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/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkCamera.h"
static SkScalar SkScalarDotDiv(int count, const SkScalar a[], int step_a,
const SkScalar b[], int step_b,
SkScalar denom) {
SkScalar prod = 0;
for (int i = 0; i < count; i++) {
prod += a[0] * b[0];
a += step_a;
b += step_b;
}
return prod / denom;
}
static SkScalar SkScalarDot(int count, const SkScalar a[], int step_a,
const SkScalar b[], int step_b) {
SkScalar prod = 0;
for (int i = 0; i < count; i++) {
prod += a[0] * b[0];
a += step_a;
b += step_b;
}
return prod;
}
///////////////////////////////////////////////////////////////////////////////
SkScalar SkPoint3D::normalize(SkUnit3D* unit) const {
SkScalar mag = SkScalarSqrt(fX*fX + fY*fY + fZ*fZ);
if (mag) {
SkScalar scale = SkScalarInvert(mag);
unit->fX = fX * scale;
unit->fY = fY * scale;
unit->fZ = fZ * scale;
} else {
unit->fX = unit->fY = unit->fZ = 0;
}
return mag;
}
SkScalar SkUnit3D::Dot(const SkUnit3D& a, const SkUnit3D& b) {
return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ;
}
void SkUnit3D::Cross(const SkUnit3D& a, const SkUnit3D& b, SkUnit3D* cross) {
SkASSERT(cross);
// use x,y,z, in case &a == cross or &b == cross
SkScalar x = a.fY * b.fZ - a.fZ * b.fY;
SkScalar y = a.fZ * b.fX - a.fX * b.fY;
SkScalar z = a.fX * b.fY - a.fY * b.fX;
cross->set(x, y, z);
}
///////////////////////////////////////////////////////////////////////////////
SkPatch3D::SkPatch3D() {
this->reset();
}
void SkPatch3D::reset() {
fOrigin.set(0, 0, 0);
fU.set(SK_Scalar1, 0, 0);
fV.set(0, -SK_Scalar1, 0);
}
void SkPatch3D::transform(const SkMatrix3D& m, SkPatch3D* dst) const {
if (dst == nullptr) {
dst = (SkPatch3D*)this;
}
m.mapVector(fU, &dst->fU);
m.mapVector(fV, &dst->fV);
m.mapPoint(fOrigin, &dst->fOrigin);
}
SkScalar SkPatch3D::dotWith(SkScalar dx, SkScalar dy, SkScalar dz) const {
SkScalar cx = fU.fY * fV.fZ - fU.fZ * fV.fY;
SkScalar cy = fU.fZ * fV.fX - fU.fX * fV.fY;
SkScalar cz = fU.fX * fV.fY - fU.fY * fV.fX;
return cx * dx + cy * dy + cz * dz;
}
///////////////////////////////////////////////////////////////////////////////
void SkMatrix3D::reset() {
memset(fMat, 0, sizeof(fMat));
fMat[0][0] = fMat[1][1] = fMat[2][2] = SK_Scalar1;
}
void SkMatrix3D::setTranslate(SkScalar x, SkScalar y, SkScalar z) {
memset(fMat, 0, sizeof(fMat));
fMat[0][0] = x;
fMat[1][1] = y;
fMat[2][2] = z;
}
void SkMatrix3D::setRotateX(SkScalar degX) {
SkScalar s, c;
s = SkScalarSinCos(SkDegreesToRadians(degX), &c);
this->setRow(0, SK_Scalar1, 0, 0);
this->setRow(1, 0, c, -s);
this->setRow(2, 0, s, c);
}
void SkMatrix3D::setRotateY(SkScalar degY) {
SkScalar s, c;
s = SkScalarSinCos(SkDegreesToRadians(degY), &c);
this->setRow(0, c, 0, -s);
this->setRow(1, 0, SK_Scalar1, 0);
this->setRow(2, s, 0, c);
}
void SkMatrix3D::setRotateZ(SkScalar degZ) {
SkScalar s, c;
s = SkScalarSinCos(SkDegreesToRadians(degZ), &c);
this->setRow(0, c, -s, 0);
this->setRow(1, s, c, 0);
this->setRow(2, 0, 0, SK_Scalar1);
}
void SkMatrix3D::preTranslate(SkScalar x, SkScalar y, SkScalar z) {
SkScalar col[3] = { x, y, z};
for (int i = 0; i < 3; i++) {
fMat[i][3] += SkScalarDot(3, &fMat[i][0], 1, col, 1);
}
}
void SkMatrix3D::preRotateX(SkScalar degX) {
SkMatrix3D m;
m.setRotateX(degX);
this->setConcat(*this, m);
}
void SkMatrix3D::preRotateY(SkScalar degY) {
SkMatrix3D m;
m.setRotateY(degY);
this->setConcat(*this, m);
}
void SkMatrix3D::preRotateZ(SkScalar degZ) {
SkMatrix3D m;
m.setRotateZ(degZ);
this->setConcat(*this, m);
}
void SkMatrix3D::setConcat(const SkMatrix3D& a, const SkMatrix3D& b) {
SkMatrix3D tmp;
