RenderState

class RenderState

Bases: NodeCachedReferenceCount

This represents a unique collection of RenderAttrib objects that correspond to a particular renderable state.

You should not attempt to create or modify a RenderState object directly. Instead, call one of the make() functions to create one for you. And instead of modifying a RenderState object, create a new one.

Inheritance diagram

ConstPointerTo<RenderState> add_attrib(RenderAttrib const *attrib, int override = 0) const: Returns a new RenderState object that represents the same as the source state, with the new RenderAttrib added. If there is already a RenderAttrib with the same type, it is replaced (unless the override is lower).

ConstPointerTo<RenderState> adjust_all_priorities(int adjustment) const: Returns a new RenderState object that represents the same as the source state, with all attributes’ override values incremented (or decremented, if negative) by the indicated amount. If the override would drop below zero, it is set to zero.

void cache_ref(void) const: Overrides this method to update PStats appropriately.

bool cache_unref(void) const: Overrides this method to update PStats appropriately.

static int clear_cache(void)

Empties the cache of composed RenderStates. This makes every RenderState forget what results when it is composed with other RenderStates.

This will eliminate any RenderState objects that have been allocated but have no references outside of the internal RenderState map. It will not eliminate RenderState objects that are still in use.

Nowadays, this method should not be necessary, as reference-count cycles in the composition cache should be automatically detected and broken.

The return value is the number of RenderStates freed by this operation.

static void clear_munger_cache(void): Completely empties the cache of state + gsg -> munger, for all states and all gsg’s. Normally there is no need to empty this cache.

int compare_mask(RenderState const &other, SlotMask compare_mask) const: This version of compare_to takes a slot mask that indicates which attributes to include in the comparison. Unlike compare_to, this method compares the attributes by pointer.

int compare_sort(RenderState const &other) const: Returns -1, 0, or 1 according to the relative sorting of these two RenderStates, with regards to rendering performance, so that “heavier” RenderAttribs (as defined by RenderAttribRegistry::get_slot_sort()) are more likely to be grouped together. This is not related to the sorting order defined by compare_to.

int compare_to(RenderState const &other) const

Provides an arbitrary ordering among all unique RenderStates, so we can store the essentially different ones in a big set and throw away the rest.

This method is not needed outside of the RenderState class because all equivalent RenderState objects are guaranteed to share the same pointer; thus, a pointer comparison is always sufficient.

ConstPointerTo<RenderState> compose(RenderState const *other) const

Returns a new RenderState object that represents the composition of this state with the other state.

The result of this operation is cached, and will be retained as long as both this RenderState object and the other RenderState object continue to exist. Should one of them destruct, the cached entry will be removed, and its pointer will be allowed to destruct as well.

bool cull_callback(CullTraverser *trav, CullTraverserData const &data) const: Calls cull_callback() on each attrib. If any attrib returns false, interrupts the list and returns false immediately; otherwise, completes the list and returns true.

static int garbage_collect(void)

Performs a garbage-collection cycle. This must be called periodically if garbage-collect-states is true to ensure that RenderStates get cleaned up appropriately. It does no harm to call it even if this variable is not true, but there is probably no advantage in that case.

This automatically calls RenderAttrib::garbage_collect() as well.

RenderAttrib const *get_attrib(TypeHandle type) const

RenderAttrib const *get_attrib(int slot) const

Looks for a RenderAttrib of the indicated type in the state, and returns it if it is found, or NULL if it is not.

Returns the RenderAttrib with the indicated slot index, or NULL if there is no such RenderAttrib in the state.

RenderAttrib const *get_attrib_def(int slot) const: Returns the RenderAttrib with the indicated slot index, or the default attrib for that slot if there is no such RenderAttrib in the state.

int get_bin_index(void) const: Returns the bin index indicated by the CullBinAttrib, if any, associated by this state (or the default bin index if there is no CullBinAttrib). This function is provided as an optimization for determining this at render time.

static TypeHandle get_class_type(void)

PyObject *get_composition_cache(void) const

std::size_t get_composition_cache_num_entries(void) const: Returns the number of entries in the composition cache for this RenderState. This is the number of other RenderStates whose composition with this one has been cached. This number is not useful for any practical reason other than performance analysis.

RenderState const *get_composition_cache_result(std::size_t n) const

Returns the result RenderState of the nth element in the composition cache. Returns NULL if there doesn’t happen to be an entry in the nth element.

In general, a->compose(a->get_composition_cache_source(n)) == a->get_composition_cache_result(n).

This has no practical value other than for examining the cache for performance analysis.

std::size_t get_composition_cache_size(void) const

Returns the number of slots in the composition cache for this RenderState. You may use this as an upper bound when walking through all of the composition cache results via get_composition_cache_source() or result().

This has no practical value other than for examining the cache for performance analysis.

RenderState const *get_composition_cache_source(std::size_t n) const

Returns the source RenderState of the nth element in the composition cache. Returns NULL if there doesn’t happen to be an entry in the nth element. See get_composition_cache_result().

This has no practical value other than for examining the cache for performance analysis.

int get_draw_order(void) const

These methods are intended for use by low-level code, but they’re also handy enough to expose to high-level users.

Returns the draw order indicated by the CullBinAttrib, if any, associated by this state (or 0 if there is no CullBinAttrib). See get_bin_index().

int get_geom_rendering(int geom_rendering) const: Returns the union of the Geom::GeomRendering bits that will be required once this RenderState is applied to a geom which includes the indicated geom_rendering bits.

std::size_t get_hash(void) const: Returns a suitable hash value for phash_map.

