/*
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.  
COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/

char palette_rcsid[] = "$Id: palette.c 1.51 1996/10/30 11:33:00 jason Exp $";

#include <conio.h>
#include <stdlib.h>
#include <stdio.h>
#include <io.h>
#include <string.h>

#include "pa_enabl.h"                   //$$POLY_ACC
#include "types.h"
#include "mem.h"
#include "gr.h"
#include "grdef.h"
#include "cfile.h"
#include "error.h"
#include "mono.h"
#include "fix.h"
#include "key.h"

#if defined(POLY_ACC)
#include "poly_acc.h"
#endif

extern int gr_installed;

#define SQUARE(x) ((x)*(x))

#define	MAX_COMPUTED_COLORS	32

int	Num_computed_colors=0;

typedef struct {
	ubyte	r,g,b,color_num;
} color_record;

color_record Computed_colors[MAX_COMPUTED_COLORS];

ubyte gr_palette[256*3];
ubyte gr_current_pal[256*3];
ubyte gr_fade_table[256*34];

// ushort gr_palette_selector;
// ushort gr_fade_table_selector;

ubyte gr_palette_gamma = 0;
int gr_palette_gamma_param = 0;
ubyte gr_palette_faded_out = 1;

//to speed up development
int grd_fades_disabled=0;

void gr_palette_set_gamma( int gamma )
{
	if ( gamma < 0 ) gamma = 0;
	if ( gamma > 8 ) gamma = 8;

	if (gr_palette_gamma_param != gamma )	{
		gr_palette_gamma_param = gamma;
		gr_palette_gamma = gamma;
		if (!gr_palette_faded_out)
			gr_palette_load( gr_palette );
	}	
}

int gr_palette_get_gamma()
{
	return gr_palette_gamma_param;
}


void gr_copy_palette(ubyte *gr_palette, ubyte *pal, int size)
{
	memcpy(gr_palette, pal, size);

	Num_computed_colors = 0;
}

void gr_use_palette_table( char * filename )
{
	CFILE *fp;
	int i,fsize;

	fp = cfopen( filename, "rb" );
	if ( fp==NULL)
		Error("Can't open palette file <%s>",filename);

	fsize	= cfilelength( fp );
	if ( fsize != 9472)
		Error("Palette file <%s> is wrong size",filename);
	cfread( gr_palette, 256*3, 1, fp );
	cfread( gr_fade_table, 256*34, 1, fp );
	cfclose(fp);

	// This is the TRANSPARENCY COLOR
	for (i=0; i<GR_FADE_LEVELS; i++ )	{
		gr_fade_table[i*256+255] = 255;
	}

	Num_computed_colors = 0;	//	Flush palette cache.
#if defined(POLY_ACC)
    pa_update_clut(gr_palette, 0, 256, 0);
#endif
}

//	Add a computed color (by gr_find_closest_color) to list of computed colors in Computed_colors.
//	If list wasn't full already, increment Num_computed_colors.
//	If was full, replace a random one.
void add_computed_color(int r, int g, int b, int color_num)
{
	int	add_index;

	if (Num_computed_colors < MAX_COMPUTED_COLORS) {
		add_index = Num_computed_colors;
		Num_computed_colors++;
	} else
		add_index = (rand() * MAX_COMPUTED_COLORS) >> 15;

	Computed_colors[add_index].r = r;
	Computed_colors[add_index].g = g;
	Computed_colors[add_index].b = b;
	Computed_colors[add_index].color_num = color_num;
}

void init_computed_colors(void)
{
	int	i;

	for (i=0; i<MAX_COMPUTED_COLORS; i++)
		Computed_colors[i].r = 255;		//	Make impossible to match.
}

int gr_find_closest_color( int r, int g, int b )
{
	int i, j;
	int best_value, best_index, value;

	if (Num_computed_colors == 0)
		init_computed_colors();

	//	If we've already computed this color, return it!
	for (i=0; i<Num_computed_colors; i++)
		if (r == Computed_colors[i].r)
			if (g == Computed_colors[i].g)
				if (b == Computed_colors[i].b) {
					if (i > 4) {
						color_record	trec;
						trec = Computed_colors[i-1];
						Computed_colors[i-1] = Computed_colors[i];
						Computed_colors[i] = trec;
						return Computed_colors[i-1].color_num;
					}
					return Computed_colors[i].color_num;
				}

