tdegraphics/kolourpaint/widgets/kpcolorsimilaritycube.cpp

/*
   Copyright (c) 2003,2004,2005 Clarence Dang <dang@kde.org>
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#define DEBUG_KP_COLOR_SIMILARITY_CUBE 0


#include <kpcolorsimilaritycube.h>

#include <math.h>

#include <tqpainter.h>
#include <tqpixmap.h>
#include <tqwhatsthis.h>

#include <kdebug.h>
#include <klocale.h>

#include <kpcolor.h>
#include <kpcolorsimilaritydialog.h>
#include <kpdefs.h>


const double kpColorSimilarityCube::colorCubeDiagonalDistance =
    sqrt (255 * 255 * 3);

kpColorSimilarityCube::kpColorSimilarityCube (int look,
                                              kpMainWindow *mainWindow,
                                              TQWidget *tqparent,
                                              const char *name)
    : TQFrame (tqparent, name, TQt::WNoAutoErase/*no flicker*/),
      m_mainWindow (mainWindow),
      m_colorSimilarity (-1)
{
    if (look & Depressed)
        setFrameStyle (TQFrame::Panel | TQFrame::Sunken);

    setColorSimilarity (0);


    // Don't cause the translators grief by appending strings
    // - duplicate text with 2 cases

    if (look & DoubleClickInstructions)
    {
        TQWhatsThis::add (this,
            i18n ("<qt><p><b>Color Similarity</b> is how close "
                  "colors must be in the RGB Color Cube "
                  "to be considered the same.</p>"

                  "<p>If you set it to something "
                  "other than <b>Exact</b>, "
                  "you can work more effectively with dithered "
                  "images and photos.</p>"

                  "<p>This feature applies to transparent selections, as well as "
                  "the Flood Fill, Color Eraser and Autocrop "
                  "tools.</p>"

                  // sync: different to else case
                  "<p>To configure it, double click on the cube.</p>"

                  "</qt>"));
    }
    else
    {
        TQWhatsThis::add (this,
            i18n ("<qt><p><b>Color Similarity</b> is how close "
                  "colors must be in the RGB Color Cube "
                  "to be considered the same.</p>"

                  "<p>If you set it to something "
                  "other than <b>Exact</b>, "
                  "you can work more effectively with dithered "
                  "images and photos.</p>"

                  "<p>This feature applies to transparent selections, as well as "
                  "the Flood Fill, Color Eraser and Autocrop "
                  "tools.</p>"

                  "</qt>"));
    }
}

kpColorSimilarityCube::~kpColorSimilarityCube ()
{
}


// public
double kpColorSimilarityCube::colorSimilarity () const
{
    return m_colorSimilarity;
}

// public
void kpColorSimilarityCube::setColorSimilarity (double similarity)
{
#if DEBUG_KP_COLOR_SIMILARITY_CUBE
    kdDebug () << "kpColorSimilarityCube::setColorSimilarity(" << similarity << ")" << endl;
#endif

    if (m_colorSimilarity == similarity)
        return;

    if (similarity < 0)
        similarity = 0;
    else if (similarity > kpColorSimilarityDialog::maximumColorSimilarity)
        similarity = kpColorSimilarityDialog::maximumColorSimilarity;

    m_colorSimilarity = similarity;

    tqrepaint (false/*no erase*/);
}


// protected virtual [base TQWidget]
TQSize kpColorSimilarityCube::tqsizeHint () const
{
    return TQSize (52, 52);
}


// protected
TQColor kpColorSimilarityCube::color (int redOrGreenOrBlue,
                                     int baseBrightness,
                                     int similarityDirection) const
{
    int brightness = int (baseBrightness +
                          similarityDirection *
                              .5 * m_colorSimilarity * kpColorSimilarityCube::colorCubeDiagonalDistance);

    if (brightness < 0)
        brightness = 0;
    else if (brightness > 255)
        brightness = 255;

    switch (redOrGreenOrBlue)
    {
    default:
    case 0: return TQColor (brightness, 0, 0);
    case 1: return TQColor (0, brightness, 0);
    case 2: return TQColor (0, 0, brightness);
    }
}

static TQPoint pointBetween (const TQPoint &p, const TQPoint &q)
{
    return TQPoint ((p.x () + q.x ()) / 2, (p.y () + q.y ()) / 2);
}

static void drawQuadrant (TQPainter *p,
                          const TQColor &col,
                          const TQPoint &p1, const TQPoint &p2, const TQPoint &p3,
                          const TQPoint pointNotOnOutline)
{
    p->save ();


    TQPointArray points (4);
    points [0] = p1;
    points [1] = p2;
    points [2] = p3;
    points [3] = pointNotOnOutline;

    p->setPen (col);
    p->setBrush (col);
    p->drawPolygon (points);


    points.resize (3);

    p->setPen (TQt::black);
    p->setBrush (TQt::NoBrush);
    p->drawPolyline (points);


    p->restore ();
}

// protected
void kpColorSimilarityCube::drawFace (TQPainter *p,
                                      int redOrGreenOrBlue,
                                      const TQPoint &tl, const TQPoint &tr,
                                      const TQPoint &bl, const TQPoint &br)
{
#if DEBUG_KP_COLOR_SIMILARITY_CUBE
    kdDebug () << "kpColorSimilarityCube(RorGorB=" << redOrGreenOrBlue
               << ",tl=" << tl
               << ",tr=" << tr
               << ",bl=" << bl
               << ",br=" << br
               << ")"
               << endl;
#endif