PyObject *get_invert_composition_cache(void) const

std::size_t get_invert_composition_cache_num_entries(void) const: Returns the number of entries in the invert_composition cache for this RenderState. This is similar to the composition cache, but it records cache entries for the invert_compose() operation. See get_composition_cache_num_entries().

RenderState const *get_invert_composition_cache_result(std::size_t n) const

Returns the result RenderState of the nth element in the invert composition cache. Returns NULL if there doesn’t happen to be an entry in the nth element.

In general, a->invert_compose(a->get_invert_composition_cache_source(n)) == a->get_invert_composition_cache_result(n).

This has no practical value other than for examining the cache for performance analysis.

std::size_t get_invert_composition_cache_size(void) const

Returns the number of slots in the composition cache for this RenderState. You may use this as an upper bound when walking through all of the composition cache results via get_invert_composition_cache_source() or result().

This has no practical value other than for examining the cache for performance analysis.

RenderState const *get_invert_composition_cache_source(std::size_t n) const

Returns the source RenderState of the nth element in the invert composition cache. Returns NULL if there doesn’t happen to be an entry in the nth element. See get_invert_composition_cache_result().

This has no practical value other than for examining the cache for performance analysis.

static int get_max_priority(void): Returns the maximum priority number (sometimes called override) that may be set on any node. This may or may not be enforced, but the scene graph code assumes that no priority numbers will be larger than this, and some effects may not work properly if you use a larger number.

static int get_num_states(void): Returns the total number of unique RenderState objects allocated in the world. This will go up and down during normal operations.

static int get_num_unused_states(void)

Returns the total number of RenderState objects that have been allocated but have no references outside of the internal RenderState cache.

A nonzero return value is not necessarily indicative of leaked references; it is normal for two RenderState objects, both of which have references held outside the cache, to have to result of their composition stored within the cache. This result will be retained within the cache until one of the base RenderStates is released.

Use list_cycles() to get an idea of the number of actual “leaked” RenderState objects.

int get_override(TypeHandle type) const

int get_override(int slot) const: Looks for a RenderAttrib of the indicated type in the state, and returns its override value if it is found, or 0 if it is not.

static PyObject *get_states(void)

ConstPointerTo<RenderState> get_unique(void) const: Returns the pointer to the unique RenderState in the cache that is equivalent to this one. This may be the same pointer as this object, or it may be a different pointer; but it will be an equivalent object, and it will be a shared pointer. This may be called from time to time to improve cache benefits.

static PyObject *get_unused_states(void)

bool has_attrib(TypeHandle type) const

bool has_attrib(int slot) const: Returns true if an attrib of the indicated type is present, false otherwise.

bool has_cull_callback(void) const: Returns true if any of the RenderAttribs in this state request a cull_callback(), false if none of them do.

ConstPointerTo<RenderState> invert_compose(RenderState const *other) const

Returns a new RenderState object that represents the composition of this state’s inverse with the other state.

This is similar to compose(), but is particularly useful for computing the relative state of a node as viewed from some other node.

bool is_empty(void) const: Returns true if the state is empty, false otherwise.

static void list_cycles(std::ostream &out)

Detects all of the reference-count cycles in the cache and reports them to standard output.

These cycles may be inadvertently created when state compositions cycle back to a starting point. Nowadays, these cycles should be automatically detected and broken, so this method should never list any cycles unless there is a bug in that detection logic.

The cycles listed here are not leaks in the strictest sense of the word, since they can be reclaimed by a call to clear_cache(); but they will not be reclaimed automatically.

static void list_states(std::ostream &out): Lists all of the RenderStates in the cache to the output stream, one per line. This can be quite a lot of output if the cache is large, so be prepared.

static explicit ConstPointerTo<RenderState> make(PyObject *args, PyObject *kwargs)

Returns a RenderState with one attribute set.

Returns a RenderState with two attributes set.

Returns a RenderState with three attributes set.

Returns a RenderState with four attributes set.

Returns a RenderState with five attributes set.

Returns a RenderState with n attributes set.

ConstPointerTo<RenderState> make_empty(void): Returns a RenderState with no attributes set.

void node_ref(void) const: Overrides this method to update PStats appropriately.

bool node_unref(void) const: Overrides this method to update PStats appropriately.

void output(std::ostream &out) const

ConstPointerTo<RenderState> remove_attrib(TypeHandle type) const

ConstPointerTo<RenderState> remove_attrib(int slot) const: Returns a new RenderState object that represents the same as the source state, with the indicated RenderAttrib removed.

ConstPointerTo<RenderState> set_attrib(RenderAttrib const *attrib) const

ConstPointerTo<RenderState> set_attrib(RenderAttrib const *attrib, int override) const

Returns a new RenderState object that represents the same as the source state, with the new RenderAttrib added. If there is already a RenderAttrib with the same type, it is replaced unconditionally. The override is not changed.

Returns a new RenderState object that represents the same as the source state, with the new RenderAttrib added. If there is already a RenderAttrib with the same type, it is replaced unconditionally. The override is also replaced unconditionally.

static bool validate_states(void): Ensures that the cache is still stored in sorted order, and that none of the cache elements have been inadvertently deleted. Returns true if so, false if there is a problem (which implies someone has modified one of the supposedly-const RenderState objects).

void write(std::ostream &out, int indent_level) const