/*
 *   O2EM Free Odyssey2 / Videopac+ Emulator
 *
 *   Created by Daniel Boris <dboris@comcast.net>  (c) 1997,1998
 *
 *   Developed by Andre de la Rocha   <adlroc@users.sourceforge.net>
 *             Arlindo M. de Oliveira <dgtec@users.sourceforge.net>
 *
 *   http://o2em.sourceforge.net
 *
 *
 *
 *   O2 Video Display Controller emulation
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "types.h"
#include "vmachine.h"
#include "config.h"
#include "keyboard.h"
#include "cset.h"
#include "cpu.h"
#include "vpp.h"
#include "vdc.h"
#include "audio.h"
#include "voice.h"
#include "bitmap.h"

#define COL_SP0 0x01
#define COL_SP1 0x02
#define COL_SP2 0x04
#define COL_SP3 0x08
#define COL_VGRID 0x10
#define COL_HGRID 0x20
#define COL_VPP 0x40
#define COL_CHAR 0x80

#define X_START 8
#define Y_START 24

static const uint32_t colortable[2][16] = {
	/* O2 palette */
	{0x000000, 0x0e3dd4, 0x00981b, 0x00bbd9, 0xc70008, 0xcc16b3, 0x9d8710,
	 0xe1dee1, 0x5f6e6b, 0x6aa1ff, 0x3df07a, 0x31ffff, 0xff4255, 0xff98ff,
	 0xd9ad5d, 0xffffff},
	/* VP+ G7400 palette */
	{0x000000, 0x0000b6, 0x00b600, 0x00b6b6, 0xb60000, 0xb600b6, 0xb6b600,
	 0xb6b6b6, 0x494949, 0x4949ff, 0x49ff49, 0x49ffff, 0xff4949, 0xff49ff,
	 0xffff49, 0xffffff}};

static Bitmap* bitmap;

/* Collision buffer */
static Byte *col = NULL;

/* The pointer to the graphics buffer */
static Byte *vscreen = NULL;

static int cached_lines[MAXLINES];

Byte coltab[256];

long clip_low;
long clip_high;

int wsize;

static void create_cmap(void);
static void draw_char(Byte ypos, Byte xpos, Byte chr, Byte col);
static void draw_quad(Byte ypos, Byte xpos, Byte cp0l, Byte cp0h, Byte cp1l,
					  Byte cp1h, Byte cp2l, Byte cp2h, Byte cp3l, Byte cp3h);
static void draw_grid(void);
void mputvid(unsigned int ad, unsigned int len, Byte d, Byte c);

void draw_region(void)
{
	int i;
	if (regionoff == 0xffff)
	{
		i = (master_clk / (LINECNT - 1) - 5);
	}
	else
	{
		i = (master_clk / 22 + regionoff);
	}
	i = (snapline(i, VDCwrite[0xA0], 0));
	if (app_data.crc == 0xA7344D1F)
	{
		i = (master_clk / 22 + regionoff) + 6;
		i = (snapline(i, VDCwrite[0xA0], 0) + 6);
	} /*Atlantis*/

	if (app_data.crc == 0xD0BC4EE6)
	{
		i = (master_clk / 24 + regionoff) - 6;
		i = (snapline(i, VDCwrite[0xA0], 0) + 7);
	} /*Frogger*/

	if (app_data.crc == 0x26517E77)
	{
		i = (master_clk / 22 + regionoff);
		i = (snapline(i, VDCwrite[0xA0], 0) - 5);
	} /*Comando Noturno*/

	if (app_data.crc == 0xA57E1724)
	{
		i = (master_clk / (LINECNT - 1) - 5);
		i = (snapline(i, VDCwrite[0xA0], 0) - 3);
	} /*Catch the ball*/

	if (i < 0)
		i = 0;
	clip_low = last_line * (long)BMPW;
	clip_high = i * (long)BMPW;
	if (clip_high > BMPW * BMPH)
		clip_high = BMPW * BMPH;
	if (clip_low < 0)
		clip_low = 0;
	if (clip_low < clip_high)
		draw_display();
	last_line = i;
}

static uint32_t colors[256];

static void create_cmap(void)
{
	int i;

