/*
 * Copyright 2011-2015 Branimir Karadzic. All rights reserved.
 * License: http://www.opensource.org/licenses/BSD-2-Clause
 */

#include "bgfx_p.h"

#if (BGFX_CONFIG_RENDERER_OPENGLES || BGFX_CONFIG_RENDERER_OPENGL)
#	include "renderer_gl.h"

#	if BGFX_USE_EGL

#		if BX_PLATFORM_RPI
#			include <bcm_host.h>
#		endif // BX_PLATFORM_RPI

#ifndef EGL_CONTEXT_MAJOR_VERSION_KHR
#	define EGL_CONTEXT_MAJOR_VERSION_KHR EGL_CONTEXT_CLIENT_VERSION
#endif // EGL_CONTEXT_MAJOR_VERSION_KHR

#ifndef EGL_CONTEXT_MINOR_VERSION_KHR
#	define EGL_CONTEXT_MINOR_VERSION_KHR 0x30FB
#endif // EGL_CONTEXT_MINOR_VERSION_KHR

namespace bgfx
{
#if BGFX_USE_GL_DYNAMIC_LIB

	typedef void (*EGLPROC)(void);

	typedef EGLPROC    (EGLAPIENTRY* PFNEGLGETPROCADDRESSPROC)(const char *procname);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLSWAPINTERVALPROC)(EGLDisplay dpy, EGLint interval);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLMAKECURRENTPROC)(EGLDisplay dpy, EGLSurface draw, EGLSurface read, EGLContext ctx);
	typedef EGLContext (EGLAPIENTRY* PFNEGLCREATECONTEXTPROC)(EGLDisplay dpy, EGLConfig config, EGLContext share_context, const EGLint *attrib_list);
	typedef EGLSurface (EGLAPIENTRY* PFNEGLCREATEWINDOWSURFACEPROC)(EGLDisplay dpy, EGLConfig config, EGLNativeWindowType win, const EGLint *attrib_list);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLCHOOSECONFIGPROC)(EGLDisplay dpy, const EGLint *attrib_list,	EGLConfig *configs, EGLint config_size,	EGLint *num_config);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLINITIALIZEPROC)(EGLDisplay dpy, EGLint *major, EGLint *minor);
	typedef EGLint     (EGLAPIENTRY* PFNEGLGETERRORPROC)(void);
	typedef EGLDisplay (EGLAPIENTRY* PFNEGLGETDISPLAYPROC)(EGLNativeDisplayType display_id);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLTERMINATEPROC)(EGLDisplay dpy);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLDESTROYSURFACEPROC)(EGLDisplay dpy, EGLSurface surface);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLDESTROYCONTEXTPROC)(EGLDisplay dpy, EGLContext ctx);
	typedef EGLBoolean (EGLAPIENTRY* PFNEGLSWAPBUFFERSPROC)(EGLDisplay dpy, EGLSurface surface);

#define EGL_IMPORT \
			EGL_IMPORT_FUNC(PFNEGLGETPROCADDRESSPROC,      eglGetProcAddress); \
			EGL_IMPORT_FUNC(PFNEGLSWAPINTERVALPROC,        eglSwapInterval); \
			EGL_IMPORT_FUNC(PFNEGLMAKECURRENTPROC,         eglMakeCurrent); \
			EGL_IMPORT_FUNC(PFNEGLCREATECONTEXTPROC,       eglCreateContext); \
			EGL_IMPORT_FUNC(PFNEGLCREATEWINDOWSURFACEPROC, eglCreateWindowSurface); \
			EGL_IMPORT_FUNC(PFNEGLCHOOSECONFIGPROC,        eglChooseConfig); \
			EGL_IMPORT_FUNC(PFNEGLINITIALIZEPROC,          eglInitialize); \
			EGL_IMPORT_FUNC(PFNEGLGETERRORPROC,            eglGetError); \
			EGL_IMPORT_FUNC(PFNEGLGETDISPLAYPROC,          eglGetDisplay); \
			EGL_IMPORT_FUNC(PFNEGLTERMINATEPROC,           eglTerminate); \
			EGL_IMPORT_FUNC(PFNEGLDESTROYSURFACEPROC,      eglDestroySurface); \
			EGL_IMPORT_FUNC(PFNEGLDESTROYCONTEXTPROC,      eglDestroyContext); \
			EGL_IMPORT_FUNC(PFNEGLSWAPBUFFERSPROC,         eglSwapBuffers);

