source/graphics/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/strings/format.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 unsupported_gl_mode::unsupported_gl_mode(const GLOptions &opts):
  30         runtime_error(format("{ .alpha=%s, .stencil=%s, .doublebuffer=%s, .multisample=%d }",
  31                 opts.alpha, opts.stencil, opts.doublebuffer, opts.multisample))
  32 { }
  33
  34
  35 #ifdef WITH_OPENGL
  36 #ifdef WIN32
  37 typedef HGLRC Context;
  38 #else
  39 typedef GLXContext Context;
  40 #endif
  41
  42 struct GLContext::Private
  43 {
  44         Context context;
  45 #ifndef WIN32
  46         // In X11, we need to create a window with the chosen visual
  47         WindowHandle subwnd;
  48 #endif
  49 };
  50 #endif
  51
  52
  53 GLContext::GLContext(Window &wnd, const GLOptions &opts):
  54         display(wnd.get_display()),
  55         window(wnd)
  56 {
  57 #ifdef WITH_OPENGL
  58         priv = new Private;
  59
  60 #ifdef WIN32
  61         HDC dc = GetDC(window.get_private().window);
  62
  63         PIXELFORMATDESCRIPTOR pfd;
  64         memset(&pfd, 0, sizeof(pfd));
  65
  66         pfd.nSize = sizeof(pfd);
  67         pfd.nVersion = 1;
  68         pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
  69         if(opts.doublebuffer)
  70                 pfd.dwFlags |= PFD_DOUBLEBUFFER;
  71         pfd.iPixelType = PFD_TYPE_RGBA;
  72         if(opts.alpha)
  73                 pfd.cAlphaBits = 1;
  74         pfd.cDepthBits = 1;
  75         if(opts.stencil)
  76                 pfd.cStencilBits = 1;
  77
  78         int pf_index = ChoosePixelFormat(dc, &pfd);
  79         if(!pf_index)
  80                 throw unsupported_gl_mode(opts);
  81         SetPixelFormat(dc, pf_index, &pfd);
  82
  83         priv->context = wglCreateContext(dc);
  84         wglMakeCurrent(dc, priv->context);
  85
  86         ReleaseDC(window.get_private().window, dc);
  87 #else
  88         std::vector<int> attribs;
  89
  90         attribs.push_back(GLX_RGBA);
  91         attribs.push_back(GLX_DEPTH_SIZE);
  92         attribs.push_back(1);
  93
  94         if(opts.alpha)
  95         {
  96                 attribs.push_back(GLX_ALPHA_SIZE);
  97                 attribs.push_back(1);
  98         }
  99
 100         if(opts.stencil)
 101         {
 102                 attribs.push_back(GLX_STENCIL_SIZE);
 103                 attribs.push_back(1);
 104         }
 105
 106         if(opts.doublebuffer)
 107                 attribs.push_back(GLX_DOUBLEBUFFER);
 108
 109         if(opts.multisample>0)
 110         {
 111                 attribs.push_back(GLX_SAMPLE_BUFFERS_ARB);
 112                 attribs.push_back(opts.multisample);
 113         }
 114
 115         attribs.push_back(0);
 116
 117         ::Display *dpy = display.get_private().display;
 118
 119         XVisualInfo *vi = glXChooseVisual(dpy, DefaultScreen(dpy), &attribs.front());
 120         if(!vi)
 121                 throw unsupported_gl_mode(opts);
 122         priv->context = glXCreateContext(dpy, vi, 0, true);
 123
 124         XSetWindowAttributes attr;
 125         attr.colormap = XCreateColormap(dpy, DefaultRootWindow(dpy), vi->visual, AllocNone);
 126
 127         priv->subwnd = XCreateWindow(dpy, window.get_private().window, 0, 0, window.get_width(), window.get_height(), 0, vi->depth, InputOutput, vi->visual, CWColormap, &attr);
 128         XMapWindow(dpy, priv->subwnd);
 129
 130         XFree(vi);
 131
 132         glXMakeCurrent(dpy, priv->subwnd, priv->context);
 133 #endif
 134 #else
 135         (void)wnd;
 136         (void)opts;
 137         throw runtime_error("no OpenGL support");
 138 #endif
 139
 140         window.signal_resize.connect(sigc::mem_fun(this, &GLContext::window_resized));
 141 }
 142
 143 GLContext::~GLContext()
 144 {
 145 #ifdef WITH_OPENGL
 146 #ifdef WIN32
 147         wglMakeCurrent(0, 0);
 148         wglDeleteContext(priv->context);
 149 #else
 150         ::Display *dpy = display.get_private().display;
 151
 152         glXMakeCurrent(dpy, 0, 0);
 153         glXDestroyContext(dpy, priv->context);
 154         XDestroyWindow(dpy, priv->subwnd);
 155 #endif
 156         delete priv;
 157 #endif
 158 }
 159
 160 void GLContext::swap_buffers()
 161 {
 162 #ifdef WITH_OPENGL
 163 #ifdef WIN32
 164         HDC dc = GetDC(window.get_private().window);
 165         SwapBuffers(dc);
 166         ReleaseDC(window.get_private().window, dc);
 167 #else
 168         glXSwapBuffers(display.get_private().display, priv->subwnd);
 169 #endif
 170 #endif
 171 }
 172
 173 void GLContext::window_resized(unsigned w, unsigned h)
 174 {
 175 #ifdef WITH_OPENGL
 176 #ifndef WIN32
 177         XMoveResizeWindow(display.get_private().display, priv->subwnd, 0, 0, w, h);
 178 #endif
 179         glViewport(0, 0, w, h);
 180 #else
 181         (void)w;
 182         (void)h;
 183 #endif
 184 }
 185
 186 } // namespace Graphics
 187 } // namespace Msp