feat(OpenGL): moving color changing rectangle

OpenGL/hello/src/main.cpp

@@ -1,6 +1,7 @@
 #include "glad/glad.h"
+#include "shader.h"
 #include <GLFW/glfw3.h>
-#include <iostream>
+#include <cmath>
 
 // 三角形顶点
 float vertices[] = {
@@ -17,33 +18,6 @@ unsigned int indices[] = {
     1, 2, 3  // 第二个三角形
 };
 
-// 顶点着色器源码
-const char *vertexShaderSource =R"(
-    #version 330 core
-    layout (location = 0) in vec3 aPos;
-    layout (location = 1) in vec3 aColor;
-
-    out vec3 color;
-
-    void main()
-    {
-        gl_Position = vec4(aPos, 1.0);
-        color = aColor;
-    }
-)";
-
-// 片段着色器源码
-const char *fragmentShaderSource = R"(
-    #version 330 core
-    in vec3 color;
-    out vec4 FragColor;
-
-    void main()
-    {
-        FragColor = vec4(color, 1.0);
-    }
-)";
-
 void framebuffer_size_callback(GLFWwindow *window, int width, int height);
 void processInput(GLFWwindow *window);
 
@@ -78,60 +52,8 @@ int main() {
   // 设置视口
   glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
-  // 创建顶点着色器
-  unsigned int vertexShader;
-  vertexShader = glCreateShader(GL_VERTEX_SHADER);
-  // 将着色器源码附加到着色器对象上
-  glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
-  // 编译着色器
-  glCompileShader(vertexShader);
-  // 检查编译是否成功
-  int success;
-  char infoLog[512];
-  glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
-  if (!success) {
-    // 获取错误信息
-    glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
-    std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n"
-              << infoLog << std::endl;
-  }
-
-  // 创建片段着色器
-  unsigned int fragmentShader;
-  fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
-  // 将着色器源码附加到着色器对象上
-  glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
-  // 编译着色器
-  glCompileShader(fragmentShader);
-  // 检查编译是否成功
-  glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
-  if (!success) {
-    // 获取错误信息
-    glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
-    std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n"
-              << infoLog << std::endl;
-  }
-
   // 创建着色器程序
-  unsigned int shaderProgram;
-  shaderProgram = glCreateProgram();
-  // 将着色器附加到程序上
-  glAttachShader(shaderProgram, vertexShader);
-  glAttachShader(shaderProgram, fragmentShader);
-  // 链接程序
-  glLinkProgram(shaderProgram);
-  // 检查链接是否成功
-  glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
-  if (!success) {
-    // 获取错误信息
-    glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
-    std::cout << "ERROR::SHADER::PROGRAM::LINK_FAILED\n"
-              << infoLog << std::endl;
-  }
-
-  // 删除着色器
-  glDeleteShader(vertexShader);
-  glDeleteShader(fragmentShader);
+  Shader shader = Shader("src/simple.vs", "src/uniformcolor.fs");
 
 
   unsigned int VAO, VBO, EBO;
@@ -163,14 +85,19 @@ int main() {
     glClearColor(1.0f, 1.0f, 1.0f, 0.0f);
     glClear(GL_COLOR_BUFFER_BIT);
 
-    // 绘制三角形, 激活程序
-    glUseProgram(shaderProgram);
+    // 激活着色器
+    shader.use();
+
+    // 更新uniform颜色
+    float timeValue = glfwGetTime();
+    float greenValue = (sin(timeValue) / 2.0f) + 0.5f;
+    shader.setFloat4("ourColor", 1.0f, greenValue, 0.0f, 0.0f);
+    shader.setFloat1("xOffset", cos(timeValue) / 2.0f);
+    shader.setFloat1("yOffset", sin(timeValue) / 2.0f);
+
+    // 绘制三角形
     glBindVertexArray(VAO);
-    //使用线框模式绘制
-    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
-    // 设置线宽
-    glLineWidth(3.0f);
-    // 绘制
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
     glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
     glBindVertexArray(0);
 

OpenGL/hello/src/simple.vs

@@ -0,0 +1,8 @@
+#version 330 core
+layout(location = 0) in vec3 aPos; // 位置变量的属性位置值为0
+uniform float xOffset;
+uniform float yOffset;
+void main() {
+  gl_Position = vec4(aPos.x + xOffset, aPos.y + yOffset, aPos.z,
+                     1.0); // 注意我们如何把一个vec3作为vec4的构造器的参数
+}

OpenGL/hello/src/stb.cpp

@@ -0,0 +1,2 @@
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"

OpenGL/hello/src/uniformcolor.fs

@@ -0,0 +1,9 @@
+#version 330 core
+out vec4 FragColor;
+
+uniform vec4 ourColor; // 在OpenGL程序代码中设定这个变量
+
+void main()
+{
+    FragColor = ourColor;
+}