GU/GU_TrimBasePatch.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * Produced by:
 *      Jeff Lait
 *      Side Effects
 *      477 Richmond Street West
 *      Toronto, Ontario
 *      Canada   M5V 3E7
 *      416-504-9876
 *
 * NAME:        GU library (C++)
 *
 * COMMENTS:    Trimmed subpatch tesselator.
 *
 */

#ifndef __GU_TrimBasePatch_h__
#define __GU_TrimBasePatch_h__

#include "GU_API.h"
#include <UT/UT_RefArray.h>

class UT_BoundingRect;
class GD_TrimLoop;
class GEO_TPSurf;
class GU_TrimCells;

// Notes on terminology:
// left/right is increasing u values.
// top/bot is increasing v values.
// +---+---+
// |   |   | has two u divisions.

class GU_API GU_TrimBasePoint {
public:
    float                u, v;          // Parameteric value of point.
    void                *worlddata;     // Position in world space, NULL if 
                                        // not evaluated.  Not owned by this.
    float                dist(const GU_TrimBasePoint &point) const
                         { return SYSsqrt((u-point.u)*(u-point.u) + 
                                        (v-point.v)*(v-point.v)); }
};

enum GU_TrimPatchPointType {
    GU_TrimNormalPointType = 0,
    GU_TrimUXsectionPointType = 1,
    GU_TrimVXsectionPointType = 2,
    GU_TrimExteriorPointType = 3        // Outside of domain!
};

class GU_API GU_TrimPatchPoint : public GU_TrimBasePoint {
public:
    GU_TrimPatchPoint   *next;          // Next point along line.
    // These are specific to crossing points, and null for curve
    // tesselation points.
    GU_TrimPatchPoint   *above, *below; // prev/next on isoparm.
                    // Above is greater u/v, below is lower.
    int                  increasing;    // Whether crosses in increasing 
                                        // direction
    GU_TrimPatchPointType type;
    int                  marker;        // Last cell id to touch this.
};

class GU_API GU_TrimCornerPoint : public GU_TrimBasePoint {
public:
};

//
// Base class for tesselating on trim surfaces.
//
class GU_API GU_TrimBaseTesselator {
public:
    GU_TrimBaseTesselator() {}
    virtual ~GU_TrimBaseTesselator() {}

    // Prepare tesselator for tesselation:
    virtual void reset() = 0;

    // Add points in counter clockwise order
    virtual void startPoly() = 0;
    virtual void endPoly() = 0;
    virtual void cancelPoly() = 0;
    virtual void addPolyPoint(GU_TrimBasePoint *point) = 0;

    // Add points two at a time:
    virtual void startTStrip() = 0; 
    virtual void endTStrip() = 0; 
    virtual void addTStripPoints(GU_TrimBasePoint *p1, 
                                 GU_TrimBasePoint *p2) = 0;
};

class GU_API GU_TrimBaseRegion {
public:
    GU_TrimBaseRegion() {}
    virtual ~GU_TrimBaseRegion() {}

    // Begins a new curve.  Closed determines if we should insert the
    // first point or assume the curve will loop back there.
    virtual GU_TrimBaseRegion   *newCurve(GU_TrimPatchPoint *point, 
                                        int closed = 0) = 0;
    // Add the segment point to point->next to any edge lists it crosses.
    virtual GU_TrimBaseRegion   *addSegment(GU_TrimPatchPoint *point) = 0;
    virtual GU_TrimBaseRegion   *addSegment(GU_TrimPatchPoint *point,
                                    int newi, int newj) = 0;
    virtual int                  endCurve(GU_TrimPatchPoint *point, 
                                        int closed = 0) = 0;

    void                         setOtherRegion(GU_TrimBaseRegion *other);

    virtual void                 tesselate(GU_TrimBaseTesselator *tesselator)
                                                 = 0;

    virtual void                 getCurrentIJ(int &i, int &j) = 0; 
protected:
    virtual void                 setCurrentIJ(int i, int j) = 0;

    GU_TrimBaseRegion           *myOtherRegion;
    // Has current curve crossed a boundary line?
    int                          hasCrossedLine;
};


class GU_API GU_TrimCoreRegion : public GU_TrimBaseRegion {
public:
    GU_TrimCoreRegion();
    virtual ~GU_TrimCoreRegion();

    // Begins a new curve.  Closed determines if we should insert the
    // first point or assume the curve will loop back there.
    virtual GU_TrimBaseRegion   *newCurve(GU_TrimPatchPoint *point, 
                                          int closed = 0);
    // Add the segment point to point->next to any edge lists it crosses.
    virtual GU_TrimBaseRegion   *addSegment(GU_TrimPatchPoint *point);
    virtual GU_TrimBaseRegion   *addSegment(GU_TrimPatchPoint *point,
                                    int forcei, int forcej);
    // Returns true if curve has crossed.
    virtual int                  endCurve(GU_TrimPatchPoint *point, 
                                            int closed = 0);

    virtual void                 tesselate(GU_TrimBaseTesselator *tesselator);

    void                         init(GU_TrimPatchPoint **edges,
                                         GU_TrimCornerPoint *corners,
                                         float *uisos, float *visos,
                                         int divu, int divv,
                                         GD_TrimLoop *origloops);

    virtual void                 getCurrentIJ(int &i, int &j)  
                                                        { i = curI; j = curJ; }

