/***************************************************************************

  video/odyssey2.c

***************************************************************************/

#include <assert.h>
#include "driver.h"
#include "mslegacy.h"
#include "cpu/i8039/i8039.h"
#include "video/generic.h"
#include "includes/odyssey2.h"

/* character sprite colors
   dark grey, red, green, orange, blue, violet, light grey, white
   dark back / grid colors
   black, dark blue, dark green, light green, red, violet, orange, light grey
   light back / grid colors
   black, blue, green, light green, red, violet, orange, light grey */

UINT8 odyssey2_colors[] =
{
	/* Background,Grid Dim */
	0x00,0x00,0x00,
	0x00,0x00,0xFF,   /* Blue */
	0x00,0x80,0x00,   /* DK Green */
	0xff,0x9b,0x60,
	0xCC,0x00,0x00,   /* Red */
	0xa9,0x80,0xff,
	0x82,0xfd,0xdb,
	0xFF,0xFF,0xFF,

	/* Background,Grid Bright */
	0x80,0x80,0x80,
	0x50,0xAE,0xFF,   /* Blue */
	0x00,0xFF,0x00,   /* Dk Green */
	0x82,0xfb,0xdb,   /* Lt Grey */
	0xEC,0x02,0x60,   /* Red */
	0xa9,0x80,0xff,   /* Violet */
	0xff,0x9b,0x60,   /* Orange */
	0xFF,0xFF,0xFF,

	/* Character,Sprite colors */
	0x71,0x71,0x71,   /* Dark Grey */
	0xFF,0x80,0x80,   /* Red */
	0x00,0xC0,0x00,   /* Green */
	0xff,0x9b,0x60,   /* Orange */
	0x50,0xAE,0xFF,   /* Blue */
	0xa9,0x80,0xff,   /* Violet */
	0x82,0xfb,0xdb,   /* Lt Grey */
	0xff,0xff,0xff    /* White */
};

