diff --git a/docs/rgbgfx.1.html b/docs/rgbgfx.1.html index e9ff1a52..f9f9f3cd 100644 --- a/docs/rgbgfx.1.html +++ b/docs/rgbgfx.1.html @@ -43,7 +43,28 @@

DESCRIPTION

The rgbgfx program converts PNG images into the - Nintendo Game Boy's planar tile format. The arguments are as follows: + Nintendo Game Boy's planar tile format. +
 
+The resulting colors and their palette indices are determined differently + depending on the input PNG file: + +
 
+The input image may not contain more colors than the selected bit depth allows. + Transparent pixels are set to palette index 0. +

ARGUMENTS

 
 
@@ -58,14 +79,14 @@ The rgbgfx program converts PNG images into the
 
-F
Same as -f, but additionally, - the input PNG file is fixed to have its parameters match the command - line's parameters.
+ the supplied command line parameters are saved within the PNG and will be + loaded and automatically used next time.
 
 
-d depth
-
The bitdepth of the output image (either 1 or 2). By - default, the bitdepth is 2 (two bits per pixel).
+
The bit depth of the output image (either 1 or 2). By + default, the bit depth is 2 (two bits per pixel).
 
 
-h
@@ -79,15 +100,16 @@ The rgbgfx program converts PNG images into the
 
-p palfile
-
Raw bytes (8 bytes for two bits per pixel, 4 bytes for one - bit per pixel) containing the RGB15 values in the little-endian byte order - and then ordered from lightest to darkest.
+
Output the image's palette in standard GBC palette format - + bytes (8 bytes for two bits per pixel, 4 bytes for one bit per pixel) + containing the RGB15 values in little-endian byte order. If the palette + contains too few colors, the remaining entries are set to black.
 
 
-P
-
Same as -p, but the pallete - file output name is made by taking the input filename, removing the file - extension, and appending .pal.
+
Same as -p, but the palette + file output name is made by taking the input PNG file's filename, removing + the file extension, and appending .pal.
 
 
-t @@ -120,7 +142,7 @@ The rgbgfx program converts PNG images into the
Trim the end of the output file by this many tiles.

EXAMPLES

-The following will take a PNG file with a bitdepth of 1, 2, or 8, and output +The following will take a PNG file with a bit depth of 1, 2, or 8, and output planar 2bpp data:
$ rgbgfx -o out.2bpp in.png
diff --git a/src/gfx/rgbgfx.1 b/src/gfx/rgbgfx.1 index b60a432d..57a0e100 100644 --- a/src/gfx/rgbgfx.1 +++ b/src/gfx/rgbgfx.1 @@ -24,7 +24,28 @@ The .Nm program converts PNG images into the Nintendo Game Boy's planar tile format. -The arguments are as follows: + +The resulting colors and their palette indices are determined differently +depending on the input PNG file: +.Bl -dash -width Ds +.It +If the file has an embedded palette, that palette's color and order are used. +.It +If not, and the image only contains shades of gray, rgbgfx maps them to the +indices appropriate for each shade. Any undetermined indices are set to +respective default shades of gray. For example: if the bit depth is 2 and the +image contains light gray and black, they become the second and fourth colors - +and the first and third colors get set to default white and dark gray. If the +image has multiple shades that map to the same index, the palette is instead +determined as if the image had color. +.It +If the image has color (or the grayscale method failed), the colors are sorted +from lightest to darkest. +.El + +The input image may not contain more colors than the selected bit depth +allows. Transparent pixels are set to palette index 0. +.Sh ARGUMENTS .Bl -tag -width Ds .It Fl D Debug features are enabled. @@ -33,24 +54,25 @@ Fix the input PNG file to be a correctly indexed image. .It Fl F Same as .Fl f , -but additionally, the input PNG file is fixed to have its parameters match the -command line's parameters. +but additionally, the supplied command line parameters are saved within the PNG +and will be loaded and automatically used next time. .It Fl d Ar depth -The bitdepth of the output image (either 1 or 2). -By default, the bitdepth is 2 (two bits per pixel). +The bit depth of the output image (either 1 or 2). +By default, the bit depth is 2 (two bits per pixel). .It Fl h Lay out tiles horizontally rather than vertically. .It Fl o Ar outfile The name of the output file. .It Fl p Ar palfile -Raw bytes (8 bytes for two bits per pixel, 4 bytes for one bit per pixel) -containing the RGB15 values in the little-endian byte order and then ordered -from lightest to darkest. +Output the image's palette in standard GBC palette format - bytes (8 bytes for +two bits per pixel, 4 bytes for one bit per pixel) containing the RGB15 values +in little-endian byte order. If the palette contains too few colors, the +remaining entries are set to black. .It Fl P Same as .Fl p , -but the pallete file output name is made by taking the input filename, -removing the file extension, and appending +but the palette file output name is made by taking the input PNG file's +filename, removing the file extension, and appending .Pa .pal . .It Fl t Ar mapfile If any tiles are the same, don't place the repeat tiles in the output file, and @@ -73,7 +95,7 @@ the PNG file don't match. Trim the end of the output file by this many tiles. .El .Sh EXAMPLES -The following will take a PNG file with a bitdepth of 1, 2, or 8, and output +The following will take a PNG file with a bit depth of 1, 2, or 8, and output planar 2bpp data: .Pp .D1 $ rgbgfx -o out.2bpp in.png