Changeset 820Tweet

Timestamp:

Apr 19, 2006, 1:50:24 PM (15 years ago)

Author:

Sam Hocevar

Message:

• Moved the technical discussion on S-Lang's palette optimisation from NOTES to tools/optipal.c.

Location:

libcaca/trunk

Files:

• NOTES (modified) (1 diff)
• tools/optipal.c (modified) (1 diff)

libcaca/trunk/NOTES

@@ -116 +116 @@
        doesn't work on konsole
 
-   o  S-Lang:
-
-      256 character pairs are definable, but only 128 can be used. This is
-      because slsmg.c's This_Color variable uses its 8th bit to indicate an
-      alternate character set. Replacing a few 0x7F with 0xFF in sldisply.c
-      works around the problem but gets rid of the alternate charset.
-
-      We can work around this problem. See this usage grid:
-
-                      bg                         1 1 1 1 1 1
-        fg                  0 1 2 3 4 5 6 7  8 9 0 1 2 3 4 5
-
-        0 (black)             C C C C C C F  B c c c c c c F
-        1 (blue)            A   h D h D i f  C C h E h E k g
-        2 (green)           A h   D h i D f  C h C E h k E g
-        3 (cyan)            A D D   i h h f  C E E C k h h g
-        4 (red)             A h h i   D D f  C h h k C E E g
-        5 (magenta)         A D i h D   h f  C E k h E C h g
-        6 (brown)           A i D h D h   f  C k E h E h C g
-        7 (light gray)      A F a a a a a    B C C C C C C B
-
-        8 (dark gray)       A C C C C C C B    d d d d d d F
-        9 (light blue)      A C h E h E j C  e   h D h D l C
-        10 (light green)    A h C E h j E C  e h   D h l D C
-        11 (light cyan)     A E E C j h h C  e D D   l h h C
-        12 (light red)      A h h j C E E C  e h h l   D D C
-        13 (light magenta)  A E j h E C h C  e D l h D   h C
-        14 (yellow)         A j E h E h C C  e l D h D h   C
-        15 (white)          A F b b b b b B  F C C C C C C  
-
-      ' ': useless colour pairs that can be emulated by printing a space in
-           any other colour pair that has the same background
-      'A': black background colour pairs that are needed for the old renderer
-      'B': gray combinations used for grayscale dithering
-      'C': white/light, light/dark, lightgray/light, darkgray/dark, dark/black
-           combinations often used for saturation/value dithering (the two
-           other possible combinations, lightgray/dark and darkgray/light, are
-           not considered here)
-      'D': next colour combinations for hue dithering (magenta/blue, blue/green
-           and so on)
-      'E': next colour combinations for hue/value dithering (blue/lightgreen,
-           green/lightblue and so on)
-      'F': black on light gray, black on white, white on dark gray, dark gray
-           on white, white on blue, light gray on blue (chosen arbitrarily)
-
-      'A': 15 colour pairs
-      'A'+'B': 20 colour pairs
-      'A'+'B'+'C': 74 colour pairs
-      'A'+'B'+'C'+'D': 98 colour pairs
-      'A'+'B'+'C'+'D'+'E': 122 colour pairs
-      'A'+'B'+'C'+'D'+'E'+'F': 128 colour pairs
-
-      The remaining slightly important colour pairs are:
-
-      'a': light gray on dark colour: emulate with light colour on dark colour
-      'b': white on dark colour: emulate with light gray on light colour
-      'c': black on light colour: emulate with dark gray on dark colour
-      'd': dark gray on light colour: emulate with dark colour on light colour
-      'e': light colour on dark gray: emulate with dark colour on dark gray
-      'f': dark colour on light gray: emulate with light colour on light gray
-      'g': dark colour on white: emulate with light colour on white
-
-      And now the seldom used pairs:
-
-      'h': 120 degree hue pairs can be emulated as well; for instance blue on
-           red can be emulated using magenta on red, and blue on green using
-           cyan on green
-
-      And the almost never used pairs:
-
-      'i': dark opposite on dark: emulate with dark opposite on black
-      'j': light opposite on dark: emulate with light opposite on black
-      'k': dark opposite on light: emulate with black on dark
-      'l': light opposite on light: emulate with white on light
-
    o  MS-DOS: all bright colours, bright backgrounds, and bright combinations
       work using <conio.h>. No need to kludge anything.