UINT8 o2_shape[0x40][8]={
    { 0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00 }, // 0
    { 0x18,0x38,0x18,0x18,0x18,0x18,0x3C,0x00 },
    { 0x3C,0x66,0x0C,0x18,0x30,0x60,0x7E,0x00 },
    { 0x7C,0xC6,0x06,0x3C,0x06,0xC6,0x7C,0x00 },
    { 0xCC,0xCC,0xCC,0xFE,0x0C,0x0C,0x0C,0x00 },
    { 0xFE,0xC0,0xC0,0x7C,0x06,0xC6,0x7C,0x00 },
    { 0x7C,0xC6,0xC0,0xFC,0xC6,0xC6,0x7C,0x00 },
    { 0xFE,0x06,0x0C,0x18,0x30,0x60,0xC0,0x00 },
    { 0x7C,0xC6,0xC6,0x7C,0xC6,0xC6,0x7C,0x00 },
    { 0x7C,0xC6,0xC6,0x7E,0x06,0xC6,0x7C,0x00 },
    { 0x00,0x18,0x18,0x00,0x18,0x18,0x00,0x00 },
    { 0x18,0x7E,0x58,0x7E,0x58,0x7E,0x18,0x00 },
    { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
    { 0x3C,0x66,0x0C,0x18,0x18,0x00,0x18,0x00 },
    { 0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,0xFE,0x00 },
    { 0xFC,0xC6,0xC6,0xFC,0xC0,0xC0,0xC0,0x00 },
    { 0x00,0x18,0x18,0x7E,0x18,0x18,0x00,0x00 },
    { 0xC6,0xC6,0xC6,0xD6,0xFE,0xEE,0xC6,0x00 },
    { 0xFE,0xC0,0xC0,0xF8,0xC0,0xC0,0xFE,0x00 },
    { 0xFC,0xC6,0xC6,0xFC,0xD8,0xCC,0xC6,0x00 },
    { 0x7E,0x18,0x18,0x18,0x18,0x18,0x18,0x00 },
    { 0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00 },
    { 0x3C,0x18,0x18,0x18,0x18,0x18,0x3C,0x00 },
    { 0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00 },
    { 0x7C,0xC6,0xC6,0xC6,0xDE,0xCC,0x76,0x00 },
    { 0x7C,0xC6,0xC0,0x7C,0x06,0xC6,0x7C,0x00 },
    { 0xFC,0xC6,0xC6,0xC6,0xC6,0xC6,0xFC,0x00 },
    { 0xFE,0xC0,0xC0,0xF8,0xC0,0xC0,0xC0,0x00 },
    { 0x7C,0xC6,0xC0,0xC0,0xCE,0xC6,0x7E,0x00 },
    { 0xC6,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0x00 },
    { 0x06,0x06,0x06,0x06,0x06,0xC6,0x7C,0x00 },
    { 0xC6,0xCC,0xD8,0xF0,0xD8,0xCC,0xC6,0x00 },
    { 0x38,0x6C,0xC6,0xC6,0xFE,0xC6,0xC6,0x00 },
    { 0x7E,0x06,0x0C,0x18,0x30,0x60,0x7E,0x00 },
    { 0xC6,0xC6,0x6C,0x38,0x6C,0xC6,0xC6,0x00 },
    { 0x7C,0xC6,0xC0,0xC0,0xC0,0xC6,0x7C,0x00 },
    { 0xC6,0xC6,0xC6,0xC6,0xC6,0x6C,0x38,0x00 },
    { 0xFC,0xC6,0xC6,0xFC,0xC6,0xC6,0xFC,0x00 },
    { 0xC6,0xEE,0xFE,0xD6,0xC6,0xC6,0xC6,0x00 },
    { 0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x00 },
    { 0x00,0x00,0x00,0x7E,0x00,0x00,0x00,0x00 },
    { 0x00,0x66,0x3C,0x18,0x3C,0x66,0x00,0x00 },
    { 0x00,0x18,0x00,0x7E,0x00,0x18,0x00,0x00 },
    { 0x00,0x00,0x7E,0x00,0x7E,0x00,0x00,0x00 },
    { 0x66,0x66,0x66,0x3C,0x18,0x18,0x18,0x00 },
    { 0xC6,0xE6,0xF6,0xFE,0xDE,0xCE,0xC6,0x00 },
    { 0x03,0x06,0x0C,0x18,0x30,0x60,0xC0,0x00 },
    { 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00 },
    { 0xCE,0xDB,0xDB,0xDB,0xDB,0xDB,0xCE,0x00 },
    { 0x00,0x00,0x3C,0x7E,0x7E,0x7E,0x3C,0x00 },
    { 0x1C,0x1C,0x18,0x1E,0x18,0x18,0x1C,0x00 },
    { 0x1C,0x1C,0x18,0x1E,0x18,0x34,0x26,0x00 },
    { 0x38,0x38,0x18,0x78,0x18,0x2C,0x64,0x00 },
    { 0x38,0x38,0x18,0x78,0x18,0x18,0x38,0x00 },
    { 0x00,0x18,0x0C,0xFE,0x0C,0x18,0x00,0x00 },
    { 0x18,0x3C,0x7E,0xFF,0xFF,0x18,0x18,0x00 },
    { 0x03,0x07,0x0F,0x1F,0x3F,0x7F,0xFF,0x00 },
    { 0xC0,0xE0,0xF0,0xF8,0xFC,0xFE,0xFF,0x00 },
    { 0x38,0x38,0x12,0xFE,0xB8,0x28,0x6C,0x00 },
    { 0xC0,0x60,0x30,0x18,0x0C,0x06,0x03,0x00 },
    { 0x00,0x00,0x0C,0x08,0x08,0x7F,0x3E,0x00 },
    { 0x00,0x03,0x63,0xFF,0xFF,0x18,0x08,0x00 },
    { 0x00,0x00,0x00,0x10,0x38,0xFF,0x7E,0x00 }
};

static UINT8 *odyssey2_display;
int odyssey2_vh_hpos;

union {
    UINT8 reg[0x100];
    struct {
	struct {
	    UINT8 y,x,color,res;
	} sprites[4];
	struct {
	    UINT8 y,x,ptr,color;
	} foreground[12];
	struct {
	    struct {
		UINT8 y,x,ptr,color;
	    } single[4];
	} quad[4];
	UINT8 shape[4][8];
	UINT8 control;
	UINT8 status;
	UINT8 collision;
	UINT8 color;
	UINT8 y;
	UINT8 x;
	UINT8 res;
	UINT8 shift1,shift2,shift3;
	UINT8 sound;
	UINT8 res2[5+0x10];
	UINT8 hgrid[2][0x10];
	UINT8 vgrid[0x10];
    } s;
} o2_vdc= { { 0 } };

static UINT8 collision[8];    /* only 7 used but easier to index */
static int line;
static mame_time line_time;
static UINT32 o2_snd_shift[2];
static UINT8 x_beam_pos;
static UINT8 y_beam_pos;

/***************************************************************************

  Start the video hardware emulation.

