michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "SkCamera.h"
michael@0: 
michael@0: static SkScalar SkScalarDotDiv(int count, const SkScalar a[], int step_a,
michael@0:                                const SkScalar b[], int step_b,
michael@0:                                SkScalar denom) {
michael@0:     SkScalar prod = 0;
michael@0:     for (int i = 0; i < count; i++) {
michael@0:         prod += a[0] * b[0];
michael@0:         a += step_a;
michael@0:         b += step_b;
michael@0:     }
michael@0:     return prod / denom;
michael@0: }
michael@0: 
michael@0: static SkScalar SkScalarDot(int count, const SkScalar a[], int step_a,
michael@0:                                        const SkScalar b[], int step_b) {
michael@0:     SkScalar prod = 0;
michael@0:     for (int i = 0; i < count; i++) {
michael@0:         prod += a[0] * b[0];
michael@0:         a += step_a;
michael@0:         b += step_b;
michael@0:     }
michael@0:     return prod;
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: SkScalar SkPoint3D::normalize(SkUnit3D* unit) const {
michael@0:     SkScalar mag = SkScalarSqrt(fX*fX + fY*fY + fZ*fZ);
michael@0:     if (mag) {
michael@0:         SkScalar scale = SkScalarInvert(mag);
michael@0:         unit->fX = fX * scale;
michael@0:         unit->fY = fY * scale;
michael@0:         unit->fZ = fZ * scale;
michael@0:     } else {
michael@0:         unit->fX = unit->fY = unit->fZ = 0;
michael@0:     }
michael@0:     return mag;
michael@0: }
michael@0: 
michael@0: SkScalar SkUnit3D::Dot(const SkUnit3D& a, const SkUnit3D& b) {
michael@0:     return a.fX * b.fX + a.fY * b.fY + a.fZ * b.fZ;
michael@0: }
michael@0: 
michael@0: void SkUnit3D::Cross(const SkUnit3D& a, const SkUnit3D& b, SkUnit3D* cross) {
michael@0:     SkASSERT(cross);
michael@0: 
michael@0:     // use x,y,z, in case &a == cross or &b == cross
michael@0: 
michael@0:     SkScalar x = a.fY * b.fZ - a.fZ * b.fY;
michael@0:     SkScalar y = a.fZ * b.fX - a.fX * b.fY;
michael@0:     SkScalar z = a.fX * b.fY - a.fY * b.fX;
michael@0: 
michael@0:     cross->set(x, y, z);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: SkPatch3D::SkPatch3D() {
michael@0:     this->reset();
michael@0: }
michael@0: 
michael@0: void SkPatch3D::reset() {
michael@0:     fOrigin.set(0, 0, 0);
michael@0:     fU.set(SK_Scalar1, 0, 0);
michael@0:     fV.set(0, -SK_Scalar1, 0);
michael@0: }
michael@0: 
michael@0: void SkPatch3D::transform(const SkMatrix3D& m, SkPatch3D* dst) const {
michael@0:     if (dst == NULL) {
michael@0:         dst = (SkPatch3D*)this;
michael@0:     }
michael@0:     m.mapVector(fU, &dst->fU);
michael@0:     m.mapVector(fV, &dst->fV);
michael@0:     m.mapPoint(fOrigin, &dst->fOrigin);
michael@0: }
michael@0: 
michael@0: SkScalar SkPatch3D::dotWith(SkScalar dx, SkScalar dy, SkScalar dz) const {
michael@0:     SkScalar cx = SkScalarMul(fU.fY, fV.fZ) - SkScalarMul(fU.fZ, fV.fY);
michael@0:     SkScalar cy = SkScalarMul(fU.fZ, fV.fX) - SkScalarMul(fU.fX, fV.fY);
michael@0:     SkScalar cz = SkScalarMul(fU.fX, fV.fY) - SkScalarMul(fU.fY, fV.fX);
michael@0: 
michael@0:     return SkScalarMul(cx, dx) + SkScalarMul(cy, dy) + SkScalarMul(cz, dz);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: void SkMatrix3D::reset() {
michael@0:     memset(fMat, 0, sizeof(fMat));
michael@0:     fMat[0][0] = fMat[1][1] = fMat[2][2] = SK_Scalar1;
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::setTranslate(SkScalar x, SkScalar y, SkScalar z) {
