This is a special kind of attribute that instructs the graphics driver to apply an offset or bias to the generated depth values for rendered polygons, before they are written to the depth buffer. More...
#include "depthOffsetAttrib.h"
Inheritance diagram for DepthOffsetAttrib:
Public Member Functions | |
| virtual TypeHandle | force_init_type () |
| PN_stdfloat | get_max_value () const |
| PN_stdfloat | get_min_value () const |
| int | get_offset () const |
| virtual int | get_slot () const |
| virtual TypeHandle | get_type () const |
| virtual void | output (std::ostream &out) const |
| virtual void | write_datagram (BamWriter *manager, Datagram &dg) |
| Writes the contents of this object to the datagram for shipping out to a Bam file. More... | |
 Public Member Functions inherited from RenderAttrib | |
| RenderAttrib (const RenderAttrib ©)=delete | |
| virtual | ~RenderAttrib () |
| The destructor is responsible for removing the RenderAttrib from the global set if it is there. More... | |
| int | compare_to (const RenderAttrib &other) const |
| CPT (RenderAttrib) compose(const RenderAttrib *other) const | |
| CPT (RenderAttrib) invert_compose(const RenderAttrib *other) const | |
| CPT (RenderAttrib) get_unique() const | |
| virtual bool | cull_callback (CullTraverser *trav, const CullTraverserData &data) const |
| If has_cull_callback() returns true, this function will be called during the cull traversal to perform any additional operations that should be performed at cull time. More... | |
| virtual void | finalize (BamReader *manager) |
| Called by the BamReader to perform any final actions needed for setting up the object after all objects have been read and all pointers have been completed. More... | |
| size_t | get_hash () const |
| virtual bool | has_cull_callback () const |
| Should be overridden by derived classes to return true if cull_callback() has been defined. More... | |
| virtual bool | lower_attrib_can_override () const |
| Intended to be overridden by derived RenderAttrib types to specify how two consecutive RenderAttrib objects of the same type interact. More... | |
| RenderAttrib & | operator= (const RenderAttrib ©)=delete |
| virtual bool | unref () const final |
| This method overrides ReferenceCount::unref() to clear the pointer from the global object pool when its reference count goes to zero. More... | |
| virtual void | write (std::ostream &out, int indent_level) const |
| Public Member Functions inherited from TypedWritableReferenceCount | |
| TypedWritableReferenceCount (const TypedWritableReferenceCount ©) | |
| virtual ReferenceCount * | as_reference_count () |
| Returns the pointer cast to a ReferenceCount pointer, if it is in fact of that type. More... | |
| void | operator= (const TypedWritableReferenceCount ©) |
| Public Member Functions inherited from TypedWritable | |
| TypedWritable (const TypedWritable ©) | |
| virtual int | complete_pointers (TypedWritable **p_list, BamReader *manager) |
| Receives an array of pointers, one for each time manager->read_pointer() was called in fillin(). More... | |
| vector_uchar | encode_to_bam_stream () const |
| Converts the TypedWritable object into a single stream of data using a BamWriter, and returns that data as a bytes object. More... | |
| bool | encode_to_bam_stream (vector_uchar &data, BamWriter *writer=nullptr) const |
| Converts the TypedWritable object into a single stream of data using a BamWriter, and stores that data in the indicated string. More... | |
| UpdateSeq | get_bam_modified () const |
| Returns the current bam_modified counter. More... | |
| void | mark_bam_modified () |
| Increments the bam_modified counter, so that this object will be invalidated and retransmitted on any open bam streams. More... | |
| void | operator= (const TypedWritable ©) |
| virtual bool | require_fully_complete () const |
| Some objects require all of their nested pointers to have been completed before the objects themselves can be completed. More... | |
| virtual void | update_bam_nested (BamWriter *manager) |
| Called by the BamWriter when this object has not itself been modified recently, but it should check its nested objects for updates. More... | |
