implementing color wheel and new color picker

engine/shader.h

@@ -25,12 +25,14 @@ enum class kShaderUniform : uint16_t
     Highlight = const_hash("highlight"),
     BlendMode = const_hash("blend_mode"),
     Noise = const_hash("noise"),
+    Direction = const_hash("dir"),
 };
 
 enum class kShader : uint16_t
 {
     Color       = const_hash("color"),
     ColorQuad   = const_hash("color-quad"),
+    ColorTri    = const_hash("color-tri"),
     ColorHue    = const_hash("color-hue"),
     Texture     = const_hash("texture"),
     TextureAlpha= const_hash("texture-alpha"),
@@ -44,6 +46,7 @@ enum class kShader : uint16_t
     Checkerboard= const_hash("checkerboard"),
     Equirect    = const_hash("equirect"),
     BrushStroke = const_hash("brush-stroke"),
+    VertexColor = const_hash("vertex-color"),
 };
 
 class Shader