libcaca/trunk/tools/optipal.c

@@ -89 +89 @@
 
 /*
- * XXX: See the NOTES file for what follows
+ *  256 character pairs are definable, but only 128 can be used. This is
+ *  because slsmg.c's This_Color variable uses its 8th bit to indicate an
+ *  alternate character set. Replacing a few 0x7F with 0xFF in sldisply.c
+ *  works around the problem but gets rid of the alternate charset.
+ *
+ *  We can work around this problem. See this usage grid:
+ *
+ *                  bg                         1 1 1 1 1 1
+ *    fg                  0 1 2 3 4 5 6 7  8 9 0 1 2 3 4 5
+ *
+ *    0 (black)             C C C C C C F  B c c c c c c F
+ *    1 (blue)            A   h D h D i f  C C h E h E k g
+ *    2 (green)           A h   D h i D f  C h C E h k E g
+ *    3 (cyan)            A D D   i h h f  C E E C k h h g
+ *    4 (red)             A h h i   D D f  C h h k C E E g
+ *    5 (magenta)         A D i h D   h f  C E k h E C h g
+ *    6 (brown)           A i D h D h   f  C k E h E h C g
+ *    7 (light gray)      A F a a a a a    B C C C C C C B
+ *
+ *    8 (dark gray)       A C C C C C C B    d d d d d d F
+ *    9 (light blue)      A C h E h E j C  e   h D h D l C
+ *    10 (light green)    A h C E h j E C  e h   D h l D C
+ *    11 (light cyan)     A E E C j h h C  e D D   l h h C
+ *    12 (light red)      A h h j C E E C  e h h l   D D C
+ *    13 (light magenta)  A E j h E C h C  e D l h D   h C
+ *    14 (yellow)         A j E h E h C C  e l D h D h   C
+ *    15 (white)          A F b b b b b B  F C C C C C C
+ *
+ *  ' ': useless colour pairs that can be emulated by printing a space in
+ *       any other colour pair that has the same background
+ *  'A': black background colour pairs that are needed for the old renderer
+ *  'B': gray combinations used for grayscale dithering
+ *  'C': white/light, light/dark, lightgray/light, darkgray/dark, dark/black
+ *       combinations often used for saturation/value dithering (the two
+ *       other possible combinations, lightgray/dark and darkgray/light, are
+ *       not considered here)
+ *  'D': next colour combinations for hue dithering (magenta/blue, blue/green
+ *       and so on)
+ *  'E': next colour combinations for hue/value dithering (blue/lightgreen,
+ *       green/lightblue and so on)
+ *  'F': black on light gray, black on white, white on dark gray, dark gray
+ *       on white, white on blue, light gray on blue (chosen arbitrarily)
+ *
+ *  'A': 15 colour pairs
+ *  'A'+'B': 20 colour pairs
+ *  'A'+'B'+'C': 74 colour pairs
+ *  'A'+'B'+'C'+'D': 98 colour pairs
+ *  'A'+'B'+'C'+'D'+'E': 122 colour pairs
+ *  'A'+'B'+'C'+'D'+'E'+'F': 128 colour pairs
+ *
+ *  The remaining slightly important colour pairs are:
+ *
+ *  'a': light gray on dark colour: emulate with light colour on dark colour
+ *  'b': white on dark colour: emulate with light gray on light colour
+ *  'c': black on light colour: emulate with dark gray on dark colour
+ *  'd': dark gray on light colour: emulate with dark colour on light colour
+ *  'e': light colour on dark gray: emulate with dark colour on dark gray
+ *  'f': dark colour on light gray: emulate with light colour on light gray
+ *  'g': dark colour on white: emulate with light colour on white
+ *
+ *  And now the seldom used pairs:
+ *
+ *  'h': 120 degree hue pairs can be emulated as well; for instance blue on
+ *       red can be emulated using magenta on red, and blue on green using
+ *       cyan on green
+ *
+ *  And the almost never used pairs:
+ *
+ *  'i': dark opposite on dark: emulate with dark opposite on black
+ *  'j': light opposite on dark: emulate with light opposite on black
+ *  'k': dark opposite on light: emulate with black on dark
+ *  'l': light opposite on light: emulate with white on light
  */