***************************************************************************/

VIDEO_START( odyssey2 )
{
	o2_snd_shift[0] = Machine->sample_rate / 983;
	o2_snd_shift[1] = Machine->sample_rate / 3933;

	odyssey2_vh_hpos = 0;
	odyssey2_display = (UINT8 *) auto_malloc(8 * 8 * 256);
	memset(odyssey2_display, 0, 8 * 8 * 256);
}

INLINE int get_horiz_clock_beam_pos( void )
{
    int h;
    h = scale_up_mame_time(sub_mame_times(mame_timer_get_time(), line_time), Machine->drv->cpu[0].cpu_clock * 8).seconds;

    return h;
}

INLINE int get_horiz_clock( void )
{
    int h;
    h = scale_up_mame_time(sub_mame_times(mame_timer_get_time(), line_time), Machine->drv->cpu[0].cpu_clock).seconds;

    return h;
}

INLINE int horiz_scan_active( void )
{
    int h;
    h = get_horiz_clock();

    if ( h > 15 )
        return 1;

    return 0;
}

INLINE int in_vblank( void )
{
    if ((line > 239) && (line < 262))
        return 1;

    return 0;
}

PALETTE_INIT( odyssey2 )
{
	palette_set_colors_rgb(machine, 0, odyssey2_colors, sizeof(odyssey2_colors) / 3);
	colortable[0] = 0;
	colortable[1] = 1;
}

extern READ8_HANDLER( odyssey2_video_r )
{
    UINT8 data = 0;
    int bit, i;

    switch (offset) 
    {
        case 0xa1: 

            if (horiz_scan_active())
                data |= 1;

            if (in_vblank())
                data |= 8;

            break;

        case 0xa2: 

            bit = 0x01;

            for (i = 0; i < 8; i++)
            {
                /* o2_vdc.s.collision at this point has the requested bit(s)
                 * to test the current collisions against.  TODO: Sometimes
                 * $A2 has more than one bit set.  What are the correct semantics 
                 * of that when reading back?  For now having an entire byte
                 * for each graphics object that can collide is working.
                 */

                if (bit & o2_vdc.s.collision) 
                    data |= (collision[i] & ~bit);

                bit <<= 1;
            }

            break;

        case 0xa4: 

            if ((o2_vdc.s.control & VDC_CONTROL_REG_STROBE_XY))
                y_beam_pos = line;

            data = y_beam_pos;

            break;


        case 0xa5:

            if ((o2_vdc.s.control & VDC_CONTROL_REG_STROBE_XY))
                x_beam_pos = get_horiz_clock_beam_pos();

            data = x_beam_pos;

            break;

        default:
            data = o2_vdc.reg[offset];
    }

    return data;
}

extern WRITE8_HANDLER( odyssey2_video_w )
{
	/* Update the sound */
	if( offset >= 0xa7 && offset <= 0xaa )
		stream_update( odyssey2_sh_channel );

    if (offset == 0xa0)
    {
        if (    o2_vdc.s.control & VDC_CONTROL_REG_STROBE_XY 
             && !(data & VDC_CONTROL_REG_STROBE_XY))
        {
            /* Toggling strobe bit, tuck away values */
            x_beam_pos = get_horiz_clock_beam_pos(); 
            y_beam_pos = line;

            /* This is wrong but more games work with it, TODO: Figure
             * out correct change.  Maybe update the screen here??
             * It seems what happens is 0x0 is written to $A0 just before 
             * VLBANK (video update) so no screen updates happen.
             */

            return;
        }
    }

    o2_vdc.reg[offset] = data;
}

extern READ8_HANDLER( odyssey2_t1_r )
{
    static int t = FALSE;

    t = !t;
    return t;
}

INTERRUPT_GEN( odyssey2_line )
{
    line_time = mame_timer_get_time();
    line = (line + 1) % 262;

    switch (line) 
    {
        case 252:
            cpunum_set_input_line(0, 0, ASSERT_LINE); /* vsync?? */
            break;
        case 253:
            cpunum_set_input_line(0, 0, CLEAR_LINE); /* vsync?? */
            break;
    }
}

INLINE void odyssey2_draw_box(UINT8 bg[][320], int x, int y, int width, int height, UINT8 collision_id)
{
    int x1,y1;
    for (y1 = 0; y1 < height; y1++)
	{
		for (x1 = 0; x1 < width; x1++)
			bg[y+y1][x+x1] |= collision_id;
    }
}

INLINE void odyssey2_draw(UINT8 bg[][320], UINT8 code, int x, int y, int scale_x, int scale_y, UINT8 collision_id)
{
    int m,x1,y1;
    for (m=0x80; m>0; m>>=1, x+=scale_x)
	{
		if (code & m)
		{
			for (y1=0; y1<scale_y; y1++)
			{
				for (x1 = 0; x1 < scale_x; x1++)
					bg[y+y1][x+x1] |= collision_id;
			}
		}
    }
}

