source/gbase/glcontext.cpp

   1 #include <vector>
   2 #ifdef WIN32
   3 #include <windows.h>
   4 #endif
   5 #ifdef WITH_OPENGL
   6 #include <GL/gl.h>
   7 #ifndef WIN32
   8 #include <GL/glx.h>
   9 #endif
  10 #endif
  11 #include <msp/core/application.h>
  12 #include <msp/core/except.h>
  13 #include "display.h"
  14 #include "glcontext.h"
  15 #include "window.h"
  16 #include "display_priv.h"
  17
  18 namespace Msp {
  19 namespace Graphics {
  20
  21 GLOptions::GLOptions():
  22         alpha(false),
  23         stencil(false),
  24         doublebuffer(true),
  25         multisample(0)
  26 { }
  27
  28
  29 #ifdef WITH_OPENGL
  30 #ifdef WIN32
  31 typedef HGLRC Context;
  32 #else
  33 typedef GLXContext Context;
  34 #endif
  35
  36 struct GLContext::Private
  37 {
  38         Context context;
  39 #ifndef WIN32
  40         // In X11, we need to create a window with the chosen visual
  41         WindowHandle subwnd;
  42 #endif
  43 };
  44 #endif
  45
  46
  47 GLContext::GLContext(Window &wnd, const GLOptions &opts):
  48         display(wnd.get_display()),
  49         window(wnd)
  50 {
  51 #ifdef WITH_OPENGL
  52         priv = new Private;
  53
  54 #ifdef WIN32
  55         HDC dc = GetDC(window.get_private().window);
  56
  57         PIXELFORMATDESCRIPTOR pfd;
  58         memset(&pfd, 0, sizeof(pfd));
  59
  60         pfd.nSize = sizeof(pfd);
  61         pfd.nVersion = 1;
  62         pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
  63         if(opts.doublebuffer)
  64                 pfd.dwFlags |= PFD_DOUBLEBUFFER;
  65         pfd.iPixelType = PFD_TYPE_RGBA;
  66         if(opts.alpha)
  67                 pfd.cAlphaBits = 1;
  68         pfd.cDepthBits = 1;
  69         if(opts.stencil)
  70                 pfd.cStencilBits = 1;
  71
  72         int pf_index = ChoosePixelFormat(dc, &pfd);
  73         if(!pf_index)
  74                 throw Exception("Couldn't find a suitable pixel format");
  75         SetPixelFormat(dc, pf_index, &pfd);
  76
  77         priv->context = wglCreateContext(dc);
  78         wglMakeCurrent(dc, priv->context);
  79
  80         ReleaseDC(window.get_private().window, dc);
  81 #else
  82         std::vector<int> attribs;
  83
  84         attribs.push_back(GLX_RGBA);
  85         attribs.push_back(GLX_DEPTH_SIZE);
  86         attribs.push_back(1);
  87
  88         if(opts.alpha)
  89         {
  90                 attribs.push_back(GLX_ALPHA_SIZE);
  91                 attribs.push_back(1);
  92         }
  93
  94         if(opts.stencil)
  95         {
  96                 attribs.push_back(GLX_STENCIL_SIZE);
  97                 attribs.push_back(1);
  98         }
  99
 100         if(opts.doublebuffer)
 101                 attribs.push_back(GLX_DOUBLEBUFFER);
 102
 103         if(opts.multisample>0)
 104         {
 105                 attribs.push_back(GLX_SAMPLE_BUFFERS_ARB);
 106                 attribs.push_back(opts.multisample);
 107         }
 108
 109         attribs.push_back(0);
 110
 111         ::Display *dpy = display.get_private().display;
 112
 113         XVisualInfo *vi = glXChooseVisual(dpy, DefaultScreen(dpy), &attribs.front());
 114         if(!vi)
 115                 throw Exception("Couldn't find a suitable GLX visual");
 116         priv->context = glXCreateContext(dpy, vi, 0, true);
 117
 118         XSetWindowAttributes attr;
 119         attr.colormap = XCreateColormap(dpy, DefaultRootWindow(dpy), vi->visual, AllocNone);
 120
 121         priv->subwnd = XCreateWindow(dpy, window.get_private().window, 0, 0, window.get_width(), window.get_height(), 0, vi->depth, InputOutput, vi->visual, CWColormap, &attr);
 122         XMapWindow(dpy, priv->subwnd);
 123
 124         XFree(vi);
 125
 126         glXMakeCurrent(dpy, priv->subwnd, priv->context);
 127 #endif
 128 #else
 129         (void)wnd;
 130         (void)opts;
 131         throw Exception("OpenGL support not compiled in");
 132 #endif
 133
 134         window.signal_resize.connect(sigc::mem_fun(this, &GLContext::window_resized));
 135 }
 136
 137 GLContext::~GLContext()
 138 {
 139 #ifdef WITH_OPENGL
 140 #ifdef WIN32
 141         wglMakeCurrent(0, 0);
 142         wglDeleteContext(priv->context);
 143 #else
 144         ::Display *dpy = display.get_private().display;
 145
 146         glXMakeCurrent(dpy, 0, 0);
 147         glXDestroyContext(dpy, priv->context);
 148         XDestroyWindow(dpy, priv->subwnd);
 149 #endif
 150         delete priv;
 151 #endif
 152 }
 153
 154 void GLContext::swap_buffers()
 155 {
 156 #ifdef WITH_OPENGL
 157 #ifdef WIN32
 158         HDC dc = GetDC(window.get_private().window);
 159         SwapBuffers(dc);
 160         ReleaseDC(window.get_private().window, dc);
 161 #else
 162         glXSwapBuffers(display.get_private().display, priv->subwnd);
 163 #endif
 164 #endif
 165 }
 166
 167 void GLContext::window_resized(unsigned w, unsigned h)
 168 {
 169 #ifdef WITH_OPENGL
 170 #ifndef WIN32
 171         XMoveResizeWindow(display.get_private().display, priv->subwnd, 0, 0, w, h);
 172 #endif
 173         glViewport(0, 0, w, h);
 174 #else
 175         (void)w;
 176         (void)h;
 177 #endif
 178 }
 179
 180 } // namespace Graphics
 181 } // namespace Msp