// Ryzom - MMORPG Framework <http://dev.ryzom.com/projects/ryzom/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "stdpch.h"
#include "view_polygon.h"
#include "view_renderer.h"
#include "interface_manager.h"


using namespace NLMISC;

// *********************************************************************************
CViewPolygon::CViewPolygon() : CViewBase(TCtorParam())
{
	// Construct
	_Color = CRGBA::White;
}


// *********************************************************************************
void CViewPolygon::setVertices(const std::vector<NLMISC::CVector> &vertices)
{
	if (vertices.size() == _Poly.Vertices.size() &&
		std::equal(vertices.begin(), vertices.end(), _Poly.Vertices.begin())) return; // remains unchanged
	_Poly.Vertices = vertices;
	_Tris.clear();
	std::list<CPolygon> polys;
	if (_Poly.toConvexPolygons(polys, NLMISC::CMatrix::Identity))
	{
		_Tris.clear();
		for(std::list<CPolygon>::iterator it = polys.begin(); it != polys.end(); ++it)
		{
			it->toTriFan(_Tris);
		}
	}
	else
	{
		nlwarning("CViewPolygon : conversion to conex polygons failed");
		_Tris.clear();
	}
	_Touched = true;
}


static inline bool totallyInside(const CVector &minCorner, const CVector &maxCorner, sint32 cx, sint32 cy, sint32 cw, sint32 ch)
{
	return (sint32) maxCorner.x < (cx + cw) &&
			(sint32) minCorner.x >= cx &&
			(sint32) maxCorner.y < (cy + ch) &&
			(sint32) minCorner.y >= cy;
}

static inline bool totallyOutside(const CVector &minCorner, const CVector &maxCorner, sint32 cx, sint32 cy, sint32 cw, sint32 ch)
{
	return (sint32) minCorner.x >= (cx + cw) ||
			(sint32) maxCorner.x < cx ||
			(sint32) minCorner.y >= (cy + ch) ||
			(sint32) maxCorner.y < cy;
}

// *********************************************************************************
void CViewPolygon::draw()
{
	if (_Tris.empty()) return;
	if (!_Parent) return;
	CInterfaceManager *im = CInterfaceManager::getInstance();
	CViewRenderer &vr = im->getViewRenderer();
	if (_Touched)
	{
		_RealTris.clear();
		uint numTris = (uint)_Tris.size();
		sint32 cornerX, cornerY;
		static std::vector<NLMISC::CTriangle> winTris;
		winTris.resize(numTris);
		_Parent->getCorner(cornerX, cornerY, _ParentPosRef);
		for(uint k = 0; k < numTris; ++k)
		{
			winTris[k].V0.set((float) (_Tris[k].V0.x + cornerX), (float) (_Tris[k].V0.y + cornerY), 0.f);
			winTris[k].V1.set((float) (_Tris[k].V1.x + cornerX), (float) (_Tris[k].V1.y + cornerY), 0.f);
			winTris[k].V2.set((float) (_Tris[k].V2.x + cornerX), (float) (_Tris[k].V2.y + cornerY), 0.f);
		}
		// recompute & reclip poly
		_RealTris.clear();
		sint32 cx, cy, cw, ch;
		vr.getClipWindow(cx, cy, cw, ch);
		// per tri clip
		NLMISC::CVector minCorner;
		NLMISC::CVector maxCorner;
		for(uint k = 0; k < numTris; ++k)
		{
			winTris[k].getMinCorner(minCorner);
			winTris[k].getMaxCorner(maxCorner);
			if (totallyOutside(minCorner, maxCorner, cx, cy, cw, ch)) continue;
			if (totallyInside(minCorner, maxCorner, cx, cy, cw, ch))
			{
				_RealTris.push_back(winTris[k]);
			}
			else
			{
				const uint maxNumCorners = 8;
				static CVector	outPos0[maxNumCorners];
				static CVector	outPos1[maxNumCorners];
				//
				outPos0[0] = winTris[k].V0;
				outPos0[1] = winTris[k].V1;
				outPos0[2] = winTris[k].V2;
				//
				CVector *pPos0 = outPos0;
				CVector *pPos1 = outPos1;
				//
				sint count = 3;
				//
				if ((sint32) minCorner.x < cx)
				{
					// clip left
					CPlane clipper(-1.f, 0.f, 0.f, (float) cx);
					count = clipper.clipPolygonBack(pPos0, pPos1, count);
					std::swap(pPos0, pPos1);
				}
				if ((sint32) maxCorner.x > cx + cw)
				{
					// clip right
					CPlane clipper(1.f, 0.f, 0.f, - (float) (cx + cw));
					count = clipper.clipPolygonBack(pPos0, pPos1, count);
					std::swap(pPos0, pPos1);
				}
				//
				if ((sint32) minCorner.y < cy)
				{
					// clip bottom
					CPlane clipper(0.f, -1.f, 0.f, (float) cy);
					count = clipper.clipPolygonBack(pPos0, pPos1, count);
					std::swap(pPos0, pPos1);
				}
				if ((sint32) maxCorner.y > cy + ch)
				{
					// clip top
					CPlane clipper(0.f, 1.f, 0.f, - (float) (cy + ch));
					count = clipper.clipPolygonBack(pPos0, pPos1, count);
					std::swap(pPos0, pPos1);
				}
				nlassert(count <= 8);
				if (count >= 3)
				{
					for(uint k = 0; k < (uint) (count - 2); ++k)
					{
						_RealTris.push_back(NLMISC::CTriangle(pPos0[0], pPos0[k + 1], pPos0[k + 2]));
					}
				}
			}
		}
		_Touched = false;
	}
	if (_RealTris.empty()) return;
	CRGBA col;
	if(getModulateGlobalColor())
	{
		col.modulateFromColor (_Color, im->getGlobalColorForContent());
	}
	else
	{
		col= _Color;
		col.A = (uint8)(((sint32)col.A*((sint32)im->getGlobalColorForContent().A+1))>>8);
	}
	vr.drawUnclippedTriangles(_RenderLayer, _RealTris, col);
}

// *********************************************************************************
void CViewPolygon::updateCoords()
{
	// assume that clipping will have to be done again, real update of triangle will be done at render time
	_Touched = true;
}

// *********************************************************************************
void CViewPolygon::setAlpha(sint32 a)
{
	_Color.A = (uint8) a;
}