441 lines
23 KiB
Plaintext
441 lines
23 KiB
Plaintext
// Copyright (c) 2015-2016 The Khronos Group Inc.
|
|
// Copyright notice at https://www.khronos.org/registry/speccopyright.html
|
|
|
|
[[tessellation]]
|
|
= Tessellation
|
|
|
|
Tessellation involves three pipeline stages. First, a
|
|
<<shaders-tessellation-control,tessellation control shader>> transforms
|
|
control points of a patch and can: produce per-patch data. Second, a
|
|
fixed-function tessellator generates multiple primitives corresponding to a
|
|
tessellation of the patch in (u,v) or (u,v,w) parameter space. Third, a
|
|
<<shaders-tessellation-evaluation,tessellation evaluation shader>>
|
|
transforms the vertices of the tessellated patch, for example to compute
|
|
their positions and attributes as part of the tessellated surface. The
|
|
tessellator is enabled when the pipeline contains both a tessellation
|
|
control shader and a tessellation evaluation shader.
|
|
|
|
|
|
== Tessellator
|
|
|
|
If a pipeline includes both tessellation shaders (control and evaluation),
|
|
the tessellator consumes each input patch (after vertex shading) and
|
|
produces a new set of independent primitives (points, lines, or triangles).
|
|
These primitives are logically produced by subdividing a geometric primitive
|
|
(rectangle or triangle) according to the per-patch tessellation levels
|
|
written by the tessellation control shader. This subdivision is performed in
|
|
an implementation-dependent manner. If no tessellation shaders are present
|
|
in the pipeline, the tessellator is disabled and incoming primitives are
|
|
passed through without modification.
|
|
|
|
The type of subdivision performed by the tessellator is
|
|
specified by an code:OpExecutionMode instruction in the tessellation
|
|
evaluation or tessellation control shader using one of execution modes
|
|
code:Triangles, code:Quads, and code:IsoLines. Other
|
|
tessellation-related execution modes can: also be specified in either the
|
|
tessellation control or tessellation evaluation shaders, and if they are
|
|
specified in both then the modes must: be the same.
|
|
|
|
Tessellation execution modes include:
|
|
|
|
* code:Triangles, code:Quads, and code:IsoLines. These control the type of
|
|
subdivision and topology of the output primitives. One mode must: be set
|
|
in at least one of the tessellation shader stages.
|
|
* code:VertexOrderCw and code:VertexOrderCcw. These control the
|
|
orientation of triangles generated by the tessellator. One mode must: be
|
|
set in at least one of the tessellation shader stages.
|
|
* code:PointMode. Controls generation of points rather than triangles or
|
|
lines. This functionality defaults to disabled, and is enabled if either
|
|
shader stage includes the execution mode.
|
|
* code:SpacingEqual, code:SpacingFractionalEven, and
|
|
code:SpacingFractionalOdd. Controls the spacing of segments on the edges
|
|
of tessellated primitives. One mode must: be set in at least one of the
|
|
tessellation shader stages.
|
|
* code:OutputVertices. Controls the size of the output patch of the
|
|
tessellation control shader. One value must: be set in at least one of
|
|
the tessellation shader stages.
|
|
|
|
For triangles, the tessellator subdivides a triangle primitive into
|
|
smaller triangles. For quads, the tessellator subdivides a rectangle
|
|
primitive into smaller triangles. For isolines, the tessellator
|
|
subdivides a rectangle primitive into a collection of line segments arranged
|
|
in strips stretching across the rectangle in the latexmath:[$u$] dimension
|
|
(i.e. the coordinates in code:TessCoord are of the form (0,x) through (1,x)
|
|
for all tessellation evaluation shader invocations that share a line).
|
|
|
|
Each vertex produced by the tessellator has an associated (u,v,w) or (u,v)
|
|
position in a normalized parameter space, with parameter values in the
|
|
latexmath:[$[0,1\]$], as illustrated in figure
|
|
<<img-tessellation-topology>>.
