com.unity.uiwidgets/com.unity.uiwidgets/Runtime/ui/renderer/common/geometry/matrix/ui_matrix.cs

using Unity.UIWidgets.foundation;
using UnityEngine;

namespace Unity.UIWidgets.uiOld{
    public partial struct uiMatrix3 {
        //Constants
        enum TypeMask {
            kIdentity_Mask = 0, //!< identity SkMatrix; all bits clear
            kTranslate_Mask = 0x01, //!< translation SkMatrix
            kScale_Mask = 0x02, //!< scale SkMatrix
            kAffine_Mask = 0x04, //!< skew or rotate SkMatrix
            kPerspective_Mask = 0x08, //!< perspective SkMatrix
        }

        const int kRectStaysRect_Mask = 0x10;

        const int kOnlyPerspectiveValid_Mask = 0x40;

        const int kUnknown_Mask = 0x80;

        const int kORableMasks =
            (int)
            (TypeMask.kTranslate_Mask |
             TypeMask.kScale_Mask |
             TypeMask.kAffine_Mask |
             TypeMask.kPerspective_Mask);

        const int kAllMasks =
            (int)
            (TypeMask.kTranslate_Mask |
             TypeMask.kScale_Mask |
             TypeMask.kAffine_Mask |
             TypeMask.kPerspective_Mask) |
            kRectStaysRect_Mask;

        enum TypeShift {
            kTranslate_Shift,
            kScale_Shift,
            kAffine_Shift,
            kPerspective_Shift,
            kRectStaysRect_Shift
        }

        const int kScalar1Int = 0x3f800000;
    }


    public partial struct uiMatrix3 {
        //Variables
        public float kMScaleX; //0
        public float kMSkewX; //1
        public float kMTransX; //2
        public float kMSkewY; //3
        public float kMScaleY; //4
        public float kMTransY; //5
        public float kMPersp0; //6
        public float kMPersp1; //7
        public float kMPersp2; //8

        public int fTypeMask;
    }

    public partial struct uiMatrix3 {
        //private methods
        void _setScale(float sx, float sy) {
            if (1 == sx && 1 == sy) {
                reset();
            }
            else {
                kMScaleX = sx;
                kMScaleY = sy;
                kMPersp2 = 1;

                kMTransX = kMTransY = kMSkewX =
                    kMSkewY = kMPersp0 = kMPersp1 = 0;

                _setTypeMask((int) TypeMask.kScale_Mask | kRectStaysRect_Mask);
            }
        }

        void _setScale(float sx, float sy, float px, float py) {
            if (1 == sx && 1 == sy) {
                reset();
            }
            else {
                _setScaleTranslate(sx, sy, px - sx * px, py - sy * py);
            }
        }

        int _computeTypeMask() {
            int mask = 0;

            if (kMPersp0 != 0 || kMPersp1 != 0 ||
                kMPersp2 != 1) {
                // Once it is determined that that this is a perspective transform,
                // all other flags are moot as far as optimizations are concerned.
                return kORableMasks;
            }

            if (kMTransX != 0 || kMTransY != 0) {
                mask |= (int) TypeMask.kTranslate_Mask;
            }

            int m00 = uiScalarUtils.ScalarAs2sCompliment(kMScaleX);
            int m01 = uiScalarUtils.ScalarAs2sCompliment(kMSkewX);
            int m10 = uiScalarUtils.ScalarAs2sCompliment(kMSkewY);
            int m11 = uiScalarUtils.ScalarAs2sCompliment(kMScaleY);

            if ((m01 != 0) | (m10 != 0)) {
                mask |= (int) TypeMask.kAffine_Mask | (int) TypeMask.kScale_Mask;

                m01 = m01 != 0 ? 1 : 0;
                m10 = m10 != 0 ? 1 : 0;

                int dp0 = 0 == (m00 | m11) ? 1 : 0;
                int ds1 = m01 & m10;

                mask |= (dp0 & ds1) << (int) TypeShift.kRectStaysRect_Shift;
            }
            else {
                if (((m00 ^ kScalar1Int) | (m11 ^ kScalar1Int)) != 0) {
                    mask |= (int) TypeMask.kScale_Mask;
                }

                m00 = m00 != 0 ? 1 : 0;
                m11 = m11 != 0 ? 1 : 0;

                mask |= (m00 & m11) << (int) TypeShift.kRectStaysRect_Shift;
            }

            return mask;
        }


        TypeMask _getType() {
            if ((fTypeMask & kUnknown_Mask) != 0) {
                fTypeMask = _computeTypeMask();
            }

