/*
	This file includes miscellaneous plot functions and logic
	for 3D, used by lorenz.c and line3d.c
	By Tim Wegner and Marc Reinig.
*/

#include <stdio.h>
#include "fractint.h"
#include "fractype.h"

/* Use these palette indices for red/blue - same on ega/vga */
#define PAL_BLUE	1
#define PAL_RED	2
#define PAL_MAGENTA	3

extern int _fastcall targa_color(int x,int y,int color);
extern int Targa_Out, sxoffs, syoffs;

int whichimage;
extern int fractype;
extern int mapset;
extern int xadjust;
extern int yadjust;
extern int xxadjust;
extern int yyadjust;
extern int xshift;
extern int yshift;
extern char MAP_name[];
extern int init3d[];
extern int xdots;
extern int ydots;
extern int colors;
extern unsigned char dacbox[256][3];
extern int debugflag;

extern int max_colors;

int xxadjust1;
int yyadjust1;
int eyeseparation = 0;
int glassestype = 0;
int xshift1;
int yshift1;
int xtrans = 0;
int ytrans = 0;
int red_local_left;
int red_local_right;
int blue_local_left;
int blue_local_right;
int red_crop_left	= 4;
int red_crop_right	= 0;
int blue_crop_left	= 0;
int blue_crop_right = 4;
int red_bright		= 80;
int blue_bright		= 100;
  
unsigned char T_RED;

/* Bresenham's algorithm for drawing line */
void _fastcall draw_line (int X1, int Y1, int X2, int Y2, int color)

{				/* uses Bresenham algorithm to draw a line */
	int dX, dY;						/* vector components */
	int row, col,
		final,						/* final row or column number */
		G,					/* used to test for new row or column */
		inc1,			/* G increment when row or column doesn't change */
		inc2;				/* G increment when row or column changes */
	char pos_slope;
	extern int xdots,ydots;

	dX = X2 - X1;					/* find vector components */
	dY = Y2 - Y1;
	pos_slope = (dX > 0);					/* is slope positive? */
	if (dY < 0)
	pos_slope = !pos_slope;
	if (abs (dX) > abs (dY))				/* shallow line case */
	{
		if (dX > 0)			/* determine start point and last column */
		{
			col = X1;
			row = Y1;
			final = X2;
		}
		else
		{
			col = X2;
			row = Y2;
			final = X1;
		}
		inc1 = 2 * abs (dY);			/* determine increments and initial G */
		G = inc1 - abs (dX);
		inc2 = 2 * (abs (dY) - abs (dX));
		if (pos_slope)
			while (col <= final)	/* step through columns checking for new row */
			{
				(*plot) (col, row, color);
				col++;
				if (G >= 0)				/* it's time to change rows */
				{
					row++;		/* positive slope so increment through the rows */
					G += inc2;
				}
				else						/* stay at the same row */
					G += inc1;
			}
		else
			while (col <= final)	/* step through columns checking for new row */
			{
				(*plot) (col, row, color);
				col++;
				if (G > 0)				/* it's time to change rows */
				{
					row--;		/* negative slope so decrement through the rows */
					G += inc2;
				}
				else						/* stay at the same row */
					G += inc1;
			}
	}	/* if |dX| > |dY| */
	else							/* steep line case */
	{
		if (dY > 0)				/* determine start point and last row */
		{
			col = X1;
			row = Y1;
			final = Y2;
		}
		else
		{
			col = X2;
			row = Y2;
			final = Y1;
		}
		inc1 = 2 * abs (dX);			/* determine increments and initial G */
		G = inc1 - abs (dY);
		inc2 = 2 * (abs (dX) - abs (dY));
		if (pos_slope)
			while (row <= final)	/* step through rows checking for new column */
			{
				(*plot) (col, row, color);
				row++;
				if (G >= 0)					/* it's time to change columns */
				{
					col++;	/* positive slope so increment through the columns */
					G += inc2;
				}
				else					/* stay at the same column */
					G += inc1;
			}
		else
			while (row <= final)	/* step through rows checking for new column */
			{
				(*plot) (col, row, color);
				row++;
				if (G > 0)					/* it's time to change columns */
				{
					col--;	/* negative slope so decrement through the columns */
					G += inc2;
				}
				else					/* stay at the same column */
					G += inc1;
			}
	}
}	/* draw_line */