    // For cells of type 0, 2, 3 determines whether trimmed in (1) or
    // trimmed out (0)
    int                          getCellState(int ucell, int vcell);
    // For the corner at the specified isoparms, determines if the corner
    // is trimmed in (1) or trimmed out (0)
    int                          getTrimStateAt(int uiso, int viso);
protected:
    virtual void                 setCurrentIJ(int i, int j);

private:
    // Adds intersection to specified edge list (U or V edges).  Position
    // is i/j, new isect point created & inserted between point & point->next.
    // Increasing set appropriately.
    void                         insertUIsection(int i, int j, 
                                        GU_TrimPatchPoint *point, float v,
                                        int uincrease = -1);
    void                         insertVIsection(int i, int j, 
                                        GU_TrimPatchPoint *point, float u,
                                        int vincrease = -1);

    // Returns intersection of point to point->next with i or jth isoparm.
    float                        findUIsection(int i, 
                                         GU_TrimPatchPoint *point, 
                                         float *d = 0);
    float                        findVIsection(int j, 
                                         GU_TrimPatchPoint *point,
                                         float *d = 0);

    // Handles tesselation of cell w/ edges present:
    // u/vtrimmed in set to 1 if bot/right has a present edge.
    void                         tesselateCell(
                                        GU_TrimBaseTesselator *tesselator,
                                        int topedge, int leftedge,
                                        int topleftcorner, int &utrimmedin,
                                        int &vtrimmedin, int i, int j);

    // Finds next inbound point not tagged with marker in counter clockwise
    // direction of first/side.  If first NULL, looks from the end.
    // If tesselator given, adds corner points to tesselator.
    // Sides: 0 top, 1: left, 2: bot, 3: right
    GU_TrimPatchPoint           *findInboundPoint(int marker,
                                        int topedge, int leftedge,
                                        int topleftcorner, int side = 0,
                                        GU_TrimPatchPoint *first = 0,
                                        GU_TrimBaseTesselator *tesselator = 0,
                                        int *utrimmed = 0, int *vtrimmed = 0);

    // top row of edges is at 0, bottom starts at vdiv*udiv.
    // So for edge on u isoparm i, and to right of v isoparm j,
    // i*udiv + j is appropriate entry.
    GU_TrimPatchPoint           **myUEdges;

    // top row of edges is at 0, bottom starts at (vdiv+1)*(udiv-1).
    // So for edge on v isoparm j, and below u isoparm i,
    // i*(udiv+1) + j is appropriate entry.
    GU_TrimPatchPoint           **myVEdges;

    // List of all corners, see base patch for layout.
    GU_TrimCornerPoint          *myCorners;

    int                          curI, curJ;    // Current cell number.
                    // u isoparm i, and v isoparm j give top/left edges.
    int                          myUDiv, myVDiv;

    // Our strips.
    GU_TrimCells                *myCells;

    // We do not own these:
    float                       *myUIsoparms, *myVIsoparms;
    GD_TrimLoop                 *myOriginalTrimLoops;
};

class GU_API GU_TrimBasePatch {
public:
    GU_TrimBasePatch();
    virtual ~GU_TrimBasePatch();

    // Traces & preps for tesselation
    void                 trace( UT_FloatArray &ubreaks, 
                                UT_FloatArray &vbreaks,
                                int uinteriordiv, int vinteriordiv,
                                float lodc = -1);

    // Performs tesselation
    void                 tesselate(GU_TrimBaseTesselator *tesselator);

    // Sets this' trim loops.  This owns these.
    int                  setTrimLoops(GD_TrimLoop *loops, float umin,
                                float vmin, float umax, float vmax);

    // Updates all points lying in certain cell boundaries.
    virtual void         refreshCells(GEO_TPSurf *surf, int umin, int umax, 
                                      int vmin, int vmax) = 0;
    
protected:
    // Initializes worlddata of given point:
    virtual void         fillPoint(GU_TrimPatchPoint *p) = 0;

    // Calls fill point for all normal curve values
    virtual void         fillCurvePoints();

    // Does fwd differencing of corner values:
    virtual void         fillCornerPoints() = 0;

    // Does fwd differencing of edge values (As along isoparms, can
    // optimize...)
    virtual void         fillEdgePoints();

    // Allocates / initializes corner points/edge arrays.
    void                 initCells();
    void                 freeCells();
    void                 freeCurves();

    // Follows a curve:
    void                 traceCurve(GD_TrimLoop *loop, float curvelod);

    GU_TrimCoreRegion   *myCoreRegion;

    // First ucorediv*(vcorediv+1) are edges along U isoparms,
    // next (ucorediv+1)*vcorediv are along V isoparms.  See TrimCoreRegion
    // for order within there.
    GU_TrimPatchPoint   **myEdgeListArray;

    // (vcorediv+1)*(ucorediv+1) points.  The intersection of the u isoparm
    // i with the v isoparm j is at index i*(ucorediv+1) + j
    // The actual values will be filled out by GU_TrimCoreRegion.
    GU_TrimCornerPoint  *myCornerPointArray;

    // Starting points of curves, linked via above pointers.
    GU_TrimPatchPoint   *myCurveStarts;

    // We own the following:
    float               *myUIsoparms, *myVIsoparms;

    GD_TrimLoop         *myTrimLoops;
    GD_TrimLoop         *myOriginalTrimLoops;

    int                  myUDiv, myVDiv;
    int                  myULod, myVLod;
};
#endif

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