/* * libcucul Canvas for ultrafast compositing of Unicode letters * Copyright (c) 2002-2006 Sam Hocevar * 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 * \brief Bitmap blitting * * This file contains bitmap blitting functions. */ #include "config.h" #if !defined(__KERNEL__) # if defined(HAVE_ENDIAN_H) # include # endif # include # include # include # include #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); 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 */