// 
//---------------------------------------------------------------------------
//
// Copyright(C) 2000-2016 Christoph Oelckers
// All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see http://www.gnu.org/licenses/
//
//--------------------------------------------------------------------------
//
/*
** hw_weapon.cpp
** Weapon sprite utilities
**
*/

#include "sbar.h"
#include "r_utility.h"
#include "v_video.h"
#include "doomstat.h"
#include "d_player.h"
#include "g_levellocals.h"
#include "r_data/models/models.h"
#include "hw_weapon.h"
#include "hw_fakeflat.h"

#include "hwrenderer/models/hw_models.h"
#include "hwrenderer/dynlights/hw_dynlightdata.h"
#include "hwrenderer/textures/hw_material.h"
#include "hwrenderer/utility/hw_lighting.h"
#include "hwrenderer/utility/hw_cvars.h"
#include "hwrenderer/scene/hw_drawinfo.h"
#include "hwrenderer/scene/hw_drawstructs.h"
#include "hwrenderer/data/flatvertices.h"
#include "hwrenderer/dynlights/hw_lightbuffer.h"
#include "hw_renderstate.h"

EXTERN_CVAR(Float, transsouls)
EXTERN_CVAR(Int, gl_fuzztype)
EXTERN_CVAR(Bool, r_drawplayersprites)
EXTERN_CVAR(Bool, r_deathcamera)


//==========================================================================
//
// R_DrawPSprite
//
//==========================================================================

void HWDrawInfo::DrawPSprite(HUDSprite *huds, FRenderState &state)
{
	if (huds->RenderStyle.BlendOp == STYLEOP_Shadow)
	{
		state.SetColor(0.2f, 0.2f, 0.2f, 0.33f, huds->cm.Desaturation);
	}
	else
	{
		state.SetColor(huds->lightlevel, 0, isFullbrightScene(), huds->cm, huds->alpha, true);
	}
	state.SetLightIndex(-1);
	state.SetRenderStyle(huds->RenderStyle);
	state.SetTextureMode(huds->RenderStyle);
	state.SetObjectColor(huds->ObjectColor);
	state.SetDynLight(huds->dynrgb[0], huds->dynrgb[1], huds->dynrgb[2]);
	state.EnableBrightmap(!(huds->RenderStyle.Flags & STYLEF_ColorIsFixed));

	if (huds->mframe)
	{
		state.AlphaFunc(Alpha_GEqual, 0);

		FGLModelRenderer renderer(this, state, huds->lightindex);
		renderer.RenderHUDModel(huds->weapon, huds->mx, huds->my);
		state.SetVertexBuffer(screen->mVertexData);
	}
	else
	{
		float thresh = (huds->tex->tex->GetTranslucency() || huds->OverrideShader != -1) ? 0.f : gl_mask_sprite_threshold;
		state.AlphaFunc(Alpha_GEqual, thresh);
		state.SetMaterial(huds->tex, CLAMP_XY_NOMIP, 0, huds->OverrideShader);
		state.Draw(DT_TriangleStrip, huds->mx, 4);
	}

	state.SetTextureMode(TM_NORMAL);
	state.AlphaFunc(Alpha_GEqual, gl_mask_sprite_threshold);
	state.SetObjectColor(0xffffffff);
	state.SetDynLight(0, 0, 0);
	state.EnableBrightmap(false);
}

//==========================================================================
//
// R_DrawPlayerSprites
//
//==========================================================================

void HWDrawInfo::DrawPlayerSprites(bool hudModelStep, FRenderState &state)
{
	int oldlightmode = level.lightmode;
	if (!hudModelStep && level.lightmode == 8) level.lightmode = 2;	// Software lighting cannot handle 2D content so revert to lightmode 2 for that.
	for (auto &hudsprite : hudsprites)
	{
		if ((!!hudsprite.mframe) == hudModelStep)
			DrawPSprite(&hudsprite, state);
	}
	level.lightmode = oldlightmode;
}


