/*
* libcucul Canvas for ultrafast compositing of Unicode letters
* Copyright (c) 2002-2006 Sam Hocevar <sam@zoy.org>
* All Rights Reserved
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the Do What The Fuck You Want To
* Public License, Version 2, as published by Sam Hocevar. See
* http://sam.zoy.org/wtfpl/COPYING for more details.
*/
/** \file bitmap.c
* \version \$Id$
* \author Sam Hocevar <sam@zoy.org>
* \brief Bitmap blitting
*
* This file contains bitmap blitting functions.
*/
#include "config.h"
#if !defined(__KERNEL__)
# if defined(HAVE_ENDIAN_H)
# include <endian.h>
# endif
# include <stdio.h>
# include <stdlib.h>
# include <limits.h>
# include <string.h>
#endif
#include "cucul.h"
#include "cucul_internals.h"
#define CP437 0
/*
* Local variables
*/
#if !defined(_DOXYGEN_SKIP_ME)
# define LOOKUP_VAL 32
# define LOOKUP_SAT 32
# define LOOKUP_HUE 16
#endif
static unsigned char hsv_distances[LOOKUP_VAL][LOOKUP_SAT][LOOKUP_HUE];
static enum cucul_color lookup_colors[8];
static int const hsv_palette[] =
{
/* weight, hue, saturation, value */
4, 0x0, 0x0, 0x0, /* black */
5, 0x0, 0x0, 0x5ff, /* 30% */
5, 0x0, 0x0, 0x9ff, /* 70% */
4, 0x0, 0x0, 0xfff, /* white */
3, 0x1000, 0xfff, 0x5ff, /* dark yellow */
2, 0x1000, 0xfff, 0xfff, /* light yellow */
3, 0x0, 0xfff, 0x5ff, /* dark red */
2, 0x0, 0xfff, 0xfff /* light red */
};
/* RGB palette for the new colour picker */
static int const rgb_palette[] =
{
0x0, 0x0, 0x0,
0x0, 0x0, 0x7ff,
0x0, 0x7ff, 0x0,
0x0, 0x7ff, 0x7ff,
0x7ff, 0x0, 0x0,
0x7ff, 0x0, 0x7ff,
0x7ff, 0x7ff, 0x0,
0xaaa, 0xaaa, 0xaaa,
0x555, 0x555, 0x555,
0x000, 0x000, 0xfff,
0x000, 0xfff, 0x000,
0x000, 0xfff, 0xfff,
0xfff, 0x000, 0x000,
0xfff, 0x000, 0xfff,
0xfff, 0xfff, 0x000,
0xfff, 0xfff, 0xfff,
};
static int const rgb_weight[] =
{
//2, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
};
/* List of glyphs */
static char const * ascii_glyphs[] =
{
" ", ".", ":", ";", "t", "%", "S", "X", "@", "8", "?"
};
static char const * shades_glyphs[] =
{
" ", ":", "░", "▒", "?"
};
static char const * blocks_glyphs[] =
{
" ", "▘", "▚", "?"
};
#if !defined(_DOXYGEN_SKIP_ME)
enum color_mode
{
COLOR_MODE_MONO,
COLOR_MODE_GRAY,
COLOR_MODE_8,
COLOR_MODE_16,
COLOR_MODE_FULLGRAY,
COLOR_MODE_FULL8,
COLOR_MODE_FULL16,
};
struct cucul_bitmap
{
int bpp, has_palette, has_alpha;
int w, h, pitch;
int rmask, gmask, bmask, amask;
int rright, gright, bright, aright;
int rleft, gleft, bleft, aleft;
void (*get_hsv)(struct cucul_bitmap *, char *, int, int);
int red[256], green[256], blue[256], alpha[256];
float gamma;
int gammatab[4097];
/* Bitmap features */
int invert, antialias;
/* Colour mode used for rendering */
enum color_mode color_mode;
/* Glyphs used for rendering */
char const * const * glyphs;
unsigned glyph_count;
/* Current dithering method */
void (*init_dither) (int);
unsigned int (*get_dither) (void);
void (*increment_dither) (void);
};
#define HSV_XRATIO 6
#define HSV_YRATIO 3
#define HSV_HRATIO 3
#define HSV_DISTANCE(h, s, v, index) \
(hsv_palette[index * 4] \
* ((HSV_XRATIO * ((v) - hsv_palette[index * 4 + 3]) \
* ((v) - hsv_palette[index * 4 + 3])) \
+ (hsv_palette[index * 4 + 3] \
? (HSV_YRATIO * ((s) - hsv_palette[index * 4 + 2]) \
* ((s) - hsv_palette[index * 4 + 2])) \
: 0) \
+ (hsv_palette[index * 4 + 2] \
? (HSV_HRATIO * ((h) - hsv_palette[index * 4 + 1]) \
* ((h) - hsv_palette[index * 4 + 1])) \
: 0)))
#endif
/*
* Local prototypes
*/
static void mask2shift(unsigned int, int *, int *);
static float gammapow(float x, float y);
static void get_rgba_default(struct cucul_bitmap const *, uint8_t *, int, int,
unsigned int *);
/* Dithering methods */
static void init_no_dither(int);
static unsigned int get_no_dither(void);
static void increment_no_dither(void);
