学习自：
https://learnopengl-cn.github.io/01%20Getting%20started/08%20Coordinate%20Systems/#3d
0，首先添加glm库文件
相关方法可以参照我指定的那篇随便
1，顶点着色器shader.vs
#version core
layout (location = ) in vec3 aPos;
layout (location = ) in vec2 aTexCoord; out vec2 TexCoord; uniform mat4 model;
uniform mat4 view;
uniform mat4 projection; void main()
{
gl_Position = projection * view * model * vec4(aPos, 1.0f);
TexCoord = vec2(aTexCoord.x, aTexCoord.y);
}
2，片段着色器shader.fs
#version core
out vec4 FragColor; in vec2 TexCoord; // texture samplers
uniform sampler2D texture1;
uniform sampler2D texture2; void main()
{
// linearly interpolate between both textures (80% container, 20% awesomeface)
FragColor = mix(texture(texture1, TexCoord), texture(texture2, TexCoord), 0.2);
}
3，主程序
#include <glad/glad.h>
#include <GLFW/glfw3.h> #include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp> #include "stb_image.h"
#include "shader_s.h"
#include <iostream> void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window); // settings
const unsigned int SCR_WIDTH = ;
const unsigned int SCR_HEIGHT = ; int main()
{
// glfw: initialize and configure
// ------------------------------
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, );
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, );
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); #ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
#endif // glfw window creation
// --------------------
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); // glad: load all OpenGL function pointers
// ---------------------------------------
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -;
} // configure global opengl state
// -----------------------------
glEnable(GL_DEPTH_TEST); // build and compile our shader zprogram
// ------------------------------------
Shader ourShader("../res/textures/texture.vs", "../res/textures/texture.fs"); // set up vertex data (and buffer(s)) and configure vertex attributes
// ------------------------------------------------------------------
/*
float vertices[] = {
// 位置信息 // 颜色信息 // 纹理 coords
0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // 右上
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // 右下
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // 左下
-0.5f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f // 左上
};
unsigned int indices[] = {
0, 1, 3, // 第一个三角形
1, 2, 3 // 第二个三角形
};
*/
float vertices[] = {
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
0.5f, -0.5f, -0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f, -0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f, -0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f, -0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f
}; unsigned int VBO, VAO;
glGenVertexArrays(, &VAO);
glGenBuffers(, &VBO); glBindVertexArray(VAO); glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW); // position attribute
glVertexAttribPointer(, , GL_FLOAT, GL_FALSE, * sizeof(float), (void*));
glEnableVertexAttribArray();
// texture coord attribute
glVertexAttribPointer(, , GL_FLOAT, GL_FALSE, * sizeof(float), (void*)( * sizeof(float)));
glEnableVertexAttribArray(); // 加载并创建纹理
// -------------------------
unsigned int texture1, texture2;
// 第一张纹理 glGenTextures(, &texture1);
glBindTexture(GL_TEXTURE_2D, texture1);
// 为当前绑定的纹理对象设置环绕、过滤方式
// 将纹理包装设置为GL_REPEAT（默认包装方法）
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// 设置纹理过滤参数
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// 加载并生成纹理
int width, height, nrChannels;
stbi_set_flip_vertically_on_load(true); //告诉stb_image.h在y轴上翻转加载的纹理。 unsigned char *data = stbi_load("../res/textures/container.jpg", &width, &height, &nrChannels, );
