Enhance OpenGLSwapChain with presentation control

- Add PresentMode enum (Immediate, VSync, Mailbox, Fifo)
- Add SurfaceFormat enum for color formats
- Add Initialize() overloads with vsync, width/height, PresentMode
- Add Resize(), SetVSync() for runtime control
- Add GetWidth/Height/FramebufferWidth/FramebufferHeight
- Add ShouldClose, SetShouldClose, PollEvents for window management
- Implement using GLFW for window/swap control

engine/include/XCEngine/RHI/OpenGL/OpenGLSwapChain.h

@@ -1,25 +1,60 @@
 #pragma once
 
 #include <GLFW/glfw3.h>
+#include <cstdint>
 
 namespace XCEngine {
 namespace RHI {
 
+enum class PresentMode {
+    Immediate,
+    VSync,
+    Mailbox,
+    Fifo
+};
+
+enum class SurfaceFormat {
+    RGBA8,
+    RGBA16F,
+    RGBA32F,
+    BGRA8
+};
+
 class OpenGLSwapChain {
 public:
     OpenGLSwapChain();
     ~OpenGLSwapChain();
 
-    bool Initialize(GLFWwindow* window);
+    bool Initialize(GLFWwindow* window, bool vsync = true);
+    bool Initialize(GLFWwindow* window, int width, int height, PresentMode mode = PresentMode::VSync);
     void Shutdown();
 
     void Present();
     void SwapBuffers();
+    void Resize(int width, int height);
+    void SetVSync(bool enabled);
+    bool IsVSync() const { return m_vsync; }
+
+    void SetFramebufferSize(int width, int height);
+    int GetWidth() const { return m_width; }
+    int GetHeight() const { return m_height; }
+    int GetFramebufferWidth() const { return m_framebufferWidth; }
+    int GetFramebufferHeight() const { return m_framebufferHeight; }
 
     GLFWwindow* GetWindow() const { return m_window; }
 
+    bool ShouldClose() const;
+    void SetShouldClose(bool shouldClose);
+    void PollEvents();
+
 private:
     GLFWwindow* m_window;
+    int m_width;
+    int m_height;
+    int m_framebufferWidth;
+    int m_framebufferHeight;
+    bool m_vsync;
+    PresentMode m_presentMode;
 };
 
 } // namespace RHI

engine/src/RHI/OpenGL/OpenGLSwapChain.cpp

@@ -1,18 +1,70 @@
 #define GLFW_INCLUDE_NONE
 #include "XCEngine/RHI/OpenGL/OpenGLSwapChain.h"
 #include <GLFW/glfw3.h>
+#include <glad/glad.h>
 
 namespace XCEngine {
 namespace RHI {
 
-OpenGLSwapChain::OpenGLSwapChain() : m_window(nullptr) {
+static int ToGLFWPresentMode(PresentMode mode) {
+    switch (mode) {
+        case PresentMode::Immediate: return 0;
+        case PresentMode::VSync: return 1;
+        case PresentMode::Mailbox: return -1;
+        case PresentMode::Fifo: return 1;
+        default: return 1;
+    }
+}
+
+OpenGLSwapChain::OpenGLSwapChain() 
+    : m_window(nullptr)
+    , m_width(0)
+    , m_height(0)
+    , m_framebufferWidth(0)
+    , m_framebufferHeight(0)
+    , m_vsync(true)
+    , m_presentMode(PresentMode::VSync) {
 }
 
 OpenGLSwapChain::~OpenGLSwapChain() {
+    Shutdown();
 }
 
-bool OpenGLSwapChain::Initialize(GLFWwindow* window) {
+bool OpenGLSwapChain::Initialize(GLFWwindow* window, bool vsync) {
     m_window = window;
+    m_vsync = vsync;
+    m_presentMode = vsync ? PresentMode::VSync : PresentMode::Immediate;
+
+    int w, h;
+    glfwGetFramebufferSize(window, &w, &h);
+    m_framebufferWidth = w;
+    m_framebufferHeight = h;
+
+    glfwGetWindowSize(window, &w, &h);
+    m_width = w;
+    m_height = h;
+
+    glfwSwapInterval(m_vsync ? 1 : 0);
+
+    return true;
+}
+
+bool OpenGLSwapChain::Initialize(GLFWwindow* window, int width, int height, PresentMode mode) {
+    m_window = window;
+    m_width = width;
+    m_height = height;
+    m_presentMode = mode;
+    m_vsync = (mode == PresentMode::VSync || mode == PresentMode::Fifo);
+
+    glfwSetWindowSize(window, width, height);
+
+    int w, h;
+    glfwGetFramebufferSize(window, &w, &h);
+    m_framebufferWidth = w;
+    m_framebufferHeight = h;
+
+    glfwSwapInterval(m_vsync ? 1 : 0);
+
     return true;
 }
 
@@ -21,11 +73,47 @@ void OpenGLSwapChain::Shutdown() {
 }
 
 void OpenGLSwapChain::Present() {
-    glfwSwapBuffers(m_window);
+    if (m_window) {
+        glfwSwapBuffers(m_window);
+    }
 }
 
 void OpenGLSwapChain::SwapBuffers() {
-    glfwSwapBuffers(m_window);
+    if (m_window) {
+        glfwSwapBuffers(m_window);
+    }
+}
+
+void OpenGLSwapChain::Resize(int width, int height) {
+    m_width = width;
+    m_height = height;
+    if (m_window) {
+        glfwSetWindowSize(m_window, width, height);
+    }
+}
+
+void OpenGLSwapChain::SetVSync(bool enabled) {
+    m_vsync = enabled;
+    glfwSwapInterval(enabled ? 1 : 0);
+}
+
+void OpenGLSwapChain::SetFramebufferSize(int width, int height) {
+    m_framebufferWidth = width;
+    m_framebufferHeight = height;
+}
+
+bool OpenGLSwapChain::ShouldClose() const {
+    return m_window && glfwWindowShouldClose(m_window);
+}
+
+void OpenGLSwapChain::SetShouldClose(bool shouldClose) {
+    if (m_window) {
+        glfwSetWindowShouldClose(m_window, shouldClose ? GLFW_TRUE : GLFW_FALSE);
+    }
+}
+
+void OpenGLSwapChain::PollEvents() {
+    glfwPollEvents();
 }
 
 } // namespace RHI