/*
 * Portions of this file are copyright Rebirth contributors and licensed as
 * described in COPYING.txt.
 * Portions of this file are copyright Parallax Software and licensed
 * according to the Parallax license below.
 * See COPYING.txt for license details.

THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/
/*
 *
 * Macros used for clipping
 *
 */


// sort two values
#define SORT2(a,b) do {                                                 \
	using std::swap;	\
	if((a) > (b)) swap(a,b);                                           \
} while(0)

# define FIXSCALE(var,arg,num,den) ((var) = fixmuldiv((arg),(num),(den)))

#define CLIPLINE(x1,y1,x2,y2,XMIN,YMIN,XMAX,YMAX,WHEN_OUTSIDE,WHEN_CLIPPED,MY_SCALE) do {       \
	int temp;                                                  \
	if(y1 > y2)                                                         \
		{																\
			using std::swap;	\
			swap(y1,y2); swap(x1,x2); }                                 \
	if((y2 < YMIN) || (y1 > YMAX))                                      \
		{ WHEN_OUTSIDE; }                                               \
	if(x1 < x2) {                                                       \
		if((x2 < XMIN) || (x1 > XMAX)) {                                \
			WHEN_OUTSIDE;                                               \
		}                                                               \
		if(x1 < XMIN) {                                                 \
			MY_SCALE(temp,(y2 - y1),(XMIN - x1),(x2 - x1)); \
			if((y1 += temp) > YMAX) { WHEN_OUTSIDE; }                   \
			x1 = XMIN;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
		if(x2 > XMAX) {                                                 \
			MY_SCALE(temp,(y2 - y1),(x2 - XMAX),(x2 - x1)); \
			if((y2 -= temp) < YMIN) { WHEN_OUTSIDE; }                   \
			x2 = XMAX;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
		if(y1 < YMIN) {                                                 \
			MY_SCALE(temp,(x2 - x1),(YMIN - y1),(y2 - y1)); \
			x1 += temp;                                                 \
			y1 = YMIN;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
		if(y2 > YMAX) {                                                 \
			MY_SCALE(temp,(x2 - x1),(y2 - YMAX),(y2 - y1)); \
			x2 -= temp;                                                 \
			y2 = YMAX;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
	}                                                                   \
	else {                                                              \
		if((x1 < XMIN) || (x2 > XMAX)) {                                \
			WHEN_OUTSIDE;                                               \
		}                                                               \
		if(x1 > XMAX) {                                                 \
			MY_SCALE(temp,(y2 - y1),(x1 - XMAX),(x1 - x2)); \
			if((y1 += temp) > YMAX) { WHEN_OUTSIDE; }                   \
			x1 = XMAX;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
		if(x2 < XMIN) {                                                 \
			MY_SCALE(temp,(y2 - y1),(XMIN - x2),(x1 - x2)); \
			if((y2 -= temp) < YMIN) { WHEN_OUTSIDE; }                   \
			x2 = XMIN;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
		if(y1 < YMIN) {                                                 \
			MY_SCALE(temp,(x1 - x2),(YMIN - y1),(y2 - y1)); \
			x1 -= temp;                                                 \
			y1 = YMIN;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
		if(y2 > YMAX) {                                                 \
			MY_SCALE(temp,(x1 - x2),(y2 - YMAX),(y2 - y1)); \
			x2 += temp;                                                 \
			y2 = YMAX;                                                  \
			WHEN_CLIPPED;                                               \
		}                                                               \
	}                                                                   \
} while(0)