/* use this for continuous colors later */
void _fastcall plot3dsuperimpose16b(int x,int y,int color)
{
	int tmp;
	if (color != 0)			/* Keeps index 0 still 0 */
	{
		color = colors - color; /*	Reverses color order */
		color = color / 4;
		if(color == 0)
			color = 1;
	}
	color = 3;
	tmp = getcolor(x,y);

	/* map to 4 colors */
	if(whichimage == 1) /* RED */
	{
		if(red_local_left < x && x < red_local_right)
		{
			putcolor(x,y,color|tmp);
			if (Targa_Out)								
				targa_color(x, y, color|tmp);
		}
	}
	else if(whichimage == 2) /* BLUE */
		if(blue_local_left < x && x < blue_local_right)
		{
			color = color <<2;
			putcolor(x,y,color|tmp);
			if (Targa_Out)								
				targa_color(x, y, color|tmp);
		}
}

void _fastcall plot3dsuperimpose16(int x,int y,int color)
{
	int tmp;

	tmp = getcolor(x,y);

	if(whichimage == 1) /* RED */
	{
		color = PAL_RED;
		if(tmp > 0 && tmp != color)
			color = PAL_MAGENTA;
		if(red_local_left < x && x < red_local_right)
		{
			putcolor(x,y,color);
			if (Targa_Out)								
				targa_color(x, y, color);
		}
	}
	else if(whichimage == 2) /* BLUE */
		if(blue_local_left < x && x < blue_local_right)
		{
			color = PAL_BLUE;
			if(tmp > 0 && tmp != color)
				color = PAL_MAGENTA;
			putcolor(x,y,color);
			if (Targa_Out)								
				targa_color(x, y, color);
		}
}


void _fastcall plot3dsuperimpose256(int x,int y,int color)
{
	int tmp;
	unsigned char t_c;

	t_c = 255-color;

	if (color != 0)			/* Keeps index 0 still 0 */
	{
		color = colors - color; /*	Reverses color order */
	    if (max_colors == 236)
		color = 1 + color / 21; /*	Maps colors 1-255 to 13 even ranges */
	    else
		color = 1 + color / 18; /*	Maps colors 1-255 to 15 even ranges */
	}

	tmp = getcolor(x,y);
	/* map to 16 colors */
	if(whichimage == 1) /* RED */
	{
		if(red_local_left < x && x < red_local_right)
		{
			/* Overwrite prev Red don't mess w/blue */
			putcolor(x,y,color|(tmp&240));
			if (Targa_Out)
				if (!ILLUMINE)
					targa_color(x, y, color|(tmp&240));
				else
					targa_writedisk (x+sxoffs, y+syoffs, t_c, 0, 0);
		}
	}
	else if(whichimage == 2) /* BLUE */
		if(blue_local_left < x && x < blue_local_right)
		{
			/* Overwrite previous blue, don't mess with existing red */
			color = color <<4;
			putcolor(x,y,color|(tmp&15));
			if (Targa_Out)								
				if (!ILLUMINE)
					targa_color(x, y, color|(tmp&15));
				else
				{
					targa_readdisk (x+sxoffs, y+syoffs, &T_RED, &tmp, &tmp);
					targa_writedisk (x+sxoffs, y+syoffs, T_RED, 0, t_c);
				}
		}
}

void _fastcall plotIFS3dsuperimpose256(int x,int y,int color)
{
	int tmp;
	unsigned char t_c;

	t_c = 255-color;

	if (color != 0)			/* Keeps index 0 still 0 */
	{
		/* my mind is fried - lower indices = darker colors is EASIER! */
		color = colors - color; /*	Reverses color order */
	    if (max_colors == 236)
		color = 1 + color / 21; /*	Maps colors 1-255 to 13 even ranges */
	    else
		color = 1 + color / 18; /*	Looks weird but maps colors 1-255 to 15
					relatively even ranges */
	}

	tmp = getcolor(x,y);
	/* map to 16 colors */
	if(whichimage == 1) /* RED */
	{
		if(red_local_left < x && x < red_local_right)
		{
			putcolor(x,y,color|tmp);
			if (Targa_Out)								
				if (!ILLUMINE)
					targa_color(x, y, color|tmp);
				else
					targa_writedisk (x+sxoffs, y+syoffs, t_c, 0, 0);
		}
	}
	else if(whichimage == 2) /* BLUE */
		if(blue_local_left < x && x < blue_local_right)
		{
			color = color <<4;
			putcolor(x,y,color|tmp);
			if (Targa_Out)								
				if (!ILLUMINE)
					targa_color(x, y, color|tmp);
				else
				{
					targa_readdisk (x+sxoffs, y+syoffs, &T_RED, &tmp, &tmp);
					targa_writedisk (x+sxoffs, y+syoffs, T_RED, 0, t_c);
				}
		}
}

void _fastcall plot3dalternate(int x,int y,int color)
{
	int tmp;
	unsigned char t_c;

	t_c = 255-color;
	/* lorez high color red/blue 3D plot function */
	/* if which image = 1, compresses color to lower 128 colors */