|
|
|
|
[[img-tessellation-topology,Domain parameterization for tessellation primitive modes]]
|
|
.Domain parameterization for tessellation primitive modes
|
|
image:images/tessparam.{svgpdf}["Domain parameterization for tessellation primitive modes",{fullimagewidth}]
|
|
|
|
For triangles, the vertex's position is a barycentric coordinate (u,v,w),
|
|
where u + v + w = 1.0, and indicates the relative influence of the three
|
|
vertices of the triangle on the position of the vertex. For quads and
|
|
isolines, the position is a (u,v) coordinate indicating the relative
|
|
horizontal and vertical position of the vertex relative to the subdivided
|
|
rectangle. The subdivision process is explained in more detail in subsequent
|
|
sections.
|
|
|
|
|
|
== Tessellator Patch Discard
|
|
|
|
A patch is discarded by the tessellator if any
|
|
relevant outer tessellation level is less than or equal to zero.
|
|
|
|
Patches will also be discarded if any relevant outer tessellation level
|
|
corresponds to a floating-point NaN (not a number) in implementations
|
|
supporting NaN.
|
|
|
|
No new primitives are generated and the tessellation evaluation shader is
|
|
not executed for patches that are discarded. For code:Quads, all four outer
|
|
levels are relevant. For code:Triangles and code:IsoLines, only the first
|
|
three or two outer levels, respectively, are relevant. Negative inner levels
|
|
will not cause a patch to be discarded; they will be clamped as described
|
|
below.
|
|
|
|
|
|
[[tessellation-tessellator-spacing]]
|
|
== Tessellator Spacing
|
|
|
|
Each of the tessellation levels is used to determine the number and
|
|
spacing of segments used to subdivide a corresponding edge. The method
|
|
used to derive the number and spacing of segments is specified by an
|
|
code:OpExecutionMode in the tessellation control or tessellation evaluation
|
|
shader using one of the identifiers code:SpacingEqual,
|
|
code:SpacingFractionalEven, or code:SpacingFractionalOdd.
|
|
|
|
If code:SpacingEqual is used, the floating-point tessellation level is first
|
|
clamped to latexmath:[$[1,\mathit{maxLevel}\]$], where
|
|
latexmath:[$\mathit{maxLevel}$] is the implementation-dependent maximum
|
|
tessellation level
|
|
(sname:VkPhysicalDeviceLimits::pname:maxTessellationGenerationLevel). The
|
|
result is rounded up to the nearest integer latexmath:[$n$], and the
|
|
corresponding edge is divided into latexmath:[$n$] segments of equal length
|
|
in (u,v) space.
|
|
|
|
If code:SpacingFractionalEven is used, the tessellation level is first
|
|
clamped to latexmath:[$[2,\mathit{maxLevel}\]$] and then rounded up to the
|
|
nearest even integer latexmath:[$n$]. If code:SpacingFractionalOdd is used,
|
|
the tessellation level is clamped to latexmath:[$[1,\mathit{maxLevel}-1\]$]
|
|
and then rounded up to the nearest odd integer latexmath:[$n$]. If
|
|
latexmath:[$n$] is one, the edge will not be subdivided. Otherwise, the
|
|
corresponding edge will be divided into latexmath:[$n-2$] segments of equal
|
|
length, and two additional segments of equal length that are typically
|
|
shorter than the other segments. The length of the two additional segments
|
|
relative to the others will decrease monotonically with the value of
|
|
latexmath:[$n-f$], where latexmath:[$f$] is the clamped floating-point
|
|
tessellation level. When latexmath:[$n-f$] is zero, the additional segments
|
|
will have equal length to the other segments. As latexmath:[$n-f$]
|
|
approaches 2.0, the relative length of the additional segments approaches
|
|
zero. The two additional segments should: be placed symmetrically on
|
|
opposite sides of the subdivided edge. The relative location of these two
|
|
segments is implementation-dependent, but must: be identical for any pair of
|
|
subdivided edges with identical values of <f>.
|
|
|
|
When the tessellator produces triangles (in the code:Triangles or
|
|
code:Quads modes), the orientation of all triangles is specified with
|
|
an code:OpExecutionMode of code:VertexOrderCw or code:VertexOrderCcw in the
|
|
tessellation control or tessellation evaluation shaders. If the order is
|
|
code:VertexOrderCw, the vertices of all generated triangles will have a
|
|
clockwise ordering in (u,v) or (u,v,w) space. If the order is
|
|
code:VertexOrderCcw, the vertices will be generated with counter-clockwise
|
|
order.
