Crude patch for LibreSprite 6ffe8472194bf :: Only allow selecting Sega MegaDrive colors

0001-limit-colors-to-genesis-palette.patch

From 158217365be2080e7d5f5de838bfae034f39c402 Mon Sep 17 00:00:00 2001
From: Lucas Pires Camargo <lucas@camargo.eng.br>
Date: Thu, 24 Aug 2023 22:48:14 +0200
Subject: [PATCH] limit colors to genesis palette

---
 src/app/color_utils.cpp                 | 21 +++++++++++++++++++++
 src/app/color_utils.h                   |  4 ++++
 src/app/commands/cmd_palette_editor.cpp | 10 ++++++----
 src/app/ui/color_sliders.cpp            |  3 ++-
 src/app/ui/color_spectrum.cpp           | 10 +++++-----
 src/app/ui/color_tint_shade_tone.cpp    |  8 +++++---
 src/app/ui/color_wheel.cpp              | 10 +++++++---
 7 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/src/app/color_utils.cpp b/src/app/color_utils.cpp
index 5d3b334f9..17b9072f1 100644
--- a/src/app/color_utils.cpp
+++ b/src/app/color_utils.cpp
@@ -18,6 +18,10 @@
 #include "doc/layer.h"
 #include "doc/palette.h"
 #include "doc/sprite.h"
+#include "color_utils.h"
+
+#include <math.h>
+
 
 namespace app {
 
@@ -163,4 +167,21 @@ doc::color_t color_utils::color_for_target(const app::Color& color, const ColorT
   return c;
 }
 
+#define approx(C) (static_cast<uint8_t>(roundf((C)/255.0*7.0)/7.0*255.0))
+
+app::Color color_utils::apply_limitations(const app::Color &color)
+{
+  return app::Color::fromRgb(approx(color.getRed()),
+                              approx(color.getGreen()),
+                              approx(color.getBlue()),
+                              approx(color.getAlpha()));
+}
+
+gfx::Color color_utils::apply_limitations(const gfx::Color &color)
+{
+  return gfx::rgba( approx(gfx::getr(color)),
+                    approx(gfx::getg(color)),
+                    approx(gfx::getb(color)),
+                    approx(gfx::geta(color)));
+}
 } // namespace app
diff --git a/src/app/color_utils.h b/src/app/color_utils.h
index d8f1ed3be..087ef9beb 100644
--- a/src/app/color_utils.h
+++ b/src/app/color_utils.h
@@ -23,11 +23,15 @@ namespace app {
     gfx::Color blackandwhite(gfx::Color color);
     gfx::Color blackandwhite_neg(gfx::Color color);
 
+    app::Color apply_limitations(const app::Color& color);
+    gfx::Color apply_limitations(const gfx::Color& color);
+
     gfx::Color color_for_ui(const app::Color& color);
     doc::color_t color_for_image(const app::Color& color, doc::PixelFormat format);
     doc::color_t color_for_layer(const app::Color& color, doc::Layer* layer);
     doc::color_t color_for_target_mask(const app::Color& color, const ColorTarget& colorTarget);
     doc::color_t color_for_target(const app::Color& color, const ColorTarget& colorTarget);
 
+
   } // namespace color_utils
 } // namespace app
diff --git a/src/app/commands/cmd_palette_editor.cpp b/src/app/commands/cmd_palette_editor.cpp
index 7270f1bed..68365ff05 100644
--- a/src/app/commands/cmd_palette_editor.cpp
+++ b/src/app/commands/cmd_palette_editor.cpp
@@ -423,10 +423,11 @@ void PaletteEntryEditor::onFgBgColorChange(const app::Color& _color)
 
 void PaletteEntryEditor::onColorSlidersChange(ColorSlidersChangeEvent& ev)
 {
-  setColor(ev.color());
+  auto color = color_utils::apply_limitations(ev.color());
+  setColor(color);
 
   if (ev.mode() == ColorSliders::Absolute)
-    setAbsolutePaletteEntryChannel(ev.channel(), ev.color());
+    setAbsolutePaletteEntryChannel(ev.channel(), color);
   else
     setRelativePaletteEntryChannel(ev.channel(), ev.delta());
 
@@ -440,8 +441,9 @@ void PaletteEntryEditor::onColorHexEntryChange(const app::Color& color)
   // is writting in the text field.
   m_disableHexUpdate = true;
 
-  setColor(color);
-  setPaletteEntry(color);
+  app::Color adj_color = color_utils::apply_limitations(color);
+  setColor(adj_color);
+  setPaletteEntry(adj_color);
   updateCurrentSpritePalette("Color Change");
   updateColorBar();
 
diff --git a/src/app/ui/color_sliders.cpp b/src/app/ui/color_sliders.cpp
index c9c9f6aba..752b9037c 100644
--- a/src/app/ui/color_sliders.cpp
+++ b/src/app/ui/color_sliders.cpp
@@ -72,7 +72,8 @@ namespace {
             color = color_utils::color_for_ui(app::Color::fromGray(255 * x / w));
             break;
         }
-        g->drawVLine(color, rc.x+x, rc.y, rc.h);
+
+        g->drawVLine(color_utils::apply_limitations(color), rc.x+x, rc.y, rc.h);
       }
     }
 
diff --git a/src/app/ui/color_spectrum.cpp b/src/app/ui/color_spectrum.cpp
index 2224c61dd..2b454176c 100644
--- a/src/app/ui/color_spectrum.cpp
+++ b/src/app/ui/color_spectrum.cpp
@@ -59,10 +59,10 @@ app::Color ColorSpectrum::getColorByPosition(const gfx::Point& pos)
   double sat = (v < vmid ? 100.0 * v / vmid : 100.0);
   double val = (v < vmid ? 100.0 : 100.0-(100.0 * (v-vmid) / vmid));
 
