/*
===========================================================================

Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company.
Copyright (C) 2013-2016 Robert Beckebans
Copyright (C) 2014-2016 Kot in Action Creative Artel

This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").

Doom 3 BFG Edition Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Doom 3 BFG Edition Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Doom 3 BFG Edition Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 BFG Edition Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 BFG Edition Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/

#ifndef __RENDERER_H__
#define __RENDERER_H__

/*
===============================================================================

	idRenderSystem is responsible for managing the screen, which can have
	multiple idRenderWorld and 2D drawing done on it.

===============================================================================
*/
enum stereo3DMode_t
{
	STEREO3D_OFF,

	// half-resolution, non-square pixel views
	STEREO3D_SIDE_BY_SIDE_COMPRESSED,
	STEREO3D_TOP_AND_BOTTOM_COMPRESSED,

	// two full resolution views side by side, as for a dual cable display
	STEREO3D_SIDE_BY_SIDE,

	STEREO3D_INTERLACED,

	// OpenGL quad buffer
	STEREO3D_QUAD_BUFFER,

	// two full resolution views stacked with a 30 pixel guard band
	// On the PC this can be configured as a custom video timing, but
	// it definitely isn't a consumer level task.  The quad_buffer
	// support can handle 720P-3D with apropriate driver support.
	STEREO3D_HDMI_720
};

typedef enum
{
	AUTORENDER_DEFAULTICON = 0,
	AUTORENDER_HELLICON,
	AUTORENDER_DIALOGICON,
	AUTORENDER_MAX
} autoRenderIconType_t ;

enum stereoDepthType_t
{
	STEREO_DEPTH_TYPE_NONE,
	STEREO_DEPTH_TYPE_NEAR,
	STEREO_DEPTH_TYPE_MID,
	STEREO_DEPTH_TYPE_FAR
};


enum graphicsVendor_t
{
	VENDOR_NVIDIA,
	VENDOR_AMD,
	VENDOR_INTEL
};

// RB: similar to Q3A - allow separate codepaths between OpenGL 3.x, OpenGL ES versions
enum graphicsDriverType_t
{
	GLDRV_OPENGL3X,							// best for development with legacy OpenGL tools
	GLDRV_OPENGL32_COMPATIBILITY_PROFILE,
	GLDRV_OPENGL32_CORE_PROFILE,			// best for shipping to PC
	GLDRV_OPENGL_ES2,
	GLDRV_OPENGL_ES3,
	GLDRV_OPENGL_MESA,						// fear this, it is probably the best to disable GPU skinning and run shaders in GLSL ES 1.0
	GLDRV_OPENGL_MESA_CORE_PROFILE,

	GLDRV_VULKAN
};

enum antiAliasingMode_t
{
	ANTI_ALIASING_NONE,
	ANTI_ALIASING_SMAA_1X,
	ANTI_ALIASING_MSAA_2X,
	ANTI_ALIASING_MSAA_4X,
	ANTI_ALIASING_MSAA_8X
};

// CPU counters and timers
struct performanceCounters_t
{
	int		c_box_cull_in;
	int		c_box_cull_out;
	int		c_createInteractions;	// number of calls to idInteraction::CreateInteraction
	int		c_createShadowVolumes;
	int		c_generateMd5;
	int		c_entityDefCallbacks;
	int		c_alloc;			// counts for R_StaticAllc/R_StaticFree
	int		c_free;
	int		c_visibleViewEntities;
	int		c_shadowViewEntities;
	int		c_viewLights;
	int		c_numViews;			// number of total views rendered
	int		c_deformedSurfaces;	// idMD5Mesh::GenerateSurface
	int		c_deformedVerts;	// idMD5Mesh::GenerateSurface
	int		c_deformedIndexes;	// idMD5Mesh::GenerateSurface
	int		c_tangentIndexes;	// R_DeriveTangents()
	int		c_entityUpdates;
	int		c_lightUpdates;
	int		c_envprobeUpdates;
	int		c_entityReferences;
	int		c_lightReferences;
	int		c_guiSurfs;

	uint64	frontEndMicroSec;	// sum of time in all RE_RenderScene's in a frame
};

