oCOSMO Cosmo 3DTM Manual

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csGeoSet Attributes

21

For example, a single color can be speciﬁed for the entire collection of primitives, for

individual primitives, or per vertex. One set of coordinates, on the other hand, cannot be

speciﬁed for the entire collection of primitives, cannot be speciﬁed for individual

primitives, but must be speciﬁed per vertex. It does not make sense for all of the

primitives in a collection to have the same coordinates, nor does it make sense for all

vertices in each primitive to have the same coordinates. Each vertex must have its own

coordinates.

Each level of speciﬁcity is called a different binding, for example, an attribute that is

speciﬁed for an entire collection of primitives is said to have an OVERALL binding. A

binding tells you how many primitives in a csGeoSet object an attribute applies to.

Table 2-3 shows the different possible bindings.

All attributes in a csGeoSet collection must share the same set of attribute bindings, for

example, you cannot specify colors-per-vertex for some primitives and

colors-per-primitive for others in the same csGeoSet object, the color binding must be the

same. You can, however, have, for example, color-per-vertex and overall normal

bindings in the same csGeoSet.

Setting Attribute Bindings

Three set...() methods in csGeoSet specify the attribute bindings for a csGeoSet object:

void setNormalBind(NormalBindEnum normalBind);

void setColorBind(ColorBindEnum colorBind);

void setTexCoordBind(TexCoordBindEnum texCoordBind);

There is a corresponding set of get...() methods that retrieve the attribute bindings for the

normals, colors, and texture coordinates, respectively.

Table 2-3 Attribute Bindings

OFF OVERALL PER_PRIMITIVE PER_VERTEX

colors yes yes yes yes

normals yes yes yes yes

texture coordinates yes no no yes

coordinates no no no yes