Window.c

#include "Window.h"

struct window
{
	Display* g_pDisplay;
	Window g_window;
	int g_bDoubleBuffered;
};

int processWindow(window* w, void (*mouseFunc)(int type, int button, int x, int y), void (*keyPress)(int code), void (*keyRelease)(int code))
{
	XEvent event;

	while( XPending(w->g_pDisplay) > 0)
	{
		XNextEvent( w->g_pDisplay, &event );

		switch( event.type )
		{
			case KeyPress:	
			{		
				int code = event.xbutton.button;
				
				keyPress(code);
			}break;
					
			case KeyRelease:
			{	
				if(XEventsQueued(w->g_pDisplay, QueuedAfterReading))
				{
					XEvent nextEvent;
					XPeekEvent(w->g_pDisplay, &nextEvent);
					if(nextEvent.type == KeyPress && nextEvent.xkey.time == event.xkey.time)
					{
						break;
					}
				}
				
			
				int code = event.xbutton.button;
				
				keyRelease(code);
				
			}break;

			case ButtonPress:
			case ButtonRelease:
			{
				XButtonEvent* mouseEvent = (XButtonEvent*)(&event);
			
				int type =  mouseEvent->type;
				int button = mouseEvent->button;
				int x = mouseEvent->x;
				int y = mouseEvent->y;
				
				mouseFunc(type, button, x, y);
			}break;

			case MotionNotify:
			{				
				int type = 0;
				int button = 0;
				int x = event.xmotion.x;
          			int y = event.xmotion.y;

				mouseFunc(type, button, x, y);
			}break;

			case ConfigureNotify:
			{
				glViewport( 0, 0, event.xconfigure.width, event.xconfigure.height );
			}break;

			case DestroyNotify:
			{
				return 0;
			}break;
		}
		
	}
	
	return 1;

}

int showWindow(window* w)
{	
	if( w->g_bDoubleBuffered )
		glXSwapBuffers( w->g_pDisplay, w->g_window ); // Buffer swap does implicit glFlush
	else
		glFlush();

	return 1;
}


window* initWindow()
{	
	window* w = (window*)malloc(sizeof(window));

	XSetWindowAttributes windowAttributes;
    XVisualInfo *visualInfo = NULL;
    Colormap colorMap;
    GLXContext glxContext;
    int errorBase;
	int eventBase;

	w->g_bDoubleBuffered = GL_TRUE;

    // Open a connection to the X server
    w->g_pDisplay = XOpenDisplay( NULL );

    if( w->g_pDisplay == NULL )
    {
        fprintf(stderr, "glxsimple: %s\n", "could not open display");
        exit(1);
    }

    // Make sure OpenGL's GLX extension supported
    if( !glXQueryExtension( w->g_pDisplay, &errorBase, &eventBase ) )
    {
        fprintf(stderr, "glxsimple: %s\n", "X server has no OpenGL GLX extension");
        exit(1);
    }
   
    //printf("Resolucao do sistema: %dx%d\n", res_x, res_y);

    // Find an appropriate visual

    int doubleBufferVisual[]  =
    {
        GLX_RGBA,           // Needs to support OpenGL
        GLX_DEPTH_SIZE, 16, // Needs to support a 16 bit depth buffer
        GLX_DOUBLEBUFFER,   // Needs to support double-buffering
        None                // end of list
    };

    int singleBufferVisual[] =
    {
        GLX_RGBA,           // Needs to support OpenGL
        GLX_DEPTH_SIZE, 16, // Needs to support a 16 bit depth buffer
        None                // end of list
    };

    // Try for the double-bufferd visual first
    visualInfo = glXChooseVisual( w->g_pDisplay, DefaultScreen(w->g_pDisplay), doubleBufferVisual );

    if( visualInfo == NULL )
    {
    	// If we can't find a double-bufferd visual, try for a single-buffered visual...
        visualInfo = glXChooseVisual( w->g_pDisplay, DefaultScreen(w->g_pDisplay), singleBufferVisual );

        if( visualInfo == NULL )
        {
            fprintf(stderr, "glxsimple: %s\n", "no RGB visual with depth buffer");
            exit(1);
        }

        w->g_bDoubleBuffered = 0;
    }

    // Create an OpenGL rendering context
    glxContext = glXCreateContext( w->g_pDisplay,
                                   visualInfo,
                                   NULL,      // No sharing of display lists
                                   GL_TRUE ); // Direct rendering if possible

    if( glxContext == NULL )
    {
        fprintf(stderr, "glxsimple: %s\n", "could not create rendering context");
        exit(1);
    }

    // Create an X colormap since we're probably not using the default visual
    colorMap = XCreateColormap( w->g_pDisplay,
                                RootWindow(w->g_pDisplay, visualInfo->screen),
                                visualInfo->visual,
                                AllocNone );

    windowAttributes.colormap     = colorMap;
    windowAttributes.border_pixel = 0;
    windowAttributes.event_mask   = ExposureMask           |
                                    VisibilityChangeMask   |
                                    KeyPressMask           |
                                    KeyReleaseMask         |
                                    ButtonPressMask        |
                                    ButtonReleaseMask      |
                                    PointerMotionMask      |
                                    StructureNotifyMask    |
                                    SubstructureNotifyMask |
                                    FocusChangeMask;

    // Create an X window with the selected visual
    w->g_window = XCreateWindow( w->g_pDisplay,
                              RootWindow(w->g_pDisplay, visualInfo->screen),
                              0, 0,     // x/y position of top-left outside corner of the window
                              600, 600, // Width and height of window
                              0,        // Border width
                              visualInfo->depth,
                              InputOutput,
                              visualInfo->visual,
                              CWBorderPixel | CWColormap | CWEventMask,
                              &windowAttributes );

    XSetStandardProperties( w->g_pDisplay,
							w->g_window,
                            "Plot",
                            "Plot",
                            None,
                            NULL,
                            0,
                            NULL );

    // Bind the rendering context to the window
    glXMakeCurrent( w->g_pDisplay, w->g_window, glxContext );

    // Request the X window to be displayed on the screen
    XMapWindow( w->g_pDisplay, w->g_window );

    return w;
}