libfbx-color.c

libfxb是linux下只写操作framebuffer的一个轻量级的库。

/*
 *  libfbx-color.c -- Color making functions
 *  (C)opyright 2000-2001 U4X Labs
 *
 *  Written by: Mike Bourgeous <[e-mail]>
 *              Sat Sep 2 17:40:09 EDT 2000
 *
 *  Updated by: Paul Mundt     <[e-mail]>
 *              Sat Dec 30 23:26:15 EST 2000
 *
 *  $Id: libfbx-color.c,v 1.8 2001/02/23 21:09:26 nitroglycerine Exp $
 *
 *       Originally part of fbgraph.c, now separate.  Responsible 
 *  for creating colors and colormaps.
 *
 *  See ChangeLog for modifications, CREDITS for credits.
 *  			
 *  All source herein is copyright U4X Labs and its original author. 
 *  Any code modifications or additions are (C)opyright the original 
 *  author and U4X Labs respectively.
 *
 *  libfbx is free software; you can redistribute it and/or modify it 
 *  under the terms of the GNU Lesser General Public License as 
 *  published by the Free Software Foundation; either version 2.1 of 
 *  the License, or (at your option) any later version.
 *
 *  libfbx is distributed in the hope that it will be useful, but 
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with libfbx; if not, write to the Free Software 
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA
 */
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <signal.h>
#include <time.h>
#include <math.h>
#include <linux/fb.h>
#include <linux/kd.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/user.h>
#include <termios.h>
#include <ctype.h>
#include <libfbx/libfbx.h>

/*
 * Function:	fb_make_color_8()
 * Arguments:	rgb values (0-255)
 * Returns:	8-bit color
 * Description: Makes a color out of specified rgb values for
 * 		specified bit depth and returns it.
 */
unsigned long fb_make_color_8(int r, int g, int b)
{
	r >>= 5;
	g >>= 5;
	b >>= 6;

	r &= 7;
	g &= 7;
	b &= 3;

	return (r << 5 | g << 2 | b << 0);
}

/*
 * Function:	fb_make_color_15()
 * Arguments:	rgb values (0-255)
 * Returns:	15-bit color
 * Description: Makes a color out of specified rgb values for
 * 		specified bit depth and returns it.
 */
unsigned long fb_make_color_15(int r, int g, int b)
{
	r >>= 3;
	g >>= 3;
	b >>= 3;

	return (r << 10 | g << 5 | b);
}

/*
 * Function:	fb_make_color_16()
 * Arguments:	rgb values (0-255)
 * Returns:	16-bit color
 * Description: Makes a color out of specified rgb values for
 * 		specified bit depth and returns it.
 */
unsigned long fb_make_color_16(int r, int g, int b)
{
	r >>= 3;
	g >>= 2;
	b >>= 3;
	
	return (r << 11 | g << 5 | b);
}

/*
 * Function:	fb_make_color_24()
 * Arguments:	rgb values (0-255)
 * Returns:	24-bit color
 * Description: Makes a color out of specified rgb values for
 * 		specified bit depth and returns it.
 */
unsigned long fb_make_color_24(int r, int g, int b)
{

	r &= 0xFF;
	g &= 0xFF;
	b &= 0xFF;

	return (r << fb_screen->red_offset | 
                g << fb_screen->green_offset | 
                b << fb_screen->blue_offset);
}

/*
 * Function:	fb_make_color_unknown()
 * Arguments:	rgb values (0-255)
 * Returns:	What is hopefully the color
 * Description:	Tries to figure out how to make a color for
 * 		an unknown bit depth.
 */
unsigned long fb_make_color_unknown(int r, int g, int b)
{
	r &= 0xFF;
	g &= 0xFF;
	b &= 0xFF;

	r <<= fb_screen->red_size - 8;
	g <<= fb_screen->green_size - 8;
	b <<= fb_screen->blue_size - 8;

	r &= 0xFF << (fb_screen->red_size - 8);
	g &= 0xFF << (fb_screen->green_size - 8);
	b &= 0xFF << (fb_screen->blue_size - 8);

	return (r << fb_screen->red_offset |
		g << fb_screen->green_offset |
		b << fb_screen->blue_offset);
}

/*
* Function:	fb_get_color()
* Arguments:	Hardware color, pointers to location to store 
* 		color components
* Returns:	None
* Description:	Stores the color components of the given hardware
* 		color in the given locations.
*/
void fb_get_color(unsigned int hwcolor, int *r, int *g, int *b)
{
       *r = ((hwcolor >> fb_screen->red_offset) & ((1 << fb_screen->red_size) - 1)) >> (fb_screen->red_size - 8);
       *g = ((hwcolor >> fb_screen->green_offset) & ((1 << fb_screen->green_size) - 1)) >> (fb_screen->green_size - 8);
       *b = ((hwcolor >> fb_screen->blue_offset) & ((1 << fb_screen->blue_size) - 1)) >> (fb_screen->blue_size - 8);
}

/*
 * Function:	fb_make_332_map()
 * Arguments:	pointer to fb colormap struct
 * Returns:	None
 * Description:	This function generates a color map for use 
 *              in 8-bit color modes. It is a simulated 
 *              truecolor palette.
 */
void fb_make_332_map(struct fb_cmap *map)
{
	int rs, gs, bs, i;
	int r = 8, g = 8, b = 4;

	map->red = red;
	map->green = green;
	map->blue = blue;

	rs = 256 / (r - 1);
	gs = 256 / (g - 1);
	bs = 256 / (b - 1);
	
	for (i = 0; i < 256; i++) {
		map->red[i]   = (rs * ((i / (g * b)) % r)) * 255;
		map->green[i] = (gs * ((i / b) % g)) * 255;
		map->blue[i]  = (bs * ((i) % b)) * 255;
	}
}

/*
 * Function:    fb_get_textcolor()
 * Arguments:   Pointers to foreground and background to
 *              place values in.
 * Returns:     None.
 * Description: Places current foreground and background
 *              colors in specified variables.
 */
void fb_get_textcolor(int *fg, int *bg)
{
	*fg = fb_screen->text.color;
	*bg = fb_screen->text.bgcolor;
}

/*
 * Function:    fb_sget_textcolor()
 * Arguments:   Pointers to surface to get values from
 *              and pointers to foreground and background to
 *              place values in.
 * Returns:     None.
 * Description: Places current foreground and background
 *              colors in specified variables.
 */
void fb_sget_textcolor(fb_surface *surface, int *fg, int *bg)
{
	*fg = surface->text.color;
	*bg = surface->text.bgcolor;
}

/*
 * Function:    fb_set_textcolor()
 * Arguments:   Foreground and background values.
 * Returns:     None.
 * Description: Sets the text color to the specified
 *              foreground and background values.
 */
void fb_set_textcolor(int fg, int bg)
{
	fb_screen->text.color   = fg;
	fb_screen->text.bgcolor = bg;
}

/*
 * Function:    fb_sset_textcolor()
 * Arguments:   Surface, foreground and background values.
 * Returns:     None.
 * Description: Sets the text color to the specified
 *              foreground and background values.
 */
void fb_sset_textcolor(fb_surface *surface, int fg, int bg)
{
	surface->text.color   = fg;
	surface->text.bgcolor = bg;
}