radare2/libr/cons/rgb.c

/* radare - LGPL - Copyright 2013-2022 - pancake, xarkes */
/* ansi 256 color extension for r_cons */
/* https://en.wikipedia.org/wiki/ANSI_color */

#include <r_cons.h>
#include <r_th.h>

static const int value_range[6] = { 0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff};

static void init_color_table(void) {
	RConsContext *ctx = r_cons_singleton ()->context;
	int i, r, g, b;
	// ansi colors
	ctx->colors[0] = 0x000000;
	ctx->colors[1] = 0x800000;
	ctx->colors[2] = 0x008000;
	ctx->colors[3] = 0x808000;
	ctx->colors[4] = 0x000080;
	ctx->colors[5] = 0x800080;
	ctx->colors[6] = 0x008080;
	ctx->colors[7] = 0xc0c0c0;
	ctx->colors[8] = 0x808080;
	ctx->colors[9] = 0xff0000;
	ctx->colors[10] = 0x00ff00;
	ctx->colors[11] = 0xffff00;
	ctx->colors[12] = 0x0000ff;
	ctx->colors[13] = 0xff00ff;
	ctx->colors[14] = 0x00ffff;
	ctx->colors[15] = 0xffffff;
	// color palette
	for (i = 0; i < 216; i++) {
		r = value_range[(i / 36) % 6];
		g = value_range[(i / 6) % 6];
		b = value_range[i % 6];
		ctx->colors[i + 16] = ((r << 16) & 0xffffff) +
			((g << 8) & 0xffff) + (b & 0xff);
	}
	// grayscale
	for (i = 0; i < 24; i++) {
		r = 8 + (i * 10);
		ctx->colors[i + 232] = ((r << 16) & 0xffffff) +
			((r << 8) & 0xffff) + (r & 0xff);
	}
}

static int __lookup_rgb(int r, int g, int b) {
	RConsContext *ctx = r_cons_singleton ()->context;
	int i, color = (r << 16) + (g << 8) + b;
	// lookup extended colors only, coz non-extended can be changed by users.
	for (i = 16; i < 232; i++) {
		if (ctx->colors[i] == color) {
			return i;
		}
	}
	return -1;
}

static ut32 __approximate_rgb(int r, int g, int b) {
	bool grey = (r > 0 && r < 255 && r == g && r == b);
	if (grey) {
		return 232 + (int)((double)r / (255 / 24.1));
	}
#if 0
	const double M = 16;
	double R = r;
	double G = g;
	double B = b;
	R = R /256 * 216;
	R /= 256 * 216;
	R /= 256 * 216;
	r = R = R_DIM (R / 16, 0, 16);
	g = G = R_DIM (G / 16, 0, 16);
	b = B = R_DIM (B / 16, 0, 16);
	r &= 0xff;
	g &= 0xff;
	b &= 0xff;
	return (ut32)((G * M * M)  + (g * M) + b) + 16;
#else
	const int k = 256 / 6;
	r = R_DIM (r / k, 0, 5);
	g = R_DIM (g / k, 0, 5);
	b = R_DIM (b / k, 0, 5);
	return 16 + (r * 36) + (g * 6) + b;
#endif
}

static int rgb(int r, int g, int b) {
	int c = __lookup_rgb (r, g, b);
	if (c == -1) {
		return __approximate_rgb (r, g, b);
	}
	return c;
}

static void __unrgb(int color, int *r, int *g, int *b) {
	RConsContext *ctx = r_cons_singleton ()->context;
	if (color < 0 || color > 255) {
		*r = *g = *b = 0;
	} else {
		int rgb = ctx->colors[color];
		*r = (rgb >> 16) & 0xff;
		*g = (rgb >> 8) & 0xff;
		*b = rgb & 0xff;
	}
}

R_API void r_cons_rgb_init(void) {
	RConsContext *ctx = r_cons_singleton ()->context;
	if (ctx->colors[255] == 0) {
		init_color_table ();
	}
}

