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

#include "display/display.h"
#include "screen.h"

void blitter(int id)
{
	int i, j;
	int w = displays[id].regs[12];
	int h = displays[id].regs[13];

	int sy = displays[id].regs[9], sx = displays[id].regs[8];
	int dy = displays[id].regs[11], dx = displays[id].regs[10];


	if ((id <0) && (id >= MAX_DISPLAY))
		return;

	if (screens[id] == NULL)
		return;


	if (displays[id].regs[7] == 0)
		return;

	if (w > (80 - dx))
		w = 80 - dx;
	if (h > (50 - dy))
		h = 50 - dy;

	if ((w < 0) || (h < 0))
	{
		displays[id].regs[7] = 0;
		return;
	}

	switch (displays[id].regs[7])
	{
		case 1:
			for (j = 0; j < h; j++)
				for (i = 0; i < w; i++)
					if (((j + dy) < 50) && ((i + dx) < 80))
					{
						screens[id]->chars.rowcol[j + dy][i + dx] = displays[id].regs[8];
						if (screens[id]->type)
							screens[id]->attributes.rowcol[j + dy][i + dx] = displays[id].regs[9];
					}
			displays[id].regs[7] = 0;
			return;
		case 2:
			for (j = 0; j < h; j++)
				for (i = 0; i < w; i++)
					if (((j + dy) < 50) && ((i + dx) < 80))
						screens[id]->chars.rowcol[j + dy][i + dx] ^= 0x80;
			displays[id].regs[7] = 0;
			return;
	}

	if (w > (80 - sx))
		w = 80 - sx;
	if (h > (50 - sy))
		h = 50 - sy;

	if ((w < 0) || (h < 0))
	{
		displays[id].regs[7] = 0;
		return;
	}

	if (displays[id].regs[7] == 3)
	{
		for (j = 0; j < h; j++)
		{
			for (i = 0; i < w; i++)
			{
				if (((j + sy) < 50) && ((i + sx) < 80) && ((j + dy) < 50) && ((i + dx) < 80))
				{
					screens[id]->chars.rowcol[j + dy][i + dx] = screens[id]->chars.rowcol[j + sy][i + sx];
					if (screens[id]->type)
						screens[id]->attributes.rowcol[j + dy][i + dx] = screens[id]->attributes.rowcol[j + sy][i + sx];
				}
			}
		}
		displays[id].regs[7] = 0;
	}
}


void init_displays()
{
	memset(&displays,0x00,sizeof(displays));
}

void reset_display(int id)
{
	if ((id >=0) && (id < MAX_DISPLAY))
	{
		if (screens[id] != NULL)
		{
			displays[id].regs[3] = 2;
			displays[id].regs[4] = 0;
			displays[id].regs[5] = 0;
			displays[id].regs[6] = 0;

			memset(screens[id]->chars.linear,0x20,SCR_SIZE);
			scrattrfill(id, 0xbd);
		}
	}
}

void disp_store(int id, int ptr, unsigned char value)
{
	if ((id >=0) && (id < MAX_DISPLAY))
	{
		if (screens[id] != NULL)
		{
			if (ptr < 16)
			{
				if ((ptr == 0x04) || (ptr == 0x05))
				{
					displays[id].regs[ptr] = value & 0x0f;
				}
				else if (ptr != 0x06)
				{
					displays[id].regs[ptr] = value;

					if (ptr == 0x01) screens[id]->cx = value;
					if (ptr == 0x02) screens[id]->cy = value;
					if (ptr == 0x03) screens[id]->blink = value;
				}
			}
			else if ((ptr >= 0x10) && (ptr < 0x60))
			{
				if (displays[id].regs[0] < 50)
					screens[id]->chars.rowcol[displays[id].regs[0]][ptr - 0x10] = value;
			}
			else if ((screens[id]->type == 1) && (ptr >= 0x60) && (ptr < 0xb0))
			{
				if (displays[id].regs[0] < 50)
					screens[id]->attributes.rowcol[displays[id].regs[0]][ptr - 0x60] = value;
			}
		}
	}
}

unsigned char disp_load(int id, int ptr)
{
	if ((id >=0) && (id < MAX_DISPLAY))
	{
		if (screens[id] != NULL)
		{
			if (ptr < 16)
			{
				if (ptr == 0x06)
					return displays[id].kbbuf[displays[id].regs[4]];

				return displays[id].regs[ptr];
			}
			else if ((ptr >= 0x10) && (ptr < 0x60))
			{
				if (displays[id].regs[0] < 50)
					return screens[id]->chars.rowcol[displays[id].regs[0]][ptr - 0x10];
			}
			else if ((screens[id]->type == 1) && (ptr >= 0x60) && (ptr < 0xb0))
			{
				if (displays[id].regs[0] < 50)
					return screens[id]->attributes.rowcol[displays[id].regs[0]][ptr - 0x60];
			}
			else if (ptr == 0xff)
				return screens[id]->type;
		}
	}
	return 0;

}

unsigned char disp_key(int id, unsigned char ch)
{
	int np;

	if ((id >=0) && (id < MAX_DISPLAY))
	{
		if (screens[id] != NULL)
		{
			np = (displays[id].regs[5] + 1) & 0x0f;
			if (np != displays[id].regs[4])
			{
				displays[id].kbbuf[displays[id].regs[5] & 0x0f] = ch;
				displays[id].regs[5] = np;
				displays[id].regs[6] = displays[id].kbbuf[displays[id].regs[4] & 0x0f];
			}
		}
	}
}