我正在做一个我的小项目,基本上是在创建自己的c ++游戏引擎/框架来创建图形和/或简单游戏。我将OpenGL与GLFW一起使用。我的目标是要拥有与各种图形框架类似的东西,例如raylib或openFrameworks(当然要精简一下)
到目前为止,实际上一切正常,但是我不知道如何正确地将输入与窗口类分开,因为对我而言,拥有窗口句柄输入似乎很笨拙,只会使窗口类混乱。
这是对我的窗口类的快速简化。 (我没有将enum类包含在键码中。)
#pragma once
#include "../extern/GLFW/glfw3.h"
#include <string>
class Window {
private:
GLFWwindow* mWindow;
int mWidth;
int mHeight;
std::string mTitle;
public:
Window();
~Window();
void createWindow(std::string title, int width, int height);
void mainLoop();
GLFWwindow* getWindow() const { return mWindow; }
// Input
private:
bool Window::getKeyStatus(KEY key) {
static void keyCallback(GLFWwindow* mWindow, int key, int scancode, int action, int mods);
bool isKeyDown(KEY key);
};
这是实现加上
#include "Window.h"
#include <iostream>
Window::Window() {}
Window::~Window() {}
void Window::createWindow(std::string title, int width, int height) {
if (!glfwInit());
mWindow = glfwCreateWindow(width, height, title.c_str(), nullptr, nullptr);
if (!getWindow()) {
glfwTerminate();
}
glfwSetWindowUserPointer(getWindow(), this);
glfwMakeContextCurrent(getWindow());
glfwSetKeyCallback(mWindow, keyCallback);
}
void Window::mainLoop() {
while (!glfwWindowShouldClose(getWindow())) {
/* Render here */
glClear(GL_COLOR_BUFFER_BIT);
/* Swap front and back buffers */
glfwSwapBuffers(getWindow());
/* Poll for and process events */
glfwPollEvents();
if (isKeyDown(KEY::A)) {
std::cout << "A down" << std::endl;
}
if (isKeyDown(KEY::B)) {
std::cout << "B down" << std::endl;
}
}
glfwTerminate();
}
void Window::keyCallback(GLFWwindow* window, int key, int scancode, int action, int mods) {
Window* win = (Window*)glfwGetWindowUserPointer(window);
if (key == (int)KEY::ESCAPE && action == GLFW_PRESS) {
glfwSetWindowShouldClose(window, GL_TRUE);
} else {
win->currentKeyState[key] = action;
}
}
bool Window::getKeyStatus(KEY key) {
return glfwGetKey(mWindow, (int)key);
}
bool Window::isKeyDown(KEY key) {
bool down = false;
if (getKeyStatus(key) == 1) {
down = true;
}
return down;
}
该如何进行呢?我的主要问题是我似乎无法连接窗口和输入类。我应该使用继承还是朋友类。我应该在window类中(我假设是)使用glfw的回调,还是应该将其移至输入类?如何连接这两个类,这样我就不必始终使用窗口指针,例如“ isKeyDown(GLFWwindow * window,Key keycode)”,而仅使用“ isKeyDown(Key keycode)”。如果不是太多,请问有人可以写一个简单的输入类吗?
预先感谢
答案 0 :(得分:0)
要指出的一件事是GLFW同时提供了轮询和基于回调的输入处理。在您的示例中,您同时使用了两种方法:轮询用于处理 A 和 B 键,以及用于处理转义键的回调。我相信您会发现在创建单独的输入类(对于键盘和鼠标)时,回调将更易于使用。
有许多方法可以使用GLFW的回调方法创建 KeyInput 类。这是我首选的技术(编写为适合您的代码)。它允许多个 KeyInput 实例(不同于单例),这意味着您可以为UI键使用 KeyInput 实例, -游戏键等
总结:每个 KeyInput 实例监视用户在构造时定义的键列表的按下状态。它具有一个getter和setter来访问任何键的按下状态(尽管getter和setter仅适用于受监视的键)。每当调用GLFW键输入回调(静态)时,它都会为 KeyInput 的所有实例调用该设置方法。实例存储在静态向量中,该向量在构造时添加到实例中,并在破坏时从中删除。
Input.h
#include "../extern/GLFW/glfw3.h"
#include <map>
#include <vector>
class KeyInput {
// Main KeyInput functionality
public:
// Takes a list of which keys to keep state for
KeyInput(std::vector<int> keysToMonitor);
~KeyInput();
// If this KeyInput is enabled and the given key is monitored,
// returns pressed state. Else returns false.
bool getIsKeyDown(int key);
// See _isEnabled for details
bool getIsEnabled() { return _isEnabled; }
void setIsEnabled(bool value) { _isEnabled = value; }
private:
// Used internally to update key states. Called by the GLFW callback.
void setIsKeyDown(int key, bool isDown);
// Map from monitored keyes to their pressed states
std::map<int, bool> _keys;
// If disabled, KeyInput.getIsKeyDown always returns false
bool _isEnabled;
// Workaround for C++ class using a c-style-callback
public:
// Must be called before any KeyInput instances will work
static void setupKeyInputs(Window& window);
private:
// The GLFW callback for key events. Sends events to all KeyInput instances
static void callback(
GLFWwindow* window, int key, int scancode, int action, int mods);
// Keep a list of all KeyInput instances and notify them all of key events
static std::vector<KeyInput*> _instances;
};
Input.cpp
#include "KeyInput.h"
#include <algorithm>
std::vector<KeyInput*> KeyInput::_instances;
KeyInput::KeyInput(std::vector<int> keysToMonitor) : _isEnabled(true) {
for (int key : keysToMonitor) {
_keys[key] = false;
}
// Add this instance to the list of instances
KeyInput::_instances.push_back(this);
}
KeyInput::~KeyInput() {
// Remove this instance from the list of instances
_instances.erase(std::remove(_instances.begin(), _instances.end(), this), _instances.end());
}
bool KeyInput::getIsKeyDown(int key) {
bool result = false;
if (_isEnabled) {
std::map<int,bool>::iterator it = _keys.find(key);
if (it != _keys.end()) {
result = _keys[key];
}
}
return result;
}
void KeyInput::setIsKeyDown(int key, bool isDown) {
std::map<int,bool>::iterator it = _keys.find(key);
if (it != _keys.end()) {
_keys[key] = isDown;
}
}
void KeyInput::setupKeyInputs(Window& window) {
glfwSetKeyCallback(window.getWindow(), KeyInput::callback);
}
void KeyInput::callback(GLFWwindow* window, int key, int scancode, int action, int mods) {
// Send key event to all KeyInput instances
for (KeyInput* keyInput : _instances) {
keyInput->setIsKeyDown(key, action != GLFW_RELEASE);
}
}