Some work for wxX11 on 8-bit visuals.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@14867 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/x11/app.cpp

@@ -30,6 +30,8 @@
 #include "wx/univ/theme.h"
 #include "wx/univ/renderer.h"
 
+#define ABS(a)	   (((a) < 0) ? -(a) : (a))
+
 #if wxUSE_THREADS
     #include "wx/thread.h"
 #endif
@@ -396,6 +398,18 @@ wxApp::wxApp()
     m_mainLoop = NULL;
     m_showIconic = FALSE;
     m_initialSize = wxDefaultSize;
+    
+    m_visualColormap = NULL;
+    m_colorCube = NULL;
+}
+
+wxApp::~wxApp()
+{
+    if (m_colorCube)
+        free( m_colorCube );
+        
+    if (m_visualColormap)
+        delete [] (XColor*)m_visualColormap;
 }
 
 bool wxApp::Initialized()
@@ -940,6 +954,24 @@ void wxApp::DeletePendingObjects()
     }
 }
 
+static void wxCalcPrecAndShift( unsigned long mask, int *shift, int *prec )
+{
+  *shift = 0;
+  *prec = 0;
+
+  while (!(mask & 0x1))
+    {
+      (*shift)++;
+      mask >>= 1;
+    }
+
+  while (mask & 0x1)
+    {
+      (*prec)++;
+      mask >>= 1;
+    }
+}
+
 // Create display, and other initialization
 bool wxApp::OnInitGui()
 {
@@ -949,12 +981,106 @@ bool wxApp::OnInitGui()
     delete wxLog::SetActiveTarget(new wxLogStderr);
 
     if (!wxAppBase::OnInitGui())
-    return FALSE;
+        return FALSE;
 
     GetMainColormap( wxApp::GetDisplay() );
 
     m_maxRequestSize = XMaxRequestSize( (Display*) wxApp::GetDisplay() );
 
+    // Get info about the current visual. It is enough
+    // to do this once here unless we support different
+    // visuals, displays and screens. Given that wxX11
+    // mostly for embedded things, that is no real
+    // limitation.
+    Display *xdisplay = (Display*) wxApp::GetDisplay();
+    int xscreen = DefaultScreen(xdisplay);
+    Visual* xvisual = DefaultVisual(xdisplay,xscreen);
+    int xdepth = DefaultDepth(xdisplay, xscreen);
+
+    XVisualInfo vinfo_template;
+    vinfo_template.visual = xvisual;
+    vinfo_template.visualid = XVisualIDFromVisual( xvisual );
+    vinfo_template.depth = xdepth;
+        
+    int nitem = 0;
+    XVisualInfo *vi = XGetVisualInfo( xdisplay, VisualIDMask|VisualDepthMask, &vinfo_template, &nitem );
+    wxASSERT_MSG( vi, wxT("No visual info") );
+    
+    m_visualType = vi->visual->c_class;
+    m_visualScreen = vi->screen;
+    
+    m_visualRedMask = vi->red_mask;
+    m_visualGreenMask = vi->green_mask;
+    m_visualBlueMask = vi->blue_mask;
+    
+    if (m_visualType != GrayScale && m_visualType != PseudoColor)
+    {
+        wxCalcPrecAndShift( m_visualRedMask, &m_visualRedShift, &m_visualRedPrec );
+        wxCalcPrecAndShift( m_visualGreenMask, &m_visualGreenShift, &m_visualGreenPrec );
+        wxCalcPrecAndShift( m_visualBlueMask, &m_visualBlueShift, &m_visualBluePrec );
+    }
+    
+    m_visualDepth = xdepth;
+    if (xdepth == 16)
+        xdepth = m_visualRedPrec + m_visualGreenPrec + m_visualBluePrec;
+        
+    m_visualColormapSize = vi->colormap_size;
+        
+    XFree( vi );
+    
+    if (m_visualDepth > 8)
+        return TRUE;
+    
+    m_visualColormap = new XColor[m_visualColormapSize];
+    XColor* colors = (XColor*) m_visualColormap;
+    
+    for (int i = 0; i < m_visualColormapSize; i++)
+	    colors[i].pixel = i;
+
+    XQueryColors( xdisplay, DefaultColormap(xdisplay,xscreen), colors, m_visualColormapSize );
+        
+    m_colorCube = (unsigned char*)malloc(32 * 32 * 32);
+
+    for (int r = 0; r < 32; r++)
+    {
+        for (int g = 0; g < 32; g++)
+        {
+            for (int b = 0; b < 32; b++)
+            {
+                int rr = (r << 3) | (r >> 2);
+                int gg = (g << 3) | (g >> 2);
+                int bb = (b << 3) | (b >> 2);
+
+                int index = -1;
+
+                if (colors)
+                {
+                    int max = 3 * 65536;
+
+                    for (int i = 0; i < m_visualColormapSize; i++)
+                    {
+                        int rdiff = ((rr << 8) - colors[i].red);
+                        int gdiff = ((gg << 8) - colors[i].green);
+                        int bdiff = ((bb << 8) - colors[i].blue);
+                        int sum = ABS (rdiff) + ABS (gdiff) + ABS (bdiff);
+                        if (sum < max)
+                        {
+                            index = i; max = sum;
+                        }
+                    }
+                }
+                else
+                {
+                    // assume 8-bit true or static colors. this really exists
+                    index = (r >> (5 - m_visualRedPrec)) << m_visualRedShift;
+                    index |= (g >> (5 - m_visualGreenPrec)) << m_visualGreenShift;
+                    index |= (b >> (5 - m_visualBluePrec)) << m_visualBlueShift;
+                }
+                m_colorCube[ (r*1024) + (g*32) + b ] = index;
+            }
+        }
+    }
+    
     return TRUE;
 }