// different bit ordering, maybe I should change rom
INLINE void odyssey2_draw_sprite(UINT8 bg[][320], UINT8 code, int x, int y, int scale_x, int scale_y, UINT8 collision_id)
{
    int m,x1,y1;

    for (m=1; m<=0x80; m<<=1, x+=scale_x)
	{
		if (code & m)
		{
			for (y1=0; y1<scale_y; y1++)
			{
				for (x1 = 0; x1 < scale_x; x1++)
					bg[y+y1][x+x1] |= collision_id;
			}
		}
    }
}

INLINE void odyssey2_draw_grid( mame_bitmap* bitmap, UINT8 bg[][320] )
{
    int width  = 16;
    int height = 24;
	int i, j, x, y;
	int color;
    int w = 2;
    int x_grid_offset = 8;
    int y_grid_offset = 24;

    color  = o2_vdc.s.color & 7;
    color |= (o2_vdc.s.color >> 3) & 8;

    for (i=0, x=0; x<9; x++, i++) 
    {
        for (j=1, y=0; y<9; y++, j<<=1) 
        {
            if ( ((j<=0x80)&&(o2_vdc.s.hgrid[0][i]&j))
                    ||((j>0x80)&&(o2_vdc.s.hgrid[1][i]&1)) )
            {
                odyssey2_draw_box(bg, x_grid_offset + x * width, y_grid_offset + y * height, width + 2, 3, COLLISION_HORIZ_GRID_DOTS);
                plot_box(bitmap, x_grid_offset + x * width, y_grid_offset + y * height, width + 2, 3, Machine->pens[color]);
            }
        }
    }

    if (o2_vdc.s.control & 0x80)        /* fill solid to end of next vert line */
        w=width;

    for (i=0, x=0; x<10; x++, i++) 
    {
        for (j=1, y=0; y<8; y++, j<<=1)
        {
            if (o2_vdc.s.vgrid[i] & j) 
            {
                odyssey2_draw_box(bg, x_grid_offset + x * width, y_grid_offset + y * height, w, height, COLLISION_VERTICAL_GRID);
                plot_box(bitmap, x_grid_offset + x * width, y_grid_offset + y * height, w, height, Machine->pens[color]);
            }
        }
    }
}

INLINE void odyssey2_draw_char(mame_bitmap *bitmap, UINT8 bg[][320], int x, int y, int ptr, int color)
{
    int n, i;
    int offset = ptr | ((color & 1) << 8);

    offset=(offset + (y >> 1)) & 0x1ff;
	/* 7-Sep-2007 - whomever wrote this crap code was dynamically remapping
	 * the color table, a vile gross hack.  Doesn't look like this is going
	 * to survive the 0.118u5 transition */
	/* Machine->gfx[0]->colortable[1]=Machine->pens[16 + ((color & 0xe) >> 1)]; */

    // don't ask me about the technical background, but also this height thingy is needed
    // invaders aliens (!) and shoot (-)
    n = 8 - (ptr & 7) - ((y >> 1) & 7);

    if (n < 3) 
        n += 7;

    for (i=0; i<n; i++) 
    {
        if (y + i * 2 >= bitmap->height )
            break;		

        odyssey2_draw(bg, ((char*)o2_shape)[offset], x, y+i*2, 1, 2, COLLISION_CHARACTERS);
        drawgfxzoom(bitmap, Machine->gfx[0], ((char*)o2_shape)[offset],0,
                0,0,x,y+i*2,
                0, TRANSPARENCY_PEN,0, 0x10000, 0x20000);	
        offset=(offset+1) & 0x1ff;
    }
}

/***************************************************************************

  Refresh the video screen

***************************************************************************/

VIDEO_UPDATE( odyssey2 )
{
	int i, j, x, y;
	UINT8 bg[300][320]= { { 0 } };

	assert(bitmap->width<=ARRAY_LENGTH(bg[0]) && bitmap->height<=ARRAY_LENGTH(bg));

	plot_box( bitmap, 0, 0, bitmap->width, bitmap->height, Machine->pens[(o2_vdc.s.color >> 3) & 0x7] );

	if (o2_vdc.s.control & 0x08)        /* show grid */
        odyssey2_draw_grid(bitmap, bg);

