source/graphics/drawcontext.cpp

   1 #include <stdexcept>
   2 #ifndef WIN32
   3 #include <sys/ipc.h>
   4 #include <sys/shm.h>
   5 #include <X11/Xlib.h>
   6 #include <X11/extensions/XShm.h>
   7 #include <X11/Xutil.h>
   8 #endif
   9 #include "display.h"
  10 #include "drawcontext.h"
  11 #include "window.h"
  12 #include "display_priv.h"
  13
  14 using namespace std;
  15
  16 namespace Msp {
  17 namespace Graphics {
  18
  19 struct DrawContext::Private
  20 {
  21 #ifndef WIN32
  22         XImage *image;
  23         bool use_shm;
  24         XShmSegmentInfo shminfo;
  25 #endif
  26 };
  27
  28 DrawContext::DrawContext(Window &w):
  29         display(w.get_display()),
  30         window(w)
  31 {
  32 #ifdef WIN32
  33         throw runtime_error("no DrawContext support on windows");
  34 #else
  35         priv = new Private;
  36
  37         ::Display *dpy = display.get_private().display;
  38
  39         priv->use_shm = XShmQueryExtension(dpy);
  40
  41         XWindowAttributes wa;
  42         XGetWindowAttributes(dpy, window.get_private().window, &wa);
  43
  44         if(priv->use_shm)
  45         {
  46                 priv->image = XShmCreateImage(dpy, wa.visual, wa.depth, ZPixmap, 0, &priv->shminfo, wa.width, wa.height);
  47                 if(!priv->image)
  48                         throw runtime_error("XShmCreateImage");
  49
  50                 priv->shminfo.shmid = shmget(IPC_PRIVATE, priv->image->bytes_per_line*priv->image->height, IPC_CREAT|0666);
  51                 priv->shminfo.shmaddr=priv->image->data = reinterpret_cast<char *>(shmat(priv->shminfo.shmid, 0, 0));
  52                 priv->shminfo.readOnly = false;
  53
  54                 XShmAttach(dpy, &priv->shminfo);
  55
  56                 XSync(dpy, false);
  57                 display.check_error();
  58         }
  59         else
  60         {
  61                 priv->image = XCreateImage(dpy, wa.visual, wa.depth, ZPixmap, 0, 0, wa.width, wa.height, 8, 0);
  62                 if(!priv->image)
  63                         throw runtime_error("XCreateImage");
  64                 priv->image->data = new char[priv->image->bytes_per_line*priv->image->height];
  65         }
  66 #endif
  67 }
  68
  69 DrawContext::~DrawContext()
  70 {
  71 #ifndef WIN32
  72         if(priv->use_shm)
  73         {
  74                 XShmDetach(display.get_private().display, &priv->shminfo);
  75                 shmdt(priv->shminfo.shmaddr);
  76                 shmctl(priv->shminfo.shmid, IPC_RMID, 0);
  77         }
  78
  79         XDestroyImage(priv->image);
  80 #endif
  81
  82         delete priv;
  83 }
  84
  85 unsigned DrawContext::get_depth() const
  86 {
  87 #ifdef WIN32
  88         return 0;
  89 #else
  90         return priv->image->bits_per_pixel;
  91 #endif
  92 }
  93
  94 unsigned char *DrawContext::get_data()
  95 {
  96 #ifdef WIN32
  97         return 0;
  98 #else
  99         return reinterpret_cast<unsigned char *>(priv->image->data);
 100 #endif
 101 }
 102
 103 void DrawContext::update()
 104 {
 105 #ifndef WIN32
 106         ::Display *dpy = display.get_private().display;
 107         WindowHandle wnd = window.get_private().window;
 108
 109         GC gc = XCreateGC(dpy, wnd, 0, 0);
 110
 111         if(priv->use_shm)
 112                 XShmPutImage(dpy, wnd, gc, priv->image, 0, 0, 0, 0, priv->image->width, priv->image->height, false);
 113         else
 114                 XPutImage(dpy, wnd, gc, priv->image, 0, 0, 0, 0, priv->image->width, priv->image->height);
 115
 116         XFreeGC(dpy, gc);
 117 #endif
 118 }
 119
 120 } // namespace Graphics
 121 } // namespace Msp