Ptex: PtexTriangleFilter.cpp Source File

Ptex

PtexTriangleFilter.cpp
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35
36#include "PtexPlatform.h"
37#include <cmath>
38#include <assert.h>
39
40#include "PtexTriangleFilter.h"
41#include "PtexTriangleKernel.h"
42#include "PtexUtils.h"
43
44namespace {
45 inline float squared(float x) { return x*x; }
46}
47
48 PTEX_NAMESPACE_BEGIN
49
50 void PtexTriangleFilter::eval(float* result, int firstChan, int nChannels,
51 int faceid, float u, float v,
52 float uw1, float vw1, float uw2, float vw2,
53 float width, float blur)
54{
55 // init
56 if (!_tx || nChannels <= 0) return;
57 if (faceid < 0 || faceid >= _tx->numFaces()) return;
58 _ntxchan = _tx->numChannels();
59 _dt = _tx->dataType();
60 _firstChanOffset = firstChan*DataSize(_dt);
61 _nchan = std::min(nChannels, _ntxchan-firstChan);
62
63 // get face info
64 const FaceInfo& f = _tx->getFaceInfo(faceid);
65
66 // if neighborhood is constant, just return constant value of face
67 if (f.isNeighborhoodConstant()) {
68 char* d = (char*) _tx->getConstantData(faceid) + _firstChanOffset;
69 Ptex::ConvertToFloat(result, d, _dt, _nchan);
70 return;
71 }
72
73 // clamp u and v
74 u = std::clamp(u, 0.0f, 1.0f);
75 v = std::clamp(v, 0.0f, 1.0f);
76
77 // build kernel
78 PtexTriangleKernel k;
79 buildKernel(k, u, v, uw1, vw1, uw2, vw2, width, blur, f.res);
80
81 // accumulate the weight as we apply
82 _weight = 0;
83
84 // allocate temporary result
85 _result = (float*) alloca(sizeof(float)*_nchan);
86 memset(_result, 0, sizeof(float)*_nchan);
87
88 // apply to faces
89 splitAndApply(k, faceid, f);
90
91 // normalize (both for data type and cumulative kernel weight applied)
92 // and output result
93 float scale = 1.0f / (_weight * OneValue(_dt));
94 for (int i = 0; i < _nchan; i++) result[i] = float(_result[i] * scale);
95
96 // clear temp result
97 _result = 0;
98}
99
100
101
102 void PtexTriangleFilter::buildKernel(PtexTriangleKernel& k, float u, float v,
103 float uw1, float vw1, float uw2, float vw2,
104 float width, float blur, Res faceRes)
105{
106 const float sqrt3 = 1.7320508075688772f;
107
108 // compute ellipse coefficients, A*u^2 + B*u*v + C*v^2 == AC - B^2/4
109 float scaleAC = 0.25f * width*width;
110 float scaleB = -2.0f * scaleAC;
111 float A = (vw1*vw1 + vw2*vw2) * scaleAC;
112 float B = (uw1*vw1 + uw2*vw2) * scaleB;
113 float C = (uw1*uw1 + uw2*uw2) * scaleAC;
114
115 // convert to cartesian domain
116 float Ac = 0.75f * A;
117 float Bc = float(sqrt3/2) * (B-A);
118 float Cc = 0.25f * A - 0.5f * B + C;
119
120 // compute min blur for eccentricity clamping
121 const float maxEcc = 15.0f; // max eccentricity
122 const float eccRatio = (maxEcc*maxEcc + 1.0f) / (maxEcc*maxEcc - 1.0f);
123 float X = sqrtf(squared(Ac - Cc) + squared(Bc));
124 float b_e = 0.5f * (eccRatio * X - (Ac + Cc));
125
126 // compute min blur for texel clamping
127 // (ensure that ellipse is no smaller than a texel)
128 float b_t = squared(0.5f / (float)faceRes.u());
129
130 // add blur
131 float b_b = 0.25f * blur * blur;
132 float b = std::max(b_b, std::max(b_e, b_t));
133 Ac += b;
134 Cc += b;
135
136 // compute minor radius
137 float m = sqrtf(2.0f*(Ac*Cc - 0.25f*Bc*Bc) / (Ac + Cc + X));
138
139 // choose desired resolution
140 int reslog2 = std::max(0, PtexUtils::calcResFromWidth(2.0f*m));
141
142 // convert back to triangular domain
143 A = float(4/3.0) * Ac;
144 B = float(2/sqrt3) * Bc + A;
145 C = -0.25f * A + 0.5f * B + Cc;
146
147 // scale by kernel width
148 float scale = PtexTriangleKernelWidth * PtexTriangleKernelWidth;
149 A *= scale;
150 B *= scale;
151 C *= scale;
152
153 // find u,v,w extents
154 float uw = std::min(sqrtf(C), 1.0f);
155 float vw = std::min(sqrtf(A), 1.0f);
156 float ww = std::min(sqrtf(A-B+C), 1.0f);
