GLContext.h

#pragma once
 
#ifdef COGS_EGL
  #ifndef __EMSCRIPTEN__
    #define EGL_EGL_PROTOTYPES 0
  #endif
  #include <EGL/egl.h>
  #include <EGL/eglext.h>
  #undef Always
  #undef None
#endif // of COGS_EGL
 
 
#ifdef __linux__
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#undef Always
#undef None
#endif
 
#ifdef COGS_GLX
#include <GL/glx.h>
#include <GL/glxext.h>
#endif // of COGS_GLX
 
#ifdef COGS_WGL
#include <KHR/khrplatform.h>
#include <GL/glcorearb.h>
#include <GL/wgl.h>
#include <GL/wglext.h>
#endif // of COGS_WGL
 
#include <stdint.h>
 
#if defined( __APPLE__ )
  #if defined __OBJC__
    @class NSOpenGLContext;
    typedef     NSOpenGLContext* NSContextPtr;
  #else
  typedef       struct NSOpenGLContext* NSContextPtr;
  #endif
#endif
 
namespace Cogs {
 
  struct WindowData;
  struct GraphicsDeviceSettings;
 
  struct GLContextBase
  {
#ifdef _WIN32
    typedef HDC NativeDisplay;
#elif defined(COGS_GLX)
    typedef Display* NativeDisplay;
#elif defined(COGS_EGL)
    typedef EGLNativeDisplayType NativeDisplay;
#else
    typedef void* NativeDisplay;
#endif
 
    enum struct Platform
    {
      None,
      ES3,
      GL
    };
    Platform platform = Platform::None;
 
  };
  bool setUpGLDebugging(const char* contextName, GLContextBase::Platform platform);
 
#ifdef _WIN32
  struct GLContext : GLContextBase
  {
    ~GLContext() { destroy(); }
 
    bool create(NativeDisplay display, WindowData* windowData, GLContext* shareContext, const GraphicsDeviceSettings* settings, Platform desiredPlatform, bool debug);
    bool makeCurrent();
    void swapBuffers(uint32_t syncInterval, uint32_t presentFlags);
    void destroy();
 
    HDC hdc = nullptr;
    HGLRC context = nullptr;
    HWND headlessHwnd = nullptr;    // Dummy window for headless contexts, null otherwise.
  };
#endif
 
#ifdef __APPLE__
struct GLContext : GLContextBase
{
  GLContext(NSContextPtr c = nullptr) : context(c) {}
  ~GLContext() { destroy(); }
 
  bool create(NativeDisplay display, WindowData* windowData, GLContext* shareContext, const GraphicsDeviceSettings* settings, Platform desiredPlatform, bool debug);
  bool makeCurrent();
  void swapBuffers(uint32_t syncInterval, uint32_t presentFlags);
  void destroy();
 
  NSContextPtr context;
};
#endif
 
#ifdef COGS_GLX
 
  struct GLContext : GLContextBase
  {
    ~GLContext() { destroy(); }
 
    bool create(NativeDisplay display, WindowData* windowData, GLContext* shareContext, const GraphicsDeviceSettings* settings, Platform desiredPlatform, bool debug);
    bool makeCurrent();
    void swapBuffers(uint32_t syncInterval, uint32_t presentFlags);
    void destroy();
 
    static GLXFBConfig getFBConfig(NativeDisplay display, int requestedSampleCount);
    static XVisualInfo* getVisualInfo(Display* display, GLXFBConfig fbConfig);
 
    Display* dpy = nullptr;
    Window win = 0;
    GLXContext glc = nullptr;
    static GLXFBConfig fbConfig;
 
    bool ownWindow = false;
    bool ownContext = false;
  };
  bool getGLXFuncPointers();
#endif
 
#ifdef COGS_EGL
  struct GLContext : GLContextBase
  {
    ~GLContext() { destroy(); }
 
    EGLDisplay  eglDisplay = nullptr;
    EGLContext  eglContext = nullptr;
    EGLSurface  eglSurface = nullptr;
    bool ownContext = false;
    bool ownDisplay = false;
 
    bool create(NativeDisplay display, WindowData* windowData, GLContext* shareContext, const GraphicsDeviceSettings* settings, Platform desiredPlatform, bool debug);
    bool makeCurrent();
    void swapBuffers(uint32_t syncInterval, uint32_t presentFlags);
    void destroy();
  };
#endif // of COGS_EGL
 
  bool getGLFuncPointers();
  bool getGLES3FuncPointers(GLContextBase::Platform platform);
 
}