Application graphics (version 6+)

Starting with BOINC version 6.0, applications graphics are generated by a separate program. The only constraints on this program are:

• If invoked with --fullscreen, it must open a full-screen borderless window, and must exit when mouse or keyboard input occurs.
• If not invoked with --fullscreen, it must open a standard window; in this case it may handle mouse/keyboard input.

The BOINC graphics API (described below) provides cross-platform support for developing such a program; however, you need not use it.

The logical name of the program must be 'v6graphics'. When you set up your application version directory, give it a filename like

v6graphics=uc2_graphics_5.10_windows_intelx86.exe

The BOINC Graphics API

BOINC supplies a library (libboinc_graphics2.a) that makes it easy to develop graphics apps. To use this library, the graphics app must call

boinc_graphics_loop(int argc, char** argv);

after its initialization. This function executes an event loop, and does not return.

The application must supply the following functions:

void app_graphics_render(int xs, ys, double time_of_day);
void app_graphics_resize(int x, int y);
void boinc_app_mouse_move();
void boinc_app_mouse_button();
void boinc_app_key_press();
void boinc_app_key_release();

These functions are described here.

Communicating with the main application

Typically the graphics app will want to get information from the main app. This can be done efficiently using shared memory. The BOINC library supplies the following functions to facilitate this:

void* boinc_graphics_make_shmem(char* appname, int size);
void* boinc_graphics_get_shmem(char* appname);

boinc_graphics_make_shmem() (called from the main app) creates a shared memory segment of the given size. 'appname' should be the name of this application (used to ensure uniqueness of the shared-memory segment name). boinc_graphics_get_shmem() (called from the graphics app) attaches to an existing segment.

The contents of the shared memory segment are up to you. You may want to include the following items:

struct UC_SHMEM {
    double update_time;
    double fraction_done;
    double cpu_time;
    BOINC_STATUS status;
};

update_time

The time of day when this structure was last modified. This can be used to implement a 'heartbeat' mechanism so that the graphics app will exit if the main app dies.

fraction_done

The last fraction done reported by the main app.

cpu_time

The last CPU time reported by the main app.

status

The BOINC status. If the 'suspended' flag is set, the graphics app should stop changing its display, and simply display an "application suspended" message.