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      1 /*
      2  * Copyright (C) 2006 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 
     18 
     19 //  Inspired by Rob Johnson's most excellent QuickDraw GX sample code
     20 
     21 #ifndef SkCamera_DEFINED
     22 #define SkCamera_DEFINED
     23 
     24 #include "Sk64.h"
     25 #include "SkMatrix.h"
     26 
     27 class SkCanvas;
     28 
     29 #ifdef SK_SCALAR_IS_FIXED
     30     typedef SkFract SkUnitScalar;
     31     #define SK_UnitScalar1          SK_Fract1
     32     #define SkUnitScalarMul(a, b)   SkFractMul(a, b)
     33     #define SkUnitScalarDiv(a, b)   SkFractDiv(a, b)
     34 #else
     35     typedef float   SkUnitScalar;
     36     #define SK_UnitScalar1          SK_Scalar1
     37     #define SkUnitScalarMul(a, b)   SkScalarMul(a, b)
     38     #define SkUnitScalarDiv(a, b)   SkScalarDiv(a, b)
     39 #endif
     40 
     41 struct SkUnit3D {
     42     SkUnitScalar    fX, fY, fZ;
     43 
     44     void set(SkUnitScalar x, SkUnitScalar y, SkUnitScalar z)
     45     {
     46         fX = x; fY = y; fZ = z;
     47     }
     48     static SkUnitScalar Dot(const SkUnit3D&, const SkUnit3D&);
     49     static void Cross(const SkUnit3D&, const SkUnit3D&, SkUnit3D* cross);
     50 };
     51 
     52 struct SkPoint3D {
     53     SkScalar    fX, fY, fZ;
     54 
     55     void set(SkScalar x, SkScalar y, SkScalar z)
     56     {
     57         fX = x; fY = y; fZ = z;
     58     }
     59     SkScalar    normalize(SkUnit3D*) const;
     60 };
     61 typedef SkPoint3D SkVector3D;
     62 
     63 struct SkMatrix3D {
     64     SkScalar    fMat[3][4];
     65 
     66     void reset();
     67 
     68     void setRow(int row, SkScalar a, SkScalar b, SkScalar c, SkScalar d = 0)
     69     {
     70         SkASSERT((unsigned)row < 3);
     71         fMat[row][0] = a;
     72         fMat[row][1] = b;
     73         fMat[row][2] = c;
     74         fMat[row][3] = d;
     75     }
     76 
     77     void setRotateX(SkScalar deg);
     78     void setRotateY(SkScalar deg);
     79     void setRotateZ(SkScalar deg);
     80     void setTranslate(SkScalar x, SkScalar y, SkScalar z);
     81 
     82     void preRotateX(SkScalar deg);
     83     void preRotateY(SkScalar deg);
     84     void preRotateZ(SkScalar deg);
     85     void preTranslate(SkScalar x, SkScalar y, SkScalar z);
     86 
     87     void setConcat(const SkMatrix3D& a, const SkMatrix3D& b);
     88     void mapPoint(const SkPoint3D& src, SkPoint3D* dst) const;
     89     void mapVector(const SkVector3D& src, SkVector3D* dst) const;
     90 
     91     void mapPoint(SkPoint3D* v) const
     92     {
     93         this->mapPoint(*v, v);
     94     }
     95     void mapVector(SkVector3D* v) const
     96     {
     97         this->mapVector(*v, v);
     98     }
     99 };
    100 
    101 class SkPatch3D {
    102 public:
    103     SkPatch3D();
    104 
    105     void    reset();
    106     void    transform(const SkMatrix3D&, SkPatch3D* dst = NULL) const;
    107 
    108     // dot a unit vector with the patch's normal
    109     SkScalar dotWith(SkScalar dx, SkScalar dy, SkScalar dz) const;
    110     SkScalar dotWith(const SkVector3D& v) const
    111     {
    112         return this->dotWith(v.fX, v.fY, v.fZ);
    113     }
    114 
    115     // depreicated, but still here for animator (for now)
    116     void rotate(SkScalar x, SkScalar y, SkScalar z) {}
    117     void rotateDegrees(SkScalar x, SkScalar y, SkScalar z) {}
    118 
    119 private:
    120 public: // make public for SkDraw3D for now
    121     SkVector3D  fU, fV;
    122     SkPoint3D   fOrigin;
    123 
    124     friend class SkCamera3D;
    125 };
    126 
    127 class SkCamera3D {
    128 public:
    129     SkCamera3D();
    130 
    131     void reset();
    132     void update();
    133     void patchToMatrix(const SkPatch3D&, SkMatrix* matrix) const;
    134 
    135     SkPoint3D   fLocation;
    136     SkPoint3D   fAxis;
    137     SkPoint3D   fZenith;
    138     SkPoint3D   fObserver;
    139 
    140 private:
    141     mutable SkMatrix    fOrientation;
    142     mutable bool        fNeedToUpdate;
    143 
    144     void doUpdate() const;
    145 };
    146 
    147 class Sk3DView : SkNoncopyable {
    148 public:
    149     Sk3DView();
    150     ~Sk3DView();
    151 
    152     void save();
    153     void restore();
    154 
    155     void translate(SkScalar x, SkScalar y, SkScalar z);
    156     void rotateX(SkScalar deg);
    157     void rotateY(SkScalar deg);
    158     void rotateZ(SkScalar deg);
    159 
    160     void getMatrix(SkMatrix*) const;
    161     void applyToCanvas(SkCanvas*) const;
    162 
    163     SkScalar dotWithNormal(SkScalar dx, SkScalar dy, SkScalar dz) const;
    164 
    165 private:
    166     struct Rec {
    167         Rec*        fNext;
    168         SkMatrix3D  fMatrix;
    169     };
    170     Rec*        fRec;
    171     Rec         fInitialRec;
    172     SkCamera3D  fCamera;
    173 };
    174 
    175 #endif
    176 
    177