//	-*- Mode: C++ -*-
//	navi2ppm.cc
//	
//	Navier-Stokes Animation Maker
//

#include "navi.h"
#include "Imag.h"

class NaviPpm : public ImagBuf {
public:
	
	int	xUnit,	yUnit;
	Bool	bDisplayRotation,
		bDisplayStream;
	int	nLinePoints;
	
	NaviPpm (void)
	{
		xUnit = 6;
		yUnit = 6;
		bDisplayRotation = True;
		bDisplayStream = True;
		nLinePoints = (xUnit > yUnit ? xUnit : yUnit) * 5 / 4;
	}
	
	void DrawRotationDensity (const NavierStokes & F)
	{
		// Draw rotation density
		for (int yFine = 0 ; yFine < ySize ; yFine++){
		    for (int xFine = 0 ; xFine < xSize ; xFine++) {
			
			Point	p = F.fldCurrent.value (xFine/xUnit, yFine/yUnit);
			Real	z = 0.1 * p.z;
			RGB	col (z,0,-z);
			
			switch (p.b) {
			case Point::SOLID:
				col = RGB (0.0,1.0,0.0);
				break;
			case Point::FREE_SURFACE:
				col = RGB (0.0,0.6,0.0);
				break;
			}
			
			set (xFine,yFine, col);
		    }
		}
	}
	
	void putLine (int x1, int y1, int x2, int y2)
	{
		int	nMax = nLinePoints;
		for (int n = 0 ; n < nMax ; n++) {
			Real	a = (double) n / (nMax - 1);
			int	x = (int) (x1 + a * (x2-x1)),
				y = (int) (y1 + a * (y2-y1));
			set (x,y, RGB (1,1,1));
		}
	}
	
	
	static inline Bool XOR (Bool a, Bool b)
	{
		return	( !a && b ) || ( a && !b );
	}
	void DrawSubContour (const NavierStokes & F, int x, int y)
	{
		for (int fm = 0 ; fm <= F.yMax ; fm++) {
			
			Real	f = (Real) fm * F.vx * F.dy;
			
			Real	f1 = F.fldCurrent.value (x  ,y  ).f,
				f2 = F.fldCurrent.value (x+1,y  ).f,
				f3 = F.fldCurrent.value (x+1,y+1).f,
				f4 = F.fldCurrent.value (x  ,y+1).f;
			
			Bool	ma1 = (f1 > f),
				ma2 = (f2 > f),
				ma3 = (f3 > f),
				ma4 = (f4 > f),
				m1 = XOR (ma1, ma2),
				m2 = XOR (ma2, ma3),
				m3 = XOR (ma3, ma4),
				m4 = XOR (ma4, ma1);
			
			Real	small = 0.0000000001;
			if (fabs(f2-f1) < small)
				m1 = False;
			if (fabs(f3-f2) < small)
				m2 = False;
			if (fabs(f3-f4) < small)
				m3 = False;
			if (fabs(f4-f1) < small)
				m4 = False;
			
			if (!( m1 || m2 || m3 || m4 ))
				continue;
			
			int	X = x * xUnit + xUnit / 2,
				Y = y * yUnit + yUnit / 2,
				dx = xUnit,
				dy = yUnit;
			
			int	x1,	x2,	x3,	x4,
				y1,	y2,	y3,	y4;
			
			if (m1) {
				x1 = (int) (X + (f-f1)/(f2-f1)*dx);
				y1 = (int) Y;
			}
			if (m2) {
				x2 = (int) (X + dx);
				y2 = (int) (Y + (f-f2)/(f3-f2)*dy);
			}
			if (m3) {
				x3 = (int) (X + (f-f4)/(f3-f4)*dx);
				y3 = (int) (Y + dy);
			}
			if (m4) {
				x4 = (int) X;
				y4 = (int) (Y + (f-f1)/(f4-f1)*dy);
			}
			if (m1 && m2)
				putLine (x1,y1, x2,y2);
			if (m1 && m3)
				putLine (x1,y1, x3,y3);
			if (m1 && m4)
				putLine (x1,y1, x4,y4);
			if (m2 && m3)
				putLine (x2,y2, x3,y3);
			if (m2 && m4)
				putLine (x2,y2, x4,y4);
			if (m3 && m4)
				putLine (x3,y3, x4,y4);
		}
	}
	void DrawStreamLine (const NavierStokes & F)
	{
		for (int y = 0 ; y < F.yMax ; y++){
		    for (int x = 0 ; x < F.xMax ; x++) {
			Point::BoundaryType	b = F.fldCurrent.value (x,y).b;
			
			switch (b) {
			case Point::FREE:
			case Point::UP_SURFACE:
			case Point::DOWN_SURFACE:
			case Point::RIGHT_SURFACE:
			case Point::LEFT_SURFACE:
		//	case Point::FREE_SURFACE:
				DrawSubContour (F, x,y);
			}
		    }
		}
	
	}
	
	void draw (const NavierStokes & F)
	{
		setSize (F.xMax*xUnit, F.yMax*yUnit);
		// Draw rotation density
		if (bDisplayRotation)
			DrawRotationDensity (F);
		
		// Draw Conter of stream function
		if (bDisplayStream)
			DrawStreamLine (F);
	}
};


void main (int nArgc, char *pszArgv[])
{
	NavierStokes	F;
	int		nStart = 0,	nEnd = -1;
	
	String	szMessage =
		"Available options: [-start ##] [-end ##] [-file FILE_NAME]\n";
	
	pszArgv++;
	for (; nArgc > 1  && (*pszArgv)[0] == '-' ; nArgc--, pszArgv++) {
		if (!strcmp (*pszArgv, "-start")) {
			nArgc--;
			pszArgv++;
			if (nArgc <= 0)
				Error (szMessage);
			nStart = atoi (*pszArgv);
			continue;
		}
		if (!strcmp (*pszArgv, "-end")) {
			nArgc--;
			pszArgv++;
			if (nArgc <= 0)
				Error (szMessage);
			nEnd = atoi (*pszArgv);
			continue;
		}
		if (!strcmp (*pszArgv, "-file")) {
			nArgc--;
			pszArgv++;
			if (nArgc <= 0)
				Error (szMessage);
			F.szLoadFileName = *pszArgv;
			continue;
		}
		Error (szMessage);
	}
	
	NaviPpm		imag;
	
	cerr << "Data File Name is <" << F.szLoadFileName << ">" << endl;
	
	for (int n = 0 ; F.ReadFileOneUnit () ; n++) {
		
		if (n < nStart)
			continue;
		if (0 <= nEnd && nEnd < n)
			break;
		
		imag.draw (F);
		
		char	szFileNameHead [64];
		sprintf (szFileNameHead, "x%03d", n);
		imag.putImag (szFileNameHead);
	}
}