//---------------------------------------------------------------------------------
//
//  Little Color Management System, fast floating point extensions
//  Copyright (c) 1998-2020 Marti Maria Saguer, all rights reserved
//
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
//---------------------------------------------------------------------------------

#include "fast_float_internal.h"

// Optimization for floating point tetrahedral interpolation
typedef struct {

    cmsContext ContextID;
    const cmsInterpParams* p;   // Tetrahedrical interpolation parameters. This is a not-owned pointer.

} FloatCLUTData;

// Allocates container
static
FloatCLUTData* FloatCLUTAlloc(cmsContext ContextID, const cmsInterpParams* p)
{
    FloatCLUTData* fd;

    fd = (FloatCLUTData*) _cmsMallocZero(ContextID, sizeof(FloatCLUTData));
    if (fd == NULL) return NULL;
    
    fd ->ContextID = ContextID;
    fd ->p = p;
    
    return fd;
}


// Sampler implemented by another LUT. 
static
int XFormSampler(CMSREGISTER const cmsFloat32Number In[], CMSREGISTER cmsFloat32Number Out[], CMSREGISTER void* Cargo)
{    
    cmsPipelineEvalFloat(In, Out, (cmsPipeline*) Cargo);
    return TRUE;
}

// A optimized interpolation for input.
#define DENS(i,j,k) (LutTable[(i)+(j)+(k)+OutChan])

static
void FloatCLUTEval(struct _cmstransform_struct* CMMcargo,
                        const void* Input,
                        void* Output,
                        cmsUInt32Number PixelsPerLine,
                        cmsUInt32Number LineCount,
                        const cmsStride* Stride)

{

    FloatCLUTData* pfloat = (FloatCLUTData*)_cmsGetTransformUserData(CMMcargo);

    cmsFloat32Number        r, g, b;
    cmsFloat32Number        px, py, pz;
    int                     x0, y0, z0;
    int                     X0, Y0, Z0, X1, Y1, Z1;
    cmsFloat32Number        rx, ry, rz;
    cmsFloat32Number        c0, c1 = 0, c2 = 0, c3 = 0;
    cmsUInt32Number         OutChan;

    const cmsInterpParams* p = pfloat->p;
    cmsUInt32Number        TotalOut = p->nOutputs;
    cmsUInt32Number        TotalPlusAlpha;
    const cmsFloat32Number* LutTable = (const cmsFloat32Number*)p->Table;

    cmsUInt32Number       i, ii;
    const cmsUInt8Number* rin;
    const cmsUInt8Number* gin;
    const cmsUInt8Number* bin;
    const cmsUInt8Number* ain = NULL;

    cmsUInt8Number* out[cmsMAXCHANNELS];
    cmsUInt32Number SourceStartingOrder[cmsMAXCHANNELS];
    cmsUInt32Number SourceIncrements[cmsMAXCHANNELS];
    cmsUInt32Number DestStartingOrder[cmsMAXCHANNELS];
    cmsUInt32Number DestIncrements[cmsMAXCHANNELS];

    cmsUInt32Number InputFormat = cmsGetTransformInputFormat((cmsHTRANSFORM)CMMcargo);
    cmsUInt32Number OutputFormat = cmsGetTransformOutputFormat((cmsHTRANSFORM)CMMcargo);

    cmsUInt32Number nchans, nalpha;
    cmsUInt32Number strideIn, strideOut;
                                                        
    _cmsComputeComponentIncrements(InputFormat, Stride->BytesPerPlaneIn, &nchans, &nalpha, SourceStartingOrder, SourceIncrements);
    _cmsComputeComponentIncrements(OutputFormat, Stride->BytesPerPlaneOut, &nchans, &nalpha, DestStartingOrder, DestIncrements);

    if (!(_cmsGetTransformFlags((cmsHTRANSFORM)CMMcargo) & cmsFLAGS_COPY_ALPHA))
        nalpha = 0;

    strideIn = strideOut = 0;
    for (i = 0; i < LineCount; i++) {

        rin = (const cmsUInt8Number*)Input + SourceStartingOrder[0] + strideIn;
        gin = (const cmsUInt8Number*)Input + SourceStartingOrder[1] + strideIn;
        bin = (const cmsUInt8Number*)Input + SourceStartingOrder[2] + strideIn;
        if (nalpha)
            ain = (const cmsUInt8Number*)Input + SourceStartingOrder[3] + strideIn;