	/* Initialise parts of the colors array */
	for (i = 0; i < 16; i++)
	{
		/* Use the color values from the color table */
		colors[i] = colortable[app_data.vpp ? 1 : 0][i];
		colors[i + 32] = colors[i];
	}

	for (i = 16; i < 32; i++)
		colors[i] = 0;
	for (i = 48; i < 256; i++)
		colors[i] = 0;
}

void clearscr(void)
{
	clear(bitmap);
}

void mputvid(unsigned int ad, unsigned int len, Byte d, Byte c)
{
	if ((ad > (unsigned long)clip_low) && (ad < (unsigned long)clip_high))
	{
		unsigned int i;
		if (((len & 3) == 0) && (sizeof(unsigned long) == 4))
		{
			unsigned long dddd = (((unsigned long)d) & 0xff) | ((((unsigned long)d) & 0xff) << 8) | ((((unsigned long)d) & 0xff) << 16) | ((((unsigned long)d) & 0xff) << 24);
			unsigned long cccc = (((unsigned long)c) & 0xff) | ((((unsigned long)c) & 0xff) << 8) | ((((unsigned long)c) & 0xff) << 16) | ((((unsigned long)c) & 0xff) << 24);
			for (i = 0; i<len>> 2; i++)
			{
				*((unsigned long *)(vscreen + ad)) = dddd;
				cccc |= *((unsigned long *)(col + ad));
				*((unsigned long *)(col + ad)) = cccc;
				coltab[c] |= ((cccc | (cccc >> 8) | (cccc >> 16) | (cccc >> 24)) & 0xff);
				ad += 4;
			}
		}
		else
		{
			for (i = 0; i < len; i++)
			{
				vscreen[ad] = d;
				col[ad] |= c;
				coltab[c] |= col[ad++];
			}
		}
	}
}

static void draw_grid(void)
{
	unsigned int pnt, pn1;
	Byte mask, d;
	int j, i, x, w;
	Byte color;

	if (VDCwrite[0xA0] & 0x40)
	{
		for (j = 0; j < 9; j++)
		{
			pnt = (((j * 24) + 24) * BMPW);
			for (i = 0; i < 9; i++)
			{
				pn1 = pnt + (i * 32) + 20;
				color = ColorVector[j * 24 + 24];
				mputvid(
					pn1,
					4,
					(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_HGRID);
				color = ColorVector[j * 24 + 25];
				mputvid(
					pn1 + BMPW,
					4,
					(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_HGRID);
				color = ColorVector[j * 24 + 26];
				mputvid(
					pn1 + BMPW * 2,
					4,
					(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_HGRID);
			}
		}
	}

	mask = 0x01;
	for (j = 0; j < 9; j++)
	{
		pnt = (((j * 24) + 24) * BMPW);
		for (i = 0; i < 9; i++)
		{
			pn1 = pnt + (i * 32) + 20;
			if ((pn1 + BMPW * 3 >= (unsigned long)clip_low) && (pn1 <= (unsigned long)clip_high))
			{
				d = VDCwrite[0xC0 + i];
				if (j == 8)
				{
					d = VDCwrite[0xD0 + i];
					mask = 1;
				}
				if (d & mask)
				{
					color = ColorVector[j * 24 + 24];
					mputvid(
						pn1,
						36,
						(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_HGRID);
					color = ColorVector[j * 24 + 25];
					mputvid(
						pn1 + BMPW,
						36,
						(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_HGRID);
					color = ColorVector[j * 24 + 26];
					mputvid(
						pn1 + BMPW * 2,
						36,
						(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_HGRID);
				}
			}
		}
		mask = mask << 1;
	}

	mask = 0x01;
	w = 4;
	if (VDCwrite[0xA0] & 0x80)
	{
		w = 32;
	}
	for (j = 0; j < 10; j++)
	{
		pnt = (j * 32);
		mask = 0x01;
		d = VDCwrite[0xE0 + j];
		for (x = 0; x < 8; x++)
		{
			pn1 = pnt + (((x * 24) + 24) * BMPW) + 20;
			if (d & mask)
			{
				for (i = 0; i < 24; i++)
				{
					if ((pn1 >= (unsigned long)clip_low) && (pn1 <= (unsigned long)clip_high))
					{
						color = ColorVector[x * 24 + 24 + i];
						mputvid(
							pn1,
							w,
							(color & 0x07) | ((color & 0x40) >> 3) | (color & 0x80 ? 0 : 8), COL_VGRID);
					}
					pn1 += BMPW;
				}
			}
			mask = mask << 1;
		}
	}
}

void finish_display(void)
{
	vpp_finish_bmp(vscreen, 9, 5, BMPW - 9, BMPH - 5, bitmap->w, bitmap->h);
}

void blit(uint32_t* dst)
{
	uint8_t* src = vscreen;
	src += 5 * BMPW;
	src += 9;
	for (int j = 0; j < 240; j++)
	{
		for (int i = 0; i < 320; i++)
		{
			*dst++ = colors[*src++];
		}
		src += 20;
	}
}

