[Lcms-user] Accessing clut details

[John J. <joh...@gl...>]

Hi Marti,

I want to know how many grid points are used in a clut tag. I've got 
code to achieve that, but I've had to do some dodgy casts in the 
process. The clut details are in _cmsStageCLutData from lcms2_plugin.h 
(I'm not using a plugin though), but to use it I've had to use 
_cmsStage_struct from lcms2_internal.h which isn't ideal. Is there some 
better way of doing this or is it something that I'll have to live with. 
I've included some simple code that I hope illustrates the problem.

Many thanks.

------------
#include "lcms2.h"
#include "lcms2_plugin.h"

#include "lcms2_internal.h"

void print_grid_points(void *p) {
     unsigned int i;
     void *pipeline;
     cmsStage *stage;
     struct _cmsStage_struct *stage_intern;
     _cmsStageCLutData *clut;

     // 'p' contains a clut.
     // We can easily find the clut stage of the A2B0 tag..
     pipeline = cmsReadTag(p, cmsSigAToB0Tag);
     stage = cmsPipelineGetPtrToFirstStage(pipeline);
     while (stage != NULL && cmsStageType(stage) != cmsSigCLutElemType)
         stage = cmsStageNext(stage);

     // Accessing the clut details from lcms2_plugin.h requires exposing 
a struct
     // from lcms2_internal.h.
     stage_intern = (struct _cmsStage_struct *) stage;
     clut = (_cmsStageCLutData *) stage_intern->Data;

     // Print the grid points.
     printf("Number of grid points =");
     for (i = 0; i < clut->Params->nInputs; i++)
         printf(" %d,", clut->Params->nSamples[i]);
     printf("\n");
}
------------

John