source/gbase/drawcontext.cpp

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