Panda3D
Public Types | Public Member Functions | Static Public Member Functions | Public Attributes | List of all members
LightRampAttrib Class Reference

A Light Ramp is any unary operator that takes a rendered pixel as input, and adjusts the brightness of that pixel. More...

Inheritance diagram for LightRampAttrib:
RenderAttrib TypedWritableReferenceCount TypedWritable ReferenceCount TypedObject

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
}
 
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
}
 

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. More...
 
int 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. 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. 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)
 
VectorUchar encodeToBamStream ()
 Converts the TypedWritable object into a single stream of data using a BamWriter, and returns that data as a bytes object. More...
 
bool encodeToBamStream (VectorUchar data, BamWriter writer)
 Converts the TypedWritable object into a single stream of data using a BamWriter, and stores that data in the indicated string. More...
 
 fillin (DatagramIterator scan, BamReader manager)
 This internal function is intended to be called by each class's make_from_bam() method to read in all of the relevant data from the BamFile for the new object. More...
 
UpdateSeq getBamModified ()
 Returns the current bam_modified counter. More...
 
 markBamModified ()
 Increments the bam_modified counter, so that this object will be invalidated and retransmitted on any open bam streams. More...
 
- Public Member Functions inherited from TypedObject
TypeHandle getType ()
 
int getTypeIndex ()
 Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. 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. More...
 
bool testRefCountIntegrity ()
 Does some easy checks to make sure that the reference count isn't completely bogus. More...
 
bool testRefCountNonzero ()
 Does some easy checks to make sure that the reference count isn't zero, or completely bogus. More...
 
bool unref ()
 Explicitly decrements the reference count. More...
 

Static Public Member Functions

static int getClassSlot ()
 
static TypeHandle getClassType ()
 
static const RenderAttrib makeDefault ()
 Constructs a new LightRampAttrib object. More...
 
static const RenderAttrib makeDoubleThreshold (float thresh0, float lev0, float thresh1, float lev1)
 Constructs a new LightRampAttrib object. More...
 
static const RenderAttrib makeHdr0 ()
 Constructs a new LightRampAttrib object. More...
 
static const RenderAttrib makeHdr1 ()
 Constructs a new LightRampAttrib object. More...
 
static const RenderAttrib makeHdr2 ()
 Constructs a new LightRampAttrib object. More...
 
static const RenderAttrib makeIdentity ()
 Constructs a new LightRampAttrib object. More...
 
static const RenderAttrib makeSingleThreshold (float thresh0, float lev0)
 Constructs a new LightRampAttrib object. More...
 
- Static Public Member Functions inherited from RenderAttrib
static int garbageCollect ()
 Performs a garbage-collection cycle. More...
 
static TypeHandle getClassType ()
 
static int getNumAttribs ()
 Returns the total number of unique RenderAttrib objects allocated in the world. More...
 
static listAttribs (Ostream out)
 Lists all of the RenderAttribs in the cache to the output stream, one per line. More...
 
static bool validateAttribs ()
 Ensures that the cache is still stored in sorted order. More...
 
- Static Public Member Functions inherited from TypedWritableReferenceCount
static TypedWritableReferenceCount decodeFromBamStream (VectorUchar data, BamReader reader)
 Reads the bytes created by a previous call to encode_to_bam_stream(), and extracts and returns the single object on those bytes. 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 ()
 

Public Attributes

int class_slot
 
LightRampAttrib::LightRampMode mode
 Returns the LightRampAttrib mode. More...
 
- Public Attributes inherited from RenderAttrib
int slot
 
- Public Attributes inherited from TypedObject
TypeHandle type
 Returns the TypeHandle representing this object's type. More...
 
- Public Attributes inherited from ReferenceCount
int ref_count
 The current reference count. More...
 

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;
}

Member Data Documentation

◆ class_slot

int class_slot

◆ mode

Returns the LightRampAttrib mode.