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引言
上一节我们讨论了 ImGUI 并运行了官方示例，今天我们来为我们的引擎编写 ImGUI 事件。
事件声明
在头文件 ImGuiLayer.h 声明 ImGUI 的交互事件：
#pragma once
#include "../Layer.h"
#include "../Events/KeyEvent.h"
#include "../Events/MouseEvent.h"
#include "../Events/ApplicationEvent.h"
namespace Infinite {
class INFINITE_API ImGuiLayer : public Layer
{
public:
ImGuiLayer();
~ImGuiLayer();
void OnAttach();
void OnDetach();
void OnUpdate();
void OnEvent(Event& event);
private:
+ bool OnMouseButtonPressedEvent(MouseButtonPressedEvent& e);
+ bool OnMouseButtonReleasedEvent(MouseButtonReleasedEvent& e);
+ bool OnMouseMovedEvent(MouseMovedEvent& e);
+ bool OnMouseScrolledEvent(MouseScrolledEvent& e);
+ bool OnKeyPressedEvent(KeyPressedEvent& e);
+ bool OnKeyReleasedEvent(KeyReleasedEvent& e);
+ bool OnKeyTypedEvent(KeyTypedEvent& e);
+ bool OnWindowResizeEvent(WindowResizeEvent& e);
private:
float m_Time = 0.0f;
};
}
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事件实现
在 ImGuiLayer.cpp 中添加头文件和事件的模板：
#include "ifnpch.h"
#include "ImGuiLayer.h"
#include "../imgui.h"
#include "Platform/OpenGL/ImGuiOpenGLRenderer.h"
// TEMPORARY
+#include <GLFW/glfw3.h>
+#include <glad/glad.h>
#include "../Application.h"
namespace Infinite {
ImGuiLayer::ImGuiLayer()
: Layer("ImGuiLayer")
{
}
ImGuiLayer::~ImGuiLayer()
{
}
void ImGuiLayer::OnAttach()
{
ImGui::CreateContext();
ImGui::StyleColorsDark();
ImGuiIO& io = ImGui::GetIO();
io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;
io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;
// TEMPORARY: should eventually use Infinite key codes
io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB;
io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT;
io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT;
io.KeyMap[ImGuiKey_UpArrow] = GLFW_KEY_UP;
io.KeyMap[ImGuiKey_DownArrow] = GLFW_KEY_DOWN;
io.KeyMap[ImGuiKey_PageUp] = GLFW_KEY_PAGE_UP;
io.KeyMap[ImGuiKey_PageDown] = GLFW_KEY_PAGE_DOWN;
io.KeyMap[ImGuiKey_Home] = GLFW_KEY_HOME;
io.KeyMap[ImGuiKey_End] = GLFW_KEY_END;
io.KeyMap[ImGuiKey_Insert] = GLFW_KEY_INSERT;
io.KeyMap[ImGuiKey_Delete] = GLFW_KEY_DELETE;
io.KeyMap[ImGuiKey_Backspace] = GLFW_KEY_BACKSPACE;
io.KeyMap[ImGuiKey_Space] = GLFW_KEY_SPACE;
io.KeyMap[ImGuiKey_Enter] = GLFW_KEY_ENTER;
io.KeyMap[ImGuiKey_Escape] = GLFW_KEY_ESCAPE;
io.KeyMap[ImGuiKey_A] = GLFW_KEY_A;
io.KeyMap[ImGuiKey_C] = GLFW_KEY_C;
io.KeyMap[ImGuiKey_V] = GLFW_KEY_V;
io.KeyMap[ImGuiKey_X] = GLFW_KEY_X;
io.KeyMap[ImGuiKey_Y] = GLFW_KEY_Y;
io.KeyMap[ImGuiKey_Z] = GLFW_KEY_Z;
ImGui_ImplOpenGL3_Init("#version 410");
}
void ImGuiLayer::OnDetach()
{
}
void ImGuiLayer::OnUpdate()
{
ImGuiIO& io = ImGui::GetIO();
Application& app = Application::Get();
io.DisplaySize = ImVec2(app.GetWindow().GetWidth(), app.GetWindow().GetHeight());
float time = (float)glfwGetTime();
io.DeltaTime = m_Time > 0.0f ? (time - m_Time) : (1.0f / 60.0f);
m_Time = time;
ImGui_ImplOpenGL3_NewFrame();
ImGui::NewFrame();
static bool show = true;
ImGui::ShowDemoWindow(&show);
ImGui::Render();
ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
}
+ void ImGuiLayer::OnEvent(Event& event)
+ {
+
+ }
+ bool ImGuiLayer::OnMouseButtonPressedEvent(MouseButtonPressedEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnMouseButtonReleasedEvent(MouseButtonReleasedEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnMouseMovedEvent(MouseMovedEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnMouseScrolledEvent(MouseScrolledEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnKeyPressedEvent(KeyPressedEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnKeyReleasedEvent(KeyReleasedEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnKeyTypedEvent(KeyTypedEvent& e)
