src/motif/glcanvas.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        glcanvas.cpp
   3 // Purpose:     wxGLCanvas, for using OpenGL with wxWindows 2.0 for Motif.
   4 //              Uses the GLX extension.
   5 // Author:      Julian Smart and Wolfram Gloger
   6 // Modified by:
   7 // Created:     1995, 1999
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) Julian Smart, Wolfram Gloger
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifdef __GNUG__
  14 #pragma implementation "glcanvas.h"
  15 #endif
  16
  17 #include "wx/setup.h"
  18
  19 #if wxUSE_GLCANVAS
  20
  21 #include "wx/glcanvas.h"
  22 #include "wx/utils.h"
  23 #include "wx/app.h"
  24
  25 #include <Xm/Xm.h>
  26 #include "wx/motif/private.h"
  27
  28 #ifdef OLD_MESA
  29 // workaround for bug in Mesa's glx.c
  30 static int bitcount( unsigned long n )
  31 {
  32     int bits;
  33     for (bits=0; n>0;) {
  34         if(n & 1) bits++;
  35         n = n >> 1;
  36     }
  37     return bits;
  38 }
  39 #endif
  40
  41 /*
  42  * GLCanvas implementation
  43  */
  44
  45 IMPLEMENT_CLASS(wxGLCanvas, wxScrolledWindow)
  46
  47 wxGLCanvas::wxGLCanvas(wxWindow *parent, wxWindowID id = -1, const wxPoint& pos,
  48   const wxSize& size, long style,
  49   const wxString& name, int *attribList, const wxPalette& palette):
  50     wxScrolledWindow(parent, id, pos, size, style, name)
  51 {
  52     XVisualInfo *vi, vi_templ;
  53     XWindowAttributes xwa;
  54     int val, n;
  55
  56     Display* display = (Display*) GetXDisplay();
  57
  58     glx_cx = 0;
  59     // Check for the presence of the GLX extension
  60     if(!glXQueryExtension(display, NULL, NULL)) {
  61         wxDebugMsg("wxGLCanvas: GLX extension is missing\n");
  62         return;
  63     }
  64
  65     if(attribList) {
  66       int data[512], arg=0, p=0;
  67
  68       while( (attribList[arg]!=0) && (p<512) )
  69       {
  70         switch( attribList[arg++] )
  71         {
  72           case WX_GL_RGBA: data[p++] = GLX_RGBA; break;
  73           case WX_GL_BUFFER_SIZE:
  74             data[p++]=GLX_BUFFER_SIZE; data[p++]=attribList[arg++]; break;
  75           case WX_GL_LEVEL:
  76             data[p++]=GLX_LEVEL; data[p++]=attribList[arg++]; break;
  77           case WX_GL_DOUBLEBUFFER: data[p++] = GLX_DOUBLEBUFFER; break;
  78           case WX_GL_STEREO: data[p++] = GLX_STEREO; break;
  79           case WX_GL_AUX_BUFFERS:
  80             data[p++]=GLX_AUX_BUFFERS; data[p++]=attribList[arg++]; break;
  81           case WX_GL_MIN_RED:
  82             data[p++]=GLX_RED_SIZE; data[p++]=attribList[arg++]; break;
  83           case WX_GL_MIN_GREEN:
  84             data[p++]=GLX_GREEN_SIZE; data[p++]=attribList[arg++]; break;
  85           case WX_GL_MIN_BLUE:
  86             data[p++]=GLX_BLUE_SIZE; data[p++]=attribList[arg++]; break;
  87           case WX_GL_MIN_ALPHA:
  88             data[p++]=GLX_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
  89           case WX_GL_DEPTH_SIZE:
  90             data[p++]=GLX_DEPTH_SIZE; data[p++]=attribList[arg++]; break;
  91           case WX_GL_STENCIL_SIZE:
  92             data[p++]=GLX_STENCIL_SIZE; data[p++]=attribList[arg++]; break;
  93           case WX_GL_MIN_ACCUM_RED:
  94             data[p++]=GLX_ACCUM_RED_SIZE; data[p++]=attribList[arg++]; break;
  95           case WX_GL_MIN_ACCUM_GREEN:
  96             data[p++]=GLX_ACCUM_GREEN_SIZE; data[p++]=attribList[arg++]; break;
  97           case WX_GL_MIN_ACCUM_BLUE:
  98             data[p++]=GLX_ACCUM_BLUE_SIZE; data[p++]=attribList[arg++]; break;
  99           case WX_GL_MIN_ACCUM_ALPHA:
 100             data[p++]=GLX_ACCUM_ALPHA_SIZE; data[p++]=attribList[arg++]; break;
 101           default:
 102             break;
 103         }
 104       }
 105       data[p] = 0;
 106
 107       attribList = (int*) data;
 108       // Get an appropriate visual
 109       vi = glXChooseVisual(display, DefaultScreen(display), attribList);
 110       if(!vi) return;
 111
 112       // Here we should make sure that vi is the same visual as the
 113       // one used by the xwindow drawable in wxCanvas.  However,
 114       // there is currently no mechanism for this in wx_canvs.cc.