michael@0:     memset(fMat, 0, sizeof(fMat));
michael@0:     fMat[0][0] = x;
michael@0:     fMat[1][1] = y;
michael@0:     fMat[2][2] = z;
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::setRotateX(SkScalar degX) {
michael@0:     SkScalar    s, c;
michael@0: 
michael@0:     s = SkScalarSinCos(SkDegreesToRadians(degX), &c);
michael@0:     this->setRow(0, SK_Scalar1, 0, 0);
michael@0:     this->setRow(1, 0, c, -s);
michael@0:     this->setRow(2, 0, s, c);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::setRotateY(SkScalar degY) {
michael@0:     SkScalar    s, c;
michael@0: 
michael@0:     s = SkScalarSinCos(SkDegreesToRadians(degY), &c);
michael@0:     this->setRow(0, c, 0, -s);
michael@0:     this->setRow(1, 0, SK_Scalar1, 0);
michael@0:     this->setRow(2, s, 0, c);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::setRotateZ(SkScalar degZ) {
michael@0:     SkScalar    s, c;
michael@0: 
michael@0:     s = SkScalarSinCos(SkDegreesToRadians(degZ), &c);
michael@0:     this->setRow(0, c, -s, 0);
michael@0:     this->setRow(1, s, c, 0);
michael@0:     this->setRow(2, 0, 0, SK_Scalar1);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::preTranslate(SkScalar x, SkScalar y, SkScalar z) {
michael@0:     SkScalar col[3] = { x, y, z};
michael@0: 
michael@0:     for (int i = 0; i < 3; i++) {
michael@0:         fMat[i][3] += SkScalarDot(3, &fMat[i][0], 1, col, 1);
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::preRotateX(SkScalar degX) {
michael@0:     SkMatrix3D m;
michael@0:     m.setRotateX(degX);
michael@0:     this->setConcat(*this, m);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::preRotateY(SkScalar degY) {
michael@0:     SkMatrix3D m;
michael@0:     m.setRotateY(degY);
michael@0:     this->setConcat(*this, m);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::preRotateZ(SkScalar degZ) {
michael@0:     SkMatrix3D m;
michael@0:     m.setRotateZ(degZ);
michael@0:     this->setConcat(*this, m);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::setConcat(const SkMatrix3D& a, const SkMatrix3D& b) {
michael@0:     SkMatrix3D  tmp;
michael@0:     SkMatrix3D* c = this;
michael@0: 
michael@0:     if (this == &a || this == &b) {
michael@0:         c = &tmp;
michael@0:     }
michael@0:     for (int i = 0; i < 3; i++) {
michael@0:         for (int j = 0; j < 3; j++) {
michael@0:             c->fMat[i][j] = SkScalarDot(3, &a.fMat[i][0], 1, &b.fMat[0][j], 4);
michael@0:         }
michael@0:         c->fMat[i][3] = SkScalarDot(3, &a.fMat[i][0], 1,
michael@0:                                     &b.fMat[0][3], 4) + a.fMat[i][3];
michael@0:     }
michael@0: 
michael@0:     if (c == &tmp) {
michael@0:         *this = tmp;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::mapPoint(const SkPoint3D& src, SkPoint3D* dst) const {
michael@0:     SkScalar x = SkScalarDot(3, &fMat[0][0], 1, &src.fX, 1) + fMat[0][3];
michael@0:     SkScalar y = SkScalarDot(3, &fMat[1][0], 1, &src.fX, 1) + fMat[1][3];
michael@0:     SkScalar z = SkScalarDot(3, &fMat[2][0], 1, &src.fX, 1) + fMat[2][3];
michael@0:     dst->set(x, y, z);
michael@0: }
michael@0: 
michael@0: void SkMatrix3D::mapVector(const SkVector3D& src, SkVector3D* dst) const {
michael@0:     SkScalar x = SkScalarDot(3, &fMat[0][0], 1, &src.fX, 1);
michael@0:     SkScalar y = SkScalarDot(3, &fMat[1][0], 1, &src.fX, 1);
michael@0:     SkScalar z = SkScalarDot(3, &fMat[2][0], 1, &src.fX, 1);
michael@0:     dst->set(x, y, z);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: SkCamera3D::SkCamera3D() {
