1*3e12c5d1SDavid du Colombier #include "mplot.h"
2*3e12c5d1SDavid du Colombier #define code(x, y) ((x<clipminx?1:x>clipmaxx?2:0)|(y<clipminy?4:y>clipmaxy?8:0))
vec(double xx,double yy)3*3e12c5d1SDavid du Colombier void vec(double xx, double yy){
4*3e12c5d1SDavid du Colombier int x0, y0, x1, y1, c0, c1, c, tx, ty;
5*3e12c5d1SDavid du Colombier double t;
6*3e12c5d1SDavid du Colombier t=SCX(e1->copyx); if(fabs(t)>BIGINT) return; x0=t;
7*3e12c5d1SDavid du Colombier t=SCY(e1->copyy); if(fabs(t)>BIGINT) return; y0=t;
8*3e12c5d1SDavid du Colombier t=SCX(xx); if(fabs(t)>BIGINT) return; x1=t;
9*3e12c5d1SDavid du Colombier t=SCY(yy); if(fabs(t)>BIGINT) return; y1=t;
10*3e12c5d1SDavid du Colombier e1->copyx=xx;
11*3e12c5d1SDavid du Colombier e1->copyy=yy;
12*3e12c5d1SDavid du Colombier /* clipping -- what a concept */
13*3e12c5d1SDavid du Colombier c0=code(x0, y0);
14*3e12c5d1SDavid du Colombier c1=code(x1, y1);
15*3e12c5d1SDavid du Colombier while(c0|c1){
16*3e12c5d1SDavid du Colombier if(c0&c1) return;
17*3e12c5d1SDavid du Colombier c=c0?c0:c1;
18*3e12c5d1SDavid du Colombier if(c&1) ty=y0+(y1-y0)*(clipminx-x0)/(x1-x0), tx=clipminx;
19*3e12c5d1SDavid du Colombier else if(c&2) ty=y0+(y1-y0)*(clipmaxx-x0)/(x1-x0), tx=clipmaxx;
20*3e12c5d1SDavid du Colombier else if(c&4) tx=x0+(x1-x0)*(clipminy-y0)/(y1-y0), ty=clipminy;
21*3e12c5d1SDavid du Colombier else tx=x0+(x1-x0)*(clipmaxy-y0)/(y1-y0), ty=clipmaxy;
22*3e12c5d1SDavid du Colombier if(c==c0) x0=tx, y0=ty, c0=code(x0, y0);
23*3e12c5d1SDavid du Colombier else x1=tx, y1=ty, c1=code(x1, y1);
24*3e12c5d1SDavid du Colombier }
25*3e12c5d1SDavid du Colombier m_vector(x0, y0, x1, y1, e1->foregr);
26*3e12c5d1SDavid du Colombier }
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