        TotalPlusAlpha = TotalOut;
        if (ain) TotalPlusAlpha++;

        for (ii = 0; ii < TotalPlusAlpha; ii++)
            out[ii] = (cmsUInt8Number*)Output + DestStartingOrder[ii] + strideOut;

        for (ii = 0; ii < PixelsPerLine; ii++) {

            r = fclamp(*(cmsFloat32Number*)rin);
            g = fclamp(*(cmsFloat32Number*)gin);
            b = fclamp(*(cmsFloat32Number*)bin);

            rin += SourceIncrements[0];
            gin += SourceIncrements[1];
            bin += SourceIncrements[2];

            px = r * p->Domain[0];
            py = g * p->Domain[1];
            pz = b * p->Domain[2];
            
            x0 = _cmsQuickFloor(px); rx = (px - (cmsFloat32Number)x0);
            y0 = _cmsQuickFloor(py); ry = (py - (cmsFloat32Number)y0);
            z0 = _cmsQuickFloor(pz); rz = (pz - (cmsFloat32Number)z0);
            

            X0 = p->opta[2] * x0;
            X1 = X0 + (r >= 1.0 ? 0 : p->opta[2]);

            Y0 = p->opta[1] * y0;
            Y1 = Y0 + (g >= 1.0 ? 0 : p->opta[1]);

            Z0 = p->opta[0] * z0;
            Z1 = Z0 + (b >= 1.0 ? 0 : p->opta[0]);

            for (OutChan = 0; OutChan < TotalOut; OutChan++) {

                // These are the 6 Tetrahedral

                c0 = DENS(X0, Y0, Z0);

                if (rx >= ry && ry >= rz) {

                    c1 = DENS(X1, Y0, Z0) - c0;
                    c2 = DENS(X1, Y1, Z0) - DENS(X1, Y0, Z0);
                    c3 = DENS(X1, Y1, Z1) - DENS(X1, Y1, Z0);

                }
                else
                    if (rx >= rz && rz >= ry) {

                        c1 = DENS(X1, Y0, Z0) - c0;
                        c2 = DENS(X1, Y1, Z1) - DENS(X1, Y0, Z1);
                        c3 = DENS(X1, Y0, Z1) - DENS(X1, Y0, Z0);

                    }
                    else
                        if (rz >= rx && rx >= ry) {

                            c1 = DENS(X1, Y0, Z1) - DENS(X0, Y0, Z1);
                            c2 = DENS(X1, Y1, Z1) - DENS(X1, Y0, Z1);
                            c3 = DENS(X0, Y0, Z1) - c0;

                        }
                        else
                            if (ry >= rx && rx >= rz) {

                                c1 = DENS(X1, Y1, Z0) - DENS(X0, Y1, Z0);
                                c2 = DENS(X0, Y1, Z0) - c0;
                                c3 = DENS(X1, Y1, Z1) - DENS(X1, Y1, Z0);

                            }
                            else
                                if (ry >= rz && rz >= rx) {

                                    c1 = DENS(X1, Y1, Z1) - DENS(X0, Y1, Z1);
                                    c2 = DENS(X0, Y1, Z0) - c0;
                                    c3 = DENS(X0, Y1, Z1) - DENS(X0, Y1, Z0);

                                }
                                else
                                    if (rz >= ry && ry >= rx) {

                                        c1 = DENS(X1, Y1, Z1) - DENS(X0, Y1, Z1);
                                        c2 = DENS(X0, Y1, Z1) - DENS(X0, Y0, Z1);
                                        c3 = DENS(X0, Y0, Z1) - c0;