//	r &= 63;
//	g &= 63;
//	b &= 63;

	best_value = SQUARE(r-gr_palette[0])+SQUARE(g-gr_palette[1])+SQUARE(b-gr_palette[2]);
	best_index = 0;
	if (best_value==0) {
		add_computed_color(r, g, b, best_index);
 		return best_index;
	}
	j=0;
	// only go to 255, 'cause we dont want to check the transparent color.
	for (i=1; i<254; i++ )	{
		j += 3;
		value = SQUARE(r-gr_palette[j])+SQUARE(g-gr_palette[j+1])+SQUARE(b-gr_palette[j+2]);
		if ( value < best_value )	{
			if (value==0) {
				add_computed_color(r, g, b, i);
				return i;
			}
			best_value = value;
			best_index = i;
		}
	}
	add_computed_color(r, g, b, best_index);
	return best_index;
}

int gr_find_closest_color_15bpp( int rgb )
{
	return gr_find_closest_color( ((rgb>>10)&31)*2, ((rgb>>5)&31)*2, (rgb&31)*2 );
}


int gr_find_closest_color_current( int r, int g, int b )
{
	int i, j;
	int best_value, best_index, value;

//	r &= 63;
//	g &= 63;
//	b &= 63;

	best_value = SQUARE(r-gr_current_pal[0])+SQUARE(g-gr_current_pal[1])+SQUARE(b-gr_current_pal[2]);
	best_index = 0;
	if (best_value==0)
 		return best_index;

	j=0;
	// only go to 255, 'cause we dont want to check the transparent color.
	for (i=1; i<254; i++ )	{
		j += 3;
		value = SQUARE(r-gr_current_pal[j])+SQUARE(g-gr_current_pal[j+1])+SQUARE(b-gr_current_pal[j+2]);
		if ( value < best_value )	{
			if (value==0)
				return i;
			best_value = value;
			best_index = i;
		}
	}
	return best_index;
}


static int last_r=0, last_g=0, last_b=0;

void gr_palette_step_up( int r, int g, int b )
{
	int i;
	ubyte *p;
	int temp;

	if (gr_palette_faded_out) return;

#if !defined(POLY_ACC)      // need this called always.
	if ( (r==last_r) && (g==last_g) && (b==last_b) ) return;
#endif

	last_r = r;
	last_g = g;
	last_b = b;
#if defined(POLY_ACC)
    if ( (r==0) && (g==0) && (b==0) ) return;
	 PA_DFX (pa_set_backbuffer_current());	
    pa_step_up(r, g, b);
    return; //POLY_ACC
#endif

	outp( 0x3c6, 0xff );
	outp( 0x3c8, 0 );
	p=gr_palette;
	for (i=0; i<256; i++ )	{
		temp = (int)(*p++) + r + gr_palette_gamma;
		if (temp<0) temp=0;
		else if (temp>63) temp=63;
		outp( 0x3c9, temp );
		temp = (int)(*p++) + g + gr_palette_gamma;
		if (temp<0) temp=0;
		else if (temp>63) temp=63;
		outp( 0x3c9, temp );
		temp = (int)(*p++) + b + gr_palette_gamma;
		if (temp<0) temp=0;
		else if (temp>63) temp=63;
		outp( 0x3c9, temp );
	}
}

// This steps up all gun values, leaving black and white to always be black and white.
void gr_palette_step_up_vr( int r, int g, int b, int white_index, int black_index )
{
	int i;
	ubyte *p;
	int temp;

	if (gr_palette_faded_out) return;

	if ( (r==last_r) && (g==last_g) && (b==last_b) ) return;

	last_r = r;
	last_g = g;
	last_b = b;
#if defined(POLY_ACC)
    return; //POLY_ACC
#endif

	outp( 0x3c6, 0xff );
	outp( 0x3c8, 0 );
	p=gr_palette;
	for (i=0; i<256; i++ )	{
		temp = (int)(*p++) + r + gr_palette_gamma;
		if (temp<0) temp=0;
		else if (temp>63) temp=63;
		if ( i==white_index )	temp = 63;
		else if ( i==black_index ) temp = 0;
		outp( 0x3c9, temp );
		temp = (int)(*p++) + g + gr_palette_gamma;
		if (temp<0) temp=0;
		else if (temp>63) temp=63;
		if ( i==white_index )	temp = 63;
		else if ( i==black_index ) temp = 0;
		outp( 0x3c9, temp );
		temp = (int)(*p++) + b + gr_palette_gamma;
		if (temp<0) temp=0;
		else if (temp>63) temp=63;
		if ( i==white_index )	temp = 63;
		else if ( i==black_index ) temp = 0;
		outp( 0x3c9, temp );
	}
}


void gr_palette_clear()
{
	int i;
#if !defined(POLY_ACC)
	outp( 0x3c6, 0xff );
	outp( 0x3c8, 0 );
	for (i=0; i<768; i++ )	{
		outp( 0x3c9, 0 );
	}
#endif
	gr_palette_faded_out = 1;
}

