Color callback for RGB to HS

You're right in that you shouldn't acquire the suite within an iterate function - this will slow your plugin down a lot! I'm not sure why you're getting an error when using it in the refcon though.

In your header:

// Define struct for refcon, including a pointer to callback suite

struct MyRefconStruct {

     PF_ColorCallbacksFloatSuite1 *ccfsP;

     // Other refcon stuff

}

In your render function:

MyRefconStruct my_refcon = {};

// Acquire pointer to suite

AEFX_AcquireSuite(..., (void**)&my_refcon.ccfsP)

// Do iterate

// Release suite

AEFX_ReleaseSuite(...);

You could just provide your own RGB to HLS function as a static function (so no suites to acquire). This example would do the trick:

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But you'd need to omit the conversion to r_percent, etc., as it looks like you're already working in float (0-1).

The reason your results look different is that PF_HLS_Pixel is an array of Fixed Point numbers rather than floating point. You'll need to use the FIX_2_FLOAT(X) macro to convert them, so:

out->red = FIX_2_FLOAT(hls[0]);

//etc.