h//GLM
#include glm/glm.hpp
#include glm/gtc/matrix_transform.hpp
#include glm/gtc/type_ptr.hpp#define GLM_ENABLE_EXPERIMENTAL
#include glm/gtx/string_cast.hpp