if (data)
{
glTexImage2D(GL_TEXTURE_2D, , GL_RGB, width, height, , GL_RGB, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
}
else
{
std::cout << "Failed to load texture" << std::endl;
}
stbi_image_free(data); // texture 2
glGenTextures(, &texture2);
glBindTexture(GL_TEXTURE_2D, texture2);
// set the texture wrapping parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); // set texture wrapping to GL_REPEAT (default wrapping method)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
// set texture filtering parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// load image, create texture and generate mipmaps
data = stbi_load("../res/textures/awesomeface.png", &width, &height, &nrChannels, );
if (data)
{
//请注意，awesomeface.png具有透明度，因此具有alpha通道，
//因此请务必告诉OpenGL数据类型为GL_RGBA
glTexImage2D(GL_TEXTURE_2D, , GL_RGBA, width, height, , GL_RGBA, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
}
else
{
std::cout << "Failed to load texture" << std::endl;
}
stbi_image_free(data); //告诉每个采样器的opengl它属于哪个纹理单元（只需要做一次）
ourShader.use(); //激活着色器
// either set it manually like so:
glUniform1i(glGetUniformLocation(ourShader.ID, "texture1"), );
// or set it via the texture class
ourShader.setInt("texture2", ); // render loop
// -----------
while (!glfwWindowShouldClose(window))
{
// input
// -----
processInput(window); // render
// ------
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // also clear the depth buffer now! // bind textures on corresponding texture units
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture1);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture2); // activate shader
ourShader.use(); // create transformations
glm::mat4 model = glm::mat4(1.0f); // make sure to initialize matrix to identity matrix first
glm::mat4 view = glm::mat4(1.0f);
glm::mat4 projection = glm::mat4(1.0f);
model = glm::rotate(model, (float)glfwGetTime(), glm::vec3(0.5f, 1.0f, 0.0f));
view = glm::translate(view, glm::vec3(0.0f, 0.0f, -3.0f));
projection = glm::perspective(glm::radians(45.0f), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
// retrieve the matrix uniform locations
unsigned int modelLoc = glGetUniformLocation(ourShader.ID, "model");
unsigned int viewLoc = glGetUniformLocation(ourShader.ID, "view");
// pass them to the shaders (3 different ways)
glUniformMatrix4fv(modelLoc, , GL_FALSE, glm::value_ptr(model));
glUniformMatrix4fv(viewLoc, , GL_FALSE, &view[][]);
// note: currently we set the projection matrix each frame, but since the projection matrix rarely changes it's often best practice to set it outside the main loop only once.
ourShader.setMat4("projection", projection); // render box
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, , ); // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
// -------------------------------------------------------------------------------
glfwSwapBuffers(window);
glfwPollEvents();
} // optional: de-allocate all resources once they've outlived their purpose:
// ------------------------------------------------------------------------
glDeleteVertexArrays(, &VAO);
glDeleteBuffers(, &VBO);
//glDeleteBuffers(1, &EBO); // glfw: terminate, clearing all previously allocated GLFW resources.
// ------------------------------------------------------------------
glfwTerminate();
return ;
} // process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow *window)
{
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
} // glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
// make sure the viewport matches the new window dimensions; note that width and
// height will be significantly larger than specified on retina displays.