//==========================================================================
//
//
//
//==========================================================================

static bool isBright(DPSprite *psp)
{
	if (psp != nullptr && psp->GetState() != nullptr)
	{
		bool disablefullbright = false;
		FTextureID lump = sprites[psp->GetSprite()].GetSpriteFrame(psp->GetFrame(), 0, 0., nullptr);
		if (lump.isValid())
		{
			FTexture * tex = TexMan(lump);
			if (tex) disablefullbright = tex->bDisableFullbright;
		}
		return psp->GetState()->GetFullbright() && !disablefullbright;
	}
	return false;
}

//==========================================================================
//
// Weapon position
//
//==========================================================================

static WeaponPosition GetWeaponPosition(player_t *player, double ticFrac)
{
	WeaponPosition w;
	P_BobWeapon(player, &w.bobx, &w.boby, ticFrac);

	// Interpolate the main weapon layer once so as to be able to add it to other layers.
	if ((w.weapon = player->FindPSprite(PSP_WEAPON)) != nullptr)
	{
		if (w.weapon->firstTic)
		{
			w.wx = (float)w.weapon->x;
			w.wy = (float)w.weapon->y;
		}
		else
		{
			w.wx = (float)(w.weapon->oldx + (w.weapon->x - w.weapon->oldx) * ticFrac);
			w.wy = (float)(w.weapon->oldy + (w.weapon->y - w.weapon->oldy) * ticFrac);
		}
	}
	else
	{
		w.wx = 0;
		w.wy = 0;
	}
	return w;
}

//==========================================================================
//
// Bobbing
//
//==========================================================================

static FVector2 BobWeapon(WeaponPosition &weap, DPSprite *psp, double ticFrac)
{
	if (psp->firstTic)
	{ // Can't interpolate the first tic.
		psp->firstTic = false;
		psp->oldx = psp->x;
		psp->oldy = psp->y;
	}

	float sx = float(psp->oldx + (psp->x - psp->oldx) * ticFrac);
	float sy = float(psp->oldy + (psp->y - psp->oldy) * ticFrac);

	if (psp->Flags & PSPF_ADDBOB)
	{
		sx += (psp->Flags & PSPF_MIRROR) ? -weap.bobx : weap.bobx;
		sy += weap.boby;
	}

	if (psp->Flags & PSPF_ADDWEAPON && psp->GetID() != PSP_WEAPON)
	{
		sx += weap.wx;
		sy += weap.wy;
	}
	return { sx, sy };
}

//==========================================================================
//
// Lighting
//
//==========================================================================

static WeaponLighting GetWeaponLighting(sector_t *viewsector, const DVector3 &pos, int cm, area_t in_area, const DVector3 &playerpos)
{
	WeaponLighting l;

	if (cm)
	{
		l.lightlevel = 255;
		l.cm.Clear();
		l.isbelow = false;
	}
	else
	{
		auto fakesec = hw_FakeFlat(viewsector, in_area, false);

		// calculate light level for weapon sprites
		l.lightlevel = hw_ClampLight(fakesec->lightlevel);

		// calculate colormap for weapon sprites
		if (viewsector->e->XFloor.ffloors.Size() && !(level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING))
		{
			TArray<lightlist_t> & lightlist = viewsector->e->XFloor.lightlist;
			for (unsigned i = 0; i<lightlist.Size(); i++)
			{
				double lightbottom;

				if (i<lightlist.Size() - 1)
				{
					lightbottom = lightlist[i + 1].plane.ZatPoint(pos);
				}
				else
				{
					lightbottom = viewsector->floorplane.ZatPoint(pos);
				}

				if (lightbottom < pos.Z)
				{
					l.cm = lightlist[i].extra_colormap;
					l.lightlevel = hw_ClampLight(*lightlist[i].p_lightlevel);
					break;
				}
			}
		}
		else
		{
			l.cm = fakesec->Colormap;
			if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING) l.cm.ClearColor();
		}