void gr_palette_load( ubyte * pal )	
{
	int i;
	ubyte c;
#if !defined(POLY_ACC)
	outp( 0x3c6, 0xff );
	outp( 0x3c8, 0 );
	for (i=0; i<768; i++ )	{
		c = pal[i] + gr_palette_gamma;
		if ( c > 63 ) c = 63;
		outp( 0x3c9,c);
 		gr_current_pal[i] = pal[i];
	}
#else
	for (i=0; i<768; i++ )  {
        c = pal[i] + gr_palette_gamma;
        if ( c > 63 ) c = 63;
        gr_current_pal[i] = c;
	}
	pa_update_clut(gr_current_pal, 0, 256, 0);
#endif
	gr_palette_faded_out = 0;

//	init_computed_colors();
}

extern void gr_sync_display(void);

int gr_palette_fade_out(ubyte *pal, int nsteps, int allow_keys )	
{
	ubyte c;
	int i,j;
	fix fade_palette[768];
	fix fade_palette_delta[768];

	allow_keys  = allow_keys;

	if (gr_palette_faded_out) return 0;

	#ifndef NDEBUG
	if (grd_fades_disabled) {
		gr_palette_clear();
		return 0;
	}
	#endif

#if defined(POLY_ACC)
        return 0;
#endif

	for (i=0; i<768; i++ )	{
		fade_palette[i] = i2f(pal[i]+gr_palette_gamma);
		fade_palette_delta[i] = fade_palette[i] / nsteps;
	}

	for (j=0; j<nsteps; j++ )	{
		gr_sync_display();
		outp( 0x3c6, 0xff );
		outp( 0x3c8, 0 );
		for (i=0; i<768; i++ )	{		
			fade_palette[i] -= fade_palette_delta[i];
			if (fade_palette[i] < 0 )
				fade_palette[i] = 0;
			c = f2i(fade_palette[i]);
			if ( c > 63 ) c = 63;
			outp( 0x3c9, c );								
		}
	}
	gr_palette_faded_out = 1;
	return 0;
}

int gr_palette_fade_in(ubyte *pal, int nsteps, int allow_keys)	
{
	int i,j;
	ubyte c;
	fix fade_palette[768];
	fix fade_palette_delta[768];

	allow_keys  = allow_keys;

	if (!gr_palette_faded_out) return 0;

	#ifndef NDEBUG
	if (grd_fades_disabled) {
		gr_palette_load(pal);
		return 0;
	}
	#endif

#if defined(POLY_ACC)
        gr_palette_load(pal);
		return 0;
#endif

	for (i=0; i<768; i++ )	{
		gr_current_pal[i] = pal[i];
		fade_palette[i] = 0;
		fade_palette_delta[i] = i2f(pal[i]+gr_palette_gamma) / nsteps;
	}

	for (j=0; j<nsteps; j++ )	{
		gr_sync_display();
		outp( 0x3c6, 0xff );
		outp( 0x3c8, 0 );
		for (i=0; i<768; i++ )	{		
			fade_palette[i] += fade_palette_delta[i];
			if (fade_palette[i] > i2f(pal[i]+gr_palette_gamma) )
				fade_palette[i] = i2f(pal[i]+gr_palette_gamma);
			c = f2i(fade_palette[i]);
			if ( c > 63 ) c = 63;
			outp( 0x3c9, c );								
		}
	}
	gr_palette_faded_out = 0;
	return 0;
}

void gr_make_cthru_table(ubyte * table, ubyte r, ubyte g, ubyte b )
{
	int i;
	ubyte r1, g1, b1;

	for (i=0; i<256; i++ )	{
		r1 = gr_palette[i*3+0] + r;
		if ( r1 > 63 ) r1 = 63;
		g1 = gr_palette[i*3+1] + g;
		if ( g1 > 63 ) g1 = 63;
		b1 = gr_palette[i*3+2] + b;
		if ( b1 > 63 ) b1 = 63;
		table[i] = gr_find_closest_color( r1, g1, b1 );
	}
}

void gr_palette_read(ubyte * palette)
{
	int i;

#if defined(POLY_ACC)
    for(i = 0; i != 256; ++i)
    {
        *palette++ = (pa_clut[i] >> 9) & 0x3E;
        *palette++ = (pa_clut[i] >> 4) & 0x3E;
        *palette++ = (pa_clut[i] << 1) & 0x3E;
    }
#else
	outp( 0x3c6, 0xff );
	outp( 0x3c7, 0 );
	for (i=0; i<768; i++ )	{
		*palette++ = inp( 0x3c9 );
	}
#endif

}