SkMatrix3D* c = this;
if (this == &a || this == &b) {
c = &tmp;
}
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
c->fMat[i][j] = SkScalarDot(3, &a.fMat[i][0], 1, &b.fMat[0][j], 4);
}
c->fMat[i][3] = SkScalarDot(3, &a.fMat[i][0], 1,
&b.fMat[0][3], 4) + a.fMat[i][3];
}
if (c == &tmp) {
*this = tmp;
}
}
void SkMatrix3D::mapPoint(const SkPoint3D& src, SkPoint3D* dst) const {
SkScalar x = SkScalarDot(3, &fMat[0][0], 1, &src.fX, 1) + fMat[0][3];
SkScalar y = SkScalarDot(3, &fMat[1][0], 1, &src.fX, 1) + fMat[1][3];
SkScalar z = SkScalarDot(3, &fMat[2][0], 1, &src.fX, 1) + fMat[2][3];
dst->set(x, y, z);
}
void SkMatrix3D::mapVector(const SkVector3D& src, SkVector3D* dst) const {
SkScalar x = SkScalarDot(3, &fMat[0][0], 1, &src.fX, 1);
SkScalar y = SkScalarDot(3, &fMat[1][0], 1, &src.fX, 1);
SkScalar z = SkScalarDot(3, &fMat[2][0], 1, &src.fX, 1);
dst->set(x, y, z);
}
///////////////////////////////////////////////////////////////////////////////
SkCamera3D::SkCamera3D() {
this->reset();
}
void SkCamera3D::reset() {
fLocation.set(0, 0, -SkIntToScalar(576)); // 8 inches backward
fAxis.set(0, 0, SK_Scalar1); // forward
fZenith.set(0, -SK_Scalar1, 0); // up
fObserver.set(0, 0, fLocation.fZ);
fNeedToUpdate = true;
}
void SkCamera3D::update() {
fNeedToUpdate = true;
}
void SkCamera3D::doUpdate() const {
SkUnit3D axis, zenith, cross;
// construct a orthonormal basis of cross (x), zenith (y), and axis (z)
fAxis.normalize(&axis);
{
SkScalar dot = SkUnit3D::Dot(*SkTCast<const SkUnit3D*>(&fZenith), axis);
zenith.fX = fZenith.fX - dot * axis.fX;
zenith.fY = fZenith.fY - dot * axis.fY;
zenith.fZ = fZenith.fZ - dot * axis.fZ;
SkTCast<SkPoint3D*>(&zenith)->normalize(&zenith);
}
SkUnit3D::Cross(axis, zenith, &cross);
{
SkMatrix* orien = &fOrientation;
SkScalar x = fObserver.fX;
SkScalar y = fObserver.fY;
SkScalar z = fObserver.fZ;
// Looking along the view axis we have:
//
// /|\ zenith
// |
// |
// | * observer (projected on XY plane)
// |
// |____________\ cross
// /
//
// So this does a z-shear along the view axis based on the observer's x and y values,
// and scales in x and y relative to the negative of the observer's z value
// (the observer is in the negative z direction).
orien->set(SkMatrix::kMScaleX, x * axis.fX - z * cross.fX);
orien->set(SkMatrix::kMSkewX, x * axis.fY - z * cross.fY);
orien->set(SkMatrix::kMTransX, x * axis.fZ - z * cross.fZ);
orien->set(SkMatrix::kMSkewY, y * axis.fX - z * zenith.fX);
orien->set(SkMatrix::kMScaleY, y * axis.fY - z * zenith.fY);
orien->set(SkMatrix::kMTransY, y * axis.fZ - z * zenith.fZ);
orien->set(SkMatrix::kMPersp0, axis.fX);
orien->set(SkMatrix::kMPersp1, axis.fY);
orien->set(SkMatrix::kMPersp2, axis.fZ);
}
}
void SkCamera3D::patchToMatrix(const SkPatch3D& quilt, SkMatrix* matrix) const {
if (fNeedToUpdate) {
this->doUpdate();
fNeedToUpdate = false;
}
const SkScalar* mapPtr = (const SkScalar*)(const void*)&fOrientation;
const SkScalar* patchPtr;
SkPoint3D diff;
SkScalar dot;
diff.fX = quilt.fOrigin.fX - fLocation.fX;
diff.fY = quilt.fOrigin.fY - fLocation.fY;
diff.fZ = quilt.fOrigin.fZ - fLocation.fZ;
dot = SkUnit3D::Dot(*SkTCast<const SkUnit3D*>(&diff),
*SkTCast<const SkUnit3D*>(SkTCast<const SkScalar*>(&fOrientation) + 6));
// This multiplies fOrientation by the matrix [quilt.fU quilt.fV diff] -- U, V, and diff are
// column vectors in the matrix -- then divides by the length of the projection of diff onto
// the view axis (which is 'dot'). This transforms the patch (which transforms from local path
// space to world space) into view space (since fOrientation transforms from world space to
// view space).
