ref: c6157665acf2520a039aa991d03f4af3d0de9001
dir: /demos/graph/grinit.c/
#include "grobjs.h" #include "grdevice.h" #include <stdio.h> #define GR_INIT_DEVICE_CHAIN ((grDeviceChain*)0) #define GR_INIT_BUILD #ifdef DEVICE_X11 #include "grx11.h" #endif #ifdef DEVICE_OS2_PM #include "gros2pm.h" #endif #ifdef DEVICE_WIN32 #include "grwin32.h" #endif #ifdef macintosh #include "grmac.h" #endif /********************************************************************** * * <Function> * grInitDevices * * <Description> * This function is in charge of initialising all system-specific * devices. A device is responsible for creating and managing one * or more "surfaces". A surface is either a window or a screen, * depending on the system. * * <Return> * a pointer to the first element of a device chain. The chain can * be parsed to find the available devices on the current system * * <Note> * If a device cannot be initialised correctly, it is not part of * the device chain returned by this function. For example, if an * X11 device was compiled in the library, it will be part of * the returned device chain only if a connection to the display * could be establisged * * If no driver could be initialised, this function returns NULL. * **********************************************************************/ extern grDeviceChain* grInitDevices( void ) { grDeviceChain* chain = GR_INIT_DEVICE_CHAIN; grDeviceChain* cur = gr_device_chain; while (chain) { /* initialize the device */ grDevice* device; device = chain->device; if ( device->init() == 0 && gr_num_devices < GR_MAX_DEVICES ) { /* successful device initialisation - add it to our chain */ cur->next = 0; cur->device = device; cur->name = device->device_name; if (cur > gr_device_chain) cur[-1].next = cur; cur++; gr_num_devices++; } chain = chain->next; } return (gr_num_devices > 0 ? gr_device_chain : 0 ); }