From b6d455a02bd338e9dc0faa09d4d8177ecd8d569a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Petr=20Mr=C3=A1zek?= Date: Sun, 10 Apr 2016 15:53:05 +0200 Subject: NOISSUE reorganize and document libraries --- libraries/rainbow/include/rainbow.h | 160 ++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 libraries/rainbow/include/rainbow.h (limited to 'libraries/rainbow/include/rainbow.h') diff --git a/libraries/rainbow/include/rainbow.h b/libraries/rainbow/include/rainbow.h new file mode 100644 index 00000000..b12052b1 --- /dev/null +++ b/libraries/rainbow/include/rainbow.h @@ -0,0 +1,160 @@ +/* This was part of the KDE project - see KGuiAddons + * Copyright (C) 2007 Matthew Woehlke + * Copyright (C) 2007 Olaf Schmidt + * Copyright (C) 2007 Thomas Zander + * Copyright (C) 2007 Zack Rusin + * Copyright (C) 2015 Petr Mrazek + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public License + * along with this library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + */ + +#pragma once + +#include "rainbow_config.h" + +#include +class QColor; + +/** + * A set of methods used to work with colors. + */ +namespace Rainbow +{ +/** + * Calculate the luma of a color. Luma is weighted sum of gamma-adjusted + * R'G'B' components of a color. The result is similar to qGray. The range + * is from 0.0 (black) to 1.0 (white). + * + * Rainbow::darken(), Rainbow::lighten() and Rainbow::shade() + * operate on the luma of a color. + * + * @see http://en.wikipedia.org/wiki/Luma_(video) + */ +RAINBOW_EXPORT qreal luma(const QColor &); + +/** + * Calculate hue, chroma and luma of a color in one call. + * @since 5.0 + */ +RAINBOW_EXPORT void getHcy(const QColor &, qreal *hue, qreal *chroma, qreal *luma, + qreal *alpha = 0); + +/** + * Calculate the contrast ratio between two colors, according to the + * W3C/WCAG2.0 algorithm, (Lmax + 0.05)/(Lmin + 0.05), where Lmax and Lmin + * are the luma values of the lighter color and the darker color, + * respectively. + * + * A contrast ration of 5:1 (result == 5.0) is the minimum for "normal" + * text to be considered readable (large text can go as low as 3:1). The + * ratio ranges from 1:1 (result == 1.0) to 21:1 (result == 21.0). + * + * @see Rainbow::luma + */ +RAINBOW_EXPORT qreal contrastRatio(const QColor &, const QColor &); + +/** + * Adjust the luma of a color by changing its distance from white. + * + * @li amount == 1.0 gives white + * @li amount == 0.5 results in a color whose luma is halfway between 1.0 + * and that of the original color + * @li amount == 0.0 gives the original color + * @li amount == -1.0 gives a color that is 'twice as far from white' as + * the original color, that is luma(result) == 1.0 - 2*(1.0 - luma(color)) + * + * @param amount factor by which to adjust the luma component of the color + * @param chromaInverseGain (optional) factor by which to adjust the chroma + * component of the color; 1.0 means no change, 0.0 maximizes chroma + * @see Rainbow::shade + */ +RAINBOW_EXPORT QColor +lighten(const QColor &, qreal amount = 0.5, qreal chromaInverseGain = 1.0); + +/** + * Adjust the luma of a color by changing its distance from black. + * + * @li amount == 1.0 gives black + * @li amount == 0.5 results in a color whose luma is halfway between 0.0 + * and that of the original color + * @li amount == 0.0 gives the original color + * @li amount == -1.0 gives a color that is 'twice as far from black' as + * the original color, that is luma(result) == 2*luma(color) + * + * @param amount factor by which to adjust the luma component of the color + * @param chromaGain (optional) factor by which to adjust the chroma + * component of the color; 1.0 means no change, 0.0 minimizes chroma + * @see Rainbow::shade + */ +RAINBOW_EXPORT QColor darken(const QColor &, qreal amount = 0.5, qreal chromaGain = 1.0); + +/** + * Adjust the luma and chroma components of a color. The amount is added + * to the corresponding component. + * + * @param lumaAmount amount by which to adjust the luma component of the + * color; 0.0 results in no change, -1.0 turns anything black, 1.0 turns + * anything white + * @param chromaAmount (optional) amount by which to adjust the chroma + * component of the color; 0.0 results in no change, -1.0 minimizes chroma, + * 1.0 maximizes chroma + * @see Rainbow::luma + */ +RAINBOW_EXPORT QColor shade(const QColor &, qreal lumaAmount, qreal chromaAmount = 0.0); + +/** + * Create a new color by tinting one color with another. This function is + * meant for creating additional colors withings the same class (background, + * foreground) from colors in a different class. Therefore when @p amount + * is low, the luma of @p base is mostly preserved, while the hue and + * chroma of @p color is mostly inherited. + * + * @param base color to be tinted + * @param color color with which to tint + * @param amount how strongly to tint the base; 0.0 gives @p base, + * 1.0 gives @p color + */ +RAINBOW_EXPORT QColor tint(const QColor &base, const QColor &color, qreal amount = 0.3); + +/** + * Blend two colors into a new color by linear combination. + * @code + QColor lighter = Rainbow::mix(myColor, Qt::white) + * @endcode + * @param c1 first color. + * @param c2 second color. + * @param bias weight to be used for the mix. @p bias <= 0 gives @p c1, + * @p bias >= 1 gives @p c2. @p bias == 0.5 gives a 50% blend of @p c1 + * and @p c2. + */ +RAINBOW_EXPORT QColor mix(const QColor &c1, const QColor &c2, qreal bias = 0.5); + +/** + * Blend two colors into a new color by painting the second color over the + * first using the specified composition mode. + * @code + QColor white(Qt::white); + white.setAlphaF(0.5); + QColor lighter = Rainbow::overlayColors(myColor, white); + @endcode + * @param base the base color (alpha channel is ignored). + * @param paint the color to be overlayed onto the base color. + * @param comp the CompositionMode used to do the blending. + */ +RAINBOW_EXPORT QColor +overlayColors(const QColor &base, const QColor &paint, + QPainter::CompositionMode comp = QPainter::CompositionMode_SourceOver); +} -- cgit v1.2.3