//
// The divide by 'dot' isn't strictly necessary as the homogeneous divide would do much the
// same thing (it's just scaling the entire matrix by 1/dot). It looks like it's normalizing
// the matrix into some canonical space.
patchPtr = (const SkScalar*)&quilt;
matrix->set(SkMatrix::kMScaleX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
matrix->set(SkMatrix::kMSkewY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
matrix->set(SkMatrix::kMPersp0, SkScalarDotDiv(3, patchPtr, 1, mapPtr+6, 1, dot));
patchPtr += 3;
matrix->set(SkMatrix::kMSkewX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
matrix->set(SkMatrix::kMScaleY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
matrix->set(SkMatrix::kMPersp1, SkScalarDotDiv(3, patchPtr, 1, mapPtr+6, 1, dot));
patchPtr = (const SkScalar*)(const void*)&diff;
matrix->set(SkMatrix::kMTransX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
matrix->set(SkMatrix::kMTransY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
matrix->set(SkMatrix::kMPersp2, SK_Scalar1);
}
///////////////////////////////////////////////////////////////////////////////
Sk3DView::Sk3DView() {
fInitialRec.fMatrix.reset();
fRec = &fInitialRec;
}
Sk3DView::~Sk3DView() {
Rec* rec = fRec;
while (rec != &fInitialRec) {
Rec* next = rec->fNext;
delete rec;
rec = next;
}
}
void Sk3DView::save() {
Rec* rec = new Rec;
rec->fNext = fRec;
rec->fMatrix = fRec->fMatrix;
fRec = rec;
}
void Sk3DView::restore() {
SkASSERT(fRec != &fInitialRec);
Rec* next = fRec->fNext;
delete fRec;
fRec = next;
}
#ifdef SK_BUILD_FOR_ANDROID
void Sk3DView::setCameraLocation(SkScalar x, SkScalar y, SkScalar z) {
// the camera location is passed in inches, set in pt
SkScalar lz = z * 72.0f;
fCamera.fLocation.set(x * 72.0f, y * 72.0f, lz);
fCamera.fObserver.set(0, 0, lz);
fCamera.update();
}
SkScalar Sk3DView::getCameraLocationX() {
return fCamera.fLocation.fX / 72.0f;
}
SkScalar Sk3DView::getCameraLocationY() {
return fCamera.fLocation.fY / 72.0f;
}
SkScalar Sk3DView::getCameraLocationZ() {
return fCamera.fLocation.fZ / 72.0f;
}
#endif
void Sk3DView::translate(SkScalar x, SkScalar y, SkScalar z) {
fRec->fMatrix.preTranslate(x, y, z);
}
void Sk3DView::rotateX(SkScalar deg) {
fRec->fMatrix.preRotateX(deg);
}
void Sk3DView::rotateY(SkScalar deg) {
fRec->fMatrix.preRotateY(deg);
}
void Sk3DView::rotateZ(SkScalar deg) {
fRec->fMatrix.preRotateZ(deg);
}
SkScalar Sk3DView::dotWithNormal(SkScalar x, SkScalar y, SkScalar z) const {
SkPatch3D patch;
patch.transform(fRec->fMatrix);
return patch.dotWith(x, y, z);
}
void Sk3DView::getMatrix(SkMatrix* matrix) const {
if (matrix != nullptr) {
SkPatch3D patch;
patch.transform(fRec->fMatrix);
fCamera.patchToMatrix(patch, matrix);
}
}
#include "SkCanvas.h"
void Sk3DView::applyToCanvas(SkCanvas* canvas) const {
SkMatrix matrix;
this->getMatrix(&matrix);
canvas->concat(matrix);
}