| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: colour.cpp |
| 3 | // Purpose: wxColour class |
| 4 | // Author: Julian Smart |
| 5 | // Modified by: |
| 6 | // Created: 17/09/98 |
| 7 | // RCS-ID: $Id$ |
| 8 | // Copyright: (c) Julian Smart |
| 9 | // Licence: wxWindows licence |
| 10 | ///////////////////////////////////////////////////////////////////////////// |
| 11 | |
| 12 | //// TODO: make wxColour a ref-counted object, |
| 13 | //// so pixel values get shared. |
| 14 | |
| 15 | #ifdef __GNUG__ |
| 16 | #pragma implementation "colour.h" |
| 17 | #endif |
| 18 | |
| 19 | #include "wx/gdicmn.h" |
| 20 | #include "wx/colour.h" |
| 21 | #include "wx/app.h" |
| 22 | |
| 23 | #ifdef __VMS__ |
| 24 | #pragma message disable nosimpint |
| 25 | #endif |
| 26 | #include <Xm/Xm.h> |
| 27 | #ifdef __VMS__ |
| 28 | #pragma message enable nosimpint |
| 29 | #endif |
| 30 | |
| 31 | #include "wx/motif/private.h" |
| 32 | |
| 33 | IMPLEMENT_DYNAMIC_CLASS(wxColour, wxObject) |
| 34 | |
| 35 | // Colour |
| 36 | |
| 37 | wxColour::wxColour () |
| 38 | { |
| 39 | m_isInit = FALSE; |
| 40 | m_red = m_blue = m_green = 0; |
| 41 | m_pixel = -1; |
| 42 | } |
| 43 | |
| 44 | wxColour::wxColour (unsigned char r, unsigned char g, unsigned char b) |
| 45 | { |
| 46 | m_red = r; |
| 47 | m_green = g; |
| 48 | m_blue = b; |
| 49 | m_isInit = TRUE; |
| 50 | m_pixel = -1; |
| 51 | } |
| 52 | |
| 53 | wxColour::wxColour (const wxColour& col) |
| 54 | { |
| 55 | m_red = col.m_red; |
| 56 | m_green = col.m_green; |
| 57 | m_blue = col.m_blue; |
| 58 | m_isInit = col.m_isInit; |
| 59 | m_pixel = col.m_pixel; |
| 60 | } |
| 61 | |
| 62 | wxColour& wxColour::operator =(const wxColour& col) |
| 63 | { |
| 64 | m_red = col.m_red; |
| 65 | m_green = col.m_green; |
| 66 | m_blue = col.m_blue; |
| 67 | m_isInit = col.m_isInit; |
| 68 | m_pixel = col.m_pixel; |
| 69 | return *this; |
| 70 | } |
| 71 | |
| 72 | void wxColour::InitFromName(const wxString& col) |
| 73 | { |
| 74 | wxColour *the_colour = wxTheColourDatabase->FindColour (col); |
| 75 | if (the_colour) |
| 76 | { |
| 77 | m_red = the_colour->Red (); |
| 78 | m_green = the_colour->Green (); |
| 79 | m_blue = the_colour->Blue (); |
| 80 | m_pixel = the_colour->m_pixel; |
| 81 | m_isInit = TRUE; |
| 82 | } |
| 83 | else |
| 84 | { |
| 85 | m_red = 0; |
| 86 | m_green = 0; |
| 87 | m_blue = 0; |
| 88 | m_isInit = FALSE; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | wxColour::~wxColour () |
| 93 | { |
| 94 | } |
| 95 | |
| 96 | void wxColour::Set (unsigned char r, unsigned char g, unsigned char b) |
| 97 | { |
| 98 | m_red = r; |
| 99 | m_green = g; |
| 100 | m_blue = b; |
| 101 | m_isInit = TRUE; |
| 102 | m_pixel = -1; |
| 103 | } |
| 104 | |
| 105 | // Allocate a colour, or nearest colour, using the given display. |
| 106 | // If realloc is TRUE, ignore the existing pixel, otherwise just return |
| 107 | // the existing one. |
| 108 | // Returns the old or allocated pixel. |
| 109 | |
| 110 | // TODO: can this handle mono displays? If not, we should have an extra |
| 111 | // flag to specify whether this should be black or white by default. |
| 112 | |
| 113 | int wxColour::AllocColour(WXDisplay* display, bool realloc) |
| 114 | { |
| 115 | if ((m_pixel != -1) && !realloc) |
| 116 | return m_pixel; |
| 117 | |
| 118 | XColor color; |
| 119 | color.red = (unsigned short) Red (); |
| 120 | color.red |= color.red << 8; |
| 121 | color.green = (unsigned short) Green (); |
| 122 | color.green |= color.green << 8; |
| 123 | color.blue = (unsigned short) Blue (); |
| 124 | color.blue |= color.blue << 8; |
| 125 | |