// CPU & GPU counters and timers
struct backEndCounters_t
{
	int		c_surfaces;
	int		c_shaders;

	int		c_drawElements;
	int		c_drawIndexes;

	int		c_shadowElements;
	int		c_shadowIndexes;

	int		c_copyFrameBuffer;

	float	c_overDraw;

	uint64	cpuTotalMicroSec;		// total microseconds for backend run
	uint64	cpuShadowMicroSec;
	uint64	gpuDepthMicroSec;
	uint64	gpuScreenSpaceAmbientOcclusionMicroSec;
	uint64	gpuScreenSpaceReflectionsMicroSec;
	uint64	gpuAmbientPassMicroSec;
	uint64	gpuInteractionsMicroSec;
	uint64	gpuShaderPassMicroSec;
	uint64	gpuPostProcessingMicroSec;
	uint64	gpuMicroSec;
};
// RB end

// Contains variables specific to the OpenGL configuration being run right now.
// These are constant once the OpenGL subsystem is initialized.
struct glconfig_t
{
	graphicsVendor_t	vendor;
	graphicsDriverType_t driverType;

	const char* 		renderer_string;
	const char* 		vendor_string;
	const char* 		version_string;
	const char* 		extensions_string;
	const char* 		wgl_extensions_string;
	const char* 		shading_language_string;

	float				glVersion;				// atof( version_string )

	int					maxTextureSize;			// queried from GL
	int					maxTextureCoords;
	int					maxTextureImageUnits;
	int					uniformBufferOffsetAlignment;
	float				maxTextureAnisotropy;

	int					colorBits;
	int					depthBits;
	int					stencilBits;

	bool				multitextureAvailable;
	bool				directStateAccess;
	bool				textureCompressionAvailable;
	bool				anisotropicFilterAvailable;
	bool				textureLODBiasAvailable;
	bool				seamlessCubeMapAvailable;
	bool				vertexBufferObjectAvailable;
	bool				mapBufferRangeAvailable;
	bool				vertexArrayObjectAvailable;
	bool				drawElementsBaseVertexAvailable;
	bool				fragmentProgramAvailable;
	bool				glslAvailable;
	bool				uniformBufferAvailable;
	bool				twoSidedStencilAvailable;
	bool				depthBoundsTestAvailable;
	bool				syncAvailable;
	bool				timerQueryAvailable;
	bool				occlusionQueryAvailable;
	bool				debugOutputAvailable;
	bool				swapControlTearAvailable;

	// RB begin
	bool				gremedyStringMarkerAvailable;
	bool				khronosDebugAvailable;
	bool				vertexHalfFloatAvailable;

	bool				framebufferObjectAvailable;
	int					maxRenderbufferSize;
	int					maxColorAttachments;
//	bool				framebufferPackedDepthStencilAvailable;
	bool				framebufferBlitAvailable;

	// only true with uniform buffer support and an OpenGL driver that supports GLSL >= 1.50
	bool				gpuSkinningAvailable;
	// RB end

	stereo3DMode_t		stereo3Dmode;
	int					nativeScreenWidth; // this is the native screen width resolution of the renderer
	int					nativeScreenHeight; // this is the native screen height resolution of the renderer

	int					displayFrequency;

	int					isFullscreen;					// monitor number
	bool				isStereoPixelFormat;
	bool				stereoPixelFormatAvailable;
	int					multisamples;

	// Screen separation for stereoscopic rendering is set based on this.
	// PC vid code sets this, converting from diagonals / inches / whatever as needed.
	// If the value can't be determined, set something reasonable, like 50cm.
	float				physicalScreenWidthInCentimeters;

	float				pixelAspect;

	// RB begin
#if !defined(__ANDROID__) && !defined(USE_VULKAN)
	GLuint				global_vao;
#endif
	// RB end
};



struct emptyCommand_t;

const int SMALLCHAR_WIDTH		= 8;
const int SMALLCHAR_HEIGHT		= 16;
const int BIGCHAR_WIDTH			= 16;
const int BIGCHAR_HEIGHT		= 16;

// all drawing is done to a 640 x 480 virtual screen size
// and will be automatically scaled to the real resolution
const int SCREEN_WIDTH			= 640;
const int SCREEN_HEIGHT			= 480;

extern idCVar r_useVirtualScreenResolution;

class idRenderWorld;


class idRenderSystem
{
public:

	virtual					~idRenderSystem() {}

	// set up cvars and basic data structures, but don't
	// init OpenGL, so it can also be used for dedicated servers
	virtual void			Init() = 0;

