目录
1、链接文件夹中的cpp
2、链接资源到输出目录
3、多编译目标
4、cmakelist添加库
4、添加glfw和glad
5、glfw运行
6、NDC、VBO、VAO
7、渐变三角形
8、渲染两个三角形
9、渲染两个三角形，同时基于原来颜色进行渐变
1、链接文件夹中的cpp
cmake_minimum_required(VERSION 3.12)
#本工程的名字
project(OpenGL)
#本工程支持的C++版本
set(CMAKE_CXX_STANDARD 17)
#将funcs文件夹纳入到编译系统
add_subdirectory(func)
#搜索所有的cpp，加入SRCS变量中
aux_source_directory(. SRCS)
#本工程主程序文件及输出程序名称
add_executable(glStudy ${SRCS})
#将myFuncs.lib链接入softRender
target_link_libraries(glStudy myFuncs)
#递归将本文件夹下所有cpp放到FUNCS中
file(GLOB_RECURSE FUNCS ./ *.cpp)
#将FUNCS中所有cpp编译为funcs这个lib库
add_library(myFuncs ${FUNCS})
2、链接资源到输出目录
cmake_minimum_required(VERSION 3.12)
#本工程的名字
project(OpenGL)
#本工程支持的C++版本
set(CMAKE_CXX_STANDARD 17)
#把需要拷贝的资源路径都放在img里
file(GLOB IMG "./img")
#把img中目录的内容，都拷贝到可执行文件目录下
file(COPY ${IMG} DESTINATION ${CMAKE_BINARY_DIR})
#将funcs文件夹纳入到编译系统
add_subdirectory(func)
#搜索所有的cpp，加入SRCS变量中
aux_source_directory(. SRCS)
#本工程主程序文件及输出程序名称
add_executable(glStudy ${SRCS})
#将myFuncs.lib链接入softRender
target_link_libraries(glStudy myFuncs)
3、多编译目标
cmake_minimum_required(VERSION 3.12)
#本工程的名字
project(OpenGL)
#本工程支持的C++版本
set(CMAKE_CXX_STANDARD 17)
#把需要拷贝的资源路径都放在img里
file(GLOB IMG "./img")
#把img中目录的内容，都拷贝到可执行文件目录下
file(COPY ${IMG} DESTINATION ${CMAKE_BINARY_DIR})
#将funcs文件夹纳入到编译系统
add_subdirectory(func)
#搜索所有的cpp，加入SRCS变量中
#aux_source_directory(. SRCS)
#本工程主程序文件及输出程序名称
add_executable(glStudy "main.cpp")
add_executable(main2 "main2.cpp")
#将myFuncs.lib链接入softRender
target_link_libraries(glStudy myFuncs)
4、cmakelist添加库
cmake_minimum_required(VERSION 3.12)
#本工程的名字
project(learn_GLFW)
#本工程支持的C++版本
set(CMAKE_CXX_STANDARD 17)
include_directories(
SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/thirdParty/include
)
link_directories(
SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/thirdParty/lib
)
#本工程所有cpp文件编译链接，生成exe
add_executable(learnGLFW "main.cpp")
target_link_libraries(learnGLFW glfw3.lib)4、添加glfw和glad
cmake_minimum_required(VERSION 3.12)
#本工程的名字
project(learn_GLFW)
#本工程支持的C++版本
set(CMAKE_CXX_STANDARD 17)
include_directories(
SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/thirdParty/include
)
link_directories(
SYSTEM ${CMAKE_CURRENT_SOURCE_DIR}/thirdParty/lib
)
#本工程所有cpp文件编译链接，生成exe
add_executable(learnGLFW "main.cpp" "glad.c")
target_link_libraries(learnGLFW glfw3.lib)5、glfw运行
#include <iostream>
#include <glad/glad.h>
#include <GLFW/glfw3.h>
int main() {
//1、初始化GLFW基本环境
glfwInit();
//1.1设置主版本号，次版本号
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
//1.2设置启用核心模式（非立即渲染模式）
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
//2、创建窗体对象
GLFWwindow* window = glfwCreateWindow(800, 600, "OpenglStudy", NULL, NULL);
//设置当前的窗体对象为Opengl的绘制舞台
glfwMakeContextCurrent(window);
//3、执行窗体循环
while (!glfwWindowShouldClose(window)) {
//接受并分发窗体消息
//检查消息队列是否有需要处理的鼠标，键盘等消息
//如果有的话就将消息批量处理，清空队列
glfwPollEvents();
}
//4、退出程序
glfwTerminate();
return 0;
}
6、NDC、VBO、VAO
7、渐变三角形
方法一：一个VBO绑定到一个VAO上
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <cmath>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"// 位置变量的属性位置值为 0
"layout (location = 1) in vec3 aColor;\n"// 颜色变量的属性位置值为 1
"out vec3 ourColor;\n"// 向片段着色器输出一个颜色
"void main()\n"
"{\n"
" gl_Position = vec4(aPos, 1.0);\n"
" ourColor = aColor;\n"// 将ourColor设置为我们从顶点数据那里得到的输入颜色
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec3 ourColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(ourColor, 1.0f);\n"
"}\n\0";
int main() {
//1.初始化配置
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
#endif // __APPLE__
//2.gltf 窗口创建
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LeranOpenGL", NULL, NULL);
if (window == NULL) {
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
//3. 加载所有GL函数指针
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
//4. 构建和编译shader 程序
//vertex shader
unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//fragment shader
unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//link shaders
unsigned int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
//4. 设置顶点数据
float vertices[] = {
// 位置 // 颜色
0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, // 右下
-0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, // 左下
0.0f, 0.5f, 0.0f, 0.0f, 0.0f, 1.0f // 顶部
};
unsigned int VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
unsigned int VAO;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));
glBindVertexArray(VAO);
//5. 循环渲染