157
158 // init kernel
159 float w = 1.0f - u - v;
160 k.set(Res((int8_t)reslog2, (int8_t)reslog2), u, v, u-uw, v-vw, w-ww, u+uw, v+vw, w+ww, A, B, C);
161}
162
163
164 void PtexTriangleFilter::splitAndApply(PtexTriangleKernel& k, int faceid, const Ptex::FaceInfo& f)
165{
166 // do we need to split? if so, split kernel and apply across edge(s)
167 if (k.u1 < 0 && f.adjface(2) >= 0) {
168 PtexTriangleKernel ka;
169 k.splitU(ka);
170 applyAcrossEdge(ka, f, 2);
171 }
172 if (k.v1 < 0 && f.adjface(0) >= 0) {
173 PtexTriangleKernel ka;
174 k.splitV(ka);
175 applyAcrossEdge(ka, f, 0);
176 }
177 if (k.w1 < 0 && f.adjface(1) >= 0) {
178 PtexTriangleKernel ka;
179 k.splitW(ka);
180 applyAcrossEdge(ka, f, 1);
181 }
182 // apply to local face
183 apply(k, faceid, f);
184}
185
186
187 void PtexTriangleFilter::applyAcrossEdge(PtexTriangleKernel& k,
188 const Ptex::FaceInfo& f, int eid)
189{
190 int afid = f.adjface(eid), aeid = f.adjedge(eid);
191 const Ptex::FaceInfo& af = _tx->getFaceInfo(afid);
192 k.reorient(eid, aeid);
193 splitAndApply(k, afid, af);
194}
195
196
197 void PtexTriangleFilter::apply(PtexTriangleKernel& k, int faceid, const Ptex::FaceInfo& f)
198{
199 // clamp kernel face (resolution and extent)
200 k.clampRes(f.res);
201 k.clampExtent();
202
203 // build kernel iterators
204 PtexTriangleKernelIter keven, kodd;
205 k.getIterators(keven, kodd);
206 if (!keven.valid && !kodd.valid) return;
207
208 if (f.isConstant() || k.res.ulog2 == 0) {
209 // texture is constant or kernel wants it to be
210 char* data = (char*)_tx->getConstantData(faceid) +_firstChanOffset;
211 if (keven.valid) {
212 keven.applyConst(_result, data, _dt, _nchan);
213 _weight += keven.weight;
214 }
215 if (kodd.valid) {
216 kodd.applyConst(_result, data, _dt, _nchan);
217 _weight += kodd.weight;
218 }
219 return;
220 }
221
222 // get face data, and apply
223 PtexPtr<PtexFaceData> dh ( _tx->getData(faceid, k.res) );
224 if (!dh) return;
225
226 if (keven.valid) applyIter(keven, dh);
227 if (kodd.valid) applyIter(kodd, dh);
228}
229
230
231 void PtexTriangleFilter::applyIter(PtexTriangleKernelIter& k, PtexFaceData* dh)
232{
233 if (dh->isConstant()) {
234 k.applyConst(_result, (char*)dh->getData()+_firstChanOffset, _dt, _nchan);
235 _weight += k.weight;
236 }
237 else if (dh->isTiled()) {
238 Ptex::Res tileres = dh->tileRes();
239 PtexTriangleKernelIter kt = k;
240 int tileresu = tileres.u();
241 int tileresv = tileres.v();
242 kt.rowlen = tileresu;
243 int ntilesu = k.rowlen / kt.rowlen;
244 int wOffsetBase = k.rowlen - tileresu;
245 for (int tilev = k.v1 / tileresv, tilevEnd = (k.v2-1) / tileresv; tilev <= tilevEnd; tilev++) {
246 int vOffset = tilev * tileresv;
247 kt.v = k.v - (float)vOffset;
248 kt.v1 = std::max(0, k.v1 - vOffset);
249 kt.v2 = std::min(k.v2 - vOffset, tileresv);
250 for (int tileu = k.u1 / tileresu, tileuEnd = (k.u2-1) / tileresu; tileu <= tileuEnd; tileu++) {
251 int uOffset = tileu * tileresu;
252 int wOffset = wOffsetBase - uOffset - vOffset;
253 kt.u = k.u - (float)uOffset;
254 kt.u1 = std::max(0, k.u1 - uOffset);
255 kt.u2 = std::min(k.u2 - uOffset, tileresu);
256 kt.w1 = k.w1 - wOffset;
257 kt.w2 = k.w2 - wOffset;
258 PtexPtr<PtexFaceData> th ( dh->getTile(tilev * ntilesu + tileu) );
259 if (th) {
260 kt.weight = 0;
261 if (th->isConstant())
262 kt.applyConst(_result, (char*)th->getData()+_firstChanOffset, _dt, _nchan);
263 else
264 kt.apply(_result, (char*)th->getData()+_firstChanOffset, _dt, _nchan, _ntxchan);
265 _weight += kt.weight;
266 }
267 }
268 }
269 }
270 else {
271 k.apply(_result, (char*)dh->getData()+_firstChanOffset, _dt, _nchan, _ntxchan);
272 _weight += k.weight;
273 }
274}
275
276 PTEX_NAMESPACE_END
PtexPlatform.h
Platform-specific classes, functions, and includes.