		l.lightlevel = hw_CalcLightLevel(l.lightlevel, getExtraLight(), true, 0);

		if (level.lightmode == 8 || l.lightlevel < 92)
		{
			// Korshun: the way based on max possible light level for sector like in software renderer.
			double min_L = 36.0 / 31.0 - ((l.lightlevel / 255.0) * (63.0 / 31.0)); // Lightlevel in range 0-63
			if (min_L < 0)
				min_L = 0;
			else if (min_L > 1.0)
				min_L = 1.0;

			l.lightlevel = int((1.0 - min_L) * 255);
		}
		else
		{
			l.lightlevel = (2 * l.lightlevel + 255) / 3;
		}
		l.lightlevel = viewsector->CheckSpriteGlow(l.lightlevel, playerpos);
		l.isbelow = fakesec != viewsector && in_area == area_below;
	}

	// Korshun: fullbright fog in opengl, render weapon sprites fullbright (but don't cancel out the light color!)
	if (level.brightfog && ((level.flags&LEVEL_HASFADETABLE) || l.cm.FadeColor != 0))
	{
		l.lightlevel = 255;
	}
	return l;
}

//==========================================================================
//
//
//
//==========================================================================

void HUDSprite::SetBright(bool isbelow)
{
	if (!isbelow)
	{
		cm.MakeWhite();
	}
	else
	{
		// under water areas keep most of their color for fullbright objects
		cm.LightColor.r = (3 * cm.LightColor.r + 0xff) / 4;
		cm.LightColor.g = (3 * cm.LightColor.g + 0xff) / 4;
		cm.LightColor.b = (3 * cm.LightColor.b + 0xff) / 4;
	}
	lightlevel = 255;
}

//==========================================================================
//
// Render Style
//
//==========================================================================

bool HUDSprite::GetWeaponRenderStyle(DPSprite *psp, AActor *playermo, sector_t *viewsector, WeaponLighting &lighting)
{
	auto rs = psp->GetRenderStyle(playermo->RenderStyle, playermo->Alpha);

	visstyle_t vis;

	vis.RenderStyle = STYLE_Count;
	vis.Alpha = rs.second;
	vis.Invert = false;
	playermo->AlterWeaponSprite(&vis);

	alpha = (psp->Flags & PSPF_FORCEALPHA) ? 0.f : vis.Alpha;

	if (vis.RenderStyle != STYLE_Count && !(psp->Flags & PSPF_FORCESTYLE))
	{
		RenderStyle = vis.RenderStyle;
	}
	else
	{
		RenderStyle = rs.first;
	}
	if (RenderStyle.BlendOp == STYLEOP_None) return false;

	if (vis.Invert)
	{
		// this only happens for Strife's inverted weapon sprite
		RenderStyle.Flags |= STYLEF_InvertSource;
	}

	// Set the render parameters

	OverrideShader = -1;
	if (RenderStyle.BlendOp == STYLEOP_Fuzz)
	{
		if (gl_fuzztype != 0)
		{
			// Todo: implement shader selection here
			RenderStyle = LegacyRenderStyles[STYLE_Translucent];
			OverrideShader = SHADER_NoTexture + gl_fuzztype;
			alpha = 0.99f;	// trans may not be 1 here
		}
		else
		{
			RenderStyle.BlendOp = STYLEOP_Shadow;
		}
	}

	if (RenderStyle.Flags & STYLEF_TransSoulsAlpha)
	{
		alpha	= transsouls;
	}
	else if (RenderStyle.Flags & STYLEF_Alpha1)
	{
		alpha = 1.f;
	}
	else if (alpha == 0.f)
	{
		alpha = vis.Alpha;
	}
	if (!RenderStyle.IsVisible(alpha)) return false;	// if it isn't visible skip the rest.

