Merge branch 'master' into artist_2024_dev

lib/include/artist/color.hpp

@@ -34,6 +34,11 @@ namespace cycfi::artist
    constexpr bool operator==(color const& a, color const& b);
    constexpr bool operator!=(color const& a, color const& b);
 
+   constexpr color operator+(color const& a, color const& b);
+   constexpr color operator-(color const& a, color const& b);
+   constexpr color operator*(color const& a, float b);
+   constexpr color operator*(float a, color const& b);
+
    ////////////////////////////////////////////////////////////////////////////
    // Inlines
    ////////////////////////////////////////////////////////////////////////////
@@ -176,6 +181,26 @@ namespace cycfi::artist
       return r;
    }
 
+   constexpr color operator+(color const& a, color const& b)
+   {
+     return color(a.red + b.red, a.green + b.green, a.blue + b.blue, a.alpha + b.alpha*(1.0-a.alpha));
+   }
+
+   constexpr color operator-(color const& a, color const& b)
+   {
+     return color(a.red - b.red, a.green - b.green, a.blue - b.blue, a.alpha + b.alpha*(1.0-a.alpha));
+   }
+
+   constexpr color operator*(color const& a, float b)
+   {
+     return color(a.red * b, a.green * b, a.blue * b, a.alpha);
+   }
+
+   constexpr color operator*(float a, color const& b)
+   {
+     return color(a * b.red, a * b.green, a * b.blue, b.alpha);
+   }
+
    ////////////////////////////////////////////////////////////////////////////
    // Common colors
    ////////////////////////////////////////////////////////////////////////////

lib/include/artist/point.hpp

@@ -8,6 +8,16 @@
 
 namespace cycfi::artist
 {
+   ////////////////////////////////////////////////////////////////////////////
+   // Axis
+   ////////////////////////////////////////////////////////////////////////////
+   enum class axis : bool { x = false, y = true};
+
+   inline constexpr axis other(axis a)
+   {
+    return axis(! bool(a));
+   }
+
    ////////////////////////////////////////////////////////////////////////////
    // Points
    ////////////////////////////////////////////////////////////////////////////
@@ -25,6 +35,9 @@ namespace cycfi::artist
       constexpr point   move_to(float x, float y) const;
       constexpr point   reflect(point p) const;
 
+      constexpr float&  operator[](axis a);
+      constexpr float   operator[](axis a) const;
+
       float             x;
       float             y;
    };
@@ -86,6 +99,16 @@ namespace cycfi::artist
    {
       return {x + (x - p.x), y + (y - p.y)};
    }
+
+   constexpr float&  point::operator[](axis a)
+   {
+      return a==axis::x ? x : y;
+   }
+
+   constexpr float  point::operator[](axis a) const
+   {
+     return a==axis::x ? x : y;
+   }
 }
 
 #endif

lib/include/artist/rect.hpp

@@ -242,6 +242,41 @@ namespace cycfi::artist
       r.right = 0.0;
       r.bottom = 0.0;
    }
+
+   inline constexpr float axis_extent(rect const &r, axis a)
+   {
+     return a == axis::x ? r.width() : r.height();
+   }
+
+   inline constexpr float axis_min(rect const &r, axis a)
+   {
+     return a == axis::x ? r.left : r.top;
+   }
+
+   inline constexpr float axis_max(rect const &r, axis a)
+   {
+     return a == axis::x ? r.right : r.bottom;
+   }
+
+   inline constexpr float& axis_min(rect &r, axis a)
+   {
+     return a == axis::x ? r.left : r.top;
+   }
+
+   inline constexpr float& axis_max(rect &r, axis a)
+   {
+     return a == axis::x ? r.right : r.bottom;
+   }
+
+   inline constexpr auto make_rect(axis a, float this_axis_min, float other_axis_min, float this_axis_max, float other_axis_max) -> rect
+   {
+     if (a == axis::x) {
+       return rect(this_axis_min, other_axis_min, this_axis_max, other_axis_max);
+     }
+     else {
+       return rect(other_axis_min, this_axis_min, other_axis_max, this_axis_max);
+     }
+   }
 }
 
 #endif

test/main.cpp

@@ -1069,4 +1069,21 @@ TEST_CASE("Misc")
 }
 
 
-
+TEST_CASE("Color Maths")
+{
+  color a(0.2, 0.25, 0.5, 1.0);
+  color b(0.5, 0.6, 0.1, 1.0);
+
+  auto check = [&](color result, color check)
+  {
+    REQUIRE_THAT(result.red, Catch::WithinRel(check.red, 0.001f));
+    REQUIRE_THAT(result.green, Catch::WithinRel(check.green, 0.001f));
+    REQUIRE_THAT(result.blue, Catch::WithinRel(check.blue, 0.001f));
+    REQUIRE_THAT(result.alpha, Catch::WithinRel(check.alpha, 0.001f));
+  };
+
+  check(a + b, color(0.7, 0.85, 0.6, 1.0));
+  check(a - b, color(-0.3, -0.35, 0.4, 1.0));
+  check(a * 2, color(0.4, 0.5, 1.0, 1.0));
+  check(2 * a, color(0.4, 0.5, 1.0, 1.0));
+}