glfwSetCharCallback
Registers a function that receives TEXT typed by the user, one Unicode character at a time.
Signature
GLFWcharfun glfwSetCharCallback(GLFWwindow* window, GLFWcharfun callback);
How it works
Keys are not characters. On a Brazilian keyboard, typing "ã" is two key presses (~ then a) but one character; Shift+2 is "@" on one layout and "\"" on another. The char callback receives the final character after the system applied the layout, Shift and accents.
The value is a Unicode code point (an unsigned int). Convert it to UTF-8 to add it to a string.
Parameters
The window to listen to.
Your function, void f(GLFWwindow* window, unsigned int codepoint), or NULL.
Return value
The callback that was set before, or NULL.
Tips & pitfalls
Backspace, Enter and arrows produce no character: handle them in the key callback.
Errors
When the call is invalid it does nothing and sets an error, which glGetError returns:
- GLFW_NOT_INITIALIZED
- Called before glfwInit or after glfwTerminate.
Example
1std::u32string typed;
2glfwSetCharCallback(window, [](GLFWwindow*, unsigned int cp) {
3 typed.push_back(static_cast<char32_t>(cp)); // 'a', 'ã', '@', '€'...
4});