Question

我想复制使用OpenGL版本＆gt; = 3.3的教程（精灵渲染）。

例如，在3.2中引入了几何着色器，我得到了这个错误：

error: ‘GL_GEOMETRY_SHADER’ was not declared in this scope

我将我的台面驱动程序更新到最新;我真的不明白，在c ++中编译/链接时如何选择更新版本的OpenGL：

➜glxinfo| grep -i“version”

server glx version string: 1.4
client glx version string: 1.4
GLX version: 1.4
    Version: 17.1.4
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
OpenGL core profile version string: 4.5 (Core Profile) Mesa 17.1.4
OpenGL core profile shading language version string: 4.50
OpenGL version string: 3.0 Mesa 17.1.4
OpenGL shading language version string: 1.30
OpenGL ES profile version string: OpenGL ES 3.1 Mesa 17.1.4
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10

我无法解释这一点，但它表示使用4.5版本的某种核心配置文件。我如何利用此个人资料？

我在我的代码中初始化GL上下文：

if(!glfwInit()) e_glfw_init();
m_window = glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT, WINDOW_TITLE.c_str(), nullptr, nullptr);
if(m_window == nullptr) e_window_context();
glfwMakeContextCurrent(m_window);
glewExperimental = true;
if(glewInit() != GLEW_OK) e_glew_init();

Answer 1

According to the glfw documentation, you can specify the OpenGL version and profile by using the glfwWindowHint function:

if(!glfwInit()) e_glfw_init();

glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 5);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

m_window = glfwCreateWindow(WINDOW_WIDTH, WINDOW_HEIGHT, WINDOW_TITLE.c_str(),
                            nullptr, nullptr);

Answer 2

我在Linux上通过在使用GLFW和着色器时包含了这三个标头解决了这个问题：

abstract class Fruit
{
    protected abstract static function name() : string;

    /*
     * Basically, if you call the default method from any child (not necessarily a direct child) class, no problems,
     * but if you call it directly from the baseclass, you get the somewhat acceptable exception :)
     */
    public static function printName()
    {
        if(!is_subclass_of(static::class, self::class))
        {
            throw new \BadMethodCallException("Can't call base Fruit class methods directly!");
        }

        return "My name is: " . static::name();
    }
}

//those are abstract now, just to match the intention of them being utility singletons
abstract class Apple extends Fruit
{
    protected static function name() : string
    {
        return "apple";
    }
}

abstract class Pear extends Fruit
{
    protected static function name() : string
    {
        return "pear";
    }
}

如何使用不同的OpenGL配置文件？

2 个答案: