ref: 91984cb7e715db9693dc8f6542a74d368b31fe51
parent: b8d5dd18240cd12ed3cb5294a8c2c239d13fb145
author: Jakub Kądziołka <kuba@kadziolka.net>
date: Tue Aug 20 10:15:07 EDT 2019
rgbgfx: Add an option to take the CGB's color profile into account
--- a/include/gfx/main.h
+++ b/include/gfx/main.h
@@ -23,6 +23,7 @@
bool horizontal;
bool mirror;
bool unique;
+ bool colorcurve;
int trim;
char *tilemapfile;
bool tilemapout;
--- a/src/gfx/gb.c
+++ b/src/gfx/gb.c
@@ -285,6 +285,30 @@
free(opts->attrmapfile);
}
+/*
+ * based on the Gaussian-like curve used by SameBoy since commit
+ * 65dd02cc52f531dbbd3a7e6014e99d5b24e71a4c (Oct 2017)
+ * with ties resolved by comparing the difference of the squares.
+ */
+static int reverse_curve[] = {+ 0, 0, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4,
+ 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10,
+ 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
+ 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13,
+ 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14,
+ 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
+ 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17,
+ 17, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18,
+ 18, 18, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19,
+ 19, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21, 21, 21, 21,
+ 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 22, 22,
+ 22, 23, 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24,
+ 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26,
+ 26, 27, 27, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 30, 30, 31,
+};
+
void output_palette_file(const struct Options *opts,
const struct RawIndexedImage *raw_image)
{@@ -297,10 +321,25 @@
err(1, "Opening palette file '%s' failed", opts->palfile);
for (i = 0; i < raw_image->num_colors; i++) {- color =
- raw_image->palette[i].blue >> 3 << 10 |
- raw_image->palette[i].green >> 3 << 5 |
- raw_image->palette[i].red >> 3;
+ int r = raw_image->palette[i].red;
+ int g = raw_image->palette[i].green;
+ int b = raw_image->palette[i].blue;
+
+ if (opts->colorcurve) {+ g = (g * 4 - b) / 3;
+ if (g < 0)
+ g = 0;
+
+ r = reverse_curve[r];
+ g = reverse_curve[g];
+ b = reverse_curve[b];
+ } else {+ r >>= 3;
+ g >>= 3;
+ b >>= 3;
+ }
+
+ color = b << 10 | g << 5 | r;
cur_bytes[0] = color & 0xFF;
cur_bytes[1] = color >> 8;
fwrite(cur_bytes, 2, 1, f);
--- a/src/gfx/main.c
+++ b/src/gfx/main.c
@@ -45,7 +45,7 @@
depth = 2;
- while ((ch = getopt(argc, argv, "Aa:Dd:Ffhmo:Tt:uPp:Vvx:")) != -1) {+ while ((ch = getopt(argc, argv, "Aa:CDd:Ffhmo:Tt:uPp:Vvx:")) != -1) { switch (ch) {case 'A':
opts.attrmapout = true;
@@ -52,6 +52,9 @@
break;
case 'a':
opts.attrmapfile = optarg;
+ break;
+ case 'C':
+ opts.colorcurve = true;
break;
case 'D':
opts.debug = true;
--- a/src/gfx/rgbgfx.1
+++ b/src/gfx/rgbgfx.1
@@ -61,6 +61,8 @@
but the attrmap file output name is made by taking the input filename, removing
the file extension, and appending
.Pa .attrmap .
+.It Fl C
+Use the color curve of the Game Boy Color when generating palettes.
.It Fl D
Debug features are enabled.
.It Fl f