| Public Member Functions inherited from TypedObject | |
| TypedObject (const TypedObject ©)=default | |
| TypedObject * | as_typed_object () |
| Returns the object, upcast (if necessary) to a TypedObject pointer. More... | |
| const TypedObject * | as_typed_object () const |
| Returns the object, upcast (if necessary) to a TypedObject pointer. More... | |
| int | get_best_parent_from_Set (const std::set< int > &) const |
| int | get_type_index () const |
| Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. More... | |
| bool | is_exact_type (TypeHandle handle) const |
| Returns true if the current object is the indicated type exactly. More... | |
| bool | is_of_type (TypeHandle handle) const |
| Returns true if the current object is or derives from the indicated type. More... | |
| TypedObject & | operator= (const TypedObject ©)=default |
| Public Member Functions inherited from ReferenceCount | |
| int | get_ref_count () const |
| WeakReferenceList * | get_weak_list () const |
| Returns the WeakReferenceList associated with this ReferenceCount object. More... | |
| bool | has_weak_list () const |
| Returns true if this particular ReferenceCount object has a WeakReferenceList created, false otherwise. More... | |
| void | local_object () |
| This function should be called, once, immediately after creating a new instance of some ReferenceCount-derived object on the stack. More... | |
| void | ref () const |
| Explicitly increments the reference count. More... | |
| bool | ref_if_nonzero () const |
| Atomically increases the reference count of this object if it is not zero. More... | |
| bool | test_ref_count_integrity () const |
| Does some easy checks to make sure that the reference count isn't completely bogus. More... | |
| bool | test_ref_count_nonzero () const |
| Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More... | |
| WeakReferenceList * | weak_ref () |
| Adds the indicated PointerToVoid as a weak reference to this object. More... | |
| void | weak_unref () |
| Removes the indicated PointerToVoid as a weak reference to this object. More... | |
Static Public Member Functions | |
| static | CPT (RenderAttrib) make(int offset |
| static | CPT (RenderAttrib) make(int offset |
| static | CPT (RenderAttrib) make_default() |
| static int | get_class_slot () |
| static TypeHandle | get_class_type () |
| static void | init_type () |
| static void | register_with_read_factory () |
| Static Public Member Functions inherited from RenderAttrib | |
| static TypedWritable * | change_this (TypedWritable *old_ptr, BamReader *manager) |
| Called immediately after complete_pointers(), this gives the object a chance to adjust its own pointer if desired. More... | |
| static int | garbage_collect () |
| Performs a garbage-collection cycle. More... | |
| static TypeHandle | get_class_type () |
| static int | get_num_attribs () |
| Returns the total number of unique RenderAttrib objects allocated in the world. More... | |
| static void | init_attribs () |
| Make sure the global _attribs map is allocated. More... | |
| static void | init_type () |
| static void | list_attribs (std::ostream &out) |
| Lists all of the RenderAttribs in the cache to the output stream, one per line. More... | |
| static int | register_slot (TypeHandle type_handle, int sort, RenderAttrib *default_attrib) |
| Adds the indicated TypeHandle to the registry, if it is not there already, and returns a unique slot number. More... | |
| static bool | validate_attribs () |
| Ensures that the cache is still stored in sorted order. More... | |
| Static Public Member Functions inherited from TypedWritableReferenceCount | |
| static TypeHandle | get_class_type () |
| static void | init_type () |
| static | PT (TypedWritableReferenceCount) decode_from_bam_stream(vector_uchar data |
| Static Public Member Functions inherited from TypedWritable | |
| static bool | decode_raw_from_bam_stream (TypedWritable *&ptr, ReferenceCount *&ref_ptr, vector_uchar data, BamReader *reader=nullptr) |
| Reads the bytes created by a previous call to encode_to_bam_stream(), and extracts the single object on those bytes. More... | |
