From 56dec05d29098b151421625c68525c2c3961e574 Mon Sep 17 00:00:00 2001

From: David Herrmann <dh.herrmann@gmail.com>

Date: Fri, 3 Oct 2014 14:44:41 +0200

Subject: [PATCH] terminal/screen: add color converter

Terminals use pseudo color-codes mixed with 8bit and 24bit colors. Provide

a color-converter so external renderers only have to deal with ARGB32

colors.

This requires a color-palette as input as there's no fixed mapping. We

provide a default, but maybe we wanna support external palettes in the

future.

---

 src/libsystemd-terminal/term-parser.c | 116 ++++++++++++++++++++++++++++++++++

 src/libsystemd-terminal/term-screen.c |  26 +-------

 src/libsystemd-terminal/term.h        |   2 +

 3 files changed, 120 insertions(+), 24 deletions(-)

diff --git a/src/libsystemd-terminal/term-parser.c b/src/libsystemd-terminal/term-parser.c

index f9326d563a..8ec6345d60 100644

--- a/src/libsystemd-terminal/term-parser.c

+++ b/src/libsystemd-terminal/term-parser.c

@@ -35,6 +35,122 @@

 #include "term-internal.h"

 #include "util.h"

+static const uint8_t default_palette[18][3] = {

+        {   0,   0,   0 }, /* black */

+        { 205,   0,   0 }, /* red */

+        {   0, 205,   0 }, /* green */

+        { 205, 205,   0 }, /* yellow */

+        {   0,   0, 238 }, /* blue */

+        { 205,   0, 205 }, /* magenta */

+        {   0, 205, 205 }, /* cyan */

+        { 229, 229, 229 }, /* light grey */

+        { 127, 127, 127 }, /* dark grey */

+        { 255,   0,   0 }, /* light red */

+        {   0, 255,   0 }, /* light green */

+        { 255, 255,   0 }, /* light yellow */

+        {  92,  92, 255 }, /* light blue */

+        { 255,   0, 255 }, /* light magenta */

+        {   0, 255, 255 }, /* light cyan */

+        { 255, 255, 255 }, /* white */

+

+        { 229, 229, 229 }, /* light grey */

+        {   0,   0,   0 }, /* black */

+};

+

+static uint32_t term_color_to_argb32(const term_color *color, const term_attr *attr, const uint8_t *palette) {

+        static const uint8_t bval[] = {

+                0x00, 0x5f, 0x87,

+                0xaf, 0xd7, 0xff,

+        };

+        uint8_t r, g, b, t;

+

+        assert(color);

+

+        if (!palette)

+                palette = (void*)default_palette;

+

+        switch (color->ccode) {

+        case TERM_CCODE_RGB:

+                r = color->red;

+                g = color->green;

+                b = color->blue;

+

+                break;

+        case TERM_CCODE_256:

+                t = color->c256;

+                if (t < 16) {

+                        r = palette[t * 3 + 0];

+                        g = palette[t * 3 + 1];

+                        b = palette[t * 3 + 2];

+                } else if (t < 232) {

+                        t -= 16;

+                        b = bval[t % 6];

+                        t /= 6;

+                        g = bval[t % 6];

+                        t /= 6;

+                        r = bval[t % 6];

+                } else {

+                        t = (t - 232) * 10 + 8;

+                        r = t;

+                        g = t;

+                        b = t;

+                }

+

+                break;

+        case TERM_CCODE_BLACK ... TERM_CCODE_LIGHT_WHITE:

+                t = color->ccode - TERM_CCODE_BLACK;

+

+                /* bold causes light colors */

+                if (t < 8 && attr->bold)

+                        t += 8;

+

+                r = palette[t * 3 + 0];

+                g = palette[t * 3 + 1];

+                b = palette[t * 3 + 2];

+                break;

+        case TERM_CCODE_DEFAULT:

+                /* fallthrough */

+        default:

+                t = 16 + !(color == &attr->fg);

+                r = palette[t * 3 + 0];

+                g = palette[t * 3 + 1];

+                b = palette[t * 3 + 2];

+                break;

+        }

+

+        return (0xff << 24) | (r << 16) | (g << 8) | b;

+}

+

+/**

+ * term_attr_to_argb32() - Encode terminal colors as native ARGB32 value

+ * @color: Terminal attributes to work on

+ * @fg: Storage for foreground color (or NULL)

+ * @bg: Storage for background color (or NULL)

+ * @palette: The color palette to use (or NULL for default)

+ *

+ * This encodes the colors attr->fg and attr->bg as native-endian ARGB32 values

+ * and returns them. Any color conversions are automatically applied.

+ */

+void term_attr_to_argb32(const term_attr *attr, uint32_t *fg, uint32_t *bg, const uint8_t *palette) {

+        uint32_t f, b, t;

+

+        assert(attr);

+

+        f = term_color_to_argb32(&attr->fg, attr, palette);

+        b = term_color_to_argb32(&attr->bg, attr, palette);

+

+        if (attr->inverse) {

+                t = f;

+                f = b;

+                b = t;

+        }

+

+        if (fg)

+                *fg = f;

+        if (bg)

+                *bg = b;

+}

+

 /**

  * term_utf8_encode() - Encode single UCS-4 character as UTF-8

  * @out_utf8: output buffer of at least 4 bytes or NULL

diff --git a/src/libsystemd-terminal/term-screen.c b/src/libsystemd-terminal/term-screen.c

index ccfb9a450c..3f7ef1cf3c 100644

--- a/src/libsystemd-terminal/term-screen.c

+++ b/src/libsystemd-terminal/term-screen.c

@@ -2944,31 +2944,9 @@ static int screen_SGR(term_screen *screen, const term_seq *seq) {

                                 if (i >= seq->n_args || seq->args[i] < 0)

                                         break;

+                                dst->ccode = TERM_CCODE_256;

                                 code = seq->args[i];

-                                if (code < 16) {

-                                        dst->ccode = code;

-                                } else if (code < 232) {

-                                        static const uint8_t bval[] = {

-                                                0x00, 0x5f, 0x87,

-                                                0xaf, 0xd7, 0xff,

-                                        };

-

-                                        dst->ccode = TERM_CCODE_256;

-                                        dst->c256 = code;

-                                        code -= 16;

-                                        dst->blue = bval[code % 6];

-                                        code /= 6;

-                                        dst->green = bval[code % 6];

-                                        code /= 6;

-                                        dst->red = bval[code % 6];

-                                } else if (code < 256) {

-                                        dst->ccode = TERM_CCODE_256;

-                                        dst->c256 = code;

-                                        code = (code - 232) * 10 + 8;

-                                        dst->red = code;

-                                        dst->green = code;

-                                        dst->blue = code;

-                                }

+                                dst->c256 = code < 256 ? code : 0;

                                 break;

                         }

diff --git a/src/libsystemd-terminal/term.h b/src/libsystemd-terminal/term.h

index 5228ce0601..8efd48b263 100644

--- a/src/libsystemd-terminal/term.h

+++ b/src/libsystemd-terminal/term.h

@@ -97,6 +97,8 @@ struct term_attr {

         unsigned int hidden : 1;                /* hidden */

 };

+void term_attr_to_argb32(const term_attr *attr, uint32_t *fg, uint32_t *bg, const uint8_t *palette);

+

 /*

  * UTF-8

  */