	// only called before quitting
	virtual void			Shutdown() = 0;

	virtual bool			IsInitialized() const = 0;

	virtual void			ResetGuiModels() = 0;

	virtual void			InitOpenGL() = 0;

	virtual void			ShutdownOpenGL() = 0;

	virtual bool			IsOpenGLRunning() const = 0;

	virtual bool			IsFullScreen() const = 0;
	virtual int				GetWidth() const = 0;
	virtual int				GetHeight() const = 0;
	virtual int				GetVirtualWidth() const = 0;
	virtual int				GetVirtualHeight() const = 0;

	// return w/h of a single pixel. This will be 1.0 for normal cases.
	// A side-by-side stereo 3D frame will have a pixel aspect of 0.5.
	// A top-and-bottom stereo 3D frame will have a pixel aspect of 2.0
	virtual float			GetPixelAspect() const = 0;

	// This is used to calculate stereoscopic screen offset for a given interocular distance.
	virtual float			GetPhysicalScreenWidthInCentimeters() const = 0;

	// GetWidth() / GetHeight() return the size of a single eye
	// view, which may be replicated twice in a stereo display
	virtual stereo3DMode_t	GetStereo3DMode() const = 0;
	virtual bool			IsStereoScopicRenderingSupported() const = 0;
	virtual stereo3DMode_t	GetStereoScopicRenderingMode() const = 0;
	virtual void			EnableStereoScopicRendering( const stereo3DMode_t mode ) const = 0;
	virtual bool			HasQuadBufferSupport() const = 0;

	// allocate a renderWorld to be used for drawing
	virtual idRenderWorld* 	AllocRenderWorld() = 0;
	virtual	void			FreeRenderWorld( idRenderWorld* rw ) = 0;

	// All data that will be used in a level should be
	// registered before rendering any frames to prevent disk hits,
	// but they can still be registered at a later time
	// if necessary.
	virtual void			BeginLevelLoad() = 0;
	virtual void			EndLevelLoad() = 0;
	virtual void			Preload( const idPreloadManifest& manifest, const char* mapName ) = 0;
	virtual void			LoadLevelImages() = 0;

	virtual void			BeginAutomaticBackgroundSwaps( autoRenderIconType_t icon = AUTORENDER_DEFAULTICON ) = 0;
	virtual void			EndAutomaticBackgroundSwaps() = 0;
	virtual bool			AreAutomaticBackgroundSwapsRunning( autoRenderIconType_t* icon = NULL ) const = 0;

	// font support
	virtual class idFont* 	RegisterFont( const char* fontName ) = 0;
	virtual void			ResetFonts() = 0;

	virtual void			SetColor( const idVec4& rgba ) = 0;
	virtual void			SetColor4( float r, float g, float b, float a )
	{
		SetColor( idVec4( r, g, b, a ) );
	}

	virtual uint32			GetColor() = 0;

	virtual void			SetGLState( const uint64 glState ) = 0;

	virtual void			DrawFilled( const idVec4& color, float x, float y, float w, float h ) = 0;
	virtual void			DrawStretchPic( float x, float y, float w, float h, float s1, float t1, float s2, float t2, const idMaterial* material ) = 0;
	void			DrawStretchPic( const idVec4& rect, const idVec4& st, const idMaterial* material )
	{
		DrawStretchPic( rect.x, rect.y, rect.z, rect.w, st.x, st.y, st.z, st.w, material );
	}
	virtual void			DrawStretchPic( const idVec4& topLeft, const idVec4& topRight, const idVec4& bottomRight, const idVec4& bottomLeft, const idMaterial* material ) = 0;
	virtual void			DrawStretchTri( const idVec2& p1, const idVec2& p2, const idVec2& p3, const idVec2& t1, const idVec2& t2, const idVec2& t3, const idMaterial* material ) = 0;
	virtual idDrawVert* 	AllocTris( int numVerts, const triIndex_t* indexes, int numIndexes, const idMaterial* material, const stereoDepthType_t stereoType = STEREO_DEPTH_TYPE_NONE ) = 0;

	virtual void			PrintMemInfo( MemInfo_t* mi ) = 0;

	virtual void			DrawSmallChar( int x, int y, int ch ) = 0;
	virtual void			DrawSmallStringExt( int x, int y, const char* string, const idVec4& setColor, bool forceColor ) = 0;
	virtual void			DrawBigChar( int x, int y, int ch ) = 0;
	virtual void			DrawBigStringExt( int x, int y, const char* string, const idVec4& setColor, bool forceColor ) = 0;