#define EGL_IMPORT_FUNC(_proto, _func) _proto _func
EGL_IMPORT
#undef EGL_IMPORT_FUNC

	void* eglOpen()
	{
		void* handle = bx::dlopen("libEGL." BX_DL_EXT);
		BGFX_FATAL(NULL != handle, Fatal::UnableToInitialize, "Failed to load libEGL dynamic library.");

#define EGL_IMPORT_FUNC(_proto, _func) \
			_func = (_proto)bx::dlsym(handle, #_func); \
			BX_TRACE("%p " #_func, _func); \
			BGFX_FATAL(NULL != _func, Fatal::UnableToInitialize, "Failed get " #_func ".")
EGL_IMPORT
#undef EGL_IMPORT_FUNC

		return handle;
	}

	void eglClose(void* _handle)
	{
		bx::dlclose(_handle);

#define EGL_IMPORT_FUNC(_proto, _func) _func = NULL
EGL_IMPORT
#undef EGL_IMPORT_FUNC
	}

#else

	void* eglOpen()
	{
		return NULL;
	}

	void eglClose(void* /*_handle*/)
	{
	}
#endif // BGFX_USE_GL_DYNAMIC_LIB

#	define GL_IMPORT(_optional, _proto, _func, _import) _proto _func = NULL
#	include "glimports.h"

	static const EGLint s_contextAttrs[] =
	{
#	if BGFX_CONFIG_RENDERER_OPENGLES >= 30
		EGL_CONTEXT_MAJOR_VERSION_KHR, 3,
#		if BGFX_CONFIG_RENDERER_OPENGLES >= 31
		EGL_CONTEXT_MINOR_VERSION_KHR, 1,
#		else
		//			EGL_CONTEXT_MINOR_VERSION_KHR, 0,
#		endif // BGFX_CONFIG_RENDERER_OPENGLES >= 31
#	elif BGFX_CONFIG_RENDERER_OPENGLES
		EGL_CONTEXT_MAJOR_VERSION_KHR, 2,
		//			EGL_CONTEXT_MINOR_VERSION_KHR, 0,
#	endif // BGFX_CONFIG_RENDERER_

		EGL_NONE
	};

	struct SwapChainGL
	{
		SwapChainGL(EGLDisplay _display, EGLConfig _config, EGLContext _context, EGLNativeWindowType _nwh)
			: m_nwh(_nwh)
			, m_display(_display)
		{
			m_surface = eglCreateWindowSurface(m_display, _config, _nwh, NULL);
			BGFX_FATAL(m_surface != EGL_NO_SURFACE, Fatal::UnableToInitialize, "Failed to create surface.");

			m_context = eglCreateContext(m_display, _config, _context, s_contextAttrs);
			BX_CHECK(NULL != m_context, "Create swap chain failed: %x", eglGetError() );

			makeCurrent();
			GL_CHECK(glClearColor(0.0f, 0.0f, 0.0f, 0.0f) );
			GL_CHECK(glClear(GL_COLOR_BUFFER_BIT) );
			swapBuffers();
			GL_CHECK(glClear(GL_COLOR_BUFFER_BIT) );
			swapBuffers();
		}

		~SwapChainGL()
		{
			eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
			eglDestroyContext(m_display, m_context);
			eglDestroySurface(m_display, m_surface);
		}

		void makeCurrent()
		{
			eglMakeCurrent(m_display, m_surface, m_surface, m_context);
		}

		void swapBuffers()
		{
			eglSwapBuffers(m_display, m_surface);
		}

		EGLNativeWindowType m_nwh;
		EGLContext m_context;
		EGLDisplay m_display;
		EGLSurface m_surface;
	};