while (!glfwWindowShouldClose(window)) {
processInput(window);
// render
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//当我们渲染一个物体要使用着色器程序
glUseProgram(shaderProgram);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
// 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(0, 0, width, height);
}方法二：两个VBO绑定到VAO上
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <cmath>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"// 位置变量的属性位置值为 0
"layout (location = 1) in vec3 aColor;\n"// 颜色变量的属性位置值为 1
"out vec3 ourColor;\n"// 向片段着色器输出一个颜色
"void main()\n"
"{\n"
" gl_Position = vec4(aPos, 1.0);\n"
" ourColor = aColor;\n"// 将ourColor设置为我们从顶点数据那里得到的输入颜色
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec3 ourColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(ourColor, 1.0f);\n"
"}\n\0";
int main() {
//1.初始化配置
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
#endif // __APPLE__
//2.gltf 窗口创建
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LeranOpenGL", NULL, NULL);
if (window == NULL) {
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
//3. 加载所有GL函数指针
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
//4. 构建和编译shader 程序
//vertex shader
unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//fragment shader
unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//link shaders
unsigned int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
//4. 设置顶点数据
float vertices[] = {
// 位置 // 颜色
0.5f, -0.5f, 0.0f, // 右下
-0.5f, -0.5f, 0.0f, // 左下
0.0f, 0.5f, 0.0f, // 顶部
};
float colors[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
unsigned int VBO[2];
glGenBuffers(2, VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors), colors, GL_STATIC_DRAW);
unsigned int VAO;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);//只有绑定了vbo，下面的属性才与vbo相关
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glBindVertexArray(0);
//5. 循环渲染
while (!glfwWindowShouldClose(window)) {
processInput(window);
// render
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//当我们渲染一个物体要使用着色器程序
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(2, VBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
// 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(0, 0, width, height);
}
8、渲染两个三角形
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <cmath>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"// 位置变量的属性位置值为 0
"layout (location = 1) in vec3 aColor;\n"// 颜色变量的属性位置值为 1
"out vec3 ourColor;\n"// 向片段着色器输出一个颜色
"void main()\n"
"{\n"
" gl_Position = vec4(aPos, 1.0);\n"
" ourColor = aColor;\n"// 将ourColor设置为我们从顶点数据那里得到的输入颜色
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec3 ourColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(ourColor, 1.0f);\n"
"}\n\0";
int main() {
//1.初始化配置
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
#endif // __APPLE__
//2.gltf 窗口创建
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LeranOpenGL", NULL, NULL);
if (window == NULL) {
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
//3. 加载所有GL函数指针
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
//4. 构建和编译shader 程序
//vertex shader
unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//fragment shader
unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//link shaders
unsigned int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
//4. 设置顶点数据
float vertices[] = {
// 位置 // 颜色
0.5f, -0.5f, 0.0f, // 右下
-0.5f, -0.5f, 0.0f, // 左下
0.0f, 0.5f, 0.0f, // 顶部
};
float colors[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
//4. 设置顶点数据
float vertices2[] = {
// 位置 // 颜色
0.7f, -0.2f, 0.0f, // 右下
-0.2f, -0.2f, 0.0f, // 左下
0.0f, 0.8f, 0.0f, // 顶部
};
float colors2[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
unsigned int VBO[4];
glGenBuffers(4, VBO);//执行一次
glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors), colors, GL_STATIC_DRAW);
//---
unsigned int VAO[2];
glGenVertexArrays(2, VAO);//执行一次
glBindVertexArray(VAO[0]);
glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);//只有绑定了vbo，下面的属性才与vbo相关
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,3 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
//-第二个三角形
glBindBuffer(GL_ARRAY_BUFFER, VBO[2]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, VBO[3]);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors2), colors2, GL_STATIC_DRAW);
glBindVertexArray(VAO[1]);
glBindBuffer(GL_ARRAY_BUFFER, VBO[2]);//只有绑定了vbo，下面的属性才与vbo相关