            // only return the public masks
            return (TypeMask) (fTypeMask & 0xF);
        }

        public void reset() {
            kMScaleX = kMScaleY = kMPersp2 = 1;

            kMSkewX = kMSkewY = kMTransX =
                kMTransY = kMPersp0 = kMPersp1 = 0;

            _setTypeMask((int) TypeMask.kIdentity_Mask | kRectStaysRect_Mask);
        }

        bool _isTriviallyIdentity() {
            if ((fTypeMask & kUnknown_Mask) != 0) {
                return false;
            }

            return (fTypeMask & 0xF) == 0;
        }

        void _setConcat(uiMatrix3 a, uiMatrix3 b) {
            TypeMask aType = a._getType();
            TypeMask bType = b._getType();

            if (a._isTriviallyIdentity()) {
                copyFrom(b);
            }
            else if (b._isTriviallyIdentity()) {
                copyFrom(a);
            }
            else if (_only_scale_and_translate((int) aType | (int) bType)) {
                _setScaleTranslate(a.kMScaleX * b.kMScaleX,
                    a.kMScaleY * b.kMScaleY,
                    a.kMScaleX * b.kMTransX + a.kMTransX,
                    a.kMScaleY * b.kMTransY + a.kMTransY);
            }
            else {
                uiMatrix3 tmp = new uiMatrix3();

                if (((aType | bType) & TypeMask.kPerspective_Mask) != 0) {
                    tmp.kMScaleX = _rowcol3(a, 0, b, 0);
                    tmp.kMSkewX = _rowcol3(a, 0, b, 1);
                    tmp.kMTransX = _rowcol3(a, 0, b, 2);
                    tmp.kMSkewY = _rowcol3(a, 3, b, 0);
                    tmp.kMScaleY = _rowcol3(a, 3, b, 1);
                    tmp.kMTransY = _rowcol3(a, 3, b, 2);
                    tmp.kMPersp0 = _rowcol3(a, 6, b, 0);
                    tmp.kMPersp1 = _rowcol3(a, 6, b, 1);
                    tmp.kMPersp2 = _rowcol3(a, 6, b, 2);

                    tmp._setTypeMask(kUnknown_Mask);
                }
                else {
                    tmp.kMScaleX = _muladdmul(a.kMScaleX,
                        b.kMScaleX,
                        a.kMSkewX,
                        b.kMSkewY);

                    tmp.kMSkewX = _muladdmul(a.kMScaleX,
                        b.kMSkewX,
                        a.kMSkewX,
                        b.kMScaleY);

                    tmp.kMTransX = _muladdmul(a.kMScaleX,
                                       b.kMTransX,
                                       a.kMSkewX,
                                       b.kMTransY) + a.kMTransX;

                    tmp.kMSkewY = _muladdmul(a.kMSkewY,
                        b.kMScaleX,
                        a.kMScaleY,
                        b.kMSkewY);

                    tmp.kMScaleY = _muladdmul(a.kMSkewY,
                        b.kMSkewX,
                        a.kMScaleY,
                        b.kMScaleY);

                    tmp.kMTransY = _muladdmul(a.kMSkewY,
                                       b.kMTransX,
                                       a.kMScaleY,
                                       b.kMTransY) + a.kMTransY;

                    tmp.kMPersp0 = 0;
                    tmp.kMPersp1 = 0;
                    tmp.kMPersp2 = 1;
                    tmp._setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
                }

                copyFrom(tmp);
            }
        }


        void _setScaleTranslate(float sx, float sy, float tx, float ty) {
            kMScaleX = sx;
            kMSkewX = 0;
            kMTransX = tx;

            kMSkewY = 0;
            kMScaleY = sy;
            kMTransY = ty;

            kMPersp0 = 0;
            kMPersp1 = 0;
            kMPersp2 = 1;

            int mask = 0;
            if (sx != 1 || sy != 1) {
                mask |= (int) TypeMask.kScale_Mask;
            }

            if (tx != 0 || ty != 0) {
                mask |= (int) TypeMask.kTranslate_Mask;
            }

