Panda3D
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LightRampAttrib Class Reference

A Light Ramp is any unary operator that takes a rendered pixel as input, and adjusts the brightness of that pixel. For example, gamma correction is a kind of light ramp. So is HDR tone mapping. So is cartoon shading. See the constructors for an explanation of each kind of ramp. More...

Inheritance diagram for LightRampAttrib:
RenderAttrib TypedWritableReferenceCount TypedWritable ReferenceCount TypedObject MemoryBase MemoryBase

Public Types

enum  LightRampMode {
  LRT_default = 0, LRT_identity = 1, LRT_single_threshold = 2, LRT_double_threshold = 3,
  LRT_hdr0 = 4, LRT_hdr1 = 5, LRT_hdr2 = 6
}
 
- Public Types inherited from RenderAttrib
enum  PandaCompareFunc {
  M_none = 0, M_never = 1, M_less = 2, M_equal = 3,
  M_less_equal = 4, M_greater = 5, M_not_equal = 6, M_greater_equal = 7,
  M_always = 8
}
 intentionally defined to match D3DCMPFUNC More...
 
enum  TexGenMode {
  M_off = 0, M_eye_sphere_map = 1, M_world_cube_map = 2, M_eye_cube_map = 3,
  M_world_normal = 4, M_eye_normal = 5, M_world_position = 6, M_unused = 7,
  M_eye_position = 8, M_point_sprite = 9, M_unused2 = 10, M_constant = 11
}
 This is the enumerated type for TexGenAttrib. It is inherited into TexGenAttrib. It is defined up at this level only to avoid circular dependencies in the header files. More...
 

Public Member Functions

float getLevel (int n)
 Returns the nth lighting level. More...
 
LightRampAttrib::LightRampMode getMode ()
 Returns the LightRampAttrib mode. More...
 
float getThreshold (int n)
 Returns the nth threshold level. More...
 
- Public Member Functions inherited from RenderAttrib
int compareTo (const RenderAttrib other)
 Provides an arbitrary ordering among all unique RenderAttribs, so we can store the essentially different ones in a big set and throw away the rest. More...
 
const RenderAttrib compose (const RenderAttrib other)
 Returns a new RenderAttrib object that represents the composition of this attrib with the other attrib. In most cases, this is the same as the other attrib; a compose b produces b. Some kinds of attributes, like a TextureTransform, for instance, might produce a new result: a compose b produces c. More...
 
const RenderAttrib getAutoShaderAttrib (const RenderState state)
 Returns the variant of this RenderAttrib that's most relevant for associating with an auto-generated shader. This should be a new RenderAttrib of the same type as this one, with any superfluous data set to neutral. Only the parts of the attrib that contribute to the shader should be reflected in the returned attrib. The idea is to associate the auto-generated shader with the most neutral form of all states, to allow it to be shared across as many RenderState objects as possible. More...
 
size_t getHash ()
 Returns a suitable hash value for phash_map. More...
 
int getSlot ()
 
const RenderAttrib getUnique ()
 Returns the pointer to the unique RenderAttrib 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. More...
 
const RenderAttrib invertCompose (const RenderAttrib other)
 Returns a new RenderAttrib object that represents the composition of the inverse of this attrib with the other attrib. In most cases, this is the same as the other attrib; !a compose b produces b. Some kinds of attributes, like a TextureTransform, for instance, might produce a new result: !a compose b produces c. More...
 
bool lowerAttribCanOverride ()
 Intended to be overridden by derived RenderAttrib types to specify how two consecutive RenderAttrib objects of the same type interact. More...
 
 output (Ostream out)
 
 write (Ostream out, int indent_level)
 
- Public Member Functions inherited from TypedWritable
object __reduce__ ()
 
object __reduce_persist__ (object pickler)
 
str encodeToBamStream ()
 Converts the TypedWritable object into a single stream of data using a BamWriter, and returns that data as a string string. Returns empty string on failure. More...
 
bool encodeToBamStream (String data, BamWriter writer)
 Converts the TypedWritable object into a single stream of data using a BamWriter, and stores that data in the indicated string. Returns true on success, false on failure. More...
 
