72 lines
2.9 KiB
C
72 lines
2.9 KiB
C
#ifndef MATH_FOR_GRAPHICS_H
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#define MATH_FOR_GRAPHICS_H
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// math stuff for graphics, from FreePCB
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/* Function FindLineSegmentIntersection
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* find intersection between line y = a + bx and line segment (xi,yi) to (xf,yf)
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* if b > DBL_MAX/10, assume vertical line at x = a
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* return false if no intersection or true if intersect
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* return coords of intersections in *x1, *y1, *x2, *y2
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* if no intersection, returns min distance in dist
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*/
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bool FindLineSegmentIntersection( double a, double b, int xi, int yi, int xf, int yf,
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double * x1, double * y1, double * x2, double * y2, double * dist=NULL );
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/* Function FindSegmentIntersections
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* find intersections between line segment (xi,yi) to (xf,yf)
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* and line segment (xi2,yi2) to (xf2,yf2)
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* returns true if intersection found
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*/
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bool FindSegmentIntersections( int xi, int yi, int xf, int yf,
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int xi2, int yi2, int xf2, int yf2 );
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/**
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* Function TestForIntersectionOfStraightLineSegments
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* Test for intersection of line segments
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* If lines are parallel, returns false
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* If true, returns also intersection coords in x, y
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* if false, returns min. distance in dist (may be 0.0 if parallel)
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* and coords on nearest point in one of the segments in (x,y)
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* @param x1i, y1i, x1f, y1f = integer coordinates of the first segment
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* @param x2i, y2i, x2f, y2f = integer coordinates of the other segment
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* @param x, y = pointers on 2 integer to store the intersection coordinates (can be NULL)
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* @param dist = pointeur on a double to store the dist.
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* @return true if intersect.
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*/
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bool TestForIntersectionOfStraightLineSegments( int x1i, int y1i, int x1f, int y1f,
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int x2i, int y2i, int x2f, int y2f,
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int * x=NULL, int * y=NULL, double * dist=NULL );
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/* Function GetClearanceBetweenSegments
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* Get clearance between 2 segments
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* Returns coordinates of the closest point between these 2 segments in x, y
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* If clearance > max_cl, just returns max_cl+1 and doesn't return x,y
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*/
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int GetClearanceBetweenSegments( int x1i, int y1i, int x1f, int y1f, int w1,
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int x2i, int y2i, int x2f, int y2f, int w2,
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int max_cl, int * x, int * y );
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/**
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* Function GetPointToLineSegmentDistance
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* Get distance between line segment and point
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* @param x,y = point
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* @param xi,yi, xf,yf = the end-points of the line segment
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* @return the distance
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*/
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double GetPointToLineSegmentDistance( int x, int y, int xi, int yi, int xf, int yf );
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/* Function GetPointToLineDistance
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* Get min. distance from (x,y) to line y = a + bx
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* if b > DBL_MAX/10, assume vertical line at x = a
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* returns closest point on line in xpp, ypp
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*/
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double GetPointToLineDistance( double a, double b, int x, int y,
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double * xp=NULL, double * yp=NULL );
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inline double Distance( double x1, double y1, double x2, double y2 )
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{
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return hypot( x1 - x2, y1 - y2 );
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}
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#endif
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