| static TypeHandle | get_class_type () |
| static void | init_type () |
| Static Public Member Functions inherited from TypedObject | |
| static TypeHandle | get_class_type () |
| static void | init_type () |
| This function is declared non-inline to work around a compiler bug in g++ 2.96. More... | |
| Static Public Member Functions inherited from ReferenceCount | |
| static TypeHandle | get_class_type () |
| static void | init_type () |
Public Attributes | |
| get_class_slot | |
| get_max_value | |
| Returns the value for the maximum (farthest) depth value to be stored in the buffer, in the range 0 . More... | |
| get_min_value | |
| Returns the value for the minimum (closest) depth value to be stored in the buffer, in the range 0 . More... | |
| get_offset | |
| Returns the depth offset represented by this attrib. More... | |
| static PN_stdfloat PN_stdfloat | max_value |
| static PN_stdfloat | min_value |
| Public Attributes inherited from RenderAttrib | |
| get_slot | |
| Public Attributes inherited from TypedWritableReferenceCount | |
| static BamReader * | reader = nullptr) |
| Public Attributes inherited from TypedObject | |
| get_type | |
| Public Attributes inherited from ReferenceCount | |
| get_ref_count | |
| Returns the current reference count. More... | |
Additional Inherited Members | |
| Public Types inherited from RenderAttrib | |
| enum | PandaCompareFunc { M_none =0, M_never, M_less, M_equal, M_less_equal, M_greater, M_not_equal, M_greater_equal, M_always } |
| enum | TexGenMode { M_off, M_eye_sphere_map, M_world_cube_map, M_eye_cube_map, M_world_normal, M_eye_normal, M_world_position, M_unused, M_eye_position, M_point_sprite, M_unused2, M_constant } |
| Static Public Attributes inherited from TypedWritable | |
| static TypedWritable *const | Null = nullptr |
Detailed Description
This is a special kind of attribute that instructs the graphics driver to apply an offset or bias to the generated depth values for rendered polygons, before they are written to the depth buffer.
This can be used to shift polygons forward slightly, to resolve depth conflicts. The cull traverser may optionally use this, for instance, to implement decals. However, driver support for this feature seems to be spotty, so use with caution.
The bias is always an integer number, and each integer increment represents the smallest possible increment in Z that is sufficient to completely resolve two coplanar polygons. Positive numbers are closer towards the camera.
Nested DepthOffsetAttrib values accumulate; that is, a DepthOffsetAttrib with a value of 1 beneath another DepthOffsetAttrib with a value of 2 presents a net offset of 3. (A DepthOffsetAttrib will not, however, combine with any other DepthOffsetAttribs with a lower override parameter.) The net value should probably not exceed 16 or drop below 0 for maximum portability.
Also, and only tangentially related, the DepthOffsetAttrib can be used to constrain the Z output value to a subset of the usual [0, 1] range (or reversing its direction) by specifying a new min_value and max_value.
Definition at line 50 of file depthOffsetAttrib.h.
Member Function Documentation
◆ write_datagram()
Writes the contents of this object to the datagram for shipping out to a Bam file.
Reimplemented from RenderAttrib.
Definition at line 161 of file depthOffsetAttrib.cxx.
References Datagram::add_int32(), Datagram::add_stdfloat(), BamWriter::get_file_minor_ver(), and RenderAttrib::write_datagram().
Member Data Documentation
◆ get_max_value
|
inline |
Returns the value for the maximum (farthest) depth value to be stored in the buffer, in the range 0 .
. 1.
Definition at line 66 of file depthOffsetAttrib.h.
◆ get_min_value
|
inline |
Returns the value for the minimum (closest) depth value to be stored in the buffer, in the range 0 .
. 1.
Definition at line 65 of file depthOffsetAttrib.h.
◆ get_offset
|
inline |
Returns the depth offset represented by this attrib.
Definition at line 64 of file depthOffsetAttrib.h.
The documentation for this class was generated from the following files:
- panda/src/pgraph/depthOffsetAttrib.h
- panda/src/pgraph/depthOffsetAttrib.cxx
- panda/src/pgraph/depthOffsetAttrib.I