void clear_collision(void)
{
	load_colplus(col);
	coltab[0x01] = coltab[0x02] = 0;
	coltab[0x04] = coltab[0x08] = 0;
	coltab[0x10] = coltab[0x20] = 0;
	coltab[0x40] = coltab[0x80] = 0;
}

void draw_display(void)
{
	int i, j, x, sm, t;
	Byte y, b, d1, cl, c;

	unsigned int pnt, pnt2;

	for (i = clip_low / BMPW; i < clip_high / BMPW; i++)
		memset(
			vscreen + i * BMPW,
			((ColorVector[i] & 0x38) >> 3) | (ColorVector[i] & 0x80 ? 0 : 8), BMPW);

	if (VDCwrite[0xA0] & 0x08)
		draw_grid();

	if (useforen && (!(VDCwrite[0xA0] & 0x20)))
		return;

	for (i = 0x10; i < 0x40; i += 4)
		draw_char(VDCwrite[i], VDCwrite[i + 1], VDCwrite[i + 2],
				  VDCwrite[i + 3]);

	/* draw quads, position mapping happens in ext_write (vmachine.c)*/
	for (i = 0x40; i < 0x80; i += 0x10)
		draw_quad(VDCwrite[i], VDCwrite[i + 1], VDCwrite[i + 2],
				  VDCwrite[i + 3], VDCwrite[i + 6], VDCwrite[i + 7],
				  VDCwrite[i + 10], VDCwrite[i + 11], VDCwrite[i + 14],
				  VDCwrite[i + 15]);

	c = 8;
	for (i = 12; i >= 0; i -= 4)
	{
		pnt2 = 0x80 + (i * 2);
		y = VDCwrite[i];
		x = VDCwrite[i + 1] - 8;
		t = VDCwrite[i + 2];
		cl = ((t & 0x38) >> 3);
		cl = ((cl & 2) | ((cl & 1) << 2) | ((cl & 4) >> 2)) + 8;
		/*174*/
		if ((x < 164) && (y > 0) && (y < 232))
		{
			pnt = y * BMPW + (x * 2) + 20 + sproff;
			if (t & 4)
			{
				if ((pnt + BMPW * 32 >= (unsigned long)clip_low) && (pnt <= (unsigned long)clip_high))
				{
					for (j = 0; j < 8; j++)
					{
						sm = (((j % 2 == 0) && (((t >> 1) & 1) != (t & 1))) || ((j % 2 == 1) && (t & 1))) ? 1 : 0;
						d1 = VDCwrite[pnt2++];
						for (b = 0; b < 8; b++)
						{
							if (d1 & 0x01)
							{
								if ((x + b + sm < 159) && (y + j < 247))
								{
									mputvid(sm + pnt, 4, cl, c);
									mputvid(sm + pnt + BMPW, 4, cl, c);
									mputvid(sm + pnt + 2 * BMPW, 4, cl, c);
									mputvid(sm + pnt + 3 * BMPW, 4, cl, c);
								}
							}
							pnt += 4;
							d1 = d1 >> 1;
						}
						pnt += BMPW * 4 - 32;
					}
				}
			}
			else
			{
				if ((pnt + BMPW * 16 >= (unsigned long)clip_low) && (pnt <= (unsigned long)clip_high))
				{
					for (j = 0; j < 8; j++)
					{
						sm = (((j % 2 == 0) && (((t >> 1) & 1) != (t & 1))) || ((j % 2 == 1) && (t & 1))) ? 1 : 0;
						d1 = VDCwrite[pnt2++];
						for (b = 0; b < 8; b++)
						{
							if (d1 & 0x01)
							{
								if ((x + b + sm < 160) && (y + j < 249))
								{
									mputvid(sm + pnt, 2, cl, c);
									mputvid(sm + pnt + BMPW, 2, cl, c);
								}
							}
							pnt += 2;
							d1 = d1 >> 1;
						}
						pnt += BMPW * 2 - 16;
					}
				}
			}
		}
		c = c >> 1;
	}
}

void draw_char(Byte ypos, Byte xpos, Byte chr, Byte col)
{
	int j, c;
	Byte cl, d1;
	int y, b, n;
	unsigned int pnt;

	y = (ypos & 0xFE);
	pnt = y * BMPW + ((xpos - 8) * 2) + 20;

	ypos = ypos >> 1;
	n = 8 - (ypos % 8) - (chr % 8);
	if (n < 3)
		n = n + 7;

