ref: 6dce09cec3bf6a689fa9a3f838df67d7d48d9d1a
dir: /libdraw/poly.c/
#include "lib9.h" #include "draw.h" static uchar* addcoord(uchar *p, int oldx, int newx) { int dx; dx = newx-oldx; /* does dx fit in 7 signed bits? */ if((unsigned)(dx - -0x40) <= 0x7F) *p++ = dx&0x7F; else{ *p++ = 0x80 | (newx&0x7F); *p++ = newx>>7; *p++ = newx>>15; } return p; } static void dopoly(int cmd, Image *dst, Point *pp, int np, int end0, int end1, int radius, Image *src, Point *sp, Drawop op) { uchar *a, *t, *u; int i, ox, oy; if(np == 0) return; t = malloc(np*2*3); if(t == nil) return; u = t; ox = oy = 0; for(i=0; i<np; i++){ u = addcoord(u, ox, pp[i].x); ox = pp[i].x; u = addcoord(u, oy, pp[i].y); oy = pp[i].y; } _setdrawop(dst->display, op); a = bufimage(dst->display, 1+4+2+4+4+4+4+2*4+(u-t)); if(a == 0){ free(t); _drawprint(2, "image poly: %r\n"); return; } a[0] = cmd; BP32INT(a+1, dst->id); BP16INT(a+5, np-1); BP32INT(a+7, end0); BP32INT(a+11, end1); BP32INT(a+15, radius); BP32INT(a+19, src->id); BP32INT(a+23, sp->x); BP32INT(a+27, sp->y); memmove(a+31, t, u-t); free(t); } void poly(Image *dst, Point *p, int np, int end0, int end1, int radius, Image *src, Point sp) { dopoly('p', dst, p, np, end0, end1, radius, src, &sp, SoverD); } void polyop(Image *dst, Point *p, int np, int end0, int end1, int radius, Image *src, Point sp, Drawop op) { dopoly('p', dst, p, np, end0, end1, radius, src, &sp, op); } void fillpoly(Image *dst, Point *p, int np, int wind, Image *src, Point sp) { dopoly('P', dst, p, np, wind, 0, 0, src, &sp, SoverD); } void fillpolyop(Image *dst, Point *p, int np, int wind, Image *src, Point sp, Drawop op) { dopoly('P', dst, p, np, wind, 0, 0, src, &sp, op); }