|
|
|
|
The vertices of a triangle are defined to be in counter-clockwise ordering
|
|
of the value
|
|
[latexmath]
|
|
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
\[
|
|
a = u_0 v_1 - u_1 v_0 + u_1 v_2 - u_2 v_1 + u_2 v_0 - u_0 v_2
|
|
\]
|
|
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
is positive, where latexmath:[$u_i$] and latexmath:[$v_i$] are the
|
|
latexmath:[$u$] and latexmath:[$v$] coordinates in normalized parameter
|
|
space of the latexmath:[$i$]th vertex of the triangle. If the value
|
|
latexmath:[$a$] is negative, the vertices of the triangle are defined to be
|
|
in clockwise ordering.
|
|
|
|
[NOTE]
|
|
.Note
|
|
====
|
|
The value latexmath:[$a$] is proportional (with a positive factor) to the
|
|
signed area of the triangle.
|
|
|
|
In code:Triangles mode, even though the vertex coordinates have a
|
|
latexmath:[$w$] value, it does not participate directly in the computation
|
|
of latexmath:[$a$], being an affine combination of latexmath:[$u$] and
|
|
latexmath:[$v$].
|
|
====
|
|
|
|
For all primitive modes, the tessellator is capable of generating points
|
|
instead of lines or triangles. If the tessellation control or tessellation
|
|
evaluation shader specifies the code:OpExecutionMode code:PointMode, the
|
|
primitive generator will generate one point for each distinct vertex
|
|
produced by tessellation. Otherwise, the tessellator will produce a
|
|
collection of line segments or triangles according to the primitive mode.
|
|
When tessellating triangles or quads in point mode with fractional odd
|
|
spacing, the tessellator may: produce _interior vertices_ that are
|
|
positioned on the edge of the patch if an inner tessellation level is less
|
|
than or equal to one. Such vertices are considered distinct from vertices
|
|
produced by subdividing the outer edge of the patch, even if there are pairs
|
|
of vertices with identical coordinates.
|
|
|
|
The points, lines, or triangles produced by the tessellator
|
|
are passed to subsequent pipeline stages in an
|
|
implementation-dependent order.
|
|
|
|
|
|
[[tessellation-triangle-tessellation]]
|
|
== Triangle Tessellation
|
|
|
|
If the tessellation primitive mode is code:Triangles, an equilateral
|
|
triangle is subdivided into a collection of triangles covering the area of
|
|
the original triangle. First, the original triangle is subdivided into a
|
|
collection of concentric equilateral triangles. The edges of each of these
|
|
triangles are subdivided, and the area between each triangle pair is filled
|
|
by triangles produced by joining the vertices on the subdivided edges. The
|
|
number of concentric triangles and the number of subdivisions along each
|
|
triangle except the outermost is derived from the first inner tessellation
|
|
level. The edges of the outermost triangle are subdivided independently,
|
|
using the first, second, and third outer tessellation levels to control the
|
|
number of subdivisions of the latexmath:[$u=0$] (left), latexmath:[$v=0$]
|
|
(bottom), and latexmath:[$w=0$] (right) edges, respectively. The second
|
|
inner tessellation level and the fourth outer tessellation level have no
|
|
effect in this mode.
|
|
|
|
If the first inner tessellation level and all three outer tessellation
|
|
levels are exactly one after clamping and rounding, only a single triangle
|
|
with (u,v,w) coordinates of (0,0,1), (1,0,0), and (0,1,0) is generated.
|
|
If the inner tessellation level is one and any of the outer tessellation
|
|
levels is greater than one, the inner tessellation level is treated as
|
|
though it were originally specified as latexmath:[$1+\epsilon$] and will
|
|
result in a two- or three-segment subdivision depending on the tessellation
|
|
spacing. When used with fractional odd spacing, the three-segment
|
|
subdivision may: produce _inner vertices_ positioned on the edge of the
|
|
triangle.
|
|
|
|
If any tessellation level is greater than one, tessellation begins by
|
|
producing a set of concentric inner triangles and subdividing their edges.
|
|
First, the three outer edges are temporarily subdivided using the clamped
|
|
and rounded first inner tessellation level and the specified tessellation
|
|
spacing, generating latexmath:[$n$] segments. For the outermost inner
|
|
triangle, the inner triangle is degenerate -- a single point at the center
|
|
of the triangle -- if latexmath:[$n$] is two. Otherwise, for each corner of
|
|
the outer triangle, an inner triangle corner is produced at the intersection
|
|
of two lines extended perpendicular to the corner's two adjacent edges
|
|
running through the vertex of the subdivided outer edge nearest that corner.
