source/gbase/drawcontext.cpp

   1 /* $Id$
   2
   3 This file is part of libmspgbase
   4 Copyright © 2007 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/Xutil.h>
  12 #endif
  13 #include <msp/core/except.h>
  14 #include "display.h"
  15 #include "drawcontext.h"
  16 #include "window.h"
  17
  18 namespace Msp {
  19 namespace Graphics {
  20
  21 DrawContext::DrawContext(Window &w):
  22         display(w.get_display()),
  23         window(w)
  24 {
  25 #ifndef WIN32
  26         ::Display *dpy=display.get_display();
  27
  28         use_shm=XShmQueryExtension(dpy);
  29
  30         XWindowAttributes wa;
  31         XGetWindowAttributes(dpy, window.get_handle(), &wa);
  32
  33         if(use_shm)
  34         {
  35                 image=XShmCreateImage(dpy, wa.visual, wa.depth, ZPixmap, 0, &shminfo, wa.width, wa.height);
  36                 if(!image)
  37                         throw Exception("Could not create shared memory XImage");
  38
  39                 shminfo.shmid=shmget(IPC_PRIVATE, image->bytes_per_line*image->height, IPC_CREAT|0666);
  40                 shminfo.shmaddr=image->data=reinterpret_cast<char *>(shmat(shminfo.shmid, 0, 0));
  41                 shminfo.readOnly=false;
  42
  43                 XShmAttach(dpy, &shminfo);
  44
  45                 XSync(dpy, false);
  46                 display.check_error();
  47         }
  48         else
  49         {
  50                 image=XCreateImage(dpy, wa.visual, wa.depth, ZPixmap, 0, 0, wa.width, wa.height, 8, 0);
  51                 if(!image)
  52                         throw Exception("Could not create XImage");
  53                 image->data=new char[image->bytes_per_line*image->height];
  54         }
  55 #endif
  56 }
  57
  58 DrawContext::~DrawContext()
  59 {
  60 #ifndef WIN32
  61         if(use_shm)
  62         {
  63                 XShmDetach(display.get_display(), &shminfo);
  64                 shmdt(shminfo.shmaddr);
  65                 shmctl(shminfo.shmid, IPC_RMID, 0);
  66         }
  67
  68         XDestroyImage(image);
  69 #endif
  70 }
  71
  72 unsigned DrawContext::get_depth() const
  73 {
  74 #ifdef WIN32
  75         return 0;
  76 #else
  77         return image->bits_per_pixel;
  78 #endif
  79 }
  80
  81 unsigned char *DrawContext::get_data()
  82 {
  83 #ifdef WIN32
  84         return 0;
  85 #else
  86         return reinterpret_cast<unsigned char *>(image->data);
  87 #endif
  88 }
  89
  90 void DrawContext::update()
  91 {
  92 #ifndef WIN32
  93         ::Display *dpy=display.get_display();
  94
  95         GC gc=XCreateGC(dpy, window.get_handle(), 0, 0);
  96
  97         if(use_shm)
  98                 XShmPutImage(dpy, window.get_handle(), gc, image, 0, 0, 0, 0, image->width, image->height, false);
  99         else
 100                 XPutImage(dpy, window.get_handle(), gc, image, 0, 0, 0, 0, image->width, image->height);
 101
 102         XFreeGC(dpy, gc);
 103 #endif
 104 }
 105
 106 } // namespace Graphics
 107 } // namespace Msp