1 /*
2 * Copyright 2006 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkCamera.h"
9
SkScalarDotDiv(int count,const SkScalar a[],int step_a,const SkScalar b[],int step_b,SkScalar denom)10 static SkScalar SkScalarDotDiv(int count, const SkScalar a[], int step_a,
11 const SkScalar b[], int step_b,
12 SkScalar denom) {
13 SkScalar prod = 0;
14 for (int i = 0; i < count; i++) {
15 prod += a[0] * b[0];
16 a += step_a;
17 b += step_b;
18 }
19 return prod / denom;
20 }
21
SkScalarDot(int count,const SkScalar a[],int step_a,const SkScalar b[],int step_b)22 static SkScalar SkScalarDot(int count, const SkScalar a[], int step_a,
23 const SkScalar b[], int step_b) {
24 SkScalar prod = 0;
25 for (int i = 0; i < count; i++) {
26 prod += a[0] * b[0];
27 a += step_a;
28 b += step_b;
29 }
30 return prod;
31 }
32
33 ///////////////////////////////////////////////////////////////////////////////
34
normalize(SkUnit3D * unit) const35 SkScalar SkPoint3D::normalize(SkUnit3D* unit) const {
36 SkScalar mag = SkScalarSqrt(fX*fX + fY*fY + fZ*fZ);
37 if (mag) {
38 SkScalar scale = SkScalarInvert(mag);
39 unit->fX = fX * scale;
40 unit->fY = fY * scale;
41 unit->fZ = fZ * scale;
42 } else {
43 unit->fX = unit->fY = unit->fZ = 0;
44 }
45 return mag;
46 }
47
Dot(const SkUnit3D & a,const SkUnit3D & b)48 SkScalar SkUnit3D::Dot(const SkUnit3D& a, const SkUnit3D& b) {
49 return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ;
50 }
51
Cross(const SkUnit3D & a,const SkUnit3D & b,SkUnit3D * cross)52 void SkUnit3D::Cross(const SkUnit3D& a, const SkUnit3D& b, SkUnit3D* cross) {
53 SkASSERT(cross);
54
55 // use x,y,z, in case &a == cross or &b == cross
56
57 SkScalar x = a.fY * b.fZ - a.fZ * b.fY;
58 SkScalar y = a.fZ * b.fX - a.fX * b.fY;
59 SkScalar z = a.fX * b.fY - a.fY * b.fX;
60
61 cross->set(x, y, z);
62 }
63
64 ///////////////////////////////////////////////////////////////////////////////
65
SkPatch3D()66 SkPatch3D::SkPatch3D() {
67 this->reset();
68 }
69
reset()70 void SkPatch3D::reset() {
71 fOrigin.set(0, 0, 0);
72 fU.set(SK_Scalar1, 0, 0);
73 fV.set(0, -SK_Scalar1, 0);
74 }
75
transform(const SkMatrix3D & m,SkPatch3D * dst) const76 void SkPatch3D::transform(const SkMatrix3D& m, SkPatch3D* dst) const {
77 if (dst == nullptr) {
78 dst = (SkPatch3D*)this;
79 }
80 m.mapVector(fU, &dst->fU);
81 m.mapVector(fV, &dst->fV);
82 m.mapPoint(fOrigin, &dst->fOrigin);
83 }
84
dotWith(SkScalar dx,SkScalar dy,SkScalar dz) const85 SkScalar SkPatch3D::dotWith(SkScalar dx, SkScalar dy, SkScalar dz) const {
86 SkScalar cx = SkScalarMul(fU.fY, fV.fZ) - SkScalarMul(fU.fZ, fV.fY);
87 SkScalar cy = SkScalarMul(fU.fZ, fV.fX) - SkScalarMul(fU.fX, fV.fY);
88 SkScalar cz = SkScalarMul(fU.fX, fV.fY) - SkScalarMul(fU.fY, fV.fX);
89
90 return SkScalarMul(cx, dx) + SkScalarMul(cy, dy) + SkScalarMul(cz, dz);
91 }
92
93 ///////////////////////////////////////////////////////////////////////////////
94
reset()95 void SkMatrix3D::reset() {