            _setTypeMask(mask | kRectStaysRect_Mask);
        }

        void _setTypeMask(int mask) {
            D.assert(kUnknown_Mask == mask || (mask & kAllMasks) == mask ||
                     ((kUnknown_Mask | kOnlyPerspectiveValid_Mask) & mask) ==
                     (kUnknown_Mask | kOnlyPerspectiveValid_Mask));
            fTypeMask = mask;
        }

        void _orTypeMask(int mask) {
            D.assert((mask & kORableMasks) == mask);
            fTypeMask |= mask;
        }

        void _clearTypeMask(int mask) {
            // only allow a valid mask
            D.assert((mask & kAllMasks) == mask);
            fTypeMask &= ~mask;
        }


        int _computePerspectiveTypeMask() {
            if (kMPersp0 != 0 || kMPersp1 != 0 ||
                kMPersp2 != 1) {
                return kORableMasks;
            }

            return kOnlyPerspectiveValid_Mask | kUnknown_Mask;
        }

        TypeMask _getPerspectiveTypeMaskOnly() {
            if ((fTypeMask & kUnknown_Mask) != 0 &&
                (fTypeMask & kOnlyPerspectiveValid_Mask) == 0) {
                fTypeMask = _computePerspectiveTypeMask();
            }

            return (TypeMask) (fTypeMask & 0xF);
        }

        bool _hasPerspective() {
            return (_getPerspectiveTypeMaskOnly() & TypeMask.kPerspective_Mask) != 0;
        }

        void _updateTranslateMask() {
            if ((kMTransX != 0) | (kMTransY != 0)) {
                fTypeMask |= (int) TypeMask.kTranslate_Mask;
            }
            else {
                fTypeMask &= ~(int) TypeMask.kTranslate_Mask;
            }
        }

        public bool _isFinite() {
            return uiScalarUtils.ScalarsAreFinite(this);
        }

        uiMatrix3? _invertNonIdentity(bool invertableCheck) {
            D.assert(!isIdentity());
            TypeMask mask = _getType();

            if (0 == (mask & ~(TypeMask.kScale_Mask | TypeMask.kTranslate_Mask))) {
                // bool invertible = true; // Fix warning: value is never used

                if (!invertableCheck) {
                    if ((mask & TypeMask.kScale_Mask) != 0) {
                        var invX = kMScaleX;
                        var invY = kMScaleY;
                        if (0 == invX || 0 == invY) {
                            return null;
                        }

                        invX = 1f / invX;
                        invY = 1f / invY;

                        var _inv = I();
                        _inv.kMSkewX = _inv.kMSkewY =
                            _inv.kMPersp0 = _inv.kMPersp1 = 0;

                        _inv.kMScaleX = invX;
                        _inv.kMScaleY = invY;
                        _inv.kMPersp2 = 1;
                        _inv.kMTransX = -kMTransX * invX;
                        _inv.kMTransY = -kMTransY * invY;

                        _inv._setTypeMask((int) mask | kRectStaysRect_Mask);
                        return _inv;
                    }
                    else {
                        var _inv = I();
                        _inv.setTranslate(-kMTransX, -kMTransY);
                        return _inv;
                    }
                }
                else {
                    if (kMScaleX == 0 || kMScaleY == 0) {
                        return null;
                    }

                    return I();
                }
            }

            int isPersp = (int) (mask & TypeMask.kPerspective_Mask);
            float invDet = uiScalarUtils.inv_determinant(this, isPersp);

            if (invDet == 0) {
                // underflow
                return null;
            }

            var inv = ComputeInv(this, invDet, isPersp != 0);
            if (!inv._isFinite()) {
                return null;
            }

            inv._setTypeMask(fTypeMask);
            return inv;
        }

        public bool _isScaleTranslate() {
            return (_getType() & ~(TypeMask.kScale_Mask | TypeMask.kTranslate_Mask)) == 0;
        }

        public uiRect _mapRectScaleTranslate(uiRect src) {
            D.assert(_isScaleTranslate());

            var sx = kMScaleX;
            var sy = kMScaleY;
            var tx = kMTransX;
            var ty = kMTransY;

            var dst = uiRectHelper.fromLTRB(
                src.left * sx + tx,
                src.top * sy + ty,
                src.right * sx + tx,
                src.bottom * sy + ty
            );