+ {
+
+ }
+ bool ImGuiLayer::OnWindowResizeEvent(WindowResizeEvent& e)
+ {
+
+ }
}
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下面我们依次实现这些事件：
Event
void ImGuiLayer::OnEvent(Event& event)
{
EventDispatcher dispatcher(event);
dispatcher.Dispatch<MouseButtonPressedEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnMouseButtonPressedEvent));
dispatcher.Dispatch<MouseButtonReleasedEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnMouseButtonReleasedEvent));
dispatcher.Dispatch<MouseMovedEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnMouseMovedEvent));
dispatcher.Dispatch<MouseScrolledEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnMouseScrolledEvent));
dispatcher.Dispatch<KeyPressedEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnKeyPressedEvent));
dispatcher.Dispatch<KeyTypedEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnKeyTypedEvent));
dispatcher.Dispatch<KeyReleasedEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnKeyReleasedEvent));
dispatcher.Dispatch<WindowResizeEvent>(IFN_BIND_EVENT_FN(ImGuiLayer::OnWindowResizeEvent));
}
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这里的 IFN_BIND_EVENT_FN 则在 Core.h 中定义：
#define IFN_BIND_EVENT_FN(fn) std::bind(&fn, this, std::placeholders::_1)
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Mouse
bool ImGuiLayer::OnMouseButtonPressedEvent(MouseButtonPressedEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.MouseDown[e.GetMouseButton()] = true;
return false;
}
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bool ImGuiLayer::OnMouseButtonReleasedEvent(MouseButtonReleasedEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.MouseDown[e.GetMouseButton()] = false;
return false;
}
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MouseMoved
bool ImGuiLayer::OnMouseMovedEvent(MouseMovedEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.MousePos = ImVec2(e.GetX(), e.GetY());
return false;
}
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bool ImGuiLayer::OnMouseScrolledEvent(MouseScrolledEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.MouseWheelH += e.GetXOffset();
io.MouseWheel += e.GetYOffset();
return false;
}
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Key
KeyPressed
bool ImGuiLayer::OnKeyPressedEvent(KeyPressedEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.KeysDown[e.GetKeyCode()] = true;
io.KeyCtrl = io.KeysDown[GLFW_KEY_LEFT_CONTROL] || io.KeysDown[GLFW_KEY_RIGHT_CONTROL];
io.KeyShift = io.KeysDown[GLFW_KEY_LEFT_SHIFT] || io.KeysDown[GLFW_KEY_RIGHT_SHIFT];
io.KeyAlt = io.KeysDown[GLFW_KEY_LEFT_ALT] || io.KeysDown[GLFW_KEY_RIGHT_ALT];
io.KeySuper = io.KeysDown[GLFW_KEY_LEFT_SUPER] || io.KeysDown[GLFW_KEY_RIGHT_SUPER];
return false;
}
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KeyReleased
bool ImGuiLayer::OnKeyReleasedEvent(KeyReleasedEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.KeysDown[e.GetKeyCode()] = false;
return false;
}
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KeyTyped
KeyTyped 的实现比较复杂，首先我们需要先在 Event.h 添加 KeyTyped 枚举类型：
enum class EventType
{
None = 0,
WindowClose, WindowResize, WindowFocus, WindowLostFocus, WindowMoved,
AppTick, AppUpdate, AppRender,
+ KeyPressed, KeyReleased, KeyTyped,
MouseButtonPressed, MouseButtonReleased, MouseMoved, MouseScrolled
