LearnOpenGL---着色器

着色器的例子

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1.颜色变化的三角形

#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);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"
"void main()\n"
"{\n"
"	gl_Position = vec4(aPos, 1.0);\n"
"}\n\0";//注意顶点和片元这块一定不要写错，；也不要忘
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"uniform vec4 ourColor;\n"
"void main()\n"
"{\n"
"	FragColor = ourColor;\n"
"}\n\0";int main()
{glfwInit();glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);if (window == NULL){std::cout << "创建窗口失败" << std::endl;glfwTerminate();return -1;}glfwMakeContextCurrent(window);glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){std::cout << "GLAD初始化失败" << std::endl;return -1;}unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);glCompileShader(vertexShader);unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);glCompileShader(fragmentShader);unsigned int shaderProgram = glCreateProgram();glAttachShader(shaderProgram, vertexShader);glAttachShader(shaderProgram, fragmentShader);glLinkProgram(shaderProgram);glDeleteShader(vertexShader);glDeleteShader(fragmentShader);float vertices[] = {0.5f, -0.3f, 0.0f,0.0f, 0.3f, 0.0f,-0.5f, -0.3f, 0.0f,};unsigned int VBO, VAO;glGenVertexArrays(1, &VAO);glGenBuffers(1, &VBO);glBindVertexArray(VAO);//复制顶点数据到缓冲中供OpenGl使用glBindBuffer(GL_ARRAY_BUFFER, VBO);glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);//如何解析数顶点据glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);glEnableVertexAttribArray(0);glBindBuffer(GL_ARRAY_BUFFER, 0);//不太懂为什么glBindVertexArray(VAO);while (!glfwWindowShouldClose(window)){processInput(window);glClearColor(0.2f, 0.3f, 0.3f, 1.0f);glClear(GL_COLOR_BUFFER_BIT);//激活着色器glUseProgram(shaderProgram);//更新uniform颜色float timeValue = glfwGetTime();float colorValue = sin(timeValue) / 2.0f + 0.5f;int vertexColorLocation = glGetUniformLocation(shaderProgram, "ourColor");glUniform4f(vertexColorLocation, 0.0f, colorValue, 0.0f, 1.0f);//绘制三角形glDrawArrays(GL_TRIANGLES, 0, 3);glfwSwapBuffers(window);glfwPollEvents();}glDeleteVertexArrays(1, &VAO);glDeleteBuffers(1, &VBO);glDeleteProgram(shaderProgram);glfwTerminate();return 0;
}void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{glViewport(0, 0, width, height);
}void processInput(GLFWwindow* window)
{if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)glfwSetWindowShouldClose(window, true);
}

2.构造三个顶点颜色不同的一个三角形

#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);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"
"layout (location = 1) in vec3 aColor;\n"
"out vec3 ourColor;\n"
"void main()\n"
"{\n"
"	gl_Position = vec4(aPos, 1.0);\n"
"	ourColor = aColor;\n"
"}\n\0";//注意顶点和片元这块一定不要写错，；也不要忘
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec3 ourColor;\n"
"void main()\n"
"{\n"
"	FragColor = vec4(ourColor, 1.0);\n"
"}\n\0";int main()
{glfwInit();glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);if (window == NULL){std::cout << "创建窗口失败" << std::endl;glfwTerminate();return -1;}glfwMakeContextCurrent(window);glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)){std::cout << "GLAD初始化失败" << std::endl;return -1;}unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);glCompileShader(vertexShader);unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);glCompileShader(fragmentShader);unsigned int shaderProgram = glCreateProgram();glAttachShader(shaderProgram, vertexShader);glAttachShader(shaderProgram, fragmentShader);glLinkProgram(shaderProgram);glDeleteShader(vertexShader);glDeleteShader(fragmentShader);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, VAO;glGenVertexArrays(1, &VAO);glGenBuffers(1, &VBO);glBindVertexArray(VAO);//复制顶点数据到缓冲中供OpenGl使用glBindBuffer(GL_ARRAY_BUFFER, VBO);glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);//如何解析数顶点据//位置属性glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);glEnableVertexAttribArray(0);//颜色属性:最后一个属性为偏移量glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3 * sizeof(float)));glEnableVertexAttribArray(1);glBindBuffer(GL_ARRAY_BUFFER, 0);//不太懂为什么glBindVertexArray(VAO);while (!glfwWindowShouldClose(window)){processInput(window);glClearColor(0.2f, 0.3f, 0.3f, 1.0f);glClear(GL_COLOR_BUFFER_BIT);//激活着色器glUseProgram(shaderProgram);glBindVertexArray(VAO);//绘制三角形glDrawArrays(GL_TRIANGLES, 0, 3);glfwSwapBuffers(window);glfwPollEvents();}glDeleteVertexArrays(1, &VAO);glDeleteBuffers(1, &VBO);glDeleteProgram(shaderProgram);glfwTerminate();return 0;
}void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{glViewport(0, 0, width, height);
}void processInput(GLFWwindow* window)
{if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)glfwSetWindowShouldClose(window, true);
}