pfTexLOD(3pf) OpenGL Performer 3.2.2 libpr C Reference Pages pfTexLOD(3pf)NAME
pfNewTLOD, pfGetTLODClassType, pfTLODRange, pfGetTLODRange, pfTLODBias,
pfGetTLODBias, pfApplyTLOD, pfGetCurTLOD - A texture level of detail
control structure.
FUNCTION SPECIFICATION
#include <Performer/pr.h>
pfTexLOD * pfNewTLOD(void *arena);
pfType * pfGetTLODClassType(void);
void pfTLODRange(pfTexLOD* tlod, float min, float max);
void pfGetTLODRange(pfTexLOD* tlod, float *min, float *max);
void pfTLODBias(pfTexLOD* tlod, float biasS, float biasT,
float biasR);
void pfGetTLODBias(pfTexLOD* tlod, float *biasS, float *biasT,
float *biasR);
void pfApplyTLOD(pfTexLOD *tlod);
pfTexLOD * pfGetCurTLOD(void);
PARENT CLASS FUNCTIONS
The OpenGL Performer class pfTexLOD is derived from the parent class
pfObject, so each of these member functions of class pfObject are also
directly usable with objects of class pfTexLOD. Casting an object of
class pfTexLOD to an object of class pfObject is taken care of
automatically. This is also true for casts to objects of ancestor
classes of class pfObject.
void pfUserDataSlot(pfObject *obj, int slot, void *data);
void pfUserData(pfObject *obj, void *data);
void* pfGetUserDataSlot(pfObject *obj, int slot);
void* pfGetUserData(pfObject *obj);
int pfGetNumUserData(pfObject *obj);
int pfGetNamedUserDataSlot(const char *name);
const char* pfGetUserDataSlotName(int slot);
int pfGetNumNamedUserDataSlots(void);
int pfGetGLHandle(pfObject *obj);
int pfDeleteGLHandle(pfObject *obj);
Since the class pfObject is itself derived from the parent class
pfMemory, objects of class pfTexLOD can also be used with these functions
designed for objects of class pfMemory.
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pfTexLOD(3pf) OpenGL Performer 3.2.2 libpr C Reference Pages pfTexLOD(3pf)
pfType * pfGetType(const void *ptr);
int pfIsOfType(const void *ptr, pfType *type);
int pfIsExactType(const void *ptr, pfType *type);
const char * pfGetTypeName(const void *ptr);
int pfRef(void *ptr);
int pfUnref(void *ptr);
int pfUnrefDelete(void *ptr);
int pfUnrefGetRef(void *ptr);
int pfGetRef(const void *ptr);
int pfCopy(void *dst, void *src);
int pfDelete(void *ptr);
int pfIsFluxed(void *ptr);
int pfCompare(const void *ptr1, const void *ptr2);
void pfPrint(const void *ptr, uint which, uint verbose,
FILE *file);
void * pfGetArena(void *ptr);
PARAMETERS
tlod identifies a pfTexLOD.
DESCRIPTIONpfNewTLOD creates and returns a handle to a pfTexLOD. arena specifies a
malloc arena out of which the pfTexLOD is allocated or NULL for
allocation off the process heap. pfTexLODs can be deleted with pfDelete.
Texture LOD control is only supported under OpenGL operation that the
texture_lod extensions. See the or OpenGL glIntro(3g) for a list of
supported extensions and their descriptions.
pfGetTLODClassType returns the pfType* for the class pfTexLOD. The
pfType* returned by pfGetTLODClassType is the same as the pfType*
returned by invoking pfGetType on any instance of class pfTexLOD.
Because OpenGL Performer allows subclassing of built-in types, when
decisions are made based on the type of an object, it is usually better
to use pfIsOfType to test if an object is of a type derived from a
Performer type rather than to test for strict equality of the pfType*'s.
pfApplyTLOD makes tlod the texture LOD control parameters. When texturing
is enabled, the texture LOD parameters set tlod will be applied to the
current texture. Texture LOD parameters set directly on a pfTexture will
take priority over those set in any pfTexLOD. Only one pfTexLOD may be
active at a time although many may be defined. Modifications to tlod,
such as changing the range, will not have effect until pfApplyTLOD is
called with tlod.
The texture LOD state element is identified by the PFSTATE_TEXLOD token.
Use this token with pfGStateAttr to set a texture LOD configuration on a
pfGeoState and with pfOverride to override subsequent texture LOD.
A pfTexLOD will only take affect if texture LOD control is currently
enabled. Texture LOD control can be enabled directly via pfEnable using
the PFEN_TEXLOD token and enable on a pfGeoState with the
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pfTexLOD(3pf) OpenGL Performer 3.2.2 libpr C Reference Pages pfTexLOD(3pf)
PFSTATE_ENTEXLOD token and the boolean value to pfGStateMode.
pfTLODRange will set the current texture lod range to use only levels min
through max where min is the highest resolution level and max is the
lowest resolution MIPmap. This can be used in conjunction with texture
paging to limit access of level of a texture that have currently been
loaded. Because the min/max limits can be floating point values, new
levels can be smoothly blended in when they become available to avoid a
popping. LOD range can also be used for more efficient use of texture
memory where allow different geometry textured with different images to
share a texture where a near object references the high resolution levels
and a object use the low resolution levels. pfGetTLODRange will return
the LOD range. Either of the arguments min,max may be NULL in which case
it will be ignored.
pfTLODBias will set s, t, and r bias values for the texture level of
detail computation to be biasS, biasT, and biasR, respectively. These
bias values can be used to compensate for asymmetric minification of a
MIPmapped texture; to force blurring of a texture to simulate motion blur
and depth of field, or to force a texture to be sharper. This
functionality uses the texture_lod_bias extension of OpenGL and the exact
use of these bias values is explained in the glIntro man page.
pfGetTLODBias will return the LOD bias. Any of the arguments
biasS,biasT,biasR may be NULL in which case it will be ignored.
pfGetCurTLOD will return the most recently applied pfTexLOD as applied
through a pfGeoState, or pfApplyTLOD.
SEE ALSO
pfDelete, pfDispList, pfEnable, pfGeoState, pfObject, pfState, pfTexture,
glIntro, glTexImage2D.
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