Add some colors, make border transparent by default,

graphics/canvas.c++

@@ -25,6 +25,7 @@
 #include "graphics/canvas.h++"
 
 #include "graphics/gradient/linear_gradient.h++"
+#include "graphics/gradient/sweep_gradient.h++"
 
 #include "graphics/shape/ellipse.h++"
 #include "graphics/shape/label.h++"
@@ -36,19 +37,29 @@ namespace skui
   {
     void canvas::draw()
     {
-      rectangle square({128, 128}, {10, 10});
+      rectangle square({140, 140}, {10, 10});
       square.fill.color = colors::red;
+      square.border.thickness = 20; // black by default
 
-      ellipse circle({64, 64}, {200, 200});
-      const std::vector<scalar_position> points{{0,0},{300,300}};
-      const std::vector<color> colors{colors::green, colors::black};
-      circle.fill.gradient = std::make_unique<linear_gradient>(points, colors);
+      rectangle marker({140,140}, {10.5,10.5});
+      marker.fill.color = colors::transparent;
+      marker.border.thickness = 1;
+      marker.border.color = colors::green;
+
+      ellipse circle({140, 140}, {150, 150});
+      const scalar_position center{220,220};
+      const std::vector<color> rainbow{colors::cyan,
+                                       colors::magenta,
+                                       colors::yellow,
+                                       colors::cyan};
+      circle.fill.gradient = std::make_unique<sweep_gradient>(center, rainbow);
 
       label text_label("Hello Skui!", {300, 300});
-      text_label.fill.color = colors::black;
+      text_label.fill.color = colors::white;
 
-      draw(colors::white);
+      draw(colors::black);
       draw(square);
+      draw(marker);
       draw(circle);
       draw(text_label);
     }

graphics/canvas.h++

@@ -46,6 +46,7 @@ namespace skui
 
     enum class canvas_flag
     {
+      none,
       anti_alias
     };
     using canvas_flags = core::bitflag<canvas_flag>;

graphics/color.h++

@@ -61,13 +61,16 @@ namespace skui
 
     namespace colors
     {
-      static constexpr color transparent{0, 0, 0, 0};
-      static constexpr color white {255, 255, 255, 255};
-      static constexpr color black {0,   0,   0,   255};
-      static constexpr color red   {255, 0,   0,   255};
-      static constexpr color green {0,   255, 0,   255};
-      static constexpr color blue  {0,   0,   255, 255};
-      static constexpr color grey  {127, 127, 127, 255};
+      static constexpr color transparent {0, 0, 0, 0};
+      static constexpr color white       {255, 255, 255, 255};
+      static constexpr color black       {0,   0,   0,   255};
+      static constexpr color red         {255, 0,   0,   255};
+      static constexpr color green       {0,   255, 0,   255};
+      static constexpr color blue        {0,   0,   255, 255};
+      static constexpr color grey        {127, 127, 127, 255};
+      static constexpr color cyan        {0,   255, 255, 255};
+      static constexpr color magenta     {255, 0,   255, 255};
+      static constexpr color yellow      {255, 255, 0,   255};
     }
   }
 }

graphics/shape.h++

@@ -57,7 +57,7 @@ namespace skui
       {
         scalar thickness = 0;
         scalar radius = 0;
-        graphics::color color = graphics::colors::black;
+        graphics::color color = graphics::colors::transparent;
       } border;
 
       scalar_position position;