#	if BX_PLATFORM_RPI
	static EGL_DISPMANX_WINDOW_T s_dispmanWindow;

	void x11SetDisplayWindow(::Display* _display, ::Window _window)
	{
		// Noop for now...
		BX_UNUSED(_display, _window);
	}
#	endif // BX_PLATFORM_RPI

	void GlContext::create(uint32_t _width, uint32_t _height)
	{
#	if BX_PLATFORM_RPI
		bcm_host_init();
#	endif // BX_PLATFORM_RPI

		m_eglLibrary = eglOpen();

		BX_UNUSED(_width, _height);
		EGLNativeDisplayType ndt = EGL_DEFAULT_DISPLAY;
		EGLNativeWindowType nwh = (EGLNativeWindowType)NULL;
#	if BX_PLATFORM_WINDOWS
		ndt = GetDC(g_bgfxHwnd);
		nwh = g_bgfxHwnd;
#	elif BX_PLATFORM_LINUX
		ndt = (EGLNativeDisplayType)g_bgfxX11Display;
		nwh = (EGLNativeWindowType)g_bgfxX11Window;
#	endif // BX_PLATFORM_
		m_display = eglGetDisplay(ndt);
		BGFX_FATAL(m_display != EGL_NO_DISPLAY, Fatal::UnableToInitialize, "Failed to create display %p", m_display);

		EGLint major = 0;
		EGLint minor = 0;
		EGLBoolean success = eglInitialize(m_display, &major, &minor);
		BGFX_FATAL(success && major >= 1 && minor >= 3, Fatal::UnableToInitialize, "Failed to initialize %d.%d", major, minor);

		EGLint attrs[] =
		{
			EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,

#	if BX_PLATFORM_ANDROID
			EGL_DEPTH_SIZE, 16,
#	else
			EGL_DEPTH_SIZE, 24,
#	endif // BX_PLATFORM_
			EGL_STENCIL_SIZE, 8,

			EGL_NONE
		};

		EGLint numConfig = 0;
		success = eglChooseConfig(m_display, attrs, &m_config, 1, &numConfig);
		BGFX_FATAL(success, Fatal::UnableToInitialize, "eglChooseConfig");

#	if BX_PLATFORM_ANDROID
		EGLint format;
		eglGetConfigAttrib(m_display, m_config, EGL_NATIVE_VISUAL_ID, &format);
		ANativeWindow_setBuffersGeometry(g_bgfxAndroidWindow, _width, _height, format);
		nwh = g_bgfxAndroidWindow;
#	elif BX_PLATFORM_RPI
		DISPMANX_DISPLAY_HANDLE_T dispmanDisplay = vc_dispmanx_display_open(0);
		DISPMANX_UPDATE_HANDLE_T  dispmanUpdate  = vc_dispmanx_update_start(0);

		VC_RECT_T dstRect = { 0, 0, _width,        _height       };
		VC_RECT_T srcRect = { 0, 0, _width  << 16, _height << 16 };

		DISPMANX_ELEMENT_HANDLE_T dispmanElement = vc_dispmanx_element_add(dispmanUpdate
			, dispmanDisplay
			, 0
			, &dstRect
			, 0
			, &srcRect
			, DISPMANX_PROTECTION_NONE
			, NULL
			, NULL
			, DISPMANX_NO_ROTATE
			);

		s_dispmanWindow.element = dispmanElement;
		s_dispmanWindow.width   = _width;
		s_dispmanWindow.height  = _height;
		nwh = &s_dispmanWindow;

		vc_dispmanx_update_submit_sync(dispmanUpdate);
#	endif // BX_PLATFORM_ANDROID

		m_surface = eglCreateWindowSurface(m_display, m_config, nwh, NULL);
		BGFX_FATAL(m_surface != EGL_NO_SURFACE, Fatal::UnableToInitialize, "Failed to create surface.");

		m_context = eglCreateContext(m_display, m_config, EGL_NO_CONTEXT, s_contextAttrs);
		BGFX_FATAL(m_context != EGL_NO_CONTEXT, Fatal::UnableToInitialize, "Failed to create context.");

		success = eglMakeCurrent(m_display, m_surface, m_surface, m_context);
		BGFX_FATAL(success, Fatal::UnableToInitialize, "Failed to set context.");
		m_current = NULL;

		eglSwapInterval(m_display, 0);

