GraphicsThreadingModel

class GraphicsThreadingModel

This represents the user’s specification of how a particular frame is handled by the various threads.

Inheritance diagram

GraphicsThreadingModel(std::string const &model = string())

GraphicsThreadingModel(GraphicsThreadingModel const &copy)

The threading model accepts a string representing the names of the two threads that will process cull and draw for the given window, separated by a slash. The names are completely arbitrary and are used only to differentiate threads. The two names may be the same, meaning the same thread, or each may be the empty string, which represents the previous thread.

Thus, for example, “cull/draw” indicates that the window will be culled in a thread called “cull”, and drawn in a separate thread called “draw”. “draw/draw” or simply “draw” indicates the window will be culled and drawn in the same thread, “draw”. On the other hand, “/draw” indicates the thread will be culled in the main, or app thread, and drawn in a separate thread named “draw”. The empty string, “” or “/”, indicates the thread will be culled and drawn in the main thread; that is to say, a single-process model.

Finally, if the threading model begins with a “-” character, then cull and draw are run simultaneously, in the same thread, with no binning or state sorting. It simplifies the cull process but it forces the scene to render in scene graph order; state sorting and alpha sorting is lost.

std::string const &get_cull_name(void) const

Returns the name of the thread that will handle culling in this model.

bool get_cull_sorting(void) const

Returns true if the model involves a separate cull pass, or false if culling happens implicitly, at the same time as draw.

int get_cull_stage(void) const

Returns the pipeline stage from which the cull thread should access data. This will be 0 if the cull is run in the same thread as app, or 1 if it is its own thread.

std::string const &get_draw_name(void) const

Returns the name of the thread that will handle sending the actual graphics primitives to the graphics API in this model.

int get_draw_stage(void) const

Returns the pipeline stage from which the draw thread should access data. This will be the same value as get_cull_stage() if cull and draw are run in the same thread, or one more than that value if draw should be in its own thread.

std::string get_model(void) const

Returns the string that describes the threading model. See the constructor.

bool is_default(void) const

Returns true if the threading model is the default, cull-then-draw single- threaded model, or false otherwise.

bool is_single_threaded(void) const

Returns true if the threading model is a single-threaded model, or false if it involves threads.

void output(std::ostream &out) const

void set_cull_name(std::string const &cull_name)

Changes the name of the thread that will handle culling in this model. This won’t change any windows that were already created with this model; this only has an effect on newly-opened windows.

void set_cull_sorting(bool cull_sorting)

Changes the flag that indicates whether the threading model involves a separate cull pass. This won’t change any windows that were already created with this model; this only has an effect on newly-opened windows.

void set_draw_name(std::string const &cull_name)

Changes the name of the thread that will handle drawing in this model. This won’t change any windows that were already created with this model; this only has an effect on newly-opened windows.