/* Parse an ANSI code string into RGB values -- Used by HTML filter only */
R_API int r_cons_rgb_parse(const char *p, ut8 *r, ut8 *g, ut8 *b, ut8 *a) {
	const char *q = 0;
	ut8 isbg = 0, bold = 127;
	if (!p) {
		return 0;
	}
	if (*p == 0x1b) {
		p++;
		if (!*p) {
			return 0;
		}
	}
	if (*p == '[') {
		p++;
		if (!*p) {
			return 0;
		}
	}
	// here, p should be just after the '['
	switch (*p) {
	case '1':
		bold = 255;
		if (!p[1] || !p[2]) {
			return 0;
		}
		p += 2;
		break;
	case '3': isbg = 0; break;
	case '4': isbg = 1; break;
	}
#define SETRGB(x,y,z) if (r) *r = (x); if (g) *g = (y); if (b) *b = (z)
	if (bold != 255 && strchr (p, ';')) {
		if (!p[0] || !p[1] || !p[2]) {
			return 0;
		}
		if (p[3] == '5')  { // \x1b[%d;5;%dm is 256 colors
			int x, y, z;
			if (!p[3] || !p[4]) {
				return 0;
			}
			int n = atoi (p + 5);
			__unrgb (n, &x, &y, &z);
			SETRGB (x, y, z);
		} else { // 16M colors (truecolor)
			/* complex rgb */
			if (!p[3] || !p[4]) {
				return 0;
			}
			p += 5;
			if (r) {
				*r = atoi (p);
			}
			q = strchr (p, ';');
			if (!q) {
				return 0;
			}
			if (g) {
				*g = atoi (q + 1);
			}
			q = strchr (q + 1, ';');
			if (!q) {
				return 0;
			}
			if (b) {
				*b = atoi (q + 1);
			}
		}
		return 1;
	} else {
		/* plain ansi escape codes */
		if (a) {
			*a = isbg;
		}
		if (!*p) {
			return 0;
		}
		switch (p[1]) {
		case '0': SETRGB (0, 0, 0); break;
		case '1': SETRGB (bold, 0, 0); break;
		case '2': SETRGB (0, bold, 0); break;
		case '3': SETRGB (bold, bold, 0); break;
		case '4': SETRGB (0, 0, bold); break;
		case '5': SETRGB (bold, 0, bold); break;
		case '6': SETRGB (0, bold, bold); break;
		case '7': SETRGB (bold, bold, bold); break;
		}
	}
	return 1;
}

R_API char *r_cons_rgb_str_off(char *outstr, size_t sz, ut64 off) {
	RColor rc = RColor_BLACK;
	rc.id16 = -1;
	rc.r = (off >> 2) & 0xff;
	rc.g = (off >> 6) & 0xff;
	rc.b = (off >> 12) & 0xff;
	return r_cons_rgb_str (outstr, sz, &rc);
}

/* Compute color string depending on cons->color */
static void r_cons_rgb_gen(RConsColorMode mode, char *outstr, size_t sz, ut8 attr, ut8 a, ut8 r, ut8 g, ut8 b, st8 id16) {
	ut8 fgbg = (a == ALPHA_BG)? 48: 38; // ANSI codes for Background/Foreground

	if (sz < 4) { // must have at least room for "<esc>[m\0"
		if (sz > 0) {
			outstr[0] = '\0';
		}
		return;
	}

	size_t i = 2;
	outstr[0] = '\x1b';
	outstr[1] = '[';
	for (; attr; attr &= attr - 1) {
		if (sz < i + 4) { // must have at least room for e.g. "1;m\0"
			outstr[0] = '\0';
			return;
		}
		switch (attr & -attr) {
		case R_CONS_ATTR_BOLD: outstr[i] = '1'; break;
		case R_CONS_ATTR_DIM: outstr[i] = '2'; break;
		case R_CONS_ATTR_ITALIC: outstr[i] = '3'; break;
		case R_CONS_ATTR_UNDERLINE: outstr[i] = '4'; break;
		case R_CONS_ATTR_BLINK: outstr[i] = '5'; break;
		}
		outstr[i + 1] = ';';
		i += 2;
	}

