color wheel and picker

engine/app_shaders.cpp

@@ -177,7 +177,7 @@ void App::initShaders()
         "}";
     static const char* shader_color_quad_f =
         SHADER_VERSION
-        "uniform mediump vec4 col;"
+        "uniform mediump vec4 col; // HSV\n"
         "in mediump vec3 uv;"
         "out mediump vec4 frag;"
         "mediump vec3 rgb2hsv(mediump vec3 c) {"
@@ -194,8 +194,7 @@ void App::initShaders()
         "   return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);"
         "}"
         "void main() {"
-        "    mediump float hue = rgb2hsv(col.rgb).x;"
-        "    frag = vec4(hsv2rgb(vec3(hue, uv.x, 1.0 - uv.y)), 1.0);"
+        "    frag = vec4(hsv2rgb(vec3(col.x, uv.x, 1.0 - uv.y)), 1.0);"
         "}";
     // COLOR TRI
         static const char* shader_color_tri_f =