mirror of
https://github.com/PixarAnimationStudios/OpenSubdiv
synced 2024-12-23 00:10:07 +00:00
248 lines
11 KiB
C++
248 lines
11 KiB
C++
//
|
|
// Copyright 2014 DreamWorks Animation LLC.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "Apache License")
|
|
// with the following modification; you may not use this file except in
|
|
// compliance with the Apache License and the following modification to it:
|
|
// Section 6. Trademarks. is deleted and replaced with:
|
|
//
|
|
// 6. Trademarks. This License does not grant permission to use the trade
|
|
// names, trademarks, service marks, or product names of the Licensor
|
|
// and its affiliates, except as required to comply with Section 4(c) of
|
|
// the License and to reproduce the content of the NOTICE file.
|
|
//
|
|
// You may obtain a copy of the Apache License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the Apache License with the above modification is
|
|
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
|
|
// KIND, either express or implied. See the Apache License for the specific
|
|
// language governing permissions and limitations under the Apache License.
|
|
//
|
|
#ifndef OPENSUBDIV3_SDC_CREASE_H
|
|
#define OPENSUBDIV3_SDC_CREASE_H
|
|
|
|
#include "../version.h"
|
|
|
|
#include "../sdc/options.h"
|
|
|
|
namespace OpenSubdiv {
|
|
namespace OPENSUBDIV_VERSION {
|
|
|
|
namespace Sdc {
|
|
|
|
///
|
|
/// \brief Types, constants and utilities related to semi-sharp creasing -- whose implementation
|
|
/// is independent of the subdivision scheme.
|
|
///
|
|
/// Crease is intended to be a light-weight, trivially constructed class that computes
|
|
/// crease-related properties -- typically sharpness values and associated interpolation
|
|
/// weights. An instance of Crease is defined with a set of options that include current
|
|
/// and future variations that will impact computations involving sharpness values.
|
|
///
|
|
/// The Crease methods do not use topological neighborhoods as input. The methods here
|
|
/// rely more on the sharpness values and less on the topology, so we choose to work directly
|
|
/// with the sharpness values. We also follow the trend of using primitive arrays in the
|
|
/// interface to encourage local gathering for re-use.
|
|
///
|
|
/// Note on the need for and use of sharpness values:
|
|
/// In general, mask queries rely on the sharpness values. The common case of a smooth
|
|
/// vertex, when known, avoids the need to inspect them, but unless the rules are well understood,
|
|
/// users will be expected to provided them -- particularly when they expect the mask queries
|
|
/// to do all of the work (just determining if a vertex is smooth will require inspection of
|
|
/// incident edge sharpness).
|
|
/// Mask queries will occasionally require the subdivided sharpness values around the
|
|
/// child vertex. So users will be expected to either provide them up front when known, or to be
|
|
/// gathered on demand. Any implementation of subdivision with creasing cannot avoid subdividing
|
|
/// the sharpness values first, so keeping them available for re-use is a worthwhile consideration.
|
|
///
|
|
|
|
class Crease {
|
|
public:
|
|
//@{
|
|
/// Constants and related queries of sharpness values:
|
|
///
|
|
static float const SHARPNESS_SMOOTH; // = 0.0f, do we really need this?
|
|
static float const SHARPNESS_INFINITE; // = 10.0f;
|
|
|
|
static bool IsSmooth(float sharpness) { return sharpness <= SHARPNESS_SMOOTH; }
|
|
static bool IsSharp(float sharpness) { return sharpness > SHARPNESS_SMOOTH; }
|
|
static bool IsInfinite(float sharpness) { return sharpness >= SHARPNESS_INFINITE; }
|
|
static bool IsSemiSharp(float sharpness) { return (SHARPNESS_SMOOTH < sharpness) && (sharpness < SHARPNESS_INFINITE); }
|
|
//@}
|
|
|
|
///
|
|
/// Enum for the types of subdivision rules applied based on sharpness values (note these
|
|
/// correspond to Hbr's vertex "mask"). The values are assigned to bit positions as it is
|
|
/// useful to use bitwise operations to inspect collections of vertices (i.e. all of the
|
|
/// vertices incident a particular face).
