diff options
Diffstat (limited to 'src/cmd/plot/libplot/vec.c')
| -rw-r--r-- | src/cmd/plot/libplot/vec.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/cmd/plot/libplot/vec.c b/src/cmd/plot/libplot/vec.c new file mode 100644 index 00000000..89a51786 --- /dev/null +++ b/src/cmd/plot/libplot/vec.c @@ -0,0 +1,26 @@ +#include "mplot.h" +#define code(x, y) ((x<clipminx?1:x>clipmaxx?2:0)|(y<clipminy?4:y>clipmaxy?8:0)) +void vec(double xx, double yy){ + int x0, y0, x1, y1, c0, c1, c, tx, ty; + double t; + t=SCX(e1->copyx); if(fabs(t)>BIGINT) return; x0=t; + t=SCY(e1->copyy); if(fabs(t)>BIGINT) return; y0=t; + t=SCX(xx); if(fabs(t)>BIGINT) return; x1=t; + t=SCY(yy); if(fabs(t)>BIGINT) return; y1=t; + e1->copyx=xx; + e1->copyy=yy; + /* clipping -- what a concept */ + c0=code(x0, y0); + c1=code(x1, y1); + while(c0|c1){ + if(c0&c1) return; + c=c0?c0:c1; + if(c&1) ty=y0+(y1-y0)*(clipminx-x0)/(x1-x0), tx=clipminx; + else if(c&2) ty=y0+(y1-y0)*(clipmaxx-x0)/(x1-x0), tx=clipmaxx; + else if(c&4) tx=x0+(x1-x0)*(clipminy-y0)/(y1-y0), ty=clipminy; + else tx=x0+(x1-x0)*(clipmaxy-y0)/(y1-y0), ty=clipmaxy; + if(c==c0) x0=tx, y0=ty, c0=code(x0, y0); + else x1=tx, y1=ty, c1=code(x1, y1); + } + m_vector(x0, y0, x1, y1, e1->foregr); +} |