michael@0:     this->reset();
michael@0: }
michael@0: 
michael@0: void SkCamera3D::reset() {
michael@0:     fLocation.set(0, 0, -SkIntToScalar(576));   // 8 inches backward
michael@0:     fAxis.set(0, 0, SK_Scalar1);                // forward
michael@0:     fZenith.set(0, -SK_Scalar1, 0);             // up
michael@0: 
michael@0:     fObserver.set(0, 0, fLocation.fZ);
michael@0: 
michael@0:     fNeedToUpdate = true;
michael@0: }
michael@0: 
michael@0: void SkCamera3D::update() {
michael@0:     fNeedToUpdate = true;
michael@0: }
michael@0: 
michael@0: void SkCamera3D::doUpdate() const {
michael@0:     SkUnit3D    axis, zenith, cross;
michael@0: 
michael@0:     fAxis.normalize(&axis);
michael@0: 
michael@0:     {
michael@0:         SkScalar dot = SkUnit3D::Dot(*SkTCast<const SkUnit3D*>(&fZenith), axis);
michael@0: 
michael@0:         zenith.fX = fZenith.fX - dot * axis.fX;
michael@0:         zenith.fY = fZenith.fY - dot * axis.fY;
michael@0:         zenith.fZ = fZenith.fZ - dot * axis.fZ;
michael@0: 
michael@0:         SkTCast<SkPoint3D*>(&zenith)->normalize(&zenith);
michael@0:     }
michael@0: 
michael@0:     SkUnit3D::Cross(axis, zenith, &cross);
michael@0: 
michael@0:     {
michael@0:         SkMatrix* orien = &fOrientation;
michael@0:         SkScalar x = fObserver.fX;
michael@0:         SkScalar y = fObserver.fY;
michael@0:         SkScalar z = fObserver.fZ;
michael@0: 
michael@0:         orien->set(SkMatrix::kMScaleX, x * axis.fX - z * cross.fX);
michael@0:         orien->set(SkMatrix::kMSkewX,  x * axis.fY - z * cross.fY);
michael@0:         orien->set(SkMatrix::kMTransX, x * axis.fZ - z * cross.fZ);
michael@0:         orien->set(SkMatrix::kMSkewY,  y * axis.fX - z * zenith.fX);
michael@0:         orien->set(SkMatrix::kMScaleY, y * axis.fY - z * zenith.fY);
michael@0:         orien->set(SkMatrix::kMTransY, y * axis.fZ - z * zenith.fZ);
michael@0:         orien->set(SkMatrix::kMPersp0, axis.fX);
michael@0:         orien->set(SkMatrix::kMPersp1, axis.fY);
michael@0:         orien->set(SkMatrix::kMPersp2, axis.fZ);
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkCamera3D::patchToMatrix(const SkPatch3D& quilt, SkMatrix* matrix) const {
michael@0:     if (fNeedToUpdate) {
michael@0:         this->doUpdate();
michael@0:         fNeedToUpdate = false;
michael@0:     }
michael@0: 
michael@0:     const SkScalar* mapPtr = (const SkScalar*)(const void*)&fOrientation;
michael@0:     const SkScalar* patchPtr;
michael@0:     SkPoint3D       diff;
michael@0:     SkScalar        dot;
michael@0: 
michael@0:     diff.fX = quilt.fOrigin.fX - fLocation.fX;
michael@0:     diff.fY = quilt.fOrigin.fY - fLocation.fY;
michael@0:     diff.fZ = quilt.fOrigin.fZ - fLocation.fZ;
michael@0: 
michael@0:     dot = SkUnit3D::Dot(*SkTCast<const SkUnit3D*>(&diff),
michael@0:                         *SkTCast<const SkUnit3D*>(SkTCast<const SkScalar*>(&fOrientation) + 6));
michael@0: 
michael@0:     patchPtr = (const SkScalar*)&quilt;
michael@0:     matrix->set(SkMatrix::kMScaleX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
michael@0:     matrix->set(SkMatrix::kMSkewY,  SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
michael@0:     matrix->set(SkMatrix::kMPersp0, SkScalarDotDiv(3, patchPtr, 1, mapPtr+6, 1, dot));
michael@0: 
michael@0:     patchPtr += 3;
michael@0:     matrix->set(SkMatrix::kMSkewX,  SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
