// vesafb.c
// Author: Josh Holtrop
// Date: 03/19/05
// Modified: 03/19/05

#include "display/display.h"
#include "display/vesafb.h"
#include "lang/lang.h"
#include "hos_defines.h"	// BIOS_CHAR_MAP

u16_t	*vmem16 = (u16_t *) VESAFB_VID_ADDR;
u32_t	*vmem32 = (u32_t *) VESAFB_VID_ADDR;
int	vesafb_bpp;
int	vesafb_multiplier;
int	vesafb_width;		// pixels
int	vesafb_height;
int	vesafb_xres;		// characters
int	vesafb_yres;
int	vesafb_cursor;		// -1 to hide, 0+ for cursor position

int	vesafb_init(int width, int height, int bpp)
{
	switch(vesafb_bpp = bpp)
	{
	case 15: case 16:
		vesafb_multiplier = 2;
		break;
	case 24:
		vesafb_multiplier = 3;
		break;
	case 32:
		vesafb_multiplier = 4;
		break;
	}
	vesafb_width = width;
	vesafb_height = height;
	vesafb_xres = (width >> 3) & 0xFFF8;	// columns divisible by 8
	vesafb_yres = height >> 3;
	return vesafb_cursor = 0;
}

void	vesafb_clear()
{
	memset(vmem32, 0, vesafb_width * vesafb_height * vesafb_multiplier);
	vesafb_update_cursor(0);
}

void	vesafb_update_cursor(int position)
{
	vesafb_draw_cursor(vesafb_cursor, 0);
	vesafb_draw_cursor(vesafb_cursor = position, 1);
}

void	vesafb_draw_cursor(int position, int onoff)
{
	int x = (position % vesafb_xres) << 3;
	int y = ( (position / vesafb_xres) << 3 ) + 7;
	int i;
	for (i = 0; i < 7; i++)
		vesafb_pset(x + i, y, onoff);
}

void	vesafb_pset(int x, int y, int onoff)
{
	switch (vesafb_bpp)
	{
	case 15: case 16:
		*(vmem16 + vesafb_width*y + x) = (onoff ? 0xFFFF : 0);
		break;
	case 24:
		*((u32_t *)(((u32_t)vmem32) + 3*vesafb_width*y + 3*x)) = (onoff ? 0x00FFFFFF : 0);
		break;
	case 32:
		*(vmem32 + vesafb_width*y + x) = (onoff ? 0x00FFFFFF : 0);
		break;
	}
}

int	vesafb_getWidth()
{
	return vesafb_xres;
}

int	vesafb_getHeight()
{
	return vesafb_yres;
}

void	vesafb_draw_char(int position, u16_t chr)
{
	int x = (position % vesafb_xres) << 3;
	int y = (position / vesafb_xres) << 3;
	int xi, yi;
	u8_t *charMap = (u8_t *) ( BIOS_CHAR_MAP + ((chr & 0xFF) << 3) );
	for (yi = 0; yi < 7; yi++)
	{
		for (xi = 0; xi < 7; xi++)
			vesafb_pset(x + xi, y + yi, (*charMap & (0x80 >> xi)));
		charMap++;
	}
}

int	vesafb_draw(u16_t *buffer, int buff_len, int cursor_position)
{
	int i;
	for (i = 0; i < buff_len; i++)
		vesafb_draw_char(i, *buffer++);
	vesafb_update_cursor(cursor_position);
	return 0;
}