96 memset(fMat, 0, sizeof(fMat));
97 fMat[0][0] = fMat[1][1] = fMat[2][2] = SK_Scalar1;
98 }
99
setTranslate(SkScalar x,SkScalar y,SkScalar z)100 void SkMatrix3D::setTranslate(SkScalar x, SkScalar y, SkScalar z) {
101 memset(fMat, 0, sizeof(fMat));
102 fMat[0][0] = x;
103 fMat[1][1] = y;
104 fMat[2][2] = z;
105 }
106
setRotateX(SkScalar degX)107 void SkMatrix3D::setRotateX(SkScalar degX) {
108 SkScalar s, c;
109
110 s = SkScalarSinCos(SkDegreesToRadians(degX), &c);
111 this->setRow(0, SK_Scalar1, 0, 0);
112 this->setRow(1, 0, c, -s);
113 this->setRow(2, 0, s, c);
114 }
115
setRotateY(SkScalar degY)116 void SkMatrix3D::setRotateY(SkScalar degY) {
117 SkScalar s, c;
118
119 s = SkScalarSinCos(SkDegreesToRadians(degY), &c);
120 this->setRow(0, c, 0, -s);
121 this->setRow(1, 0, SK_Scalar1, 0);
122 this->setRow(2, s, 0, c);
123 }
124
setRotateZ(SkScalar degZ)125 void SkMatrix3D::setRotateZ(SkScalar degZ) {
126 SkScalar s, c;
127
128 s = SkScalarSinCos(SkDegreesToRadians(degZ), &c);
129 this->setRow(0, c, -s, 0);
130 this->setRow(1, s, c, 0);
131 this->setRow(2, 0, 0, SK_Scalar1);
132 }
133
preTranslate(SkScalar x,SkScalar y,SkScalar z)134 void SkMatrix3D::preTranslate(SkScalar x, SkScalar y, SkScalar z) {
135 SkScalar col[3] = { x, y, z};
136
137 for (int i = 0; i < 3; i++) {
138 fMat[i][3] += SkScalarDot(3, &fMat[i][0], 1, col, 1);
139 }
140 }
141
preRotateX(SkScalar degX)142 void SkMatrix3D::preRotateX(SkScalar degX) {
143 SkMatrix3D m;
144 m.setRotateX(degX);
145 this->setConcat(*this, m);
146 }
147
preRotateY(SkScalar degY)148 void SkMatrix3D::preRotateY(SkScalar degY) {
149 SkMatrix3D m;
150 m.setRotateY(degY);
151 this->setConcat(*this, m);
152 }
153
preRotateZ(SkScalar degZ)154 void SkMatrix3D::preRotateZ(SkScalar degZ) {
155 SkMatrix3D m;
156 m.setRotateZ(degZ);
157 this->setConcat(*this, m);
158 }
159
setConcat(const SkMatrix3D & a,const SkMatrix3D & b)160 void SkMatrix3D::setConcat(const SkMatrix3D& a, const SkMatrix3D& b) {
161 SkMatrix3D tmp;
162 SkMatrix3D* c = this;
163
164 if (this == &a || this == &b) {
165 c = &tmp;
166 }
167 for (int i = 0; i < 3; i++) {
168 for (int j = 0; j < 3; j++) {
169 c->fMat[i][j] = SkScalarDot(3, &a.fMat[i][0], 1, &b.fMat[0][j], 4);
170 }
171 c->fMat[i][3] = SkScalarDot(3, &a.fMat[i][0], 1,
172 &b.fMat[0][3], 4) + a.fMat[i][3];
173 }
174
175 if (c == &tmp) {
176 *this = tmp;
177 }
178 }
179
mapPoint(const SkPoint3D & src,SkPoint3D * dst) const180 void SkMatrix3D::mapPoint(const SkPoint3D& src, SkPoint3D* dst) const {
181 SkScalar x = SkScalarDot(3, &fMat[0][0], 1, &src.fX, 1) + fMat[0][3];
182 SkScalar y = SkScalarDot(3, &fMat[1][0], 1, &src.fX, 1) + fMat[1][3];
183 SkScalar z = SkScalarDot(3, &fMat[2][0], 1, &src.fX, 1) + fMat[2][3];
184 dst->set(x, y, z);
185 }
186
mapVector(const SkVector3D & src,SkVector3D * dst) const187 void SkMatrix3D::mapVector(const SkVector3D& src, SkVector3D* dst) const {
188 SkScalar x = SkScalarDot(3, &fMat[0][0], 1, &src.fX, 1);