|
|
If latexmath:[$n$] is three, the edges of the inner triangle are not
|
|
subdivided and is the final triangle in the set of concentric triangles.
|
|
Otherwise, each edge of the inner triangle is divided into latexmath:[$n-2$]
|
|
segments, with the latexmath:[$n-1$] vertices of this subdivision produced
|
|
by intersecting the inner edge with lines perpendicular to the edge running
|
|
through the latexmath:[$n-1$] innermost vertices of the subdivision of the
|
|
outer edge. Once the outermost inner triangle is subdivided, the previous
|
|
subdivision process repeats itself, using the generated triangle as an outer
|
|
triangle. This subdivision process is illustrated in <<img-innertri,Inner
|
|
Triangle Tessellation>>.
|
|
|
|
[[img-innertri,Inner Triangle Tessellation]]
|
|
.Inner Triangle Tessellation
|
|
image:images/innertri.{svgpdf}["Inner Triangle Tessellation",{fullimagewidth}]
|
|
|
|
// TODO: Add caption:
|
|
// Inner triangle tessellation with inner tessellation
|
|
// levels of (a) five and (b) four, respectively (not to scale). Solid
|
|
// black circles depict vertices along the edges of the concentric
|
|
// triangles. The edges of inner triangles are subdivided by intersecting
|
|
// the edge with segments perpendicular to the edge passing through each
|
|
// inner vertex of the subdivided outer edge. Dotted lines depict edges
|
|
// connecting corresponding vertices on the inner and outer triangle
|
|
// edges.
|
|
|
|
Once all the concentric triangles are produced and their edges are
|
|
subdivided, the area between each pair of adjacent inner triangles is
|
|
filled completely with a set of non-overlapping triangles. In this
|
|
subdivision, two of the three vertices of each triangle are taken from
|
|
adjacent vertices on a subdivided edge of one triangle; the third is one
|
|
of the vertices on the corresponding edge of the other triangle. If the
|
|
innermost triangle is degenerate (i.e., a point), the triangle containing
|
|
it is subdivided into six triangles by connecting each of the six vertices
|
|
on that triangle with the center point. If the innermost triangle is not
|
|
degenerate, that triangle is added to the set of generated triangles
|
|
as-is.
|
|
|
|
After the area corresponding to any inner triangles is filled, the
|
|
tessellator generates triangles to cover the area between the outermost
|
|
triangle and the outermost inner triangle. To do this, the temporary
|
|
subdivision of the outer triangle edge above is discarded. Instead, the
|
|
latexmath:[$u=0$], latexmath:[$v=0$], and latexmath:[$w=0$] edges are
|
|
subdivided according to the first, second, and third outer tessellation
|
|
levels, respectively, and the tessellation spacing. The original subdivision
|
|
of the first inner triangle is retained. The area between the outer and
|
|
first inner triangles is completely filled by non-overlapping triangles as
|
|
described above. If the first (and only) inner triangle is degenerate, a set
|
|
of triangles is produced by connecting each vertex on the outer triangle
|
|
edges with the center point.
|
|
|
|
After all triangles are generated, each vertex in the subdivided triangle
|
|
is assigned a barycentric (u,v,w) coordinate based on its location
|
|
relative to the three vertices of the outer triangle.
|
|
|
|
The algorithm used to subdivide the triangular domain in (u,v,w) space into
|
|
individual triangles is implementation-dependent. However, the set of
|
|
triangles produced will completely cover the domain, and no portion of the
|
|
domain will be covered by multiple triangles. The order in which the
|
|
generated triangles passed to subsequent pipeline stages and the order of
|
|
the vertices in those triangles are both implementation-dependent. However,
|
|
when depicted in a manner similar to <<img-innertri,Inner Triangle
|
|
Tessellation>>, the order of the vertices in the generated triangles will be
|
|
either all clockwise or all counter-clockwise, according to the vertex order
|
|
layout declaration.
|
|
|
|
|
|
[[tessellation-quad-tessellation]]
|
|
== Quad Tessellation
|
|
|
|
If the tessellation primitive mode is code:Quads, a rectangle is subdivided
|
|
into a collection of triangles covering the area of the original rectangle.