	PalEntry ThingColor = (playermo->RenderStyle.Flags & STYLEF_ColorIsFixed) ? playermo->fillcolor : 0xffffff;
	ThingColor.a = 255;

	const bool bright = isBright(psp);
	ObjectColor = bright ? ThingColor : ThingColor.Modulate(viewsector->SpecialColors[sector_t::sprites]);

	lightlevel = lighting.lightlevel;
	cm = lighting.cm;
	if (bright) SetBright(lighting.isbelow);

	return true;
}

//==========================================================================
//
// Coordinates
//
//==========================================================================

bool HUDSprite::GetWeaponRect(HWDrawInfo *di, DPSprite *psp, float sx, float sy, player_t *player)
{
	float			tx;
	float			scale;
	float			scalex;
	float			ftexturemid;

	// decide which patch to use
	bool mirror;
	FTextureID lump = sprites[psp->GetSprite()].GetSpriteFrame(psp->GetFrame(), 0, 0., &mirror);
	if (!lump.isValid()) return false;

	FMaterial * tex = FMaterial::ValidateTexture(lump, true, false);
	if (!tex) return false;

	float vw = (float)viewwidth;
	float vh = (float)viewheight;

	FloatRect r;
	tex->GetSpriteRect(&r);

	// calculate edges of the shape
	scalex = (320.0f / (240.0f * r_viewwindow.WidescreenRatio)) * vw / 320;

	float x1, y1, x2, y2, u1, v1, u2, v2;

	tx = (psp->Flags & PSPF_MIRROR) ? ((160 - r.width) - (sx + r.left)) : (sx - (160 - r.left));
	x1 = tx * scalex + vw / 2;
	if (x1 > vw)	return false; // off the right side
	x1 += viewwindowx;


	tx += r.width;
	x2 = tx * scalex + vw / 2;
	if (x2 < 0) return false; // off the left side
	x2 += viewwindowx;

	// killough 12/98: fix psprite positioning problem
	ftexturemid = 100.f - sy - r.top - psp->GetYAdjust(screenblocks >= 11);

	scale = (SCREENHEIGHT*vw) / (SCREENWIDTH * 200.0f);
	y1 = viewwindowy + vh / 2 - (ftexturemid * scale);
	y2 = y1 + (r.height * scale) + 1;


	if (!(mirror) != !(psp->Flags & (PSPF_FLIP)))
	{
		u2 = tex->GetSpriteUL();
		v1 = tex->GetSpriteVT();
		u1 = tex->GetSpriteUR();
		v2 = tex->GetSpriteVB();
	}
	else
	{
		u1 = tex->GetSpriteUL();
		v1 = tex->GetSpriteVT();
		u2 = tex->GetSpriteUR();
		v2 = tex->GetSpriteVB();
	}

	auto verts = screen->mVertexData->AllocVertices(4);
	mx = verts.second;

	verts.first[0].Set(x1, y1, 0, u1, v1);
	verts.first[1].Set(x1, y2, 0, u1, v2);
	verts.first[2].Set(x2, y1, 0, u2, v1);
	verts.first[3].Set(x2, y2, 0, u2, v2);

	this->tex = tex;
	return true;
}

//==========================================================================
//
// R_DrawPlayerSprites
//
//==========================================================================

void HWDrawInfo::PreparePlayerSprites(sector_t * viewsector, area_t in_area)
{

	bool brightflash = false;
	AActor * playermo = players[consoleplayer].camera;
	player_t * player = playermo->player;
	const bool hudModelStep = IsHUDModelForPlayerAvailable(player);
    
    const auto &vp = Viewpoint;

	AActor *camera = vp.camera;

	// this is the same as the software renderer
	if (!player ||
		!r_drawplayersprites ||
		!camera->player ||
		(player->cheats & CF_CHASECAM) ||
		(r_deathcamera && camera->health <= 0))
		return;

	WeaponPosition weap = GetWeaponPosition(camera->player, vp.TicFrac);
	WeaponLighting light = GetWeaponLighting(viewsector, vp.Pos, isFullbrightScene(), in_area, camera->Pos());