            dst = uiRectHelper.normalize(dst);
            return dst;
        }
    }


    public partial struct uiMatrix3 {
        //public methods  
        public uiMatrix3(uiMatrix3 other) {
            kMScaleX = other.kMScaleX;
            kMSkewX = other.kMSkewX;
            kMTransX = other.kMTransX;
            kMSkewY = other.kMSkewY;
            kMScaleY = other.kMScaleY;

            kMTransY = other.kMTransY;

            kMPersp0 = other.kMPersp0;

            kMPersp1 = other.kMPersp1;
            kMPersp2 = other.kMPersp2;
            fTypeMask = other.fTypeMask;
        }


        public void copyFrom(uiMatrix3 other) {
            kMScaleX = other.kMScaleX;
            kMSkewX = other.kMSkewX;
            kMTransX = other.kMTransX;
            kMSkewY = other.kMSkewY;
            kMScaleY = other.kMScaleY;

            kMTransY = other.kMTransY;

            kMPersp0 = other.kMPersp0;

            kMPersp1 = other.kMPersp1;

            kMPersp2 = other.kMPersp2;
            fTypeMask = other.fTypeMask;
        }


        public bool isIdentity() {
            return _getType() == 0;
        }

        public float getScaleX() {
            return kMScaleX;
        }

        public float getScaleY() {
            return kMScaleY;
        }

        public float getSkewY() {
            return kMSkewY;
        }

        public float getSkewX() {
            return kMSkewX;
        }

        public float getTranslateX() {
            return kMTransX;
        }

        public float getTranslateY() {
            return kMTransY;
        }

        public float getPerspX() {
            return kMPersp0;
        }

        public float getPerspY() {
            return kMPersp1;
        }

        public void postConcat(uiMatrix3 mat) {
            if (!mat.isIdentity()) {
                _setConcat(mat, this);
            }
        }

        public void setSinCos(float sinV, float cosV, float px, float py) {
            var oneMinusCosV = 1 - cosV;

            kMScaleX = cosV;
            kMSkewX = -sinV;
            kMTransX = uiScalarUtils.sdot(sinV, py, oneMinusCosV, px);

            kMSkewY = sinV;
            kMScaleY = cosV;
            kMTransY = uiScalarUtils.sdot(-sinV, px, oneMinusCosV, py);

            kMPersp0 = kMPersp1 = 0;
            kMPersp2 = 1;

            _setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
        }

        public void setSinCos(float sinV, float cosV) {
            kMScaleX = cosV;
            kMSkewX = -sinV;
            kMTransX = 0;

            kMSkewY = sinV;
            kMScaleY = cosV;
            kMTransY = 0;

            kMPersp0 = kMPersp1 = 0;
            kMPersp2 = 1;

            _setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
        }

        public void setTranslate(float dx, float dy) {
            if ((dx != 0) | (dy != 0)) {
                kMTransX = dx;
                kMTransY = dy;

                kMScaleX = kMScaleY = kMPersp2 = 1;
                kMSkewX = kMSkewY =
                    kMPersp0 = kMPersp1 = 0;

                _setTypeMask((int) TypeMask.kTranslate_Mask | kRectStaysRect_Mask);
            }
            else {
                reset();
            }
        }


        public void postTranslate(float dx, float dy) {
            if (_hasPerspective()) {
                var m = new uiMatrix3();
                m.setTranslate(dx, dy);
                postConcat(m);
            }
            else {
                kMTransX += dx;
                kMTransY += dy;
                _updateTranslateMask();
            }
        }

        public void postScale(float sx, float sy) {
            if (1 == sx && 1 == sy) {
                return;
            }

            var m = new uiMatrix3();
            m._setScale(sx, sy);
            postConcat(m);
        }

        public bool rectStaysRect() {
            if ((fTypeMask & kUnknown_Mask) != 0) {
                fTypeMask = _computeTypeMask();
            }

            return (fTypeMask & kRectStaysRect_Mask) != 0;
        }

        public uiMatrix3? invert(bool invertableCheck = false) {
            if (isIdentity()) {
                return I();
            }

            return _invertNonIdentity(invertableCheck);
        }

        public uiRect mapRect(uiRect src) {
            if (_getType() <= TypeMask.kTranslate_Mask) {
                var tx = kMTransX;
                var ty = kMTransY;

                var dst = uiRectHelper.fromLTRB(
                    src.left + tx,
                    src.top + ty,
                    src.right + tx,
                    src.bottom + ty
                );
                dst = uiRectHelper.normalize(dst);
                return dst;
            }