|
|
///
|
|
enum Rule {
|
|
RULE_UNKNOWN = 0,
|
|
RULE_SMOOTH = (1 << 0),
|
|
RULE_DART = (1 << 1),
|
|
RULE_CREASE = (1 << 2),
|
|
RULE_CORNER = (1 << 3)
|
|
};
|
|
|
|
public:
|
|
Crease() : _options() { }
|
|
Crease(Options const& options) : _options(options) { }
|
|
~Crease() { }
|
|
|
|
bool IsUniform() const { return _options.GetCreasingMethod() == Options::CREASE_UNIFORM; }
|
|
|
|
//@{
|
|
/// Optional sharp features:
|
|
/// Since options treat certain topological features as infinitely sharp -- boundaries
|
|
/// or (in future) non-manifold features -- sharpness values should be adjusted before use.
|
|
/// The following methods will adjust (by return) specific values according to the options
|
|
/// applied.
|
|
///
|
|
float SharpenBoundaryEdge(float edgeSharpness) const;
|
|
float SharpenBoundaryVertex(float edgeSharpness) const;
|
|
|
|
// For future consideration
|
|
//float SharpenNonManifoldEdge(float edgeSharpness) const;
|
|
//float SharpenNonManifoldVertex(float edgeSharpness) const;
|
|
//@}
|
|
|
|
//@{
|
|
/// Sharpness subdivision:
|
|
/// The computation of a Uniform subdivided sharpness value is as follows:
|
|
/// - Smooth edges or verts stay Smooth
|
|
/// - Sharp edges or verts stay Sharp
|
|
/// - semi-sharp edges or verts are decremented by 1.0
|
|
/// but for Chaikin (and potentially future non-uniform schemes that improve upon it) the
|
|
/// computation is more involved. In the case of edges in particular, the sharpness of a
|
|
/// child edge is determined by the sharpness in the neighborhood of the end vertex
|
|
/// corresponding to the child. For this reason, an alternative to subdividing sharpness
|
|
/// that computes all child edges around a vertex is given.
|
|
///
|
|
float SubdivideUniformSharpness(float vertexOrEdgeSharpness) const;
|
|
|
|
float SubdivideVertexSharpness(float vertexSharpness) const;
|
|
|
|
float SubdivideEdgeSharpnessAtVertex(float edgeSharpness,
|
|
int incidentEdgeCountAtEndVertex,
|
|
float const* edgeSharpnessAroundEndVertex) const;
|
|
|
|
void SubdivideEdgeSharpnessesAroundVertex(int incidentEdgeCountAtVertex,
|
|
float const* incidentEdgeSharpnessAroundVertex,
|
|
float* childEdgesSharpnessAroundVertex) const;
|
|
//@}
|
|
|
|
//@{
|
|
/// Rule determination:
|
|
/// Mask queries do not require the Rule to be known, it can be determined from
|
|
/// the information provided, but it is generally more efficient when the Rule is known
|
|
/// and provided. In particular, the Smooth case dominates and is known to be applicable
|
|
/// based on the origin of the vertex without inspection of sharpness.
|
|
///
|
|
Rule DetermineVertexVertexRule(float vertexSharpness,
|
|
int incidentEdgeCount,
|
|
float const* incidentEdgeSharpness) const;
|
|
Rule DetermineVertexVertexRule(float vertexSharpness,
|
|
int sharpEdgeCount) const;
|
|
//@}
|
|
|
|
/// \brief Transitional weighting:
|
|
/// When the rules applicable to a parent vertex and its child differ, one or more
|
|
/// sharpness values has "decayed" to zero. Both rules are then applicable and blended
|
|
/// by a weight between 0 and 1 that reflects the transition. Most often this will be
|
|
/// a single sharpness value that decays from within the interval [0,1] to zero -- and
|
|
/// the weight to apply is exactly that sharpness value -- but more than one may decay,
|
|
/// and values > 1 may also decay to 0 in a single step while others within [0,1] may
|
|
/// remain > 0.