                                    }
                                    else {
                                        c1 = c2 = c3 = 0;
                                    }

                *(cmsFloat32Number*)(out[OutChan]) = c0 + c1 * rx + c2 * ry + c3 * rz;

                out[OutChan] += DestIncrements[OutChan];
            }

            if (ain)
                *out[TotalOut] = *ain;
        }

        strideIn  += Stride->BytesPerLineIn;
        strideOut += Stride->BytesPerLineOut;
    }
}

#undef DENS



// --------------------------------------------------------------------------------------------------------------

cmsBool OptimizeCLUTRGBTransform(_cmsTransform2Fn* TransformFn,
                                  void** UserData,
                                  _cmsFreeUserDataFn* FreeDataFn,
                                  cmsPipeline** Lut, 
                                  cmsUInt32Number* InputFormat, 
                                  cmsUInt32Number* OutputFormat, 
                                  cmsUInt32Number* dwFlags)      
{
    cmsPipeline* OriginalLut;
    int nGridPoints;    
    cmsPipeline* OptimizedLUT = NULL;    
    cmsStage* OptimizedCLUTmpe;
    cmsStage* mpe;
    FloatCLUTData* pfloat;
    cmsContext ContextID;
    _cmsStageCLutData* data;

    // For empty transforms, do nothing
    if (*Lut == NULL) return FALSE;

    // Check for floating point only
    if (!T_FLOAT(*InputFormat) || !T_FLOAT(*OutputFormat)) return FALSE;

    // Only on floats
    if (T_BYTES(*InputFormat) != sizeof(cmsFloat32Number) || 
        T_BYTES(*OutputFormat) != sizeof(cmsFloat32Number)) return FALSE;

    // Input has to be RGB, Output may be any
    if (T_COLORSPACE(*InputFormat) != PT_RGB) return FALSE;

    OriginalLut = *Lut;

   // Named color pipelines cannot be optimized either
   for (mpe = cmsPipelineGetPtrToFirstStage(OriginalLut);
         mpe != NULL;
         mpe = cmsStageNext(mpe)) {
            if (cmsStageType(mpe) == cmsSigNamedColorElemType) return FALSE;
    }

    ContextID        = cmsGetPipelineContextID(OriginalLut);
    nGridPoints      = _cmsReasonableGridpointsByColorspace(cmsSigRgbData, *dwFlags);
             
    // Create the result LUT
    OptimizedLUT = cmsPipelineAlloc(cmsGetPipelineContextID(OriginalLut), 3, cmsPipelineOutputChannels(OriginalLut));
    if (OptimizedLUT == NULL) goto Error;
    
    // Allocate the CLUT for result
    OptimizedCLUTmpe = cmsStageAllocCLutFloat(ContextID, nGridPoints, 3, cmsPipelineOutputChannels(OriginalLut), NULL);

    // Add the CLUT to the destination LUT
    cmsPipelineInsertStage(OptimizedLUT, cmsAT_BEGIN, OptimizedCLUTmpe);

    // Resample the LUT
    if (!cmsStageSampleCLutFloat(OptimizedCLUTmpe, XFormSampler, (void*)OriginalLut, 0)) goto Error;

    // Set the evaluator, copy parameters   
    data = (_cmsStageCLutData*) cmsStageData(OptimizedCLUTmpe);

    pfloat = FloatCLUTAlloc(ContextID, data ->Params);
    if (pfloat == NULL) return FALSE;   

    // And return the obtained LUT
    cmsPipelineFree(OriginalLut);

    *Lut = OptimizedLUT;
    *TransformFn = FloatCLUTEval;
    *UserData   = pfloat;
    *FreeDataFn = _cmsFree;
    *dwFlags &= ~cmsFLAGS_CAN_CHANGE_FORMATTER;
    return TRUE;

Error:
      
    if (OptimizedLUT != NULL) cmsPipelineFree(OptimizedLUT);

    return FALSE;    
}