            if (_isScaleTranslate()) {
                return _mapRectScaleTranslate(src);
            }
            else {
                float x1, y1, x2, y2, x3, y3, x4, y4;
                mapXY(src.left, src.top, out x1, out y1);
                mapXY(src.right, src.top, out x2, out y2);
                mapXY(src.right, src.bottom, out x3, out y3);
                mapXY(src.left, src.bottom, out x4, out y4);

                var minX = x1;
                var minY = y1;
                var maxX = x1;
                var maxY = y1;

                if (x2 < minX) {
                    minX = x2;
                }

                if (x2 > maxX) {
                    maxX = x2;
                }

                if (y2 < minY) {
                    minY = y2;
                }

                if (y2 > maxY) {
                    maxY = y2;
                }

                if (x3 < minX) {
                    minX = x3;
                }

                if (x3 > maxX) {
                    maxX = x3;
                }

                if (y3 < minY) {
                    minY = y3;
                }

                if (y3 > maxY) {
                    maxY = y3;
                }

                if (x4 < minX) {
                    minX = x4;
                }

                if (x4 > maxX) {
                    maxX = x4;
                }

                if (y4 < minY) {
                    minY = y4;
                }

                if (y4 > maxY) {
                    maxY = y4;
                }

                var dst = uiRectHelper.fromLTRB(minX, minY, maxX, maxY);
                return dst;
            }
        }

        public void mapXY(float x, float y, out float x1, out float y1) {
            _getMapXYProc()(this, x, y, out x1, out y1);
        }

        public Matrix4x4 toMatrix4x4() {
            var matrix = Matrix4x4.identity;

            matrix[0, 0] = kMScaleX; // row 0
            matrix[0, 1] = kMSkewX;
            matrix[0, 3] = kMTransX;

            matrix[1, 0] = kMSkewY; // row 1
            matrix[1, 1] = kMScaleY;
            matrix[1, 3] = kMTransY;

            matrix[3, 0] = kMPersp0; // row 2
            matrix[3, 1] = kMPersp1;
            matrix[3, 3] = kMPersp2;

            return matrix;
        }

        public void preTranslate(float dx, float dy) {
            var mask = _getType();

            if (mask <= TypeMask.kTranslate_Mask) {
                kMTransX += dx;
                kMTransY += dy;
            }
            else if ((mask & TypeMask.kPerspective_Mask) != 0) {
                var m = new uiMatrix3();
                m.setTranslate(dx, dy);
                preConcat(m);
                return;
            }
            else {
                kMTransX += kMScaleX * dx + kMSkewX * dy;
                kMTransY += kMSkewY * dx + kMScaleY * dy;
            }

            _updateTranslateMask();
        }

        public void preConcat(uiMatrix3 other) {
            if (!other.isIdentity()) {
                _setConcat(this, other);
            }
        }

        public void preScale(float sx, float sy, float px, float py) {
            if (1 == sx && 1 == sy) {
                return;
            }

            var m = new uiMatrix3();
            m.setScale(sx, sy, px, py);
            preConcat(m);
        }

        public void preScale(float sx, float sy) {
            if (1 == sx && 1 == sy) {
                return;
            }

            kMScaleX *= sx;
            kMSkewY *= sx;
            kMPersp0 *= sx;

            kMSkewX *= sy;
            kMScaleY *= sy;
            kMPersp1 *= sy;

            if (kMScaleX == 1 && kMScaleY == 1 && (fTypeMask &
                                                             (int) (TypeMask.kPerspective_Mask | TypeMask.kAffine_Mask)
                ) == 0) {
                _clearTypeMask((int) TypeMask.kScale_Mask);
            }
            else {
                _orTypeMask((int) TypeMask.kScale_Mask);
            }
        }

        public void preRotate(float radians, float px, float py) {
            var m = new uiMatrix3();
            m.setRotate(radians, px, py);
            preConcat(m);
        }

        public void preRotate(float radians) {
            var m = new uiMatrix3();
            m.setRotate(radians);
            preConcat(m);
        }

        public void preSkew(float kx, float ky) {
            var m = new uiMatrix3();
            m.setSkew(kx, ky);
            preConcat(m);
        }

        public void setScale(float sx, float sy, float px, float py) {
            if (1 == sx && 1 == sy) {
                reset();
            }
            else {
                _setScaleTranslate(sx, sy, px - sx * px, py - sy * py);
            }
        }
    }
}