	int written = -1;
	switch (mode) {
	case COLOR_MODE_256: // 256 color palette
		written = snprintf (outstr + i, sz - i, "%d;5;%dm", fgbg, rgb (r, g, b));
		break;
	case COLOR_MODE_16M: // 16M (truecolor)
		written = snprintf (outstr + i, sz - i, "%d;2;%d;%d;%dm", fgbg, r, g, b);
		break;
	case COLOR_MODE_16: { // ansi 16 colors
		ut8 bright, c;
		fgbg -= 8;
		if (id16 >= 0 && id16 <= 15) {
			c = id16 % 8;
			bright = id16 >= 8 ? 60 : 0;
		} else {
			bright = (r == 0x80 && g == 0x80 && b == 0x80)
				? 53
				: (r == 0xff || g == 0xff || b == 0xff)
					? 60
					: 0;  // eco bright-specific
			ut8 k = (r + g + b) / 3;
			r = (r >= k) ? 1 : 0;
			g = (g >= k) ? 1 : 0;
			b = (b >= k) ? 1 : 0;
			c = r + (g << 1) + (b << 2);
		}
		written = snprintf (outstr + i, sz - i, "%dm", fgbg + bright + c);
		break;
	}
	default:
		break;
	}

	if (written < 0 || written >= sz - i) {
		outstr[0] = '\0';
	}
}

/* Return the computed color string for the specified color in the specified mode */
R_API char *r_cons_rgb_str_mode(RConsColorMode mode, char *outstr, size_t sz, RColor *rcolor) {
	if (!rcolor) {
		return NULL;
	}
	if (!outstr) {
		sz = 64;
		outstr = calloc (sz, 1);
	}
	*outstr = 0;
	if (rcolor->a == ALPHA_RESET) {
		strcpy (outstr, Color_RESET);
		return outstr;
	}
	// If the color handles both foreground and background, also add background
	if (rcolor->a == ALPHA_FGBG) {
		r_cons_rgb_gen (mode, outstr, sz, 0, ALPHA_BG, rcolor->r2, rcolor->g2, rcolor->b2, rcolor->id16);
	}
	// APPEND
	size_t len = strlen (outstr);
	r_cons_rgb_gen (mode, outstr + len, sz - len, rcolor->attr, rcolor->a, rcolor->r, rcolor->g, rcolor->b,
			rcolor->id16);

	return outstr;
}

/* Return the computed color string for the specified color */
R_API char *r_cons_rgb_str(char *outstr, size_t sz, RColor *rcolor) {
	return r_cons_rgb_str_mode (r_cons_context ()->color_mode, outstr, sz, rcolor);
}

R_API char *r_cons_rgb_tostring(ut8 r, ut8 g, ut8 b) {
	const char *str = NULL;
	if (r == 0x00 && g == b && g == 0) {
		str = "black";
	}
	if (r == 0xff && g == b && g == 0xff) {
		str = "white";
	}
	if (r == 0xff && g == b && g == 0) {
		str = "red";
	}
	if (g == 0xff && r == b && r == 0) {
		str = "green";
	}
	if (b == 0xff && r == g && r == 0) {
		str = "blue";
	}
	if (r == 0xff && g == 0xff && b == 0x00) {
		str = "yellow";
	}
	if (r == 0x00 && g == 0xff && b == 0xff) {
		str = "cyan";
	}
	if (r == 0xff && g == 0x00 && b == 0xff) {
		str = "magenta";
	}
	return str? strdup (str) : r_str_newf ("#%02x%02x%02x", r, g, b);
}