    if (o2_vdc.s.control & 0x20)        /* show foreground objects */
	{
		for (i=0; i<ARRAY_LENGTH(o2_vdc.s.foreground); i++) 
        {
			odyssey2_draw_char(bitmap, bg,
				o2_vdc.s.foreground[i].x, o2_vdc.s.foreground[i].y,
				o2_vdc.s.foreground[i].ptr, o2_vdc.s.foreground[i].color);
		}

		for (i=0; i<ARRAY_LENGTH(o2_vdc.s.quad); i++)
		{
			x=o2_vdc.s.quad[i].single[0].x;
			for (j=0; j<ARRAY_LENGTH(o2_vdc.s.quad[0].single); j++, x+=2*8)
			{
				odyssey2_draw_char(bitmap, bg,
					x, y=o2_vdc.s.quad[i].single[0].y,
					o2_vdc.s.quad[i].single[j].ptr, o2_vdc.s.quad[i].single[j].color);
			}
		}

		for (i=0; i<ARRAY_LENGTH(o2_vdc.s.sprites); i++)
		{
			/* 7-Sep-2007 - whomever wrote this crap code was dynamically remapping
			 * the color table, a vile gross hack.  Doesn't look like this is going
			 * to survive the 0.118u5 transition */
			/* Machine->gfx[0]->colortable[1]=Machine->pens[16+((o2_vdc.s.sprites[i].color>>3)&7)]; */

			y=o2_vdc.s.sprites[i].y;
			x=o2_vdc.s.sprites[i].x;

			for (j=0; j<8; j++)
			{
				if (o2_vdc.s.sprites[i].color & 4)
				{
					if (y+4*j>=bitmap->height) 
                        break;
					odyssey2_draw_sprite(bg, o2_vdc.s.shape[i][j], x, y+j*4, 2, 4, 1<<i);    /* 1 << i is sprite collision index */
					drawgfxzoom(bitmap, Machine->gfx[1], o2_vdc.s.shape[i][j],0,
						0,0,x,y+j*4,
						0, TRANSPARENCY_PEN,0,0x20000, 0x40000);
				}

				else
				{
					if (y+j*2>=bitmap->height) 
                        break;
					odyssey2_draw_sprite(bg, o2_vdc.s.shape[i][j], x, y+j*2, 1, 2, 1<<i);    /* 1 << i is sprite collision index */
					drawgfxzoom(bitmap, Machine->gfx[1], o2_vdc.s.shape[i][j],0,
						0,0,x,y+j*2,
						0, TRANSPARENCY_PEN,0, 0x10000, 0x20000);
				}
			}
		}
	}

	memset( collision, 0, sizeof( collision ) );

	for (y=0; y<300; y++)
	{
		for (x=0; x<320; x++)
		{
			switch (bg[y][x]) 
            {
                case 0: case 1: case 2: case 4: case 8:
                case 0x10: case 0x20: case 0x80:
                    /* Only one collidable entity in this spot, no collision to mark */
                    break;

                default:
                    {
                        int bit = 0x01;
                        for (i = 0; i < 8; i++)
                        {
                        if (bit & o2_vdc.s.collision && bit & bg[y][x])
                                collision[i] |= bg[y][x] & ~bit;

                            bit <<= 1;
                        }
                    break;
			}
		}
	}
	}

	return 0;
}

void odyssey2_sh_update( void *param,stream_sample_t **inputs, stream_sample_t **_buffer,int length )
{
	static UINT32 signal;
	static UINT16 count = 0;
	int ii;
	int period;
	stream_sample_t *buffer = _buffer[0];

	/* Generate the signal */
	signal = o2_vdc.s.shift3 | (o2_vdc.s.shift2 << 8) | (o2_vdc.s.shift1 << 16);

	if( o2_vdc.s.sound & 0x80 )	/* Sound is enabled */
	{
		for( ii = 0; ii < length; ii++, buffer++ )
		{
			*buffer = 0;
			*buffer = signal & 0x1;
			period = (o2_vdc.s.sound & 0x20) ? 11 : 44;
			if( ++count >= period )
			{
				count = 0;
				signal >>= 1;
				/* Loop sound */
				if( o2_vdc.s.sound & 0x40 )
				{
					signal |= *buffer << 23;
				}
			}

			/* Throw an interrupt if enabled */
			if( o2_vdc.s.control & 0x4 )
			{
				cpunum_set_input_line(0, 1, HOLD_LINE); /* Is this right? */
			}

			/* Adjust volume */
			*buffer *= o2_vdc.s.sound & 0xf;
			/* Pump the volume up */
			*buffer <<= 10;
		}
	}
	else
	{
		/* Sound disabled, so clear the buffer */
		for( ii = 0; ii < length; ii++, buffer++ )
			*buffer = 0;
	}
}