PtexTriangleFilter.h
PtexTriangleKernel.h
C
#define C(eid, aeid)
PtexTriangleKernelWidth
PTEX_NAMESPACE_BEGIN const float PtexTriangleKernelWidth
Definition PtexTriangleKernel.h:50
PtexUtils.h
PTEX_NAMESPACE_END
#define PTEX_NAMESPACE_END
Definition PtexVersion.h:62
PtexFaceData
Per-face texture data accessor.
Definition Ptexture.h:409
PtexFaceData::getTile
virtual PtexFaceData * getTile(int tile)=0
Access a tile from the data block.
PtexFaceData::isTiled
virtual bool isTiled()=0
True if this data block is tiled.
PtexFaceData::tileRes
virtual Ptex::Res tileRes()=0
Resolution of each tile in this data block.
PtexFaceData::isConstant
virtual bool isConstant()=0
True if this data block is constant.
PtexFaceData::getData
virtual void * getData()=0
Access the data from this data block.
PtexPtr
Smart-pointer for acquiring and releasing API objects.
Definition Ptexture.h:1067
PtexTriangleFilter::_ntxchan
int _ntxchan
Definition PtexTriangleFilter.h:76
PtexTriangleFilter::splitAndApply
void splitAndApply(PtexTriangleKernel &k, int faceid, const Ptex::FaceInfo &f)
Definition PtexTriangleFilter.cpp:164
PtexTriangleFilter::_weight
float _weight
Definition PtexTriangleFilter.h:73
PtexTriangleFilter::applyIter
void applyIter(PtexTriangleKernelIter &k, PtexFaceData *dh)
Definition PtexTriangleFilter.cpp:231
PtexTriangleFilter::apply
void apply(PtexTriangleKernel &k, int faceid, const Ptex::FaceInfo &f)
Definition PtexTriangleFilter.cpp:197
PtexTriangleFilter::_result
float * _result
Definition PtexTriangleFilter.h:72
PtexTriangleFilter::buildKernel
void buildKernel(PtexTriangleKernel &k, float u, float v, float uw1, float vw1, float uw2, float vw2, float width, float blur, Res faceRes)
Definition PtexTriangleFilter.cpp:102
PtexTriangleFilter::_firstChanOffset
int _firstChanOffset
Definition PtexTriangleFilter.h:74
PtexTriangleFilter::applyAcrossEdge
void applyAcrossEdge(PtexTriangleKernel &k, const Ptex::FaceInfo &f, int eid)
Definition PtexTriangleFilter.cpp:187
PtexTriangleFilter::_nchan
int _nchan
Definition PtexTriangleFilter.h:75
PtexTriangleFilter::eval
virtual void eval(float *result, int firstchan, int nchannels, int faceid, float u, float v, float uw1, float vw1, float uw2, float vw2, float width, float blur)
Apply filter to a ptex data file.
Definition PtexTriangleFilter.cpp:50
PtexTriangleFilter::_dt
DataType _dt
Definition PtexTriangleFilter.h:77
PtexTriangleFilter::_tx
PtexTexture * _tx
Definition PtexTriangleFilter.h:70
PtexTriangleKernelIter
Triangle filter kernel iterator (in texel coords).