	if ((pnt + BMPW * 2 * n >= (unsigned long)clip_low) && (pnt <= (unsigned long)clip_high))
	{

		c = (int)chr + ypos;
		if (col & 0x01)
			c += 256;
		if (c > 511)
			c = c - 512;

		cl = ((col & 0x0E) >> 1);
		cl = ((cl & 2) | ((cl & 1) << 2) | ((cl & 4) >> 2)) + 8;

		if ((y > 0) && (y < 232) && (xpos < 157))
		{
			for (j = 0; j < n; j++)
			{
				d1 = cset[c + j];
				for (b = 0; b < 8; b++)
				{
					if (d1 & 0x80)
					{
						if ((xpos - 8 + b < 160) && (y + j < 240))
						{
							mputvid(pnt, 2, cl, COL_CHAR);
							mputvid(pnt + BMPW, 2, cl, COL_CHAR);
						}
					}
					pnt += 2;
					d1 = d1 << 1;
				}
				pnt += BMPW * 2 - 16;
			}
		}
	}
}

/* This quad drawing routine can display the quad cut off effect used in KTAA.
 * It needs more testing with other games, especially the clipping.
 * This code is quite slow and needs a rewrite by somebody with more experience
 * than I (sgust) have */

void draw_quad(Byte ypos, Byte xpos, Byte cp0l, Byte cp0h, Byte cp1l, Byte cp1h,
			   Byte cp2l, Byte cp2h, Byte cp3l, Byte cp3h)
{
	/* char set pointers */
	int chp[4];
	/* colors */
	Byte col[4];
	/* pointer into screen bitmap */
	unsigned int pnt;
	/* offset into current line */
	unsigned int off;
	/* loop variables */
	int i, j, lines;

	/* get screen bitmap position of quad */
	pnt = (ypos & 0xfe) * BMPW + ((xpos - 8) * 2) + 20;
	/* abort drawing if completely below the bottom clip */
	if (pnt > (unsigned long)clip_high)
		return;
	/* extract and convert char-set offsets */
	chp[0] = cp0l | ((cp0h & 1) << 8);
	chp[1] = cp1l | ((cp1h & 1) << 8);
	chp[2] = cp2l | ((cp2h & 1) << 8);
	chp[3] = cp3l | ((cp3h & 1) << 8);
	for (i = 0; i < 4; i++)
		chp[i] = (chp[i] + (ypos >> 1)) & 0x1ff;
	lines = 8 - (chp[3] + 1) % 8;
	/* abort drawing if completely over the top clip */
	if (pnt + BMPW * 2 * lines < (unsigned long)clip_low)
		return;
	/* extract and convert color information */
	col[0] = (cp0h & 0xe) >> 1;
	col[1] = (cp1h & 0xe) >> 1;
	col[2] = (cp2h & 0xe) >> 1;
	col[3] = (cp3h & 0xe) >> 1;
	for (i = 0; i < 4; i++)
		col[i] = ((col[i] & 2) | ((col[i] & 1) << 2) | ((col[i] & 4) >> 2)) + 8;
	/* now draw the quad line by line controlled by the last quad */
	while (lines-- > 0)
	{
		off = 0;
		/* draw all 4 sub-quads */
		for (i = 0; i < 4; i++)
		{
			/* draw sub-quad pixel by pixel, but stay in same line */
			for (j = 0; j < 8; j++)
			{
				if ((cset[chp[i]] & (1 << (7 - j))) && (off < BMPW))
				{
					mputvid(pnt + off, 2, col[i], COL_CHAR);
					mputvid(pnt + off + BMPW, 2, col[i], COL_CHAR);
				}
				/* next pixel */
				off += 2;
			}
			/* space between sub-quads */
			off += 16;
		}
		/* advance char-set pointers */
		for (i = 0; i < 4; i++)
			chp[i] = (chp[i] + 1) & 0x1ff;
		/* advance screen bitmap pointer */
		pnt += BMPW * 2;
	}
}

void init_display(void)
{
	create_cmap();
	bitmap = NewBitmap(BMPW, BMPH);
	if (!bitmap)
	{
		fprintf(stderr, "Could not allocate memory for screen buffer.\n");
		exit(EXIT_FAILURE);
	}
	vscreen = (Byte *)bitmap->dat;
	clear(bitmap);
	col = (Byte *)malloc(BMPW * BMPH);
	if (!col)
	{
		fprintf(stderr, "Could not allocate memory for collision buffer.\n");
		free(vscreen);
		exit(EXIT_FAILURE);
	}
	memset(col, 0, BMPW * BMPH);
}