From d13fa3900a40cbbc9da321205b499c80ee84cfca Mon Sep 17 00:00:00 2001
From: Elle Stone <ellestone@ninedegreesbelow.com>
Date: Thu, 1 Jun 2017 04:38:19 -0400
Subject: [PATCH] Bug 749902 - Add Hue-Chroma operation/tool and LCH color
 selector

This patch increases the LCH Chroma slider maximum value from 100 to
200 and also makes the Chroma slider properly display out of gamut
Chroma selections for any given Hue/Lightness combinations.

The current Chroma slider only runs to 100. But quite a few sRGB
colors have LCH chroma values that are greater than 100. For example
reddest red has a chroma of 107, and bluest blue has a chroma of 131.
So it's inconvenient to have to deal with a Chroma slider limit of
100.

Also, the current Chroma slider doesn't properly show out of gamut
areas on the Chroma slider. So for example picking a given LCH Hue and
then moving the Lightness slider doesn't allow to see which Lightness
value allows for choosing the maximum in-gamut chroma for the chosen
Hue.
---
 libgimpwidgets/gimpcolorscale.c  |  2 +-
 libgimpwidgets/gimpcolorscales.c |  2 +-
 libgimpwidgets/gimpcolorselect.c | 18 +++++++++---------
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/libgimpwidgets/gimpcolorscale.c b/libgimpwidgets/gimpcolorscale.c
index e9ad36a5ad..52ca7d5e7a 100644
--- a/libgimpwidgets/gimpcolorscale.c
+++ b/libgimpwidgets/gimpcolorscale.c
@@ -833,7 +833,7 @@ gimp_color_scale_render (GimpColorScale *scale)
       from_lch = TRUE;
       break;
     case GIMP_COLOR_SELECTOR_LCH_CHROMA:
-      multiplier = 100;
+      multiplier = 200;
       from_lch = TRUE;
       break;
     case GIMP_COLOR_SELECTOR_LCH_HUE:
diff --git a/libgimpwidgets/gimpcolorscales.c b/libgimpwidgets/gimpcolorscales.c
index 5e16e3ebe0..77b523cfe2 100644
--- a/libgimpwidgets/gimpcolorscales.c
+++ b/libgimpwidgets/gimpcolorscales.c
@@ -151,7 +151,7 @@ gimp_color_scales_init (GimpColorScales *scales)
   static const gdouble slider_min_vals[] =
     {   0,   0,   0,      0,    0,    0,   0,     0,   0,   0 };
   static const gdouble slider_max_vals[] =
-    { 360, 100, 100,    100,  100,  100, 100,   100, 100, 360 };
+    { 360, 100, 100,    100,  100,  100, 100,   100, 200, 360 };
   static const gdouble slider_incs[] =
     {  30,  10,  10,     16,   16,   16,  10,    10,  10,  30 };
 
diff --git a/libgimpwidgets/gimpcolorselect.c b/libgimpwidgets/gimpcolorselect.c
index 99e5d5fb60..5eb439bc14 100644
--- a/libgimpwidgets/gimpcolorselect.c
+++ b/libgimpwidgets/gimpcolorselect.c
@@ -691,16 +691,16 @@ gimp_color_select_update_values (GimpColorSelect *select)
 
     case COLOR_SELECT_LCH_LIGHTNESS:
       lch.h = select->pos[0] * 360;
-      lch.c = select->pos[1] * 100;
+      lch.c = select->pos[1] * 200;
       lch.l = select->pos[2] * 100;
       break;
     case COLOR_SELECT_LCH_CHROMA:
       lch.h = select->pos[0] * 360;
       lch.l = select->pos[1] * 100;
-      lch.c = select->pos[2] * 100;
+      lch.c = select->pos[2] * 200;
       break;
     case COLOR_SELECT_LCH_HUE:
-      lch.c = select->pos[0] * 100;
+      lch.c = select->pos[0] * 200;
       lch.l = select->pos[1] * 100;
       lch.h = select->pos[2] * 360;
       break;
@@ -779,16 +779,16 @@ gimp_color_select_update_pos (GimpColorSelect *select)
 
     case COLOR_SELECT_LCH_LIGHTNESS:
       select->pos[0] = CLAMP (lch.h / 360, 0.0, 1.0);
-      select->pos[1] = CLAMP (lch.c / 100, 0.0, 1.0);
+      select->pos[1] = CLAMP (lch.c / 200, 0.0, 1.0);
       select->pos[2] = CLAMP (lch.l / 100, 0.0, 1.0);
       break;
     case COLOR_SELECT_LCH_CHROMA:
       select->pos[0] = CLAMP (lch.h / 360, 0.0, 1.0);
       select->pos[1] = CLAMP (lch.l / 100, 0.0, 1.0);
-      select->pos[2] = CLAMP (lch.c / 100, 0.0, 1.0);
+      select->pos[2] = CLAMP (lch.c / 200, 0.0, 1.0);
       break;
     case COLOR_SELECT_LCH_HUE:
-      select->pos[0] = CLAMP (lch.c / 100, 0.0, 1.0);
+      select->pos[0] = CLAMP (lch.c / 200, 0.0, 1.0);
       select->pos[1] = CLAMP (lch.l / 100, 0.0, 1.0);
       select->pos[2] = CLAMP (lch.h / 360, 0.0, 1.0);
       break;
@@ -1432,7 +1432,7 @@ color_select_render_lch_chroma (ColorSelectFill *csf)
   guchar   rgb[3];
   gint     i;
 
-  lch.c = (csf->height - 1 - csf->y) * 100.0 / csf->height ;
+  lch.c = (csf->height - 1 - csf->y) * 200.0 / csf->height ;
   babl_process (fish_lch_to_rgb_u8, &lch, &rgb, 1);
 
   for (i = 0; i < csf->width; i++)
@@ -1821,7 +1821,7 @@ color_select_render_lch_chroma_lightness (ColorSelectFill *csf)
     {
       GimpRGB rgb;
 
-      lch.c = i * 100.0 / csf->width;
+      lch.c = i * 200.0 / csf->width;
 
       babl_process (fish_lch_to_rgb, &lch, &rgb, 1);
 
@@ -1885,7 +1885,7 @@ color_select_render_lch_hue_chroma (ColorSelectFill *csf)
   gint     i;
 
   lch.l = csf->lch.l;
-  lch.c = (csf->height - 1 - csf->y) * 100.0 / csf->height;
+  lch.c = (csf->height - 1 - csf->y) * 200.0 / csf->height;
 
   for (i = 0; i < csf->width; i++)
     {