static void init_fstein_dither(int);
static unsigned int get_fstein_dither(void);
static void increment_fstein_dither(void);
static void init_ordered2_dither(int);
static unsigned int get_ordered2_dither(void);
static void increment_ordered2_dither(void);
static void init_ordered4_dither(int);
static unsigned int get_ordered4_dither(void);
static void increment_ordered4_dither(void);
static void init_ordered8_dither(int);
static unsigned int get_ordered8_dither(void);
static void increment_ordered8_dither(void);
static void init_random_dither(int);
static unsigned int get_random_dither(void);
static void increment_random_dither(void);
static inline int sq(int x)
{
return x * x;
}
static inline void rgb2hsv_default(int r, int g, int b,
int *hue, int *sat, int *val)
{
int min, max, delta;
min = r; max = r;
if(min > g) min = g; if(max < g) max = g;
if(min > b) min = b; if(max < b) max = b;
delta = max - min; /* 0 - 0xfff */
*val = max; /* 0 - 0xfff */
if(delta)
{
*sat = 0xfff * delta / max; /* 0 - 0xfff */
/* Generate *hue between 0 and 0x5fff */
if( r == max )
*hue = 0x1000 + 0x1000 * (g - b) / delta;
else if( g == max )
*hue = 0x3000 + 0x1000 * (b - r) / delta;
else
*hue = 0x5000 + 0x1000 * (r - g) / delta;
}
else
{
*sat = 0;
*hue = 0;
}
}
/**
* \brief Create an internal bitmap object.
*
* Create a bitmap structure from its coordinates (depth, width, height and
* pitch) and pixel mask values. If the depth is 8 bits per pixel, the mask
* values are ignored and the colour palette should be set using the
* cucul_set_bitmap_palette() function. For depths greater than 8 bits per
* pixel, a zero alpha mask causes the alpha values to be ignored.
*
* \param bpp Bitmap depth in bits per pixel.
* \param w Bitmap width in pixels.
* \param h Bitmap height in pixels.
* \param pitch Bitmap pitch in bytes.
* \param rmask Bitmask for red values.
* \param gmask Bitmask for green values.
* \param bmask Bitmask for blue values.
* \param amask Bitmask for alpha values.
* \return Bitmap object, or NULL upon error.
*/
struct cucul_bitmap *cucul_create_bitmap(unsigned int bpp, unsigned int w,
unsigned int h, unsigned int pitch,
unsigned int rmask, unsigned int gmask,
unsigned int bmask, unsigned int amask)
{
struct cucul_bitmap *bitmap;
int i;
/* Minor sanity test */
if(!w || !h || !pitch || bpp > 32 || bpp < 8)
return NULL;
bitmap = malloc(sizeof(struct cucul_bitmap));
if(!bitmap)
return NULL;
bitmap->bpp = bpp;
bitmap->has_palette = 0;
bitmap->has_alpha = amask ? 1 : 0;
bitmap->w = w;
bitmap->h = h;
bitmap->pitch = pitch;
bitmap->rmask = rmask;
bitmap->gmask = gmask;
bitmap->bmask = bmask;
bitmap->amask = amask;
/* Load bitmasks */
if(rmask || gmask || bmask || amask)
{
mask2shift(rmask, &bitmap->rright, &bitmap->rleft);
mask2shift(gmask, &bitmap->gright, &bitmap->gleft);
mask2shift(bmask, &bitmap->bright, &bitmap->bleft);
mask2shift(amask, &bitmap->aright, &bitmap->aleft);
}
/* In 8 bpp mode, default to a grayscale palette */
if(bpp == 8)
{
bitmap->has_palette = 1;
bitmap->has_alpha = 0;
for(i = 0; i < 256; i++)
{
bitmap->red[i] = i * 0xfff / 256;
bitmap->green[i] = i * 0xfff / 256;
bitmap->blue[i] = i * 0xfff / 256;
}
}
/* Default features */
bitmap->invert = 0;
bitmap->antialias = 1;
/* Default gamma value */
for(i = 0; i < 4096; i++)
bitmap->gammatab[i] = i;
/* Default colour mode */
bitmap->color_mode = COLOR_MODE_FULL16;
/* Default character set */
bitmap->glyphs = ascii_glyphs;
bitmap->glyph_count = sizeof(ascii_glyphs) / sizeof(*ascii_glyphs);
/* Default dithering mode */
bitmap->init_dither = init_fstein_dither;
bitmap->get_dither = get_fstein_dither;
bitmap->increment_dither = increment_fstein_dither;
return bitmap;
}
/**
* \brief Set the palette of an 8bpp bitmap object.