UpdateSeq getBamModified ()
 Returns the current bam_modified counter. This counter is normally incremented automatically whenever the object is modified. More...
 
 markBamModified ()
 Increments the bam_modified counter, so that this object will be invalidated and retransmitted on any open bam streams. This should normally not need to be called by user code; it should be called internally when the object has been changed in a way that legitimately requires its retransmission to any connected clients. More...
 
- Public Member Functions inherited from TypedObject
TypeHandle getType ()
 Derived classes should override this function to return get_class_type(). More...
 
int getTypeIndex ()
 Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. This is equivalent to get_type().get_index(). More...
 
bool isExactType (TypeHandle handle)
 Returns true if the current object is the indicated type exactly. More...
 
bool isOfType (TypeHandle handle)
 Returns true if the current object is or derives from the indicated type. More...
 
- Public Member Functions inherited from ReferenceCount
int getRefCount ()
 Returns the current reference count. More...
 
 ref ()
 Explicitly increments the reference count. User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. More...
 
bool testRefCountIntegrity ()
 Does some easy checks to make sure that the reference count isn't completely bogus. Returns true if ok, false otherwise. More...
 
bool testRefCountNonzero ()
 Does some easy checks to make sure that the reference count isn't zero, or completely bogus. Returns true if ok, false otherwise. More...
 
bool unref ()
 Explicitly decrements the reference count. Note that the object will not be implicitly deleted by unref() simply because the reference count drops to zero. (Having a member function delete itself is problematic.) However, see the helper function unref_delete(). More...
 

Static Public Member Functions

static int getClassSlot ()
 
static TypeHandle getClassType ()
 
static const RenderAttrib makeDefault ()
 Constructs a new LightRampAttrib object. This is the standard OpenGL lighting ramp, which clamps the final light total to the 0-1 range. More...
 
static const RenderAttrib makeDoubleThreshold (float thresh0, float lev0, float thresh1, float lev1)
 Constructs a new LightRampAttrib object. This causes the luminance of the diffuse lighting contribution to be quantized using two thresholds: More...
 
static const RenderAttrib makeHdr0 ()
 Constructs a new LightRampAttrib object. This causes an HDR tone mapping operation to be applied. More...
 
static const RenderAttrib makeHdr1 ()
 Constructs a new LightRampAttrib object. This causes an HDR tone mapping operation to be applied. More...
 
static const RenderAttrib makeHdr2 ()
 Constructs a new LightRampAttrib object. This causes an HDR tone mapping operation to be applied. More...
 
static const RenderAttrib makeIdentity ()
 Constructs a new LightRampAttrib object. This differs from the usual OpenGL lighting model in that it does not clamp the final lighting total to (0,1). More...
 
static const RenderAttrib makeSingleThreshold (float thresh0, float lev0)
 Constructs a new LightRampAttrib object. This causes the luminance of the diffuse lighting contribution to be quantized using a single threshold: More...
 
- Static Public Member Functions inherited from RenderAttrib
static int garbageCollect ()
 Performs a garbage-collection cycle. This is called automatically from RenderState::garbage_collect(); see that method for more information. More...
 
static TypeHandle getClassType ()
 
static int getNumAttribs ()
 Returns the total number of unique RenderAttrib objects allocated in the world. This will go up and down during normal operations. More...
 
static listAttribs (Ostream out)
 Lists all of the RenderAttribs 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. More...
 
static bool validateAttribs ()
 Ensures that the cache is still stored in sorted order. Returns true if so, false if there is a problem (which implies someone has modified one of the supposedly-const RenderAttrib objects). More...
 
- Static Public Member Functions inherited from TypedWritableReferenceCount
static TypedWritableReferenceCount decodeFromBamStream (str data, BamReader reader)
 Reads the string created by a previous call to encode_to_bam_stream(), and extracts and returns the single object on that string. Returns NULL on error. More...
 
static TypeHandle getClassType ()
 
- Static Public Member Functions inherited from TypedWritable
static TypeHandle getClassType ()
 
- Static Public Member Functions inherited from TypedObject
static TypeHandle getClassType ()
 
- Static Public Member Functions inherited from ReferenceCount
static TypeHandle getClassType ()
 

Detailed Description

A Light Ramp is any unary operator that takes a rendered pixel as input, and adjusts the brightness of that pixel. For example, gamma correction is a kind of light ramp. So is HDR tone mapping. So is cartoon shading. See the constructors for an explanation of each kind of ramp.

