#include "vidhrdw/generic.h"

int eolith_buffer=0;
static struct mame_bitmap *bitmaps[2];
static data32_t *eo_vram;

READ32_HANDLER(eolith_vram_r)
{
	return eo_vram[offset+(0x80000/4)*eolith_buffer];
}

static void plot_pixel_rgb( int x, int y, int color)
{
	if (Machine->color_depth == 32)
	{
		UINT32 cr=(color&0x1f)<<3;
		UINT32 cg=(color&0x3e0)>>2;
		UINT32 cb=(color&0x7c00)>>7;
		((UINT32 *)bitmaps[eolith_buffer]->line[y])[x] = cb | (cg<<8) | (cr<<16);
	}
	else
	{
		((UINT16 *)bitmaps[eolith_buffer]->line[y])[x] = color;
	}
}

WRITE32_HANDLER(eolith_vram_w)
{
	int x,y;
	switch(mem_mask)
	{
		case 0:
			eolith_vram_w(offset,data,0xffff);
			eolith_vram_w(offset,data,0xffff0000);
		return;

		case 0xffff:
			if(data&0x80000000)
				return;
		break;

		case 0xffff0000:
			if(data&0x8000)
				return;
		break;
	}

	COMBINE_DATA(&eo_vram[offset+(0x80000/4)*eolith_buffer]);
	/*logical line width = 336; */
	x=offset%(336/2);
	y=offset/(336/2);
	if(x<320 && y<240)
	{
		plot_pixel_rgb(x*2,y,(eo_vram[offset+(0x80000/4)*eolith_buffer]>>16)&0xffff);
		plot_pixel_rgb(x*2+1,y,eo_vram[offset+(0x80000/4)*eolith_buffer]&0xffff);

	}
}

VIDEO_START(eolith)
{
	eo_vram=auto_malloc(0x80000*2);
	bitmaps[0] = auto_bitmap_alloc(Machine->drv->screen_width,Machine->drv->screen_height);
	bitmaps[1] = auto_bitmap_alloc(Machine->drv->screen_width,Machine->drv->screen_height);
	return 0;
}

VIDEO_UPDATE( eolith )
{
	copybitmap(bitmap,bitmaps[ eolith_buffer^1 ],0,0,0,0,cliprect,TRANSPARENCY_NONE, 0);
}
