简介

OpenGLES是平台无关的，是用c语言写的。ios12已经被放弃，使用metal库代替
苹果开发者OpenGLES文档链接

• 检查OpenGL ES 3.0扩展

BOOL CheckForExtension(NSString *searchName)
{
    // Create a set containing all extension names.
    // (For better performance, create the set only once and cache it for future use.)

    int max = 0;
    glGetIntegerv(GL_NUM_EXTENSIONS, &max);
    NSMutableSet *extensions = [NSMutableSet set];
    for (int i = 0; i < max; i++) {
        [extensions addObject: @( (char *)glGetStringi(GL_EXTENSIONS, i) )];
    }
    return [extensions containsObject: searchName];
}