michael@0:     matrix->set(SkMatrix::kMScaleY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
michael@0:     matrix->set(SkMatrix::kMPersp1, SkScalarDotDiv(3, patchPtr, 1, mapPtr+6, 1, dot));
michael@0: 
michael@0:     patchPtr = (const SkScalar*)(const void*)&diff;
michael@0:     matrix->set(SkMatrix::kMTransX, SkScalarDotDiv(3, patchPtr, 1, mapPtr, 1, dot));
michael@0:     matrix->set(SkMatrix::kMTransY, SkScalarDotDiv(3, patchPtr, 1, mapPtr+3, 1, dot));
michael@0:     matrix->set(SkMatrix::kMPersp2, SK_Scalar1);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: Sk3DView::Sk3DView() {
michael@0:     fInitialRec.fMatrix.reset();
michael@0:     fRec = &fInitialRec;
michael@0: }
michael@0: 
michael@0: Sk3DView::~Sk3DView() {
michael@0:     Rec* rec = fRec;
michael@0:     while (rec != &fInitialRec) {
michael@0:         Rec* next = rec->fNext;
michael@0:         SkDELETE(rec);
michael@0:         rec = next;
michael@0:     }
michael@0: }
michael@0: 
michael@0: void Sk3DView::save() {
michael@0:     Rec* rec = SkNEW(Rec);
michael@0:     rec->fNext = fRec;
michael@0:     rec->fMatrix = fRec->fMatrix;
michael@0:     fRec = rec;
michael@0: }
michael@0: 
michael@0: void Sk3DView::restore() {
michael@0:     SkASSERT(fRec != &fInitialRec);
michael@0:     Rec* next = fRec->fNext;
michael@0:     SkDELETE(fRec);
michael@0:     fRec = next;
michael@0: }
michael@0: 
michael@0: #ifdef SK_BUILD_FOR_ANDROID
michael@0: void Sk3DView::setCameraLocation(SkScalar x, SkScalar y, SkScalar z) {
michael@0:     // the camera location is passed in inches, set in pt
michael@0:     SkScalar lz = z * 72.0f;
michael@0:     fCamera.fLocation.set(x * 72.0f, y * 72.0f, lz);
michael@0:     fCamera.fObserver.set(0, 0, lz);
michael@0:     fCamera.update();
michael@0: 
michael@0: }
michael@0: 
michael@0: SkScalar Sk3DView::getCameraLocationX() {
michael@0:     return fCamera.fLocation.fX / 72.0f;
michael@0: }
michael@0: 
michael@0: SkScalar Sk3DView::getCameraLocationY() {
michael@0:     return fCamera.fLocation.fY / 72.0f;
michael@0: }
michael@0: 
michael@0: SkScalar Sk3DView::getCameraLocationZ() {
michael@0:     return fCamera.fLocation.fZ / 72.0f;
michael@0: }
michael@0: #endif
michael@0: 
michael@0: void Sk3DView::translate(SkScalar x, SkScalar y, SkScalar z) {
michael@0:     fRec->fMatrix.preTranslate(x, y, z);
michael@0: }
michael@0: 
michael@0: void Sk3DView::rotateX(SkScalar deg) {
michael@0:     fRec->fMatrix.preRotateX(deg);
michael@0: }
michael@0: 
michael@0: void Sk3DView::rotateY(SkScalar deg) {
michael@0:     fRec->fMatrix.preRotateY(deg);
michael@0: }
michael@0: 
michael@0: void Sk3DView::rotateZ(SkScalar deg) {
michael@0:     fRec->fMatrix.preRotateZ(deg);
michael@0: }
michael@0: 
michael@0: SkScalar Sk3DView::dotWithNormal(SkScalar x, SkScalar y, SkScalar z) const {
michael@0:     SkPatch3D   patch;
michael@0:     patch.transform(fRec->fMatrix);
michael@0:     return patch.dotWith(x, y, z);
michael@0: }
michael@0: 
michael@0: void Sk3DView::getMatrix(SkMatrix* matrix) const {
michael@0:     if (matrix != NULL) {
michael@0:         SkPatch3D   patch;
michael@0:         patch.transform(fRec->fMatrix);
michael@0:         fCamera.patchToMatrix(patch, matrix);
michael@0:     }
michael@0: }
michael@0: 
michael@0: #include "SkCanvas.h"
michael@0: 
michael@0: void Sk3DView::applyToCanvas(SkCanvas* canvas) const {
michael@0:     SkMatrix    matrix;
michael@0: 
michael@0:     this->getMatrix(&matrix);
michael@0:     canvas->concat(matrix);
michael@0: }