*
* Set the palette of an 8 bits per pixel bitmap. Values should be between
* 0 and 4095 (0xfff).
*
* \param bitmap Bitmap object.
* \param red Array of 256 red values.
* \param green Array of 256 green values.
* \param blue Array of 256 blue values.
* \param alpha Array of 256 alpha values.
*/
void cucul_set_bitmap_palette(struct cucul_bitmap *bitmap,
unsigned int red[], unsigned int green[],
unsigned int blue[], unsigned int alpha[])
{
int i, has_alpha = 0;
if(bitmap->bpp != 8)
return;
for(i = 0; i < 256; i++)
{
if(red[i] >= 0 && red[i] < 0x1000 &&
green[i] >= 0 && green[i] < 0x1000 &&
blue[i] >= 0 && blue[i] < 0x1000 &&
alpha[i] >= 0 && alpha[i] < 0x1000)
{
bitmap->red[i] = red[i];
bitmap->green[i] = green[i];
bitmap->blue[i] = blue[i];
if(alpha[i])
{
bitmap->alpha[i] = alpha[i];
has_alpha = 1;
}
}
}
bitmap->has_alpha = has_alpha;
}
/**
* \brief Set the brightness of a bitmap object.
*
* Set the brightness of bitmap.
*
* \param bitmap Bitmap object.
* \param brightness brightness value.
*/
void cucul_set_bitmap_brightness(struct cucul_bitmap *bitmap, float brightness)
{
/* FIXME */
}
/**
* \brief Set the gamma of a bitmap object.
*
* Set the gamma of bitmap.
*
* \param bitmap Bitmap object.
* \param gamma Gamma value.
*/
void cucul_set_bitmap_gamma(struct cucul_bitmap *bitmap, float gamma)
{
/* FIXME: we don't need 4096 calls to gammapow(), we can just compute
* 128 of them and do linear interpolation for the rest. This will
* probably speed up things a lot. */
int i;
if(gamma <= 0.0)
return;
bitmap->gamma = gamma;
for(i = 0; i < 4096; i++)
bitmap->gammatab[i] = 4096.0 * gammapow((float)i / 4096.0, 1.0 / gamma);
}
/**
* \brief Set the contrast of a bitmap object.
*
* Set the contrast of bitmap.
*
* \param bitmap Bitmap object.
* \param contrast contrast value.
*/
void cucul_set_bitmap_contrast(struct cucul_bitmap *bitmap, float contrast)
{
/* FIXME */
}
/**
* \brief Set bitmap antialiasing
*
* Tell the renderer whether to antialias the bitmap. Antialiasing smoothen
* the rendered image and avoids the commonly seen staircase effect. The
* method used is a simple prefilter antialiasing.
*
* \param bitmap Bitmap object.
* \param value 0 to disable antialiasing, 1 to activate it.
*/
void cucul_set_bitmap_antialias(struct cucul_bitmap *bitmap, int value)
{
bitmap->antialias = value ? 1 : 0;
}
/**
* \brief Invert colors of bitmap
*
* Invert colors of bitmap
*
* \param bitmap Bitmap object.
* \param value 0 for normal behaviour, 1 for invert
*/
void cucul_set_bitmap_invert(struct cucul_bitmap *bitmap, int value)
{
bitmap->invert = value ? 1 : 0;
}
/**
* \brief Choose colours used for bitmap rendering
*
* Tell the renderer which colours should be used to render the
* bitmap. Valid values for \e str are:
*
* \li \e "mono": use light gray on a black background.
*
* \li \e "gray": use white and two shades of gray on a black background.
*
* \li \e "8": use the 8 ANSI colours on a black background.
*
* \li \e "16": use the 16 ANSI colours on a black background.
*
* \li \e "fullgray": use black, white and two shades of gray for both the
* characters and the background.
*
* \li \e "full8": use the 8 ANSI colours for both the characters and the
* background.
*
* \li \e "full16": use the 16 ANSI colours for both the characters and the
* background. This is the default value.
*
* \param bitmap Bitmap object.
* \param str A string describing the colour set that will be used
* for the bitmap rendering.
*/
void cucul_set_bitmap_color(struct cucul_bitmap *bitmap, char const *str)
{
if(!strcasecmp(str, "mono"))
bitmap->color_mode = COLOR_MODE_MONO;
else if(!strcasecmp(str, "gray"))
bitmap->color_mode = COLOR_MODE_GRAY;
else if(!strcasecmp(str, "8"))
bitmap->color_mode = COLOR_MODE_8;
else if(!strcasecmp(str, "16"))
bitmap->color_mode = COLOR_MODE_16;
else if(!strcasecmp(str, "fullgray"))
bitmap->color_mode = COLOR_MODE_FULLGRAY;
else if(!strcasecmp(str, "full8"))
bitmap->color_mode = COLOR_MODE_FULL8;
else /* "full16" is the default */
bitmap->color_mode = COLOR_MODE_FULL16;
}
/**
* \brief Get available colour modes
*
* Return a list of available colour modes for a given bitmap. The list
* is a NULL-terminated array of strings, interleaving a string containing
* the internal value for the colour mode, to be used with
* \e cucul_set_bitmap_color(), and a string containing the natural
* language description for that colour mode.
