refactor: cleanup opengl

src/gui/viewport/ViewportGLWidget.cpp

@@ -0,0 +1,93 @@
+#include "gui/viewport/OpenGLWidget.h"
+
+void ViewportGLWidget::initializeGL()
+{
+    // Set up the rendering context, load shaders and other resources, etc.:
+    initializeOpenGLFunctions();
+
+    glGenVertexArrays(1, &vao);
+    glBindVertexArray(vao);
+
+    float vertices[] = {
+        -0.5f, -0.5f, 0.0f,
+         0.5f, -0.5f, 0.0f,
+         0.0f,  0.5f, 0.0f
+    };
+
+    GLuint vbo;
+    // create buffer of vertices
+    glGenBuffers(1, &vbo);
+    // set purpose
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    // store data in the buffer
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+
+    // vertex shader
+    const std::string vertexShaderSource = "#version 330 core\n"
+    "layout (location = 0) in vec3 aPos;\n"
+    "void main()\n"
+    "{\n"
+    "   gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
+    "}\n";
+    // shader type
+    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
+    // convert source
+    const GLchar* vertexShaderSourceC = vertexShaderSource.c_str();
+    // create shader object
+    glShaderSource(vertexShader, 1, &vertexShaderSourceC, NULL);
+    // compile shader object
+    glCompileShader(vertexShader);
+    
+    
+    // fragment shader
+    const std::string fragmentShaderSource = "#version 330 core\n"
+    "out vec4 FragColor;\n"
+    "void main()\n"
+    "{\n"
+    "    FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
+    "}\n";
+    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+    const GLchar* fragmentShaderSourceC = fragmentShaderSource.c_str();
+    glShaderSource(fragmentShader, 1, &fragmentShaderSourceC, NULL);
+    glCompileShader(fragmentShader);
+
+    // create shader program
+    shaderProgram = glCreateProgram();
+    // attach shaders
+    glAttachShader(shaderProgram, vertexShader);
+    glAttachShader(shaderProgram, fragmentShader);
+    // link program
+    glLinkProgram(shaderProgram);
+    
+    // delete shaders now that the program is complete
+    glDeleteShader(vertexShader);
+    glDeleteShader(fragmentShader);
+
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3*sizeof(GLfloat), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // unbind vertex array
+    glBindVertexArray(0);
+
+    QSurfaceFormat fmt = context()->format();
+    std::cout << "format: " << (fmt.renderableType() == QSurfaceFormat::OpenGLES ? "GLES" : "Desktop") << "\n";
+    std::cout << "format: " << (fmt.renderableType() == QSurfaceFormat::OpenGL ? "true" : "false") << "\n";
+
+    glClearColor(0.16f, 0.16f, 0.16f, 1.0f);
+}
+
+
+
+void ViewportGLWidget::resizeGL(int w, int h)
+{
+}
+
+void ViewportGLWidget::paintGL()
+{
+    initializeOpenGLFunctions();
+    glClear(GL_COLOR_BUFFER_BIT);
+    glUseProgram(shaderProgram);
+    glBindVertexArray(vao);
+    glDrawArrays(GL_TRIANGLES, 0, 3);
+}