| 126 | color.flags = DoRed | DoGreen | DoBlue; |
| 127 | |
| 128 | WXColormap cmap = wxTheApp->GetMainColormap(display); |
| 129 | |
| 130 | if (!XAllocColor ((Display*) display, (Colormap) cmap, &color)) |
| 131 | { |
| 132 | m_pixel = wxGetBestMatchingPixel((Display*) display, &color,(Colormap) cmap); |
| 133 | return m_pixel; |
| 134 | } |
| 135 | else |
| 136 | { |
| 137 | m_pixel = (int) color.pixel; |
| 138 | return m_pixel; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | /*------------------------------------------- |
| 143 | Markus Emmenegger <mege@iqe.ethz.ch> |
| 144 | Find the pixel value with an assigned color closest to the desired color |
| 145 | Used if color cell allocation fails |
| 146 | As the returned pixel value may be in use by another application, |
| 147 | the color might change anytime. |
| 148 | But in many cases, that is still better than always using black. |
| 149 | -- |
| 150 | Chris Breeze <chris@hel.co.uk> |
| 151 | Improvements: |
| 152 | 1) More efficient calculation of RGB distance of colour cell from |
| 153 | the desired colour. There is no need to take the sqrt of 'dist', and |
| 154 | since we are only interested in the top 8-bits of R, G and B we |
| 155 | can perform integer arithmetic. |
| 156 | 2) Attempt to allocate a read-only colour when a close match is found. |
| 157 | A read-only colour will not change. |
| 158 | 3) Fall back to the closest match if no read-only colours are available. |
| 159 | |
| 160 | Possible further improvements: |
| 161 | 1) Scan the lookup table and sort the colour cells in order of |
| 162 | increasing |
| 163 | distance from the desired colour. Then attempt to allocate a |
| 164 | read-only |
| 165 | colour starting from the nearest match. |
| 166 | 2) Linear RGB distance is not a particularly good method of colour |
| 167 | matching |
| 168 | (though it is quick). Converting the colour to HLS and then comparing |
| 169 | may give better matching. |
| 170 | -------------------------------------------*/ |
| 171 | |
| 172 | int wxGetBestMatchingPixel(Display *display, XColor *desiredColor, Colormap cmap) |
| 173 | { |
| 174 | if (cmap == (Colormap) NULL) |
| 175 | cmap = (Colormap) wxTheApp->GetMainColormap(display); |
| 176 | |
| 177 | int numPixVals = XDisplayCells(display, DefaultScreen (display)); |
| 178 | int mindist = 256 * 256 * 3; |
| 179 | int bestpixel = (int) BlackPixel (display, DefaultScreen (display)); |
| 180 | int red = desiredColor->red >> 8; |
| 181 | int green = desiredColor->green >> 8; |
| 182 | int blue = desiredColor->blue >> 8; |
| 183 | const int threshold = 2 * 2 * 3; // allow an error of up to 2 in R,G & B |
| 184 | |
| 185 | for (int pixelcount = 0; pixelcount < numPixVals; pixelcount++) |
| 186 | { |
| 187 | XColor matching_color; |
| 188 | matching_color.pixel = pixelcount; |
| 189 | XQueryColor(display,cmap,&matching_color); |
| 190 | |
| 191 | int delta_red = red - (matching_color.red >> 8); |
| 192 | int delta_green = green - (matching_color.green >> 8); |
| 193 | int delta_blue = blue - (matching_color.blue >> 8); |
| 194 | |
| 195 | int dist = delta_red * delta_red + |
| 196 | delta_green * delta_green + |
| 197 | delta_blue * delta_blue; |
| 198 | |
| 199 | if (dist <= threshold) |
| 200 | { |
| 201 | // try to allocate a read-only colour... |
| 202 | if (XAllocColor (display, cmap, &matching_color)) |
| 203 | { |
| 204 | return matching_color.pixel; |
| 205 | } |
| 206 | } |
| 207 | if (dist < mindist) |
| 208 | { |
| 209 | bestpixel = pixelcount; |
| 210 | mindist = dist; |
| 211 | } |
| 212 | } |
| 213 | return bestpixel; |
| 214 | } |