gp_line_clip.h File Reference

Line clipping algorithm. More...

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Functions
int	gp_line_clip (int *px0, int *py0, int *px1, int *py1, int xmax, int ymax)
	Clips a line.

Detailed Description

Line clipping algorithm.

Definition in file gp_line_clip.h.

Function Documentation

gp_line_clip()

int gp_line_clip	(	int *	px0,
		int *	py0,
		int *	px1,
		int *	py1,
		int	xmax,
		int	ymax
	)

Clips a line.

Clips a line so that the start and end points are within (0, xmax) and (0, ymax). This is used by the line drawing algorithms to make sure that the we only draw the part of line within pixmap.

Parameters

px0	A starting x coordinate to clip.
py0	A starting y cooridinate to clip.
px1	An ending x coordinate to clip.
py1	An ending y coordinate to clip.
xmax	A x coordinate upper limit.
ymax	A y coordinate upper limit.

Returns

Zero if the line is completely outside of the pixmap, non-zero otherwise.