|
|
First, the original rectangle is subdivided into a regular mesh of
|
|
rectangles, where the number of rectangles along the latexmath:[$u=0$] and
|
|
latexmath:[$u=1$] (vertical) and latexmath:[$v=0$] and latexmath:[$v=1$]
|
|
(horizontal) edges are derived from the first and second inner tessellation
|
|
levels, respectively. All rectangles, except those adjacent to one of the
|
|
outer rectangle edges, are decomposed into triangle pairs. The outermost
|
|
rectangle edges are subdivided independently, using the first, second,
|
|
third, and fourth outer tessellation levels to control the number of
|
|
subdivisions of the latexmath:[$u=0$] (left), latexmath:[$v=0$] (bottom),
|
|
latexmath:[$u=1$] (right), and latexmath:[$v=1$] (top) edges, respectively.
|
|
The area between the inner rectangles of the mesh and the outer rectangle
|
|
edges are filled by triangles produced by joining the vertices on the
|
|
subdivided outer edges to the vertices on the edge of the inner rectangle
|
|
mesh.
|
|
|
|
If both clamped inner tessellation levels and all four clamped outer
|
|
tessellation levels are exactly one, only a single triangle pair covering
|
|
the outer rectangle is generated. Otherwise, if either clamped inner
|
|
tessellation level is one, that tessellation level is treated as though it
|
|
were originally specified as latexmath:[$1+\epsilon$] and will result in a
|
|
two- or three-segment subdivision depending on the tessellation spacing.
|
|
When used with fractional odd spacing, the three-segment subdivision may:
|
|
produce _inner vertices_ positioned on the edge of the rectangle.
|
|
|
|
If any tessellation level is greater than one, tessellation begins by
|
|
subdividing the latexmath:[$u=0$] and latexmath:[$u=1$] edges of the outer
|
|
rectangle into latexmath:[$m$] segments using the clamped and rounded first
|
|
inner tessellation level and the tessellation spacing. The latexmath:[$v=0$]
|
|
and latexmath:[$v=1$] edges are subdivided into latexmath:[$n$] segments
|
|
using the second inner tessellation level. Each vertex on the
|
|
latexmath:[$u=0$] and latexmath:[$v=0$] edges are joined with the
|
|
corresponding vertex on the latexmath:[$u=1$] and latexmath:[$v=1$] edges to
|
|
produce a set of vertical and horizontal lines that divide the rectangle
|
|
into a grid of smaller rectangles. The primitive generator emits a pair of
|
|
non-overlapping triangles covering each such rectangle not adjacent to an
|
|
edge of the outer rectangle. The boundary of the region covered by these
|
|
triangles forms an inner rectangle, the edges of which are subdivided by the
|
|
grid vertices that lie on the edge. If either latexmath:[$m$] or
|
|
latexmath:[$n$] is two, the inner rectangle is degenerate, and one or both
|
|
of the rectangle's _edges_ consist of a single point. This subdivision is
|
|
illustrated in Figure <<img-innerquad,Inner Quad Tessellation>>.
|
|
|
|
[[img-innerquad,Inner Quad Tessellation]]
|
|
.Inner Quad Tessellation
|
|
image:images/innerquad.{svgpdf}["Inner Quad Tessellation",{fullimagewidth}]
|
|
|
|
// TODO: Add caption:
|
|
// Inner quad tessellation with inner tessellation
|
|
// levels of
|
|
// (a) $(4,2)$ and (b) $(7,4)$, respectively. Gray regions on the
|
|
// bottom figure
|
|
// depict the 10 inner rectangles, each of which will be subdivided
|
|
// into two triangles.
|
|
// Solid black circles depict vertices on the boundary of the outer and
|
|
// inner rectangles,
|
|
// where the inner rectangle on the top figure
|
|
// is degenerate (a single line segment). Dotted lines depict the
|
|
// horizontal and vertical edges connecting corresponding
|
|
// vertices on the inner and outer rectangle edges.