    //  tl --- tm --- tr
    //  |      |       |
    //  |      |       |
    //  ml --- mm --- mr
    //  |      |       |
    //  |      |       |
    //  bl --- bm --- br

    const TQPoint tm (::pointBetween (tl, tr));
    const TQPoint bm (::pointBetween (bl, br));

    const TQPoint ml (::pointBetween (tl, bl));
    const TQPoint mr (::pointBetween (tr, br));
    const TQPoint mm (::pointBetween (ml, mr));


    const int baseBrightness = TQMAX (127,
                                     255 - int (kpColorSimilarityDialog::maximumColorSimilarity *
                                                kpColorSimilarityCube::colorCubeDiagonalDistance / 2));
    TQColor colors [2] =
    {
        color (redOrGreenOrBlue, baseBrightness, -1),
        color (redOrGreenOrBlue, baseBrightness, +1)
    };

    if (!isEnabled ())
    {
    #if DEBUG_KP_COLOR_SIMILARITY_CUBE
        kdDebug () << "\tnot enabled - making us grey" << endl;
    #endif
        colors [0] = tqcolorGroup ().background ();
        colors [1] = tqcolorGroup ().background ();
    }

#if DEBUG_KP_COLOR_SIMILARITY_CUBE
    kdDebug () << "\tmaxColorSimilarity=" << kpColorSimilarityDialog::maximumColorSimilarity
               << " colorCubeDiagDist=" << kpColorSimilarityCube::colorCubeDiagonalDistance
               << endl
               << "\tbaseBrightness=" << baseBrightness
               << " color[0]=" << ((colors [0].rgb () & TQRGB_MASK) >> ((2 - redOrGreenOrBlue) * 8))
               << " color[1]=" << ((colors [1].rgb () & TQRGB_MASK) >> ((2 - redOrGreenOrBlue) * 8))
               << endl;
#endif


    ::drawQuadrant (p, colors [0], tm, tl, ml, mm);
    ::drawQuadrant (p, colors [1], tm, tr, mr, mm);
    ::drawQuadrant (p, colors [1], ml, bl, bm, mm);
    ::drawQuadrant (p, colors [0], bm, br, mr, mm);
}

// protected virtual [base TQFrame]
void kpColorSimilarityCube::drawContents (TQPainter *p)
{
    TQRect cr (contentsRect ());

    TQPixmap backBuffer (cr.width (), cr.height ());
    backBuffer.fill (tqcolorGroup ().background ());

    TQPainter backBufferPainter (&backBuffer);

    int cubeRectSize = TQMIN (cr.width () * 6 / 8, cr.height () * 6 / 8);
    int dx = (cr.width () - cubeRectSize) / 2,
        dy = (cr.height () - cubeRectSize) / 2;
    backBufferPainter.translate (dx, dy);

    //
    //      P------- Q  ---  ---
    //     /       / |   |    |
    //    /A      /  |  side  |
    //   R-------S   T  --- cubeRectSize
    //   |       |  /   /     |
    // S |       | /  side    |
    //   U-------V   ---     ---
    //   |-------|
    //      side
    //   |-----------|
    //    cubeRectSize
    //
    //

    const double angle = KP_DEGREES_TO_RADIANS (45);
    // S + S sin A = cubeRectSize
    // (1 + sin A) x S = cubeRectSize
    const double side = double (cubeRectSize) / (1 + sin (angle));


    const TQPoint pointP ((int) (side * cos (angle)), 0);
    const TQPoint pointQ ((int) (side * cos (angle) + side), 0);
    const TQPoint pointR (0, (int) (side * sin (angle)));
    const TQPoint pointS ((int) (side), (int) (side * sin (angle)));
    const TQPoint pointU (0, (int) (side * sin (angle) + side));
    const TQPoint pointT ((int) (side + side * cos (angle)), (int) (side));
    const TQPoint pointV ((int) (side), (int) (side * sin (angle) + side));


    // Top Face
    drawFace (&backBufferPainter,
              0/*red*/,
              pointP, pointQ,
              pointR, pointS);


    // Bottom Face
    drawFace (&backBufferPainter,
              1/*green*/,
              pointR, pointS,
              pointU, pointV);


    // Right Face
    drawFace (&backBufferPainter,
              2/*blue*/,
              pointS, pointQ,
              pointV, pointT);


#if 0
    backBufferPainter.save ();
    backBufferPainter.setPen (TQt::cyan);
    backBufferPainter.drawRect (0, 0, cubeRectSize, cubeRectSize);
    backBufferPainter.restore ();
#endif


    backBufferPainter.end ();

    p->drawPixmap (cr, backBuffer);
}