};
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接着在 KeyEvent.h 中添加事件：
class INFINITE_API KeyTypedEvent : public KeyEvent
{
public:
KeyTypedEvent(int keycode)
: KeyEvent(keycode) {}
std::string ToString() const override
{
std::stringstream ss;
ss << "KeyTypedEvent: " << m_KeyCode;
return ss.str();
}
EVENT_CLASS_TYPE(KeyTyped)
};
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最后回到 ImGuiLayer.cpp 实现事件：
bool ImGuiLayer::OnKeyTypedEvent(KeyTypedEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
int keycode = e.GetKeyCode();
if (keycode > 0 && keycode < 0x10000)
io.AddInputCharacter((unsigned short)keycode);
return false;
}
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Windows
bool ImGuiLayer::OnWindowResizeEvent(WindowResizeEvent& e)
{
ImGuiIO& io = ImGui::GetIO();
io.DisplaySize = ImVec2(e.GetWidth(), e.GetHeight());
io.DisplayFramebufferScale = ImVec2(1.0f, 1.0f);
glViewport(0, 0 , e.GetWidth(), e.GetHeight());
return false;
}
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预生成文件
workspace "Infinite"
architecture "x64"
startproject "Sandbox"
configurations
{
"Debug",
"Release",
"Dist"
}
outputdir = "%{cfg.buildcfg}-%{cfg.system}-%{cfg.architecture}"
-- Include directories relative to root folder (solution directory)
IncludeDir = {}
IncludeDir["GLFW"] = "Infinite/vendor/GLFW/include"
IncludeDir["GLAD"] = "Infinite/vendor/GLAD/include"
IncludeDir["ImGui"] = "Infinite/vendor/imgui/include"
include "Infinite/vendor/GLFW"
include "Infinite/vendor/GLAD"
include "Infinite/vendor/imgui"
project "Infinite"
location "Infinite"
kind "SharedLib"
language "C++"
+ staticruntime "off"
targetdir ("bin/" .. outputdir .. "/%{prj.name}")
objdir ("bin-int/" .. outputdir .. "/%{prj.name}")
pchheader "ifnpch.h"
pchsource "Infinite/src/ifnpch.cpp"
files
{
"%{prj.name}/src/**.h",
"%{prj.name}/src/**.cpp"
}
includedirs
{
"%{prj.name}/src",
"%{prj.name}/vendor/spdlog/include",
"%{IncludeDir.GLFW}",
"%{IncludeDir.GLAD}",
"%{IncludeDir.ImGui}"
}
links
{
"GLFW",
"GLAD",
"ImGui",
"opengl32.lib"
}
filter "system:windows"
cppdialect "C++17"
systemversion "latest"
defines
{
"IFN_PLATFORM_WINDOWS",
"IFN_BUILD_DLL",
"GLFW_INCLUDE_NONE"
}
postbuildcommands
{
+ ("{COPY} %{cfg.buildtarget.relpath} \"../bin/" .. outputdir .. "/Sandbox/\"")
}
filter "configurations:Debug"
defines "IFN_DEBUG"
+ runtime "Debug"
symbols "On"
filter "configurations:Release"
defines "IFN_RELEASE"
+ runtime "Release"
optimize "On"
filter "configurations:Dist"
defines "IFN_DIST"
+ runtime "Release"
optimize "On"
project "Sandbox"
location "Sandbox"
kind "ConsoleApp"
+ staticruntime "off"
language "C++"
targetdir ("bin/" .. outputdir .. "/%{prj.name}")
objdir ("bin-int/" .. outputdir .. "/%{prj.name}")
files
{
"%{prj.name}/src/**.h",
"%{prj.name}/src/**.cpp"
}
includedirs
{
"Infinite/vendor/spdlog/include",
"Infinite/src/Infinite",
"Infinite/src/Events",
"Infinite/src/**.h",
"Infinite/src/**.cpp"
}
links
{
"Infinite"
}
filter "system:windows"
cppdialect "C++17"
systemversion "latest"
defines
{
"IFN_PLATFORM_WINDOWS"
}
filter "configurations:Debug"
defines "IFN_DEBUG"
+ runtime "Debug"
symbols "On"
filter "configurations:Release"
defines "IFN_RELEASE"
+ runtime "Release"
optimize "On"
filter "configurations:Dist"
defines "IFN_DIST"
+ runtime "Release"
optimize "On"
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调试
在调试过程中由于没有给事件实现添加作用域，运行时报错外部符号无法解析，以后需要多加注意。
Mouse
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Key
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