source/gbase/drawcontext.cpp

   1 /* $Id$
   2
   3 This file is part of libmspgbase
   4 Copyright © 2008  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #ifndef WIN32
   9 #include <sys/ipc.h>
  10 #include <sys/shm.h>
  11 #include <X11/Xlib.h>
  12 #include <X11/extensions/XShm.h>
  13 #include <X11/Xutil.h>
  14 #endif
  15 #include <msp/core/except.h>
  16 #include "display.h"
  17 #include "drawcontext.h"
  18 #include "window.h"
  19 #include "display_priv.h"
  20
  21 namespace Msp {
  22 namespace Graphics {
  23
  24 struct DrawContext::Private
  25 {
  26 #ifndef WIN32
  27         XImage *image;
  28         bool use_shm;
  29         XShmSegmentInfo shminfo;
  30 #endif
  31 };
  32
  33 DrawContext::DrawContext(Window &w):
  34         display(w.get_display()),
  35         window(w)
  36 {
  37 #ifdef WIN32
  38         throw Exception("DrawContext not supported on win32 yet");
  39 #else
  40         priv=new Private;
  41
  42         ::Display *dpy=display.get_private().display;
  43
  44         priv->use_shm=XShmQueryExtension(dpy);
  45
  46         XWindowAttributes wa;
  47         XGetWindowAttributes(dpy, window.get_private().window, &wa);
  48
  49         if(priv->use_shm)
  50         {
  51                 priv->image=XShmCreateImage(dpy, wa.visual, wa.depth, ZPixmap, 0, &priv->shminfo, wa.width, wa.height);
  52                 if(!priv->image)
  53                         throw Exception("Could not create shared memory XImage");
  54
  55                 priv->shminfo.shmid=shmget(IPC_PRIVATE, priv->image->bytes_per_line*priv->image->height, IPC_CREAT|0666);
  56                 priv->shminfo.shmaddr=priv->image->data=reinterpret_cast<char *>(shmat(priv->shminfo.shmid, 0, 0));
  57                 priv->shminfo.readOnly=false;
  58
  59                 XShmAttach(dpy, &priv->shminfo);
  60
  61                 XSync(dpy, false);
  62                 display.check_error();
  63         }
  64         else
  65         {
  66                 priv->image=XCreateImage(dpy, wa.visual, wa.depth, ZPixmap, 0, 0, wa.width, wa.height, 8, 0);
  67                 if(!priv->image)
  68                         throw Exception("Could not create XImage");
  69                 priv->image->data=new char[priv->image->bytes_per_line*priv->image->height];
  70         }
  71 #endif
  72 }
  73
  74 DrawContext::~DrawContext()
  75 {
  76 #ifndef WIN32
  77         if(priv->use_shm)
  78         {
  79                 XShmDetach(display.get_private().display, &priv->shminfo);
  80                 shmdt(priv->shminfo.shmaddr);
  81                 shmctl(priv->shminfo.shmid, IPC_RMID, 0);
  82         }
  83
  84         XDestroyImage(priv->image);
  85 #endif
  86
  87         delete priv;
  88 }
  89
  90 unsigned DrawContext::get_depth() const
  91 {
  92 #ifdef WIN32
  93         return 0;
  94 #else
  95         return priv->image->bits_per_pixel;
  96 #endif
  97 }
  98
  99 unsigned char *DrawContext::get_data()
 100 {
 101 #ifdef WIN32
 102         return 0;
 103 #else
 104         return reinterpret_cast<unsigned char *>(priv->image->data);
 105 #endif
 106 }
 107
 108 void DrawContext::update()
 109 {
 110 #ifndef WIN32
 111         ::Display *dpy=display.get_private().display;
 112         WindowHandle wnd=window.get_private().window;
 113
 114         GC gc=XCreateGC(dpy, wnd, 0, 0);
 115
 116         if(priv->use_shm)
 117                 XShmPutImage(dpy, wnd, gc, priv->image, 0, 0, 0, 0, priv->image->width, priv->image->height, false);
 118         else
 119                 XPutImage(dpy, wnd, gc, priv->image, 0, 0, 0, 0, priv->image->width, priv->image->height);
 120
 121         XFreeGC(dpy, gc);
 122 #endif
 123 }
 124
 125 } // namespace Graphics
 126 } // namespace Msp