*
* \param bitmap Bitmap object.
* \return An array of strings.
*/
char const * const *
cucul_get_bitmap_color_list(struct cucul_bitmap const *bitmap)
{
static char const * const list[] =
{
"mono", "white on black",
"gray", "grayscale on black",
"8", "8 colours on black",
"16", "16 colours on black",
"fullgray", "full grayscale",
"full8", "full 8 colours",
"full16", "full 16 colours",
NULL, NULL
};
return list;
}
/**
* \brief Choose characters used for bitmap rendering
*
* Tell the renderer which characters should be used to render the
* bitmap. Valid values for \e str are:
*
* \li \e "ascii": use only ASCII characters. This is the default value.
*
* \li \e "shades": use Unicode characters "U+2591 LIGHT SHADE", "U+2592
* MEDIUM SHADE" and "U+2593 DARK SHADE". These characters are also
* present in the CP437 codepage available on DOS and VGA.
*
* \li \e "blocks": use Unicode quarter-cell block combinations. These
* characters are only found in the Unicode set.
*
* \param bitmap Bitmap object.
* \param str A string describing the characters that need to be used
* for the bitmap rendering.
*/
void cucul_set_bitmap_charset(struct cucul_bitmap *bitmap, char const *str)
{
if(!strcasecmp(str, "shades"))
{
bitmap->glyphs = shades_glyphs;
bitmap->glyph_count = sizeof(shades_glyphs) / sizeof(*shades_glyphs);
}
else if(!strcasecmp(str, "blocks"))
{
bitmap->glyphs = blocks_glyphs;
bitmap->glyph_count = sizeof(blocks_glyphs) / sizeof(*blocks_glyphs);
}
else /* "ascii" is the default */
{
bitmap->glyphs = ascii_glyphs;
bitmap->glyph_count = sizeof(ascii_glyphs) / sizeof(*ascii_glyphs);
}
}
/**
* \brief Get available bitmap character sets
*
* Return a list of available character sets for a given bitmap. The list
* is a NULL-terminated array of strings, interleaving a string containing
* the internal value for the character set, to be used with
* \e cucul_set_bitmap_charset(), and a string containing the natural
* language description for that character set.
*
* \param bitmap Bitmap object.
* \return An array of strings.
*/
char const * const *
cucul_get_bitmap_charset_list(struct cucul_bitmap const *bitmap)
{
static char const * const list[] =
{
"ascii", "plain ASCII",
"shades", "CP437 shades",
"blocks", "Unicode blocks",
NULL, NULL
};
return list;
}
/**
* \brief Set bitmap dithering method
*
* Tell the renderer which dithering method should be used to render the
* bitmap. Dithering is necessary because the picture being rendered has
* usually far more colours than the available palette. Valid values for
* \e str are:
*
* \li \e "none": no dithering is used, the nearest matching colour is used.
*
* \li \e "ordered2": use a 2x2 Bayer matrix for dithering.
*
* \li \e "ordered4": use a 4x4 Bayer matrix for dithering.
*
* \li \e "ordered8": use a 8x8 Bayer matrix for dithering.
*
* \li \e "random": use random dithering.
*
* \li \e "fstein": use Floyd-Steinberg dithering. This is the default value.
*
* \param bitmap Bitmap object.
* \param str A string describing the dithering method that needs to be used
* for the bitmap rendering.
*/
void cucul_set_bitmap_dithering(struct cucul_bitmap *bitmap, char const *str)
{
if(!strcasecmp(str, "none"))
{
bitmap->init_dither = init_no_dither;
bitmap->get_dither = get_no_dither;
bitmap->increment_dither = increment_no_dither;
}
else if(!strcasecmp(str, "ordered2"))
{
bitmap->init_dither = init_ordered2_dither;
bitmap->get_dither = get_ordered2_dither;
bitmap->increment_dither = increment_ordered2_dither;
}
else if(!strcasecmp(str, "ordered4"))
{
bitmap->init_dither = init_ordered4_dither;
bitmap->get_dither = get_ordered4_dither;
bitmap->increment_dither = increment_ordered4_dither;
}
else if(!strcasecmp(str, "ordered4"))
{
bitmap->init_dither = init_ordered8_dither;
bitmap->get_dither = get_ordered8_dither;
bitmap->increment_dither = increment_ordered8_dither;
}
else if(!strcasecmp(str, "random"))
{
bitmap->init_dither = init_random_dither;
bitmap->get_dither = get_random_dither;
bitmap->increment_dither = increment_random_dither;
}
else /* "fstein" is the default */
{
bitmap->init_dither = init_fstein_dither;
bitmap->get_dither = get_fstein_dither;
bitmap->increment_dither = increment_fstein_dither;
}
}
/**
* \brief Get bitmap dithering methods
*
* Return a list of available dithering methods for a given bitmap. The list
* is a NULL-terminated array of strings, interleaving a string containing
* the internal value for the dithering method, to be used with
* \e cucul_set_bitmap_dithering(), and a string containing the natural
* language description for that dithering method.