|
|
|
|
After the area corresponding to the inner rectangle is filled, the
|
|
tessellator must: produce triangles to cover the area between the inner and
|
|
outer rectangles. To do this, the subdivision of the outer rectangle edge
|
|
above is discarded. Instead, the latexmath:[$u=0$], latexmath:[$v=0$],
|
|
latexmath:[$u=1$], and latexmath:[$v=1$] edges are subdivided according to
|
|
the first, second, third, and fourth outer tessellation levels,
|
|
respectively, and the tessellation spacing. The original subdivision of the
|
|
inner rectangle is retained. The area between the outer and inner rectangles
|
|
is completely filled by non-overlapping triangles. Two of the three vertices
|
|
of each triangle are adjacent vertices on a subdivided edge of one
|
|
rectangle; the third is one of the vertices on the corresponding edge of the
|
|
other triangle. If either edge of the innermost rectangle is degenerate, the
|
|
area near the corresponding outer edges is filled by connecting each vertex
|
|
on the outer edge with the single vertex making up the _inner edge_.
|
|
|
|
The algorithm used to subdivide the rectangular domain in (u,v) space into
|
|
individual triangles is implementation-dependent. However, the set of
|
|
triangles produced will completely cover the domain, and no portion of the
|
|
domain will be covered by multiple triangles. The order in which the
|
|
generated triangles passed to subsequent pipeline stages and the order of
|
|
the vertices in those triangles are both implementation-dependent.
|
|
However, when depicted in a manner similar to <<img-innerquad,Inner Quad
|
|
Tessellation>>, the order of the vertices in the generated triangles will be
|
|
either all clockwise or all counter-clockwise, according to the vertex order
|
|
layout declaration.
|
|
|
|
|
|
[[tessellation-isoline-tessellation]]
|
|
== Isoline Tessellation
|
|
|
|
If the tessellation primitive mode is code:IsoLines, a set of independent
|
|
horizontal line segments is drawn. The segments are arranged into
|
|
connected strips called _isolines_, where the vertices of each isoline
|
|
have a constant v coordinate and u coordinates covering the full range
|
|
[0,1]. The number of isolines generated is derived from the first outer
|
|
tessellation level; the number of segments in each isoline is derived from
|
|
the second outer tessellation level. Both inner tessellation levels and
|
|
the third and fourth outer tessellation levels have no effect in this
|
|
mode.
|
|
|
|
As with quad tessellation above, isoline tessellation begins with a
|
|
rectangle. The latexmath:[$u=0$] and latexmath:[$u=1$] edges of the
|
|
rectangle are subdivided according to the first outer tessellation level.
|
|
For the purposes of this subdivision, the tessellation spacing mode is
|
|
ignored and treated as equal_spacing. An isoline is drawn connecting each
|
|
vertex on the latexmath:[$u=0$] rectangle edge to the corresponding vertex
|
|
on the latexmath:[$u=1$] rectangle edge, except that no line is drawn
|
|
between (0,1) and (1,1). If the number of isolines on the subdivided
|
|
latexmath:[$u=0$] and latexmath:[$u=1$] edges is latexmath:[$n$], this
|
|
process will result in latexmath:[$n$] equally spaced lines with constant v
|
|
coordinates of 0, latexmath:[$\frac{1}{n}, \frac{2}{n}, \ldots,
|
|
\frac{n-1}{n}$].
|
|
|
|
Each of the latexmath:[$n$] isolines is then subdivided according to the
|
|
second outer tessellation level and the tessellation spacing, resulting in
|
|
latexmath:[$m$] line segments. Each segment of each line is emitted by the
|
|
tessellator.
|
|
|
|
The order in which the generated line segments are passed to subsequent
|
|
pipeline stages and the order of the vertices in each generated line
|
|
segment are both implementation-dependent.
|
|
|
|
|
|
== Tessellation Pipeline State
|
|
|
|
The pname:pTessellationState member of slink:VkGraphicsPipelineCreateInfo is
|
|
of type sname:VkPipelineTessellationStateCreateInfo:
|
|
|
|
include::../structs/VkPipelineTessellationStateCreateInfo.txt[]
|
|
|
|
The members of the sname:VkPipelineTessellationStateCreateInfo structure are
|
|
as follows:
|
|
|
|
* pname:sType is the type of this structure.
|
|
* pname:pNext is `NULL` or a pointer to an extension-specific structure.
|
|
* pname:flags is reserved for future use.
|
|
* pname:patchControlPoints number of control points per patch.
|
|
|
|
include::../validity/structs/VkPipelineTessellationStateCreateInfo.txt[]
|