glViewport(, , width, height);
}
TestShader.cpp
注意一点的是，我们的着色器类，在这里要添加几个方法，我去百度了一下，找到了常用的一些方法，把各个类型的的set函数都加进来了。
#include "shader_s.h" Shader::Shader(const GLchar * vertexPath, const GLchar * fragmentPath)
{
// 1. 从文件路径中获取顶点/片段着色器
std::string vertexCode;
std::string fragmentCode;
std::ifstream vShaderFile;
std::ifstream fShaderFile;
// 保证ifstream对象可以抛出异常：
vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
try
{
// 打开文件
vShaderFile.open(vertexPath);
fShaderFile.open(fragmentPath);
std::stringstream vShaderStream, fShaderStream;
// 读取文件的缓冲内容到数据流中
vShaderStream << vShaderFile.rdbuf();
fShaderStream << fShaderFile.rdbuf();
// 关闭文件处理器
vShaderFile.close();
fShaderFile.close();
// 转换数据流到string
vertexCode = vShaderStream.str();
fragmentCode = fShaderStream.str();
}
catch (std::ifstream::failure e)
{
std::cout << "ERROR::SHADER::FILE_NOT_SUCCESFULLY_READ" << std::endl;
}
const char* vShaderCode = vertexCode.c_str();
const char * fShaderCode = fragmentCode.c_str();
// 2. 编译着色器
unsigned int vertex, fragment;
// 顶点着色器 vs
vertex = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertex, , &vShaderCode, NULL);
glCompileShader(vertex);
checkCompileErrors(vertex, "VERTEX");
// 片段着色器 fs
fragment = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragment, , &fShaderCode, NULL);
glCompileShader(fragment);
checkCompileErrors(fragment, "FRAGMENT");
// 着色器程序
ID = glCreateProgram();
glAttachShader(ID, vertex);
glAttachShader(ID, fragment);
glLinkProgram(ID);
checkCompileErrors(ID, "PROGRAM");
// 删除着色器，它们已经链接到我们的程序中了，已经不再需要了 glDeleteShader(vertex);
glDeleteShader(fragment);
} void Shader::use()
{
glUseProgram(ID);
} void Shader::setBool(const std::string & name, bool value) const
{
glUniform1i(glGetUniformLocation(ID, name.c_str()), (int)value);
} void Shader::setInt(const std::string & name, int value) const
{
glUniform1i(glGetUniformLocation(ID, name.c_str()), value);
} void Shader::setFloat(const std::string & name, float value) const
{
glUniform1f(glGetUniformLocation(ID, name.c_str()), value);
} void Shader::setVec2(const std::string & name, const glm::vec2 & value) const
{
glUniform2fv(glGetUniformLocation(ID, name.c_str()), , &value[]);
} void Shader::setVec2(const std::string & name, float x, float y) const
{
glUniform2f(glGetUniformLocation(ID, name.c_str()), x, y);
} void Shader::setVec3(const std::string & name, const glm::vec3 & value) const
{
glUniform3fv(glGetUniformLocation(ID, name.c_str()), , &value[]);
} void Shader::setVec3(const std::string & name, float x, float y, float z) const
{
glUniform3f(glGetUniformLocation(ID, name.c_str()), x, y, z);
} void Shader::setVec4(const std::string & name, const glm::vec4 & value) const
{
glUniform4fv(glGetUniformLocation(ID, name.c_str()), , &value[]);
} void Shader::setVec4(const std::string & name, float x, float y, float z, float w)
{
glUniform4f(glGetUniformLocation(ID, name.c_str()), x, y, z, w);
} void Shader::setMat2(const std::string & name, const glm::mat2 & mat) const
{
glUniformMatrix2fv(glGetUniformLocation(ID, name.c_str()), , GL_FALSE, &mat[][]);
} void Shader::setMat3(const std::string & name, const glm::mat3 & mat) const
{
glUniformMatrix3fv(glGetUniformLocation(ID, name.c_str()), , GL_FALSE, &mat[][]);
} void Shader::setMat4(const std::string & name, const glm::mat4 & mat) const
{
glUniformMatrix4fv(glGetUniformLocation(ID, name.c_str()), , GL_FALSE, &mat[][]);
} void Shader::checkCompileErrors(unsigned int shader, std::string type)
{
int success;
char infoLog[];
if (type != "PROGRAM")
{
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(shader, , NULL, infoLog);
std::cout << "ERROR::SHADER_COMPILATION_ERROR of type: " << type << "\n" << infoLog << "\n -- --------------------------------------------------- -- " << std::endl;
}
}
else
{
glGetProgramiv(shader, GL_LINK_STATUS, &success);
if (!success)
{
glGetProgramInfoLog(shader, , NULL, infoLog);
std::cout << "ERROR::PROGRAM_LINKING_ERROR of type: " << type << "\n" << infoLog << "\n -- --------------------------------------------------- -- " << std::endl;
}
}
}
shader_s.cpp
自己把相关的类定义写道头文件中就可以了。
4，运行结果