|
|
/// So to properly determine a transitional weight, sharpness values for both the
|
|
/// parent and child must be inspected, combined and clamped accordingly.
|
|
///
|
|
float ComputeFractionalWeightAtVertex(float vertexSharpness,
|
|
float childVertexSharpness,
|
|
int incidentEdgeCount,
|
|
float const* incidentEdgeSharpness,
|
|
float const* childEdgesSharpness) const;
|
|
|
|
void GetSharpEdgePairOfCrease(float const * incidentEdgeSharpness,
|
|
int incidentEdgeCount,
|
|
int sharpEdgePair[2]) const;
|
|
|
|
// Would these really help? Maybe only need Rules for the vertex-vertex case...
|
|
//
|
|
// Rule DetermineEdgeVertexRule(float parentEdgeSharpness) const;
|
|
// Rule DetermineEdgeVertexRule(float childEdge1Sharpness, float childEdge2Sharpness) const;
|
|
|
|
protected:
|
|
float decrementSharpness(float sharpness) const;
|
|
|
|
private:
|
|
Options _options;
|
|
};
|
|
|
|
|
|
//
|
|
// Inline declarations:
|
|
//
|
|
inline float
|
|
Crease::SharpenBoundaryEdge(float /* edgeSharpness */) const {
|
|
|
|
//
|
|
// Despite the presence of the BOUNDARY_NONE option, boundary edges are always sharpened.
|
|
// Much of the code relies on sharpness to indicate boundaries to avoid the more complex
|
|
// topological inspection
|
|
//
|
|
return SHARPNESS_INFINITE;
|
|
}
|
|
|
|
inline float
|
|
Crease::SharpenBoundaryVertex(float vertexSharpness) const {
|
|
|
|
return (_options.GetVtxBoundaryInterpolation() == Options::VTX_BOUNDARY_EDGE_AND_CORNER) ?
|
|
SHARPNESS_INFINITE : vertexSharpness;
|
|
}
|
|
|
|
inline float
|
|
Crease::decrementSharpness(float sharpness) const {
|
|
|
|
if (IsSmooth(sharpness)) return Crease::SHARPNESS_SMOOTH; // redundant but most common
|
|
if (IsInfinite(sharpness)) return Crease::SHARPNESS_INFINITE;
|
|
if (sharpness > 1.0f) return (sharpness - 1.0f);
|
|
return Crease::SHARPNESS_SMOOTH;
|
|
}
|
|
|
|
inline float
|
|
Crease::SubdivideUniformSharpness(float vertexOrEdgeSharpness) const {
|
|
|
|
return decrementSharpness(vertexOrEdgeSharpness);
|
|
}
|
|
|
|
inline float
|
|
Crease::SubdivideVertexSharpness(float vertexSharpness) const {
|
|
|
|
return decrementSharpness(vertexSharpness);
|
|
}
|
|
|
|
inline void
|
|
Crease::GetSharpEdgePairOfCrease(float const * incidentEdgeSharpness, int incidentEdgeCount,
|
|
int sharpEdgePair[2]) const {
|
|
|
|
// Only to be called when a crease is present at a vertex -- exactly two sharp
|
|
// edges are expected here:
|
|
//
|
|
sharpEdgePair[0] = 0;
|
|
while (IsSmooth(incidentEdgeSharpness[sharpEdgePair[0]])) ++ sharpEdgePair[0];
|
|
|
|
sharpEdgePair[1] = incidentEdgeCount - 1;
|
|
while (IsSmooth(incidentEdgeSharpness[sharpEdgePair[1]])) -- sharpEdgePair[1];
|
|
}
|
|
|
|
} // end namespace sdc
|
|
|
|
} // end namespace OPENSUBDIV_VERSION
|
|
using namespace OPENSUBDIV_VERSION;
|
|
} // end namespace OpenSubdiv
|
|
|
|
#endif /* OPENSUBDIV3_SDC_CREASE_H */
|