Member Enumeration Documentation

◆ LightRampMode

Enumerator
LRT_default 
LRT_identity 
LRT_single_threshold 
LRT_double_threshold 
LRT_hdr0 
LRT_hdr1 
LRT_hdr2 

Member Function Documentation

◆ getClassSlot()

static int getClassSlot ( )
static

◆ getClassType()

static TypeHandle getClassType ( )
static

◆ getLevel()

float getLevel ( int  n)

Returns the nth lighting level.

◆ getMode()

Returns the LightRampAttrib mode.

◆ getThreshold()

float getThreshold ( int  n)

Returns the nth threshold level.

◆ makeDefault()

static const RenderAttrib makeDefault ( )
static

Constructs a new LightRampAttrib object. This is the standard OpenGL lighting ramp, which clamps the final light total to the 0-1 range.

◆ makeDoubleThreshold()

static const RenderAttrib makeDoubleThreshold ( float  thresh0,
float  lev0,
float  thresh1,
float  lev1 
)
static

Constructs a new LightRampAttrib object. This causes the luminance of the diffuse lighting contribution to be quantized using two thresholds:

if (original_luminance > threshold1) {
luminance = level1;
} else if (original_luminance > threshold0) {
luminance = level0;
} else {
luminance = 0.0;
}

◆ makeHdr0()

static const RenderAttrib makeHdr0 ( )
static

Constructs a new LightRampAttrib object. This causes an HDR tone mapping operation to be applied.

Normally, brightness values greater than 1 cannot be distinguished from each other, causing very brightly lit objects to wash out white and all detail to be erased. HDR tone mapping remaps brightness values in the range 0-infinity into the range (0,1), making it possible to distinguish detail in scenes whose brightness exceeds 1.

However, the monitor has finite contrast. Normally, all of that contrast is used to represent brightnesses in the range 0-1. The HDR0 tone mapping operator 'steals' one quarter of that contrast to represent brightnesses in the range 1-infinity.

FINAL_RGB = (RGB^3 + RGB^2 + RGB) / (RGB^3 + RGB^2 + RGB + 1)

◆ makeHdr1()

static const RenderAttrib makeHdr1 ( )
static

Constructs a new LightRampAttrib object. This causes an HDR tone mapping operation to be applied.

Normally, brightness values greater than 1 cannot be distinguished from each other, causing very brightly lit objects to wash out white and all detail to be erased. HDR tone mapping remaps brightness values in the range 0-infinity into the range (0,1), making it possible to distinguish detail in scenes whose brightness exceeds 1.

However, the monitor has finite contrast. Normally, all of that contrast is used to represent brightnesses in the range 0-1. The HDR1 tone mapping operator 'steals' one third of that contrast to represent brightnesses in the range 1-infinity.

FINAL_RGB = (RGB^2 + RGB) / (RGB^2 + RGB + 1)

◆ makeHdr2()

static const RenderAttrib makeHdr2 ( )
static

Constructs a new LightRampAttrib object. This causes an HDR tone mapping operation to be applied.

Normally, brightness values greater than 1 cannot be distinguished from each other, causing very brightly lit objects to wash out white and all detail to be erased. HDR tone mapping remaps brightness values in the range 0-infinity into the range (0,1), making it possible to distinguish detail in scenes whose brightness exceeds 1.

However, the monitor has finite contrast. Normally, all of that contrast is used to represent brightnesses in the range 0-1. The HDR2 tone mapping operator 'steals' one half of that contrast to represent brightnesses in the range 1-infinity.

FINAL_RGB = (RGB) / (RGB + 1)

◆ makeIdentity()

static const RenderAttrib makeIdentity ( )
static

Constructs a new LightRampAttrib object. This differs from the usual OpenGL lighting model in that it does not clamp the final lighting total to (0,1).

◆ makeSingleThreshold()

static const RenderAttrib makeSingleThreshold ( float  thresh0,
float  lev0 
)
static

Constructs a new LightRampAttrib object. This causes the luminance of the diffuse lighting contribution to be quantized using a single threshold:

if (original_luminance > threshold0) {
luminance = level0;
} else {
luminance = 0.0;
}