	/* my mind is STILL fried - lower indices = darker colors is EASIER! */
	color = colors - color;
	if((whichimage == 1) && !((x+y)&1)) /* - lower half palette */
	{
		if(red_local_left < x && x < red_local_right)
		{
			putcolor(x,y,color>>1);
			if (Targa_Out)								
				if (!ILLUMINE)
					targa_color(x, y, color>>1);
				else
					targa_writedisk (x+sxoffs, y+syoffs, t_c, &tmp, &tmp);
		}
	}
	else if((whichimage == 2) && ((x+y)&1) ) /* - upper half palette */
	{
		if(blue_local_left < x && x < blue_local_right)
		{
			putcolor(x,y,(color>>1)+(colors>>1));
			if (Targa_Out)								
				if (!ILLUMINE)
					targa_color(x, y, (color>>1)+(colors>>1));
				else
					targa_writedisk (x+sxoffs, y+syoffs, T_RED, 0, t_c);
		}
	}
}

void plot_setup()
{
	double d_red_bright, d_blue_bright;
	int i;

	/* set funny glasses plot function */
	switch(glassestype)
	{
	case 1:
		standardplot = plot3dalternate;
		break;

	case 2:
		if(colors == 256)
			if (fractype != IFS3D)
			{
				standardplot = plot3dsuperimpose256;
			}
			else
				standardplot = plotIFS3dsuperimpose256;
		else
		  	standardplot = plot3dsuperimpose16;
		break;

	default:
		standardplot = putcolor;
		break;
	}

	xshift1 = xshift = (XSHIFT * (double)xdots)/100;
	yshift1 = yshift = (YSHIFT * (double)ydots)/100;

	if(glassestype)
	{
		red_local_left	=	(red_crop_left		* (double)xdots)/100.0;
		red_local_right	=	((100 - red_crop_right)	* (double)xdots)/100.0;
		blue_local_left	=	(blue_crop_left		* (double)xdots)/100.0;
		blue_local_right =	((100 - blue_crop_right) * (double)xdots)/100.0;
		d_red_bright	=	(double)red_bright/100.0;
		d_blue_bright	=	(double)blue_bright/100.0;

		switch(whichimage)
		{
		case 1:
			xshift	+= (eyeseparation* (double)xdots)/200;
			xxadjust = ((xtrans+xadjust)* (double)xdots)/100;
			xshift1	-= (eyeseparation* (double)xdots)/200;
			xxadjust1 = ((xtrans-xadjust)* (double)xdots)/100;
			break;

		case 2:
			xshift	-= (eyeseparation* (double)xdots)/200;
			xxadjust = ((xtrans-xadjust)* (double)xdots)/100;
			break;
		}
	}
	else
		xxadjust = (xtrans* (double)xdots)/100;
		yyadjust = -(ytrans* (double)ydots)/100;

	if (mapset)
	{
		ValidateLuts(MAP_name);	/* read the palette file */
		if(glassestype==1 || glassestype==2)
		{
			if(glassestype == 2 && colors < 256)
			{
				dacbox[PAL_RED	][0] = 63;
				dacbox[PAL_RED	][1] =	0;
				dacbox[PAL_RED	][2] =	0;

				dacbox[PAL_BLUE	][0] =	0;
				dacbox[PAL_BLUE	][1] =	0;
				dacbox[PAL_BLUE	][2] = 63;

				dacbox[PAL_MAGENTA][0] = 63;
				dacbox[PAL_MAGENTA][1] =	0;
				dacbox[PAL_MAGENTA][2] = 63;
			}
			for (i=0;i<256;i++)
			{
				dacbox[i][0] = dacbox[i][0] * d_red_bright;
				dacbox[i][2] = dacbox[i][2] * d_blue_bright;
			}
		}
		spindac(0,1); /* load it, but don't spin */
	}
}