Definition PtexTriangleKernel.h:54
PtexTriangleKernelIter::v1
int v1
Definition PtexTriangleKernel.h:58
PtexTriangleKernelIter::v2
int v2
Definition PtexTriangleKernel.h:59
PtexTriangleKernelIter::rowlen
int rowlen
Definition PtexTriangleKernel.h:56
PtexTriangleKernelIter::w1
int w1
Definition PtexTriangleKernel.h:58
PtexTriangleKernelIter::u
float u
Definition PtexTriangleKernel.h:57
PtexTriangleKernelIter::apply
void apply(float *dst, void *data, DataType dt, int nChan, int nTxChan)
Definition PtexTriangleKernel.h:65
PtexTriangleKernelIter::w2
int w2
Definition PtexTriangleKernel.h:59
PtexTriangleKernelIter::u1
int u1
Definition PtexTriangleKernel.h:58
PtexTriangleKernelIter::weight
float weight
Definition PtexTriangleKernel.h:63
PtexTriangleKernelIter::valid
bool valid
Definition PtexTriangleKernel.h:61
PtexTriangleKernelIter::u2
int u2
Definition PtexTriangleKernel.h:59
PtexTriangleKernelIter::applyConst
void applyConst(float *dst, void *data, DataType dt, int nChan)
Definition PtexTriangleKernel.cpp:153
PtexTriangleKernelIter::v
float v
Definition PtexTriangleKernel.h:57
PtexTriangleKernel
Triangle filter kernel (in normalized triangle coords).
Definition PtexTriangleKernel.h:82
PtexTriangleKernel::reorient
void reorient(int eid, int aeid)
Definition PtexTriangleKernel.h:151
PtexTriangleKernel::clampExtent
void clampExtent()
Definition PtexTriangleKernel.h:178
PtexTriangleKernel::set
void set(Res resVal, float uVal, float vVal, float u1Val, float v1Val, float w1Val, float u2Val, float v2Val, float w2Val, float AVal, float BVal, float CVal)
Definition PtexTriangleKernel.h:90
PtexTriangleKernel::u1
float u1
Definition PtexTriangleKernel.h:86
PtexTriangleKernel::splitW
void splitW(PtexTriangleKernel &ka)
Definition PtexTriangleKernel.h:130
PtexTriangleKernel::v1
float v1
Definition PtexTriangleKernel.h:86
PtexTriangleKernel::splitV
void splitV(PtexTriangleKernel &ka)
Definition PtexTriangleKernel.h:123
PtexTriangleKernel::splitU
void splitU(PtexTriangleKernel &ka)
Definition PtexTriangleKernel.h:116
PtexTriangleKernel::res
Res res
Definition PtexTriangleKernel.h:84
PtexTriangleKernel::getIterators
void getIterators(PtexTriangleKernelIter &ke, PtexTriangleKernelIter &ko)
Definition PtexTriangleKernel.h:188
PtexTriangleKernel::w1
float w1
Definition PtexTriangleKernel.h:86
PtexTriangleKernel::clampRes
void clampRes(Res fres)
Definition PtexTriangleKernel.h:172
PTEX_NAMESPACE_BEGIN
Definition PtexSeparableKernel.cpp:42
PtexUtils::calcResFromWidth
int calcResFromWidth(float w)
Definition PtexUtils.h:111
Ptex::ConvertToFloat
void ConvertToFloat(float *dst, const void *src, Ptex::DataType dt, int numChannels)
Convert a number of data values from the given data type to float.
Ptex::FaceInfo
Information about a face, as stored in the Ptex file header.
Definition Ptexture.h:232
Ptex::FaceInfo::res
Res res
Resolution of face.
Definition Ptexture.h:233
Ptex::FaceInfo::adjedge
EdgeId adjedge(int eid) const
Access an adjacent edge id. The eid value must be 0..3.
Definition Ptexture.h:259
Ptex::FaceInfo::isConstant
bool isConstant() const
Determine if face is constant (by checking a flag).
Definition Ptexture.h:265
Ptex::FaceInfo::adjface
int adjface(int eid) const
Access an adjacent face id. The eid value must be 0..3.
Definition Ptexture.h:262
Ptex::Res
Pixel resolution of a given texture.
Definition Ptexture.h:159
Ptex::Res::v
int v() const
V resolution in texels.
Definition Ptexture.h:176
Ptex::Res::u
int u() const
U resolution in texels.
Definition Ptexture.h:173