*
* \param bitmap Bitmap object.
* \return An array of strings.
*/
char const * const *
cucul_get_bitmap_dithering_list(struct cucul_bitmap const *bitmap)
{
static char const * const list[] =
{
"none", "no dithering",
"ordered2", "2x2 ordered dithering",
"ordered2", "2x2 ordered dithering",
"ordered2", "2x2 ordered dithering",
"random", "random dithering",
"fstein", "Floyd-Steinberg dithering",
NULL, NULL
};
return list;
}
/**
* \brief Draw a bitmap on the screen.
*
* Draw a bitmap at the given coordinates. The bitmap can be of any size and
* will be stretched to the text area.
*
* \param x1 X coordinate of the upper-left corner of the drawing area.
* \param y1 Y coordinate of the upper-left corner of the drawing area.
* \param x2 X coordinate of the lower-right corner of the drawing area.
* \param y2 Y coordinate of the lower-right corner of the drawing area.
* \param bitmap Bitmap object to be drawn.
* \param pixels Bitmap's pixels.
*/
void cucul_draw_bitmap(cucul_t *qq, int x1, int y1, int x2, int y2,
struct cucul_bitmap const *bitmap, void *pixels)
{
int *floyd_steinberg, *fs_r, *fs_g, *fs_b;
int fs_length;
int x, y, w, h, pitch, deltax, deltay;
unsigned int dchmax;
if(!bitmap || !pixels)
return;
w = bitmap->w;
h = bitmap->h;
pitch = bitmap->pitch;
if(x1 > x2)
{
int tmp = x2; x2 = x1; x1 = tmp;
}
if(y1 > y2)
{
int tmp = y2; y2 = y1; y1 = tmp;
}
deltax = x2 - x1 + 1;
deltay = y2 - y1 + 1;
dchmax = bitmap->glyph_count;
fs_length = ((int)qq->width <= x2 ? (int)qq->width : x2) + 1;
floyd_steinberg = malloc(3 * (fs_length + 2) * sizeof(int));
memset(floyd_steinberg, 0, 3 * (fs_length + 2) * sizeof(int));
fs_r = floyd_steinberg + 1;
fs_g = fs_r + fs_length + 2;
fs_b = fs_g + fs_length + 2;
for(y = y1 > 0 ? y1 : 0; y <= y2 && y <= (int)qq->height; y++)
{
int remain_r = 0, remain_g = 0, remain_b = 0;
for(x = x1 > 0 ? x1 : 0, bitmap->init_dither(y);
x <= x2 && x <= (int)qq->width;
x++)
{
unsigned int i;
int ch = 0, distmin;
unsigned int rgba[4];
int fg_r = 0, fg_g = 0, fg_b = 0, bg_r, bg_g, bg_b;
int fromx, fromy, tox, toy, myx, myy, dots, dist;
int error[3];
enum cucul_color outfg = 0, outbg = 0;
char const *outch;
rgba[0] = rgba[1] = rgba[2] = rgba[3] = 0;
/* First get RGB */
if(bitmap->antialias)
{
fromx = (x - x1) * w / deltax;
fromy = (y - y1) * h / deltay;
tox = (x - x1 + 1) * w / deltax;
toy = (y - y1 + 1) * h / deltay;
/* We want at least one pixel */
if(tox == fromx) tox++;
if(toy == fromy) toy++;
dots = 0;
for(myx = fromx; myx < tox; myx++)
for(myy = fromy; myy < toy; myy++)
{
dots++;
get_rgba_default(bitmap, pixels, myx, myy, rgba);
}
/* Normalize */
rgba[0] /= dots;
rgba[1] /= dots;
rgba[2] /= dots;
rgba[3] /= dots;
}
else
{
fromx = (x - x1) * w / deltax;
fromy = (y - y1) * h / deltay;
tox = (x - x1 + 1) * w / deltax;
toy = (y - y1 + 1) * h / deltay;
/* tox and toy can overflow the screen, but they cannot overflow
* when averaged with fromx and fromy because these are guaranteed
* to be within the pixel boundaries. */
myx = (fromx + tox) / 2;
myy = (fromy + toy) / 2;
get_rgba_default(bitmap, pixels, myx, myy, rgba);
}
if(bitmap->has_alpha && rgba[3] < 0x800)
{
remain_r = remain_g = remain_b = 0;
fs_r[x] = 0;
fs_g[x] = 0;
fs_b[x] = 0;
continue;
}
/* XXX: OMG HAX */