#	if BX_PLATFORM_EMSCRIPTEN
		emscripten_set_canvas_size(_width, _height);
#	endif // BX_PLATFORM_EMSCRIPTEN

		import();
	}

	void GlContext::destroy()
	{
		eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
		eglDestroyContext(m_display, m_context);
		eglDestroySurface(m_display, m_surface);
		eglTerminate(m_display);
		m_context = NULL;

		eglClose(m_eglLibrary);

#	if BX_PLATFORM_RPI
		bcm_host_deinit();
#	endif // BX_PLATFORM_RPI
	}

	void GlContext::resize(uint32_t _width, uint32_t _height, bool _vsync)
	{
		BX_UNUSED(_width, _height);
#	if BX_PLATFORM_ANDROID
		EGLint format;
		eglGetConfigAttrib(m_display, m_config, EGL_NATIVE_VISUAL_ID, &format);
		ANativeWindow_setBuffersGeometry(g_bgfxAndroidWindow, _width, _height, format);
#	endif // BX_PLATFORM_ANDROID

		eglSwapInterval(m_display, _vsync ? 1 : 0);
	}

	bool GlContext::isSwapChainSupported()
	{
		return BX_ENABLED(0
						| BX_PLATFORM_LINUX
						| BX_PLATFORM_WINDOWS
						);
	}

	SwapChainGL* GlContext::createSwapChain(void* _nwh)
	{
		return BX_NEW(g_allocator, SwapChainGL)(m_display, m_config, m_context, (EGLNativeWindowType)_nwh);
	}

	void GlContext::destroySwapChain(SwapChainGL* _swapChain)
	{
		BX_DELETE(g_allocator, _swapChain);
	}

	void GlContext::swap(SwapChainGL* _swapChain)
	{
		makeCurrent(_swapChain);

		if (NULL == _swapChain)
		{
			eglSwapBuffers(m_display, m_surface);
		}
		else
		{
			_swapChain->swapBuffers();
		}
	}

	void GlContext::makeCurrent(SwapChainGL* _swapChain)
	{
		if (m_current != _swapChain)
		{
			m_current = _swapChain;

			if (NULL == _swapChain)
			{
				eglMakeCurrent(m_display, m_surface, m_surface, m_context);
			}
			else
			{
				_swapChain->makeCurrent();
			}
		}
	}

	void GlContext::import()
	{
		BX_TRACE("Import:");
#	if BX_PLATFORM_WINDOWS || BX_PLATFORM_LINUX
		void* glesv2 = bx::dlopen("libGLESv2." BX_DL_EXT);
#		define GL_EXTENSION(_optional, _proto, _func, _import) \
					{ \
						if (NULL == _func) \
						{ \
							_func = (_proto)bx::dlsym(glesv2, #_import); \
							BX_TRACE("\t%p " #_func " (" #_import ")", _func); \
							BGFX_FATAL(_optional || NULL != _func, Fatal::UnableToInitialize, "Failed to create OpenGLES context. eglGetProcAddress(\"%s\")", #_import); \
						} \
					}
#	else
#		define GL_EXTENSION(_optional, _proto, _func, _import) \
					{ \
						if (NULL == _func) \
						{ \
							_func = (_proto)eglGetProcAddress(#_import); \
							BX_TRACE("\t%p " #_func " (" #_import ")", _func); \
							BGFX_FATAL(_optional || NULL != _func, Fatal::UnableToInitialize, "Failed to create OpenGLES context. eglGetProcAddress(\"%s\")", #_import); \
						} \
					}
#	endif // BX_PLATFORM_
#	include "glimports.h"
	}

} // namespace bgfx

#	endif // BGFX_USE_EGL
#endif // (BGFX_CONFIG_RENDERER_OPENGLES || BGFX_CONFIG_RENDERER_OPENGL)