Color changes

README.md

@@ -18,14 +18,14 @@ int main()
     std::cout
         << escape(Brush{
                 .background = XColor::Cyan,
-                .foreground = TrueColor{0xF02127},
+                .foreground = TColor{0xF02127},
                 .traits     = Trait::Italic,
            }) << "Hello"
 
         << escape(Brush{}) << " 👽 "
 
         << escape(
-                fg(TrueColor{0x76F09C}),
+                fg(TColor{0x76F09C}),
                 Trait::Bold | Trait::Underline
            ) << "World!"
 

examples/pong.cpp

@@ -328,19 +328,15 @@ using EventResponse = std::optional<State>;
         return std::string(std::max((dimensions.width - width) / 2, 0), ' ');
     }();
 
-    auto hsl = HSL{
-        .hue        = hue,
-        .saturation = 90,
-        .lightness  = 70,
-    };
+    auto hsl = HSL{.hue = hue, .saturation = 90, .lightness = 70};
 
     auto bytes = escape(Cursor{.x = 0, .y = 6}, Trait::Bold);
-    bytes += escape(fg(TrueColor{hsl})) + padding;
+    bytes += escape(fg(TColor{hsl})) + padding;
     for (char c : state.display) {
         bytes += c;
         if (c == '\n') {
             hsl.hue = (hsl.hue + 20) % 360;
-            bytes += escape(fg(TrueColor{hsl})) + padding;
+            bytes += escape(fg(TColor{hsl})) + padding;
         }
     }
 
@@ -390,7 +386,7 @@ using EventResponse = std::optional<State>;
     auto const speed =
         std::sqrt(velocity.dx * velocity.dx + velocity.dy * velocity.dy);
 
-    return TrueColor{HSL{
+    return TColor{HSL{
         .hue        = std::uint16_t((90 + (int)(speed * 160)) % 360),
         .saturation = 80,
         .lightness  = 70,

include/esc/brush.hpp

@@ -12,8 +12,8 @@ namespace esc {
  *          escape(Brush) in sequence.hpp
  */
 struct Brush {
-    Color background = DefaultColor{};
-    Color foreground = DefaultColor{};
+    Color background = XColor::Default;
+    Color foreground = XColor::Default;
     Traits traits    = Traits{Trait::None};
 
     [[nodiscard]] constexpr bool operator==(Brush const&) const = default;

include/esc/color.hpp

@@ -6,20 +6,6 @@
 
 namespace esc {
 
-/**
- * Represents the default color of the terminal.
- *
- * @details When used with foregound() this will be the default foreground color
- *          of the terminal. When used with background() this will be the
- *          default background color of the terminal.
- */
-struct DefaultColor {
-    [[nodiscard]] constexpr bool operator==(DefaultColor const&) const =
-        default;
-    [[nodiscard]] constexpr bool operator!=(DefaultColor const&) const =
-        default;
-};
-
 // -----------------------------------------------------------------------------
 
 /**
@@ -35,8 +21,9 @@ struct DefaultColor {
  * @see https://www.ditig.com/publications/256-colors-cheat-sheet
  */
 struct XColor {
-    std::uint8_t value;
+    std::uint16_t value;
 
+    static XColor const Default;
     static XColor const Black;
     static XColor const Red;
     static XColor const Green;
@@ -59,6 +46,7 @@ struct XColor {
 };
 
 // Yes, defining constexpr with const declaration is legal here.
+constexpr XColor XColor::Default       = XColor{256};
 constexpr XColor XColor::Black         = XColor{0};
 constexpr XColor XColor::Red           = XColor{1};
 constexpr XColor XColor::Green         = XColor{2};
@@ -269,14 +257,19 @@ struct TrueColor {
     [[nodiscard]] constexpr bool operator!=(TrueColor const&) const = default;
 };
 
+/**
+ * Alias for TrueColor.
+ */
+using TColor = TrueColor;
+
 // -----------------------------------------------------------------------------
 
 /**
  * Variant holding any of the color types that can be used.
  *
  * @details escape(Color) will generate an escape sequence for the color.
  */
-using Color = std::variant<XColor, TrueColor, DefaultColor>;
+using Color = std::variant<XColor, TrueColor>;
 
