/*

 * jccolext.c

 *

 * This file was part of the Independent JPEG Group's software:

 * Copyright (C) 1991-1996, Thomas G. Lane.

 * libjpeg-turbo Modifications:

 * Copyright (C) 2009-2012, 2015, D. R. Commander.

 * For conditions of distribution and use, see the accompanying README.ijg

 * file.

 *

 * This file contains input colorspace conversion routines.

 */

/* This file is included by jccolor.c */

/*

 * Convert some rows of samples to the JPEG colorspace.

 *

 * Note that we change from the application's interleaved-pixel format

 * to our internal noninterleaved, one-plane-per-component format.

 * The input buffer is therefore three times as wide as the output buffer.

 *

 * A starting row offset is provided only for the output buffer.  The caller

 * can easily adjust the passed input_buf value to accommodate any row

 * offset required on that side.

 */

INLINE

LOCAL(void)

rgb_ycc_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,

                         JSAMPIMAGE output_buf, JDIMENSION output_row,

                         int num_rows)

{

  my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;

  register int r, g, b;

  register JLONG *ctab = cconvert->rgb_ycc_tab;

  register JSAMPROW inptr;

  register JSAMPROW outptr0, outptr1, outptr2;

  register JDIMENSION col;

  JDIMENSION num_cols = cinfo->image_width;

  while (--num_rows >= 0) {

    inptr = *input_buf++;

    outptr0 = output_buf[0][output_row];

    outptr1 = output_buf[1][output_row];

    outptr2 = output_buf[2][output_row];

    output_row++;

    for (col = 0; col < num_cols; col++) {

      r = GETJSAMPLE(inptr[RGB_RED]);

      g = GETJSAMPLE(inptr[RGB_GREEN]);

      b = GETJSAMPLE(inptr[RGB_BLUE]);

      inptr += RGB_PIXELSIZE;

      /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations

       * must be too; we do not need an explicit range-limiting operation.

       * Hence the value being shifted is never negative, and we don't

       * need the general RIGHT_SHIFT macro.

       */

      /* Y */

      outptr0[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +

                                ctab[b + B_Y_OFF]) >> SCALEBITS);

      /* Cb */

      outptr1[col] = (JSAMPLE)((ctab[r + R_CB_OFF] + ctab[g + G_CB_OFF] +

                                ctab[b + B_CB_OFF]) >> SCALEBITS);

      /* Cr */

      outptr2[col] = (JSAMPLE)((ctab[r + R_CR_OFF] + ctab[g + G_CR_OFF] +

                                ctab[b + B_CR_OFF]) >> SCALEBITS);

    }

  }

}

/**************** Cases other than RGB -> YCbCr **************/

/*

 * Convert some rows of samples to the JPEG colorspace.

 * This version handles RGB->grayscale conversion, which is the same

 * as the RGB->Y portion of RGB->YCbCr.

 * We assume rgb_ycc_start has been called (we only use the Y tables).

 */

INLINE

LOCAL(void)

rgb_gray_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,

                          JSAMPIMAGE output_buf, JDIMENSION output_row,

                          int num_rows)

{

  my_cconvert_ptr cconvert = (my_cconvert_ptr)cinfo->cconvert;

  register int r, g, b;

  register JLONG *ctab = cconvert->rgb_ycc_tab;

  register JSAMPROW inptr;

  register JSAMPROW outptr;

  register JDIMENSION col;

  JDIMENSION num_cols = cinfo->image_width;

  while (--num_rows >= 0) {

    inptr = *input_buf++;

    outptr = output_buf[0][output_row];

    output_row++;

    for (col = 0; col < num_cols; col++) {

      r = GETJSAMPLE(inptr[RGB_RED]);

      g = GETJSAMPLE(inptr[RGB_GREEN]);

      b = GETJSAMPLE(inptr[RGB_BLUE]);

      inptr += RGB_PIXELSIZE;

      /* Y */

      outptr[col] = (JSAMPLE)((ctab[r + R_Y_OFF] + ctab[g + G_Y_OFF] +

                               ctab[b + B_Y_OFF]) >> SCALEBITS);

    }

  }

}

/*

 * Convert some rows of samples to the JPEG colorspace.

 * This version handles extended RGB->plain RGB conversion

 */

INLINE

LOCAL(void)

rgb_rgb_convert_internal(j_compress_ptr cinfo, JSAMPARRAY input_buf,

                         JSAMPIMAGE output_buf, JDIMENSION output_row,

                         int num_rows)

{

  register JSAMPROW inptr;

  register JSAMPROW outptr0, outptr1, outptr2;

  register JDIMENSION col;

  JDIMENSION num_cols = cinfo->image_width;

  while (--num_rows >= 0) {

    inptr = *input_buf++;

    outptr0 = output_buf[0][output_row];

    outptr1 = output_buf[1][output_row];

    outptr2 = output_buf[2][output_row];

    output_row++;

    for (col = 0; col < num_cols; col++) {

      outptr0[col] = GETJSAMPLE(inptr[RGB_RED]);

      outptr1[col] = GETJSAMPLE(inptr[RGB_GREEN]);

      outptr2[col] = GETJSAMPLE(inptr[RGB_BLUE]);

      inptr += RGB_PIXELSIZE;

    }

  }

}