	// dump all 2D drawing so far this frame to the demo file
	virtual void			WriteDemoPics() = 0;
	virtual void			WriteEndFrame() = 0;

	// draw the 2D pics that were saved out with the current demo frame
	virtual void			DrawDemoPics() = 0;

	// Performs final closeout of any gui models being defined.
	//
	// Waits for the previous GPU rendering to complete and vsync.
	//
	// Returns the head of the linked command list that was just closed off.
	//
	// Returns timing information from the previous frame.
	//
	// After this is called, new command buffers can be built up in parallel
	// with the rendering of the closed off command buffers by RenderCommandBuffers()
	virtual const emptyCommand_t* 	SwapCommandBuffers( uint64* frontEndMicroSec, uint64* backEndMicroSec, uint64* shadowMicroSec, uint64* gpuMicroSec, backEndCounters_t* bc, performanceCounters_t* pc ) = 0;

	// SwapCommandBuffers operation can be split in two parts for non-smp rendering
	// where the GPU is idled intentionally for minimal latency.
	virtual void			SwapCommandBuffers_FinishRendering( uint64* frontEndMicroSec, uint64* backEndMicroSec, uint64* shadowMicroSec, uint64* gpuMicroSec, backEndCounters_t* bc, performanceCounters_t* pc ) = 0;
	virtual const emptyCommand_t* 	SwapCommandBuffers_FinishCommandBuffers() = 0;

	// issues GPU commands to render a built up list of command buffers returned
	// by SwapCommandBuffers().  No references should be made to the current frameData,
	// so new scenes and GUIs can be built up in parallel with the rendering.
	virtual void			RenderCommandBuffers( const emptyCommand_t* commandBuffers ) = 0;

	// aviDemo uses this.
	// Will automatically tile render large screen shots if necessary
	// Samples is the number of jittered frames for anti-aliasing
	// If ref == NULL, common->UpdateScreen will be used
	// This will perform swapbuffers, so it is NOT an approppriate way to
	// generate image files that happen during gameplay, as for savegame
	// markers.  Use WriteRender() instead.
	virtual void			TakeScreenshot( int width, int height, const char* fileName, int samples, struct renderView_s* ref, int exten ) = 0;

	// RB
	virtual byte*			CaptureRenderToBuffer( int width, int height, renderView_t* ref ) = 0;

	// the render output can be cropped down to a subset of the real screen, as
	// for save-game reviews and split-screen multiplayer.  Users of the renderer
	// will not know the actual pixel size of the area they are rendering to

	// the x,y,width,height values are in virtual SCREEN_WIDTH / SCREEN_HEIGHT coordinates

	// to render to a texture, first set the crop size with makePowerOfTwo = true,
	// then perform all desired rendering, then capture to an image
	// if the specified physical dimensions are larger than the current cropped region, they will be cut down to fit
	virtual void			CropRenderSize( int width, int height ) = 0;
	virtual void			CaptureRenderToImage( const char* imageName, bool clearColorAfterCopy = false ) = 0;
	// fixAlpha will set all the alpha channel values to 0xff, which allows screen captures
	// to use the default tga loading code without having dimmed down areas in many places
	virtual void			CaptureRenderToFile( const char* fileName, bool fixAlpha = false ) = 0;
	virtual void			UnCrop() = 0;

	// the image has to be already loaded ( most straightforward way would be through a FindMaterial )
	// texture filter / mipmapping / repeat won't be modified by the upload
	// returns false if the image wasn't found
	virtual bool			UploadImage( const char* imageName, const byte* data, int width, int height ) = 0;

	// consoles switch stereo 3D eye views each 60 hz frame
	virtual int				GetFrameCount() const = 0;

	virtual void			OnFrame() = 0;
};

extern idRenderSystem* 			renderSystem;

//
// functions mainly intended for editor and dmap integration
//

// for use by dmap to do the carving-on-light-boundaries and for the editor for display
void R_LightProjectionMatrix( const idVec3& origin, const idPlane& rearPlane, idVec4 mat[4] );

// used by the view shot taker
void R_ScreenshotFilename( int& lastNumber, const char* base, idStr& fileName );

#endif /* !__RENDERER_H__ */