 // -----------------------------------------------------------------------------
 

include/esc/sequence.hpp

@@ -128,14 +128,6 @@ struct BlankScreen {};
  */
 [[nodiscard]] auto escape_bg(TrueColor c) -> std::string;
 
-/// Return control sequence to reset the background to the terminal default
-
-/**
- * Get the control sequence to reset the background to the terminal default.
- * @return The control sequence to reset the background to the terminal default.
- */
-[[nodiscard]] auto escape_bg(DefaultColor c) -> std::string;
-
 /**
  * Get the last Color that was created with escape(ColorBG).
  *
@@ -174,12 +166,6 @@ struct BlankScreen {};
  */
 [[nodiscard]] auto escape_fg(TrueColor c) -> std::string;
 
-/**
- * Get the control sequence to reset the foreground to the terminal default.
- * @return The control sequence to reset the foreground to the terminal default.
- */
-[[nodiscard]] auto escape_fg(DefaultColor c) -> std::string;
-
 /**
  * Get the last Color that was created with escape(ColorFG).
  *

src/sequence.cpp

@@ -15,8 +15,8 @@ namespace {
 
 // Mutable, currently set Traits & Colors. Yes, they are global to this TU.
 auto current_traits     = esc::Traits{esc::Trait::None};
-auto current_background = esc::Color{esc::DefaultColor{}};
-auto current_foreground = esc::Color{esc::DefaultColor{}};
+auto current_background = esc::Color{esc::XColor::Default};
+auto current_foreground = esc::Color{esc::XColor::Default};
 
 /**
  * Translate a single Trait into its control sequence parameter integer.
@@ -128,9 +128,15 @@ auto escape(ColorBG c) -> std::string
 auto escape_bg(XColor c) -> std::string
 {
     ::current_background = c;
-    return "\033["
-           "48;5;" +
-           std::to_string(c.value) + 'm';
+    if (c == XColor::Default) {
+        return "\033["
+               "49m";
+    }
+    else {
+        return "\033["
+               "48;5;" +
+               std::to_string(c.value) + 'm';
+    }
 }
 
 auto escape_bg(TrueColor c) -> std::string
@@ -142,13 +148,6 @@ auto escape_bg(TrueColor c) -> std::string
            std::to_string(c.blue) + 'm';
 }
 
-auto escape_bg(DefaultColor c) -> std::string
-{
-    ::current_background = c;
-    return "\033["
-           "49m";
-}
-
 auto background_color() -> Color { return ::current_background; }
 
 auto escape(ColorFG c) -> std::string
@@ -159,9 +158,15 @@ auto escape(ColorFG c) -> std::string
 auto escape_fg(XColor c) -> std::string
 {
     ::current_foreground = c;
-    return "\033["
-           "38;5;" +
-           std::to_string(c.value) + 'm';
+    if (c == XColor::Default) {
+        return "\033["
+               "39m";
+    }
+    else {
+        return "\033["
+               "38;5;" +
+               std::to_string(c.value) + 'm';
+    }
 }
 
 auto escape_fg(TrueColor c) -> std::string
@@ -173,13 +178,6 @@ auto escape_fg(TrueColor c) -> std::string
            std::to_string(c.blue) + 'm';
 }
 
-auto escape_fg(DefaultColor c) -> std::string
-{
-    ::current_foreground = c;
-    return "\033["
-           "39m";
-}
-
 auto foreground_color() -> Color { return ::current_foreground; }
 
 auto escape(Brush b) -> std::string

tools/termcaps.cpp

@@ -198,7 +198,7 @@ using namespace esc;
             }, bg(XColor{static_cast<std::uint8_t>(i)})));
         result.push_back(' ');
     }
-    return result.append(escape(bg(DefaultColor{})));
+    return result.append(escape(bg(XColor::Default)));
 }
 
 [[nodiscard]] auto hue_increment_row(int width, HSL start) -> std::string
@@ -253,7 +253,7 @@ using namespace esc;
         saturation_increment_row(width, init) +
         escape(Cursor{offset.x, offset.y + 3}) +
         lightness_increment_row(width, init) +
-        escape(bg(DefaultColor{})
+        escape(bg(XColor::Default)
     );
 }