	// hack alert! Rather than changing everything in the underlying lighting code let's just temporarily change
	// light mode here to draw the weapon sprite.
	int oldlightmode = level.lightmode;
	if (level.lightmode == 8) level.lightmode = 2;

	for (DPSprite *psp = player->psprites; psp != nullptr && psp->GetID() < PSP_TARGETCENTER; psp = psp->GetNext())
	{
		if (!psp->GetState()) continue;
		FSpriteModelFrame *smf = playermo->player->ReadyWeapon ? FindModelFrame(playermo->player->ReadyWeapon->GetClass(), psp->GetState()->sprite, psp->GetState()->GetFrame(), false) : nullptr;
		// This is an 'either-or' proposition. This maybe needs some work to allow overlays with weapon models but as originally implemented this just won't work.
		if (smf && !hudModelStep) continue;
		if (!smf && hudModelStep) continue;

		HUDSprite hudsprite;
		hudsprite.owner = playermo;
		hudsprite.mframe = smf;
		hudsprite.weapon = psp;

		if (!hudsprite.GetWeaponRenderStyle(psp, camera, viewsector, light)) continue;

		FVector2 spos = BobWeapon(weap, psp, vp.TicFrac);

		hudsprite.dynrgb[0] = hudsprite.dynrgb[1] = hudsprite.dynrgb[2] = 0;
		hudsprite.lightindex = -1;
		// set the lighting parameters
		if (hudsprite.RenderStyle.BlendOp != STYLEOP_Shadow && level.HasDynamicLights && !isFullbrightScene() && gl_light_sprites)
		{
			if (!hudModelStep)
			{
				GetDynSpriteLight(playermo, nullptr, hudsprite.dynrgb);
			}
			else
			{
				hw_GetDynModelLight(playermo, lightdata);
				hudsprite.lightindex = screen->mLights->UploadLights(lightdata);
			}
		}

		// [BB] In the HUD model step we just render the model and break out. 
		if (hudModelStep)
		{
			hudsprite.mx = spos.X;
			hudsprite.my = spos.Y;
		}
		else
		{
			if (!hudsprite.GetWeaponRect(this, psp, spos.X, spos.Y, player)) continue;
		}
		hudsprites.Push(hudsprite);
	}
	level.lightmode = oldlightmode;
	PrepareTargeterSprites();
}


//==========================================================================
//
// R_DrawPlayerSprites
//
//==========================================================================

void HWDrawInfo::PrepareTargeterSprites()
{
	AActor * playermo = players[consoleplayer].camera;
	player_t * player = playermo->player;
	AActor *camera = Viewpoint.camera;

	// this is the same as above
	if (!player ||
		!r_drawplayersprites ||
		!camera->player ||
		(player->cheats & CF_CHASECAM) ||
		(r_deathcamera && camera->health <= 0))
		return;

	HUDSprite hudsprite;

	hudsprite.owner = playermo;
	hudsprite.mframe = nullptr;
	hudsprite.cm.Clear();
	hudsprite.lightlevel = 255;
	hudsprite.ObjectColor = 0xffffffff;
	hudsprite.alpha = 1;
	hudsprite.RenderStyle = DefaultRenderStyle();
	hudsprite.OverrideShader = -1;
	hudsprite.dynrgb[0] = hudsprite.dynrgb[1] = hudsprite.dynrgb[2] = 0;

	// The Targeter's sprites are always drawn normally.
	for (DPSprite *psp = player->FindPSprite(PSP_TARGETCENTER); psp != nullptr; psp = psp->GetNext())
	{
		if (psp->GetState() != nullptr && (psp->GetID() != PSP_TARGETCENTER || CrosshairImage == nullptr))
		{
			hudsprite.weapon = psp;
			if (hudsprite.GetWeaponRect(this, psp, psp->x, psp->y, player))
			{
				hudsprites.Push(hudsprite);
			}
		}
	}
}