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, VBO[3]);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glBindVertexArray(0);
//5. 循环渲染
while (!glfwWindowShouldClose(window)) {
processInput(window);
// render
glClearColor(0.0f, 0.f, 0.f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//当我们渲染一个物体要使用着色器程序
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glUseProgram(shaderProgram);
glBindVertexArray(VAO[0]);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindVertexArray(VAO[1]);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteVertexArrays(2, VAO);
glDeleteBuffers(4, VBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
// 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(0, 0, width, height);
}
9、渲染两个三角形，同时基于原来颜色进行渐变
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include <cmath>
#include <glm/vec3.hpp>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"// 位置变量的属性位置值为 0
"layout (location = 1) in vec3 aColor;\n"// 颜色变量的属性位置值为 1
"out vec3 ourColor;\n"// 向片段着色器输出一个颜色
"void main()\n"
"{\n"
" gl_Position = vec4(aPos, 1.0);\n"
" ourColor = aColor;\n"// 将ourColor设置为我们从顶点数据那里得到的输入颜色
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec3 ourColor;\n"
"uniform vec3 dynamicColor;\n"
"void main()\n"
"{\n"
" vec3 finalColor= ourColor + dynamicColor;\n"
" finalColor = clamp(finalColor, 0.0, 1.0);\n"
" FragColor = vec4(finalColor, 1.0);\n"
"}\n\0";
int main() {
//1.初始化配置
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
#endif // __APPLE__
//2.gltf 窗口创建
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LeranOpenGL", NULL, NULL);
if (window == NULL) {
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
//3. 加载所有GL函数指针
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
//4. 构建和编译shader 程序
//vertex shader
unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//fragment shader
unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//link shaders
unsigned int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
//4. 设置顶点数据
float vertices[] = {
// 位置 // 颜色
0.5f, -0.5f, 0.0f, // 右下
-0.5f, -0.5f, 0.0f, // 左下
0.0f, 0.5f, 0.0f, // 顶部
};
float colors[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
//4. 设置顶点数据
float vertices2[] = {
// 位置 // 颜色
0.7f, -0.2f, 0.0f, // 右下
-0.2f, -0.2f, 0.0f, // 左下
0.0f, 0.8f, 0.0f, // 顶部
};
float colors2[] = {
1.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 1.0f
};
unsigned int VBO[4];
glGenBuffers(4, VBO);//执行一次
glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors), colors, GL_STATIC_DRAW);
//---
unsigned int VAO[2];
glGenVertexArrays(2, VAO);//执行一次
glBindVertexArray(VAO[0]);
glBindBuffer(GL_ARRAY_BUFFER, VBO[0]);//只有绑定了vbo，下面的属性才与vbo相关
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,3 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, VBO[1]);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
//-第二个三角形
glBindBuffer(GL_ARRAY_BUFFER, VBO[2]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices2), vertices2, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, VBO[3]);
glBufferData(GL_ARRAY_BUFFER, sizeof(colors2), colors2, GL_STATIC_DRAW);
glBindVertexArray(VAO[1]);
glBindBuffer(GL_ARRAY_BUFFER, VBO[2]);//只有绑定了vbo，下面的属性才与vbo相关
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glBindBuffer(GL_ARRAY_BUFFER, VBO[3]);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glBindVertexArray(0);
//5. 循环渲染
while (!glfwWindowShouldClose(window)) {
processInput(window);
// render
glClearColor(0.0f, 0.f, 0.f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//当我们渲染一个物体要使用着色器程序
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glUseProgram(shaderProgram);
glBindVertexArray(VAO[0]);
glDrawArrays(GL_TRIANGLES, 0, 3);
double timeValue = glfwGetTime();
float greenValue = static_cast<float>(sin(timeValue) / 2.0 + 0.5);
// 假设您要添加的动态颜色只影响绿色分量
glm::vec3 dynamicColor = glm::vec3(0.0f, greenValue, 0.0f);
int dynamicColorLocation = glGetUniformLocation(shaderProgram, "dynamicColor");
glUniform3f(dynamicColorLocation, dynamicColor.x, dynamicColor.y, dynamicColor.z);
glBindVertexArray(VAO[1]);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteVertexArrays(2, VAO);
glDeleteBuffers(4, VBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
// 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(0, 0, width, height);
}
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