/*

File: HexGrid.m

Abstract: Hexagonal grid.

Version: 1.0

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*/

#import "HexGrid.h"

#import "Game.h"

/**  WARNING: THIS CODE REQUIRES GARBAGE COLLECTION!

 **  This sample application uses Objective-C 2.0 garbage collection.

 **  Therefore, the source code in this file does NOT perform manual object memory management.

 **  If you reuse any of this code in a process that isn't garbage collected, you will need to

 **  add all necessary retain/release/autorelease calls, and implement -dealloc methods,

 **  otherwise unpleasant leakage will occur!

 **/

@implementation HexGrid

- (id) initWithRows: (unsigned)nRows columns: (unsigned)nColumns

            spacing: (CGSize)spacing

           position: (CGPoint)pos

{

    // Ignore given spacing.height; set it to make the hexagons regular.

    CGFloat capHeight = spacing.height / 2 * tan(M_PI/6);

    CGFloat side = spacing.height / 2 / cos(M_PI/6);

    spacing.height = side + capHeight;

    self = [super initWithRows: nRows columns: nColumns

                       spacing: spacing

                      position: pos];

    if( self ) {

        _capHeight = capHeight;

        _side = side;

        self.bounds = CGRectMake(-1, -1, 

                                 (nColumns+0.5)*spacing.width + 2,

                                 nRows*spacing.height+capHeight + 2);

        _cellClass = [Hex class];

    }

    return self;

}

- (id) initWithRows: (unsigned)nRows columns: (unsigned)nColumns

              frame: (CGRect)frame;

{

    // Compute the horizontal spacing:

    CGFloat s = floor(MIN( (frame.size.width -2.0)/nColumns,

                         (frame.size.height-2.0)/(nRows+0.5*tan(M_PI/6)) / (0.5*(tan(M_PI/6)+1/cos(M_PI/6))) ));

    return [self initWithRows: nRows columns: nColumns

                      spacing: CGSizeMake(s,s)

                     position: frame.origin];

}

- (void) addCellsInHexagon

{

    int size = _nRows - !(_nRows & 1);      // make it odd

    for( int row=0; row<_nRows; row++ ) {

        int n;                              // # of hexes remaining in this row

        if( row < size )

            n = size - abs(row-size/2);

        else

            n = 0;

        int c0 = floor(((int)_nRows+1-n -(row&1))/2.0);       // col of 1st remaining hex

        for( int col=0; col<_nColumns; col++ )

            if( col>=c0 && col<c0+n )

                [self addCellAtRow: row column: col];

    }

}

- (GridCell*) createCellAtRow: (unsigned)row column: (unsigned)col 

               suggestedFrame: (CGRect)frame

{

    // Overridden to stagger the odd-numbered rows

    if( row & 1 )

        frame.origin.x += _spacing.width/2;

    frame.size.height += _capHeight;

    return [super createCellAtRow: row column: col suggestedFrame: frame];

}

// Returns a hexagonal CG path defining a cell's outline. Used by cells when drawing & hit-testing.

- (CGPathRef) cellPath

{

    if( ! _cellPath ) {

        CGFloat x1 = _spacing.width/2;

        CGFloat x2 = _spacing.width;

        CGFloat y1 = _capHeight;

        CGFloat y2 = y1 + _side;

        CGFloat y3 = y2 + _capHeight;

        CGPoint p[6] = { {0,y1}, {x1,0}, {x2,y1}, {x2,y2}, {x1,y3}, {0,y2} };

        CGMutablePathRef path = CGPathCreateMutable();

        CGPathAddLines(path, NULL, p, 6);

        CGPathCloseSubpath(path);

        _cellPath = path;

    }

    return _cellPath;

}

@end

#pragma mark -

@implementation Hex

- (void) drawInParentContext: (CGContextRef)ctx fill: (BOOL)fill

{

    CGContextSaveGState(ctx);

    CGPoint pos = self.position;

    CGContextTranslateCTM(ctx, pos.x, pos.y);

    CGContextBeginPath(ctx);

    CGContextAddPath(ctx, ((HexGrid*)_grid).cellPath);

    CGContextDrawPath(ctx, (fill ?kCGPathFill :kCGPathStroke));

    if( !fill && self.highlighted ) {

        // Highlight by drawing my outline in the highlight color:

        CGContextSetStrokeColorWithColor(ctx, self.borderColor);

        CGContextSetLineWidth(ctx,6);

        CGContextBeginPath(ctx);

        CGContextAddPath(ctx, ((HexGrid*)_grid).cellPath);

        CGContextDrawPath(ctx, kCGPathStroke);

    }

    CGContextRestoreGState(ctx);

}

- (BOOL)containsPoint:(CGPoint)p

{

    return [super containsPoint: p]

        && CGPathContainsPoint( ((HexGrid*)_grid).cellPath, NULL, p, NO );

}

- (void) setHighlighted: (BOOL)highlighted

{

    if( highlighted != self.highlighted ) {

        [super setHighlighted: highlighted];

        [_grid setNeedsDisplay];        // So I'll be asked to redraw myself

    }

}

#pragma mark -

#pragma mark NEIGHBORS:

- (NSArray*) neighbors

{

    NSMutableArray *neighbors = [NSMutableArray arrayWithCapacity: 6];

    Hex* n[6] = {self.nw, self.ne, self.w, self.e, self.sw, self.se};

    for( int i=0; i<6; i++ )

        if( n[i] )

            [neighbors addObject: n[i]];

    return neighbors;

}

- (Hex*) nw     {return (Hex*)[_grid cellAtRow: _row+1 column: _column - ((_row+1)&1)];}

- (Hex*) ne     {return (Hex*)[_grid cellAtRow: _row+1 column: _column + (_row&1)];}

- (Hex*) e      {return (Hex*)[_grid cellAtRow: _row   column: _column + 1];}

- (Hex*) se     {return (Hex*)[_grid cellAtRow: _row-1 column: _column + (_row&1)];}

- (Hex*) sw     {return (Hex*)[_grid cellAtRow: _row-1 column: _column - ((_row-1)&1)];}

- (Hex*) w      {return (Hex*)[_grid cellAtRow: _row   column: _column - 1];}

// Directions relative to the current player:

- (Hex*) fl     {return self.fwdIsN ?self.nw :self.se;}

- (Hex*) fr     {return self.fwdIsN ?self.ne :self.sw;}

- (Hex*) r      {return self.fwdIsN ?self.e  :self.w;}

- (Hex*) br     {return self.fwdIsN ?self.se :self.nw;}

- (Hex*) bl     {return self.fwdIsN ?self.sw :self.ne;}

- (Hex*) l      {return self.fwdIsN ?self.w  :self.e;}

@end