 115     } else {
 116         // By default, we use the visual of xwindow
 117         // NI: is this really senseful ? opengl in e.g. color index mode ?
 118         XGetWindowAttributes(display, (Window) GetXWindow(), &xwa);
 119         vi_templ.visualid = XVisualIDFromVisual(xwa.visual);
 120         vi = XGetVisualInfo(display, VisualIDMask, &vi_templ, &n);
 121         if(!vi) return;
 122         glXGetConfig(display, vi, GLX_USE_GL, &val);
 123         if(!val) return;
 124         // Basically, this is it.  It should be possible to use vi
 125         // in glXCreateContext() below.  But this fails with Mesa.
 126         // I notified the Mesa author about it; there may be a fix.
 127 #ifdef OLD_MESA
 128         // Construct an attribute list matching the visual
 129         int a_list[32];
 130         n = 0;
 131         if(vi->c_class==TrueColor || vi->c_class==DirectColor) { // RGBA visual
 132             a_list[n++] = GLX_RGBA;
 133             a_list[n++] = GLX_RED_SIZE;
 134             a_list[n++] = bitcount(vi->red_mask);
 135             a_list[n++] = GLX_GREEN_SIZE;
 136             a_list[n++] = bitcount(vi->green_mask);
 137             a_list[n++] = GLX_BLUE_SIZE;
 138             a_list[n++] = bitcount(vi->blue_mask);
 139             glXGetConfig(display, vi, GLX_ALPHA_SIZE, &val);
 140             a_list[n++] = GLX_ALPHA_SIZE;
 141             a_list[n++] = val;
 142         } else { // Color index visual
 143             glXGetConfig(display, vi, GLX_BUFFER_SIZE, &val);
 144             a_list[n++] = GLX_BUFFER_SIZE;
 145             a_list[n++] = val;
 146         }
 147         a_list[n] = None;
 148         XFree(vi);
 149         vi = glXChooseVisual(display, DefaultScreen(display), a_list);
 150         if(!vi) return;
 151 #endif /* OLD_MESA */
 152     }
 153
 154     // Create the GLX context and make it current
 155     glx_cx = glXCreateContext(display, vi, 0, GL_TRUE);
 156 #ifndef OLD_MESA
 157     XFree(vi);
 158 #endif
 159     SetCurrent();
 160 }
 161
 162 wxGLCanvas::~wxGLCanvas(void)
 163 {
 164     Display* display = (Display*) GetXDisplay();
 165     if(glx_cx) glXDestroyContext(display, glx_cx);
 166 }
 167
 168 void wxGLCanvas::SwapBuffers()
 169 {
 170     Display* display = (Display*) GetXDisplay();
 171     if(glx_cx) glXSwapBuffers(display, (Window) GetXWindow());
 172 }
 173
 174 void wxGLCanvas::SetCurrent()
 175 {
 176     Display* display = (Display*) GetXDisplay();
 177     if(glx_cx) glXMakeCurrent(display, (Window) GetXWindow(), glx_cx);
 178 }
 179
 180 void wxGLCanvas::SetColour(const char *col)
 181 {
 182     wxColour *the_colour = wxTheColourDatabase->FindColour(col);
 183     if(the_colour) {
 184         GLboolean b;
 185         glGetBooleanv(GL_RGBA_MODE, &b);
 186         if(b) {
 187             glColor3ub(the_colour->Red(),
 188                        the_colour->Green(),
 189                        the_colour->Blue());
 190         } else {
 191             GLint pix = (GLint)the_colour->m_pixel;
 192             if(pix == -1) {
 193                 XColor exact_def;
 194                 exact_def.red = (unsigned short)the_colour->Red() << 8;
 195                 exact_def.green = (unsigned short)the_colour->Green() << 8;
 196                 exact_def.blue = (unsigned short)the_colour->Blue() << 8;
 197                 exact_def.flags = DoRed | DoGreen | DoBlue;
 198                 if(!XAllocColor((Display*) GetXDisplay(), (Colormap) wxTheApp->GetMainColormap(GetXDisplay()), &exact_def)) {
 199                     wxDebugMsg("wxGLCanvas: cannot allocate color\n");
 200                     return;
 201                 }
 202                 pix = the_colour->m_pixel = exact_def.pixel;
 203             }
 204             glIndexi(pix);
 205         }
 206     }
 207 }
 208
 209 #endif
 210     // wxUSE_GLCANVAS
 211