if(bitmap->init_dither == init_fstein_dither)
{
rgba[0] += remain_r;
rgba[1] += remain_g;
rgba[2] += remain_b;
}
else
{
rgba[0] += (bitmap->get_dither() - 0x80) * 4;
rgba[1] += (bitmap->get_dither() - 0x80) * 4;
rgba[2] += (bitmap->get_dither() - 0x80) * 4;
}
distmin = INT_MAX;
for(i = 0; i < 16; i++)
{
dist = sq(rgba[0] - rgb_palette[i * 3])
+ sq(rgba[1] - rgb_palette[i * 3 + 1])
+ sq(rgba[2] - rgb_palette[i * 3 + 2]);
dist *= rgb_weight[i];
if(dist < distmin)
{
outbg = i;
distmin = dist;
}
}
bg_r = rgb_palette[outbg * 3];
bg_g = rgb_palette[outbg * 3 + 1];
bg_b = rgb_palette[outbg * 3 + 2];
/* FIXME: we currently only honour "full16" */
if(bitmap->color_mode == COLOR_MODE_FULL16)
{
distmin = INT_MAX;
for(i = 0; i < 16; i++)
{
if(i == outbg)
continue;
dist = sq(rgba[0] - rgb_palette[i * 3])
+ sq(rgba[1] - rgb_palette[i * 3 + 1])
+ sq(rgba[2] - rgb_palette[i * 3 + 2]);
dist *= rgb_weight[i];
if(dist < distmin)
{
outfg = i;
distmin = dist;
}
}
fg_r = rgb_palette[outfg * 3];
fg_g = rgb_palette[outfg * 3 + 1];
fg_b = rgb_palette[outfg * 3 + 2];
distmin = INT_MAX;
for(i = 0; i < dchmax - 1; i++)
{
int newr = i * fg_r + ((2*dchmax-1) - i) * bg_r;
int newg = i * fg_g + ((2*dchmax-1) - i) * bg_g;
int newb = i * fg_b + ((2*dchmax-1) - i) * bg_b;
dist = abs(rgba[0] * (2*dchmax-1) - newr)
+ abs(rgba[1] * (2*dchmax-1) - newg)
+ abs(rgba[2] * (2*dchmax-1) - newb);
if(dist < distmin)
{
ch = i;
distmin = dist;
}
}
outch = bitmap->glyphs[ch];
/* XXX: OMG HAX */
if(bitmap->init_dither == init_fstein_dither)
{
error[0] = rgba[0] - (fg_r * ch + bg_r * ((2*dchmax-1) - ch)) / (2*dchmax-1);
error[1] = rgba[1] - (fg_g * ch + bg_g * ((2*dchmax-1) - ch)) / (2*dchmax-1);
error[2] = rgba[2] - (fg_b * ch + bg_b * ((2*dchmax-1) - ch)) / (2*dchmax-1);
}
}
else
{
unsigned int lum = rgba[0];
if(rgba[1] > lum) lum = rgba[1];
if(rgba[2] > lum) lum = rgba[2];
outfg = outbg;
outbg = CUCUL_COLOR_BLACK;
ch = lum * dchmax / 0x1000;
if(ch < 0)
ch = 0;
else if(ch > (int)(dchmax - 1))
ch = dchmax - 1;
outch = bitmap->glyphs[ch];
/* XXX: OMG HAX */
if(bitmap->init_dither == init_fstein_dither)
{
error[0] = rgba[0] - bg_r * ch / (dchmax-1);
error[1] = rgba[1] - bg_g * ch / (dchmax-1);
error[2] = rgba[2] - bg_b * ch / (dchmax-1);
}
}
/* XXX: OMG HAX */
if(bitmap->init_dither == init_fstein_dither)
{
remain_r = fs_r[x+1] + 7 * error[0] / 16;
remain_g = fs_g[x+1] + 7 * error[1] / 16;
remain_b = fs_b[x+1] + 7 * error[2] / 16;
fs_r[x-1] += 3 * error[0] / 16;
fs_g[x-1] += 3 * error[1] / 16;
fs_b[x-1] += 3 * error[2] / 16;
fs_r[x] = 5 * error[0] / 16;
fs_g[x] = 5 * error[1] / 16;
fs_b[x] = 5 * error[2] / 16;
fs_r[x+1] = 1 * error[0] / 16;
fs_g[x+1] = 1 * error[1] / 16;
fs_b[x+1] = 1 * error[2] / 16;
}
if(bitmap->invert)
{
outfg = 15 - outfg;
outbg = 15 - outbg;
}
/* Now output the character */
cucul_set_color(qq, outfg, outbg);
cucul_putstr(qq, x, y, outch);
bitmap->increment_dither();
}
/* end loop */
}
free(floyd_steinberg);
}
/**
* \brief Free the memory associated with a bitmap.
*
* Free the memory allocated by cucul_create_bitmap().
*
* \param bitmap Bitmap object.
*/
void cucul_free_bitmap(struct cucul_bitmap *bitmap)
{
if(!bitmap)
return;
free(bitmap);
}
/*
* XXX: The following functions are local.