-  return app::Color::fromHsv(
+  return color_utils::apply_limitations (app::Color::fromHsv(
     MID(0.0, hue, 360.0),
     MID(0.0, sat, 100.0),
-    MID(0.0, val, 100.0));
+    MID(0.0, val, 100.0)));
 }
 
 void ColorSpectrum::onPaint(ui::PaintEvent& ev)
@@ -99,13 +99,13 @@ void ColorSpectrum::onPaint(ui::PaintEvent& ev)
       double sat = (v < vmid ? 100.0 * v / vmid : 100.0);
       double val = (v < vmid ? 100.0 : 100.0-(100.0 * (v-vmid) / vmid));
 
-      gfx::Color color = color_utils::color_for_ui(
+      gfx::Color color = color_utils::apply_limitations(color_utils::color_for_ui(
         app::Color::fromHsv(
           MID(0.0, hue, 360.0),
           MID(0.0, sat, 100.0),
-          MID(0.0, val, 100.0)));
+          MID(0.0, val, 100.0))));
 
-      g->putPixel(color, rc.x+x, rc.y+y);
+      //g->putPixel(color, rc.x+x, rc.y+y);
     }
   }
 
diff --git a/src/app/ui/color_tint_shade_tone.cpp b/src/app/ui/color_tint_shade_tone.cpp
index 20842a76e..41c968992 100644
--- a/src/app/ui/color_tint_shade_tone.cpp
+++ b/src/app/ui/color_tint_shade_tone.cpp
@@ -64,10 +64,10 @@ app::Color ColorTintShadeTone::getColorByPosition(const gfx::Point& pos)
     val = (100.0 - 100.0 * v / vmax);
   }
 
-  return app::Color::fromHsv(
+  return color_utils::apply_limitations(app::Color::fromHsv(
     MID(0.0, hue, 360.0),
     MID(0.0, sat, 100.0),
-    MID(0.0, val, 100.0));
+    MID(0.0, val, 100.0)));
 }
 
 void ColorTintShadeTone::onPaint(ui::PaintEvent& ev)
@@ -99,7 +99,7 @@ void ColorTintShadeTone::onPaint(ui::PaintEvent& ev)
           hue,
           MID(0.0, sat, 100.0),
           MID(0.0, val, 100.0)));
-
+      color = color_utils::apply_limitations(color);
       g->putPixel(color, rc.x+x, rc.y+y);
     }
   }
@@ -110,6 +110,7 @@ void ColorTintShadeTone::onPaint(ui::PaintEvent& ev)
         gfx::Color color = color_utils::color_for_ui(
           app::Color::fromHsv(
             (360.0 * x / rc.w), 100.0, 100.0));
+        color = color_utils::apply_limitations(color);
 
         g->putPixel(color, rc.x+x, rc.y+y);
       }
@@ -160,6 +161,7 @@ bool ColorTintShadeTone::onProcessMessage(ui::Message* msg)
           m_capturedInHue = inHueBarArea(mouseMsg->position());
 
       app::Color color = getColorByPosition(mouseMsg->position());
+      color = color_utils::apply_limitations(color);
       if (color != app::Color::fromMask()) {
         StatusBar::instance()->showColor(0, "", color);
         if (hasCapture())
diff --git a/src/app/ui/color_wheel.cpp b/src/app/ui/color_wheel.cpp
index 309da870f..015ea02b3 100644
--- a/src/app/ui/color_wheel.cpp
+++ b/src/app/ui/color_wheel.cpp
@@ -111,10 +111,10 @@ app::Color ColorWheel::getColorInClientPos(const gfx::Point& pos)
       sat = int(100.0 * d / m_wheelRadius);
     }
 
-    return app::Color::fromHsv(
+    return color_utils::apply_limitations(app::Color::fromHsv(
       MID(0, hue, 360),
       MID(0, sat, 100),
-      100);
+      100));
   }
 
   // Pick harmonies
@@ -134,6 +134,8 @@ app::Color ColorWheel::getColorInClientPos(const gfx::Point& pos)
         color = app::Color::fromHsv(convertHueAngle(int(color.getHue()), 1),
                                     color.getSaturation(),
                                     color.getValue());
+
+        color = color_utils::apply_limitations(color);
         return color;
       }
     }
@@ -178,9 +180,11 @@ app::Color ColorWheel::getColorInHarmony(int j) const
   j = MID(0, j, harmonies[i].n-1);
   double hue = convertHueAngle(int(m_color.getHue()), -1) + harmonies[i].hues[j];
   double sat = m_color.getSaturation() * harmonies[i].sats[j] / 100.0;
-  return app::Color::fromHsv(std::fmod(hue, 360),
+  app::Color color = app::Color::fromHsv(std::fmod(hue, 360),
                              MID(0.0, sat, 100.0),
                              m_color.getValue());
+  color = color_utils::apply_limitations(color);
+  return color;
 }
 
 void ColorWheel::onResize(ui::ResizeEvent& ev)
-- 
2.41.0