189 SkScalar y = SkScalarDot(3, &fMat[1][0], 1, &src.fX, 1);
190 SkScalar z = SkScalarDot(3, &fMat[2][0], 1, &src.fX, 1);
191 dst->set(x, y, z);
192 }
193
194 ///////////////////////////////////////////////////////////////////////////////
195
SkCamera3D()196 SkCamera3D::SkCamera3D() {
197 this->reset();
198 }
199
reset()200 void SkCamera3D::reset() {
201 fLocation.set(0, 0, -SkIntToScalar(576)); // 8 inches backward
202 fAxis.set(0, 0, SK_Scalar1); // forward
203 fZenith.set(0, -SK_Scalar1, 0); // up
204
205 fObserver.set(0, 0, fLocation.fZ);
206
207 fNeedToUpdate = true;
208 }
209
update()210 void SkCamera3D::update() {
211 fNeedToUpdate = true;
212 }
213
doUpdate() const214 void SkCamera3D::doUpdate() const {
215 SkUnit3D axis, zenith, cross;
216
217 fAxis.normalize(&axis);
218
219 {
220 SkScalar dot = SkUnit3D::Dot(*SkTCast<const SkUnit3D*>(&fZenith), axis);
221
222 zenith.fX = fZenith.fX - dot * axis.fX;
223 zenith.fY = fZenith.fY - dot * axis.fY;
224 zenith.fZ = fZenith.fZ - dot * axis.fZ;
225
226 SkTCast<SkPoint3D*>(&zenith)->normalize(&zenith);
227 }
228
229 SkUnit3D::Cross(axis, zenith, &cross);
230
231 {
232 SkMatrix* orien = &fOrientation;
233 SkScalar x = fObserver.fX;
234 SkScalar y = fObserver.fY;
235 SkScalar z = fObserver.fZ;
236
237 orien->set(SkMatrix::kMScaleX, x * axis.fX - z * cross.fX);
238 orien->set(SkMatrix::kMSkewX, x * axis.fY - z * cross.fY);
239 orien->set(SkMatrix::kMTransX, x * axis.fZ - z * cross.fZ);
240 orien->set(SkMatrix::kMSkewY, y * axis.fX - z * zenith.fX);
241 orien->set(SkMatrix::kMScaleY, y * axis.fY - z * zenith.fY);
242 orien->set(SkMatrix::kMTransY, y * axis.fZ - z * zenith.fZ);
243 orien->set(SkMatrix::kMPersp0, axis.fX);
244 orien->set(SkMatrix::kMPersp1, axis.fY);
245 orien->set(SkMatrix::kMPersp2, axis.fZ);
246 }
247 }
248
patchToMatrix(const SkPatch3D & quilt,SkMatrix * matrix) const249 void SkCamera3D::patchToMatrix(const SkPatch3D& quilt, SkMatrix* matrix) const {
250 if (fNeedToUpdate) {
251 this->doUpdate();
252 fNeedToUpdate = false;
253 }
254
255 const SkScalar* mapPtr = (const SkScalar*)(const void*)&fOrientation;
256 const SkScalar* patchPtr;
257 SkPoint3D diff;
258 SkScalar dot;
259
260 diff.fX = quilt.fOrigin.fX - fLocation.fX;
261 diff.fY = quilt.fOrigin.fY - fLocation.fY;
262 diff.fZ = quilt.fOrigin.fZ - fLocation.fZ;
263
264 dot = SkUnit3D::Dot(*SkTCast<const SkUnit3D*>(&diff),
265 *SkTCast<const SkUnit3D*>(SkTCast<const SkScalar*>(&fOrientation) + 6));
266
267 patchPtr = (const SkScalar*)&quilt;
268 matrix->set(SkMatrix::kMScaleX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
269 matrix->set(SkMatrix::kMSkewY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
270 matrix->set(SkMatrix::kMPersp0, SkScalarDotDiv(3, patchPtr, 1, mapPtr+6, 1, dot));
271
272 patchPtr += 3;
273 matrix->set(SkMatrix::kMSkewX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
274 matrix->set(SkMatrix::kMScaleY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