*/
/* Convert a mask, eg. 0x0000ff00, to shift values, eg. 8 and -4. */
static void mask2shift(unsigned int mask, int *right, int *left)
{
int rshift = 0, lshift = 0;
if(!mask)
{
*right = *left = 0;
return;
}
while(!(mask & 1))
{
mask >>= 1;
rshift++;
}
*right = rshift;
while(mask & 1)
{
mask >>= 1;
lshift++;
}
*left = 12 - lshift;
}
/* Compute x^y without relying on the math library */
static float gammapow(float x, float y)
{
#ifdef HAVE_FLDLN2
register double logx;
register long double v, e;
#else
register float tmp, t, t2, r;
int i;
#endif
if(x == 0.0)
return y == 0.0 ? 1.0 : 0.0;
#ifdef HAVE_FLDLN2
/* FIXME: this can be optimised by directly calling fyl2x for x and y */
asm volatile("fldln2; fxch; fyl2x"
: "=t" (logx) : "0" (x) : "st(1)");
asm volatile("fldl2e\n\t"
"fmul %%st(1)\n\t"
"fst %%st(1)\n\t"
"frndint\n\t"
"fxch\n\t"
"fsub %%st(1)\n\t"
"f2xm1\n\t"
: "=t" (v), "=u" (e) : "0" (y * logx));
v += 1.0;
asm volatile("fscale"
: "=t" (v) : "0" (v), "u" (e));
return v;
#else
/* Compute ln(x) for x ∈ ]0,1]
* ln(x) = 2 * (t + t^3/3 + t^5/5 + ...) with t = (x-1)/(x+1)
* The convergence is a bit slow, especially when x is near 0. */
t = (x - 1.0) / (x + 1.0);
t2 = t * t;
tmp = r = t;
for(i = 3; i < 20; i += 2)
{
r *= t2;
tmp += r / i;
}
/* Compute -y*ln(x) */
tmp = - y * 2.0 * tmp;
/* Compute x^-y as e^t where t = -y*ln(x):
* e^t = 1 + t/1! + t^2/2! + t^3/3! + t^4/4! + t^5/5! ...
* The convergence is quite faster here, thanks to the factorial. */
r = t = tmp;
tmp = 1.0 + t;
for(i = 2; i < 16; i++)
{
r = r * t / i;
tmp += r;
}
/* Return x^y as 1/(x^-y) */
return 1.0 / tmp;
#endif
}
static void get_rgba_default(struct cucul_bitmap const *bitmap, uint8_t *pixels,
int x, int y, unsigned int *rgba)
{
uint32_t bits;
pixels += (bitmap->bpp / 8) * x + bitmap->pitch * y;
switch(bitmap->bpp / 8)
{
case 4:
bits = *(uint32_t *)pixels;
break;
case 3:
{
#if defined(HAVE_ENDIAN_H)
if(__BYTE_ORDER == __BIG_ENDIAN)
#else
/* This is compile-time optimised with at least -O1 or -Os */
uint32_t const rmask = 0x12345678;
if(*(uint8_t const *)&rmask == 0x12)
#endif
bits = ((uint32_t)pixels[0] << 16) |
((uint32_t)pixels[1] << 8) |
((uint32_t)pixels[2]);
else
bits = ((uint32_t)pixels[2] << 16) |
((uint32_t)pixels[1] << 8) |
((uint32_t)pixels[0]);
break;
}
case 2:
bits = *(uint16_t *)pixels;
break;
case 1:
default:
bits = pixels[0];
break;
}
if(bitmap->has_palette)
{
rgba[0] += bitmap->gammatab[bitmap->red[bits]];
rgba[1] += bitmap->gammatab[bitmap->green[bits]];
rgba[2] += bitmap->gammatab[bitmap->blue[bits]];
rgba[3] += bitmap->alpha[bits];
}
else
{
rgba[0] += bitmap->gammatab[((bits & bitmap->rmask) >> bitmap->rright) << bitmap->rleft];
rgba[1] += bitmap->gammatab[((bits & bitmap->gmask) >> bitmap->gright) << bitmap->gleft];
rgba[2] += bitmap->gammatab[((bits & bitmap->bmask) >> bitmap->bright) << bitmap->bleft];
rgba[3] += ((bits & bitmap->amask) >> bitmap->aright) << bitmap->aleft;
}
}
/*
* No dithering
*/
static void init_no_dither(int line)
{
;
}
static unsigned int get_no_dither(void)
{
return 0x80;
}
static void increment_no_dither(void)
{
return;
}
/*
* Floyd-Steinberg dithering
*/
static void init_fstein_dither(int line)
{
;
}
static unsigned int get_fstein_dither(void)
{
return 0x80;
}
static void increment_fstein_dither(void)
{
return;
}
/*
* Ordered 2 dithering
*/
static unsigned int const *ordered2_table;
static unsigned int ordered2_index;
