Graphics Reference
In-Depth Information
Figure 3.6. A number of vertices to be used to create a variety of primitive types.
but it can only represent a connected list of lines. The input assembler produces the first
line from the first two vertices in the vertex stream. Every vertex after the first two defines
a new line, where the other vertex of the line is the previous vertex in the stream. This pro-
vides a more dense representation of vertices in situations where the lines to be drawn are
connected end to end. Both of these primitive topologies are shown in Figure 3.7.
Triangle primitives. The standard triangle primitive topologies follow the same para-
digm as their line primitive counterparts. The triangle list topology creates a triangle primi-
tive from every three vertices in the vertex stream. The triangle strip creates a triangle
primitive out of the first three vertices in the stream, then a new triangle primitive is created
for every subsequent vertex, using the prior two vertices in the stream to define the remain-
ing portion of the triangle. As with the line strip primitives, the triangle strip primitive
topology can only represent connected "strips" of triangles. These primitive topologies and
their ordering are shown in Figure 3.8.
Figure 3.7, Line list and line strip primitives created from our input vertices.
Search WWH ::




Custom Search