275 matrix->set(SkMatrix::kMPersp1, SkScalarDotDiv(3, patchPtr, 1, mapPtr+6, 1, dot));
276
277 patchPtr = (const SkScalar*)(const void*)&diff;
278 matrix->set(SkMatrix::kMTransX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
279 matrix->set(SkMatrix::kMTransY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
280 matrix->set(SkMatrix::kMPersp2, SK_Scalar1);
281 }
282
283 ///////////////////////////////////////////////////////////////////////////////
284
Sk3DView()285 Sk3DView::Sk3DView() {
286 fInitialRec.fMatrix.reset();
287 fRec = &fInitialRec;
288 }
289
~Sk3DView()290 Sk3DView::~Sk3DView() {
291 Rec* rec = fRec;
292 while (rec != &fInitialRec) {
293 Rec* next = rec->fNext;
294 delete rec;
295 rec = next;
296 }
297 }
298
save()299 void Sk3DView::save() {
300 Rec* rec = new Rec;
301 rec->fNext = fRec;
302 rec->fMatrix = fRec->fMatrix;
303 fRec = rec;
304 }
305
restore()306 void Sk3DView::restore() {
307 SkASSERT(fRec != &fInitialRec);
308 Rec* next = fRec->fNext;
309 delete fRec;
310 fRec = next;
311 }
312
313 #ifdef SK_BUILD_FOR_ANDROID
setCameraLocation(SkScalar x,SkScalar y,SkScalar z)314 void Sk3DView::setCameraLocation(SkScalar x, SkScalar y, SkScalar z) {
315 // the camera location is passed in inches, set in pt
316 SkScalar lz = z * 72.0f;
317 fCamera.fLocation.set(x * 72.0f, y * 72.0f, lz);
318 fCamera.fObserver.set(0, 0, lz);
319 fCamera.update();
320
321 }
322
getCameraLocationX()323 SkScalar Sk3DView::getCameraLocationX() {
324 return fCamera.fLocation.fX / 72.0f;
325 }
326
getCameraLocationY()327 SkScalar Sk3DView::getCameraLocationY() {
328 return fCamera.fLocation.fY / 72.0f;
329 }
330
getCameraLocationZ()331 SkScalar Sk3DView::getCameraLocationZ() {
332 return fCamera.fLocation.fZ / 72.0f;
333 }
334 #endif
335
translate(SkScalar x,SkScalar y,SkScalar z)336 void Sk3DView::translate(SkScalar x, SkScalar y, SkScalar z) {
337 fRec->fMatrix.preTranslate(x, y, z);
338 }
339
rotateX(SkScalar deg)340 void Sk3DView::rotateX(SkScalar deg) {
341 fRec->fMatrix.preRotateX(deg);
342 }
343
rotateY(SkScalar deg)344 void Sk3DView::rotateY(SkScalar deg) {
345 fRec->fMatrix.preRotateY(deg);
346 }
347
rotateZ(SkScalar deg)348 void Sk3DView::rotateZ(SkScalar deg) {
349 fRec->fMatrix.preRotateZ(deg);
350 }
351
dotWithNormal(SkScalar x,SkScalar y,SkScalar z) const352 SkScalar Sk3DView::dotWithNormal(SkScalar x, SkScalar y, SkScalar z) const {
353 SkPatch3D patch;
354 patch.transform(fRec->fMatrix);
355 return patch.dotWith(x, y, z);
356 }
357
getMatrix(SkMatrix * matrix) const358 void Sk3DView::getMatrix(SkMatrix* matrix) const {
359 if (matrix != nullptr) {
360 SkPatch3D patch;
361 patch.transform(fRec->fMatrix);
362 fCamera.patchToMatrix(patch, matrix);
363 }
364 }
365
366 #include "SkCanvas.h"
367
applyToCanvas(SkCanvas * canvas) const368 void Sk3DView::applyToCanvas(SkCanvas* canvas) const {
369 SkMatrix matrix;
370
371 this->getMatrix(&matrix);
372 canvas->concat(matrix);
373 }
374