diff options
Diffstat (limited to 'libX11/src/xcms/LabMxC.c')
| -rw-r--r-- | libX11/src/xcms/LabMxC.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/libX11/src/xcms/LabMxC.c b/libX11/src/xcms/LabMxC.c new file mode 100644 index 000000000..acd83f2d5 --- /dev/null +++ b/libX11/src/xcms/LabMxC.c @@ -0,0 +1,205 @@ +/* $Xorg: LabMxC.c,v 1.3 2000/08/17 19:44:40 cpqbld Exp $ */ + +/* + * Code and supporting documentation (c) Copyright 1990 1991 Tektronix, Inc. + * All Rights Reserved + * + * This file is a component of an X Window System-specific implementation + * of XCMS based on the TekColor Color Management System. Permission is + * hereby granted to use, copy, modify, sell, and otherwise distribute this + * software and its documentation for any purpose and without fee, provided + * that this copyright, permission, and disclaimer notice is reproduced in + * all copies of this software and in supporting documentation. TekColor + * is a trademark of Tektronix, Inc. + * + * Tektronix makes no representation about the suitability of this software + * for any purpose. It is provided "as is" and with all faults. + * + * TEKTRONIX DISCLAIMS ALL WARRANTIES APPLICABLE TO THIS SOFTWARE, + * INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE. IN NO EVENT SHALL TEKTRONIX BE LIABLE FOR ANY + * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER + * RESULTING FROM LOSS OF USE, DATA, OR PROFITS, WHETHER IN AN ACTION OF + * CONTRACT, NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR THE PERFORMANCE OF THIS SOFTWARE. + * + * + * + * NAME + * CIELabMxC.c + * + * DESCRIPTION + * Source for the XcmsCIELabQueryMaxC() gamut boundary + * querying routine. + * + */ +/* $XFree86: xc/lib/X11/LabMxC.c,v 1.3 2001/01/17 19:41:39 dawes Exp $ */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "Xlibint.h" +#include "Xcmsint.h" +#include <math.h> +#include "Cv.h" + +/* + * DEFINES + */ +#define MAXBISECTCOUNT 100 +#define EPS (XcmsFloat)0.001 +#define START_CHROMA (XcmsFloat)3.6 +#define TOPL (XcmsFloat)100.0 + + +/************************************************************************ + * * + * PUBLIC ROUTINES * + * * + ************************************************************************/ + +/* + * NAME + * XcmsCIELabQueryMaxC - max chroma for a hue_angle and L_star + * + * SYNOPSIS + */ +Status +XcmsCIELabQueryMaxC( + XcmsCCC ccc, + XcmsFloat hue_angle, /* hue angle in degrees */ + XcmsFloat L_star, + XcmsColor *pColor_return) +/* + * DESCRIPTION + * Return the maximum chroma for a specific hue_angle and L_star. + * The returned format is in XcmsCIELabFormat. + * + * + * ASSUMPTIONS + * This routine assumes that the white point associated with + * the color specification is the Screen White Point. The + * Screen White Point will also be associated with the + * returned color specification. + * + * RETURNS + * XcmsFailure - Failure + * XcmsSuccess - Succeeded + * + */ +{ + XcmsCCCRec myCCC; + XcmsColor tmp; + XcmsColor max_lc; + XcmsFloat n_L_star, last_L_star, prev_L_star; + XcmsFloat hue, lastaStar, lastbStar, /*lastChroma,*/ maxDist, nT, rFactor; + XcmsRGBi rgb_saved; + int nCount, nMaxCount; + + /* + * Check Arguments + */ + if (ccc == NULL || pColor_return == NULL) { + return(XcmsFailure); + } + + /* Use my own CCC and inherit screen white Pt */ + memcpy ((char *)&myCCC, (char *)ccc, sizeof(XcmsCCCRec)); + myCCC.clientWhitePt.format = XcmsUndefinedFormat; + myCCC.gamutCompProc = (XcmsCompressionProc)NULL;/* no gamut comp func */ + + while (hue_angle < 0.0) { + hue_angle += 360.0; + } + while (hue_angle >= 360.0) { + hue_angle -= 360.0; + } + + hue = radians(hue_angle); + tmp.spec.CIELab.L_star = L_star; + tmp.spec.CIELab.a_star = XCMS_CIEASTAROFHUE(hue, START_CHROMA); + tmp.spec.CIELab.b_star = XCMS_CIEBSTAROFHUE(hue, START_CHROMA); + tmp.pixel = pColor_return->pixel; + tmp.format = XcmsCIELabFormat; + + /* Step 1: compute the maximum L_star and chroma for this hue. */ + memcpy((char *)&max_lc, (char *)&tmp, sizeof(XcmsColor)); + if (_XcmsCIELabQueryMaxLCRGB(&myCCC, hue, &max_lc, &rgb_saved) + == XcmsFailure) { + return(XcmsFailure); + } + + /* + * Step 2: Do a bisection here to compute the maximum chroma + * Note the differences between when the point to be found + * is above the maximum LC point and when it is below. + */ + if (L_star <= max_lc.spec.CIELab.L_star) { + maxDist = max_lc.spec.CIELab.L_star; + } else { + maxDist = TOPL - max_lc.spec.CIELab.L_star; + } + + n_L_star = L_star; + last_L_star = -1.0; + nMaxCount = MAXBISECTCOUNT; + rFactor = 1.0; + + for (nCount = 0; nCount < nMaxCount; nCount++) { + prev_L_star = last_L_star; + last_L_star = tmp.spec.CIELab.L_star; +/* lastChroma = XCMS_CIELAB_PMETRIC_CHROMA(tmp.spec.CIELab.a_star, */ +/* tmp.spec.CIELab.b_star); */ + lastaStar = tmp.spec.CIELab.a_star; + lastbStar = tmp.spec.CIELab.b_star; + nT = (n_L_star - max_lc.spec.CIELab.L_star) / maxDist * rFactor; + if (nT > 0) { + tmp.spec.RGBi.red = rgb_saved.red * (1.0 - nT) + nT; + tmp.spec.RGBi.green = rgb_saved.green * (1.0 - nT) + nT; + tmp.spec.RGBi.blue = rgb_saved.blue * (1.0 - nT) + nT; + } else { + tmp.spec.RGBi.red = rgb_saved.red + (rgb_saved.red * nT); + tmp.spec.RGBi.green = rgb_saved.green + (rgb_saved.green * nT); + tmp.spec.RGBi.blue = rgb_saved.blue + (rgb_saved.blue * nT); + } + tmp.format = XcmsRGBiFormat; + + /* convert from RGB to CIELab */ + if (_XcmsConvertColorsWithWhitePt(&myCCC, &tmp, + ScreenWhitePointOfCCC(&myCCC), 1, XcmsCIELabFormat, + (Bool *) NULL) == XcmsFailure) { + return(XcmsFailure); + } + + /* + * Now check if we've reached the target L_star + */ + /* printf("result Lstar = %lf\n", tmp.spec.CIELab.L_star); */ + if (tmp.spec.CIELab.L_star <= L_star + EPS && + tmp.spec.CIELab.L_star >= L_star - EPS) { + memcpy((char *)pColor_return, (char *)&tmp, sizeof(XcmsColor)); + return(XcmsSuccess); + } + if (nT > 0) { + n_L_star += ((TOPL - n_L_star) * + (L_star - tmp.spec.CIELab.L_star)) / (TOPL - L_star); + } else { + n_L_star *= L_star / tmp.spec.CIELuv.L_star; + } + if (tmp.spec.CIELab.L_star <= prev_L_star + EPS && + tmp.spec.CIELab.L_star >= prev_L_star - EPS) { + rFactor *= 0.5; /* selective relaxation employed */ + /* printf("rFactor = %lf\n", rFactor); */ + } + } + if (XCMS_FABS(last_L_star - L_star) < + XCMS_FABS(tmp.spec.CIELab.L_star - L_star)) { + tmp.spec.CIELab.a_star = lastaStar; + tmp.spec.CIELab.b_star = lastbStar; +/* tmp.spec.CIELab.a_star = XCMS_CIEASTAROFHUE(hue, lastChroma); */ +/* tmp.spec.CIELab.b_star = XCMS_CIEBSTAROFHUE(hue, lastChroma); */ + } + tmp.spec.CIELab.L_star = L_star; + memcpy((char *)pColor_return, (char *)&tmp, sizeof(XcmsColor)); + return(XcmsSuccess); +} |