static void init_ordered2_dither(int line)
{
static unsigned int const dither2x2[] =
{
0x00, 0x80,
0xc0, 0x40,
};
ordered2_table = dither2x2 + (line % 2) * 2;
ordered2_index = 0;
}
static unsigned int get_ordered2_dither(void)
{
return ordered2_table[ordered2_index];
}
static void increment_ordered2_dither(void)
{
ordered2_index = (ordered2_index + 1) % 2;
}
/*
* Ordered 4 dithering
*/
/*static int dither4x4[] = { 5, 0, 1, 6,
-1, -6, -5, 2,
-2, -7, -8, 3,
4, -3, -4, -7};*/
static unsigned int const *ordered4_table;
static unsigned int ordered4_index;
static void init_ordered4_dither(int line)
{
static unsigned int const dither4x4[] =
{
0x00, 0x80, 0x20, 0xa0,
0xc0, 0x40, 0xe0, 0x60,
0x30, 0xb0, 0x10, 0x90,
0xf0, 0x70, 0xd0, 0x50
};
ordered4_table = dither4x4 + (line % 4) * 4;
ordered4_index = 0;
}
static unsigned int get_ordered4_dither(void)
{
return ordered4_table[ordered4_index];
}
static void increment_ordered4_dither(void)
{
ordered4_index = (ordered4_index + 1) % 4;
}
/*
* Ordered 8 dithering
*/
static unsigned int const *ordered8_table;
static unsigned int ordered8_index;
static void init_ordered8_dither(int line)
{
static unsigned int const dither8x8[] =
{
0x00, 0x80, 0x20, 0xa0, 0x08, 0x88, 0x28, 0xa8,
0xc0, 0x40, 0xe0, 0x60, 0xc8, 0x48, 0xe8, 0x68,
0x30, 0xb0, 0x10, 0x90, 0x38, 0xb8, 0x18, 0x98,
0xf0, 0x70, 0xd0, 0x50, 0xf8, 0x78, 0xd8, 0x58,
0x0c, 0x8c, 0x2c, 0xac, 0x04, 0x84, 0x24, 0xa4,
0xcc, 0x4c, 0xec, 0x6c, 0xc4, 0x44, 0xe4, 0x64,
0x3c, 0xbc, 0x1c, 0x9c, 0x34, 0xb4, 0x14, 0x94,
0xfc, 0x7c, 0xdc, 0x5c, 0xf4, 0x74, 0xd4, 0x54,
};
ordered8_table = dither8x8 + (line % 8) * 8;
ordered8_index = 0;
}
static unsigned int get_ordered8_dither(void)
{
return ordered8_table[ordered8_index];
}
static void increment_ordered8_dither(void)
{
ordered8_index = (ordered8_index + 1) % 8;
}
/*
* Random dithering
*/
static void init_random_dither(int line)
{
;
}
static unsigned int get_random_dither(void)
{
return cucul_rand(0x00, 0xff);
}
static void increment_random_dither(void)
{
return;
}
#if !defined(_DOXYGEN_SKIP_ME)
int _cucul_init_bitmap(void)
{
unsigned int v, s, h;
/* These ones are constant */
lookup_colors[0] = CUCUL_COLOR_BLACK;
lookup_colors[1] = CUCUL_COLOR_DARKGRAY;
lookup_colors[2] = CUCUL_COLOR_LIGHTGRAY;
lookup_colors[3] = CUCUL_COLOR_WHITE;
/* These ones will be overwritten */
lookup_colors[4] = CUCUL_COLOR_MAGENTA;
lookup_colors[5] = CUCUL_COLOR_LIGHTMAGENTA;
lookup_colors[6] = CUCUL_COLOR_RED;
lookup_colors[7] = CUCUL_COLOR_LIGHTRED;
for(v = 0; v < LOOKUP_VAL; v++)
for(s = 0; s < LOOKUP_SAT; s++)
for(h = 0; h < LOOKUP_HUE; h++)
{
int i, distbg, distfg, dist;
int val, sat, hue;
unsigned char outbg, outfg;
val = 0xfff * v / (LOOKUP_VAL - 1);
sat = 0xfff * s / (LOOKUP_SAT - 1);
hue = 0xfff * h / (LOOKUP_HUE - 1);
/* Initialise distances to the distance between pure black HSV
* coordinates and our white colour (3) */
outbg = outfg = 3;
distbg = distfg = HSV_DISTANCE(0, 0, 0, 3);
/* Calculate distances to eight major colour values and store the
* two nearest points in our lookup table. */
for(i = 0; i < 8; i++)
{
dist = HSV_DISTANCE(hue, sat, val, i);
if(dist <= distbg)
{
outfg = outbg;
distfg = distbg;
outbg = i;
distbg = dist;
}
else if(dist <= distfg)
{
outfg = i;
distfg = dist;
}
}
hsv_distances[v][s][h] = (outfg << 4) | outbg;
}
return 0;
}
int _cucul_end_bitmap(void)
{
return 0;
}
#endif /* _DOXYGEN_SKIP_ME */