ref: 6d9a739ab64ff1c33b336569708e2736957bcaf9
dir: /sys/src/libgeometry/rframe.c/
#include <u.h> #include <libc.h> #include <geometry.h> Point2 rframexform(Point2 p, RFrame rf) { Matrix m = { rf.bx.x, rf.bx.y, -dotvec2(rf.bx, rf.p), rf.by.x, rf.by.y, -dotvec2(rf.by, rf.p), 0, 0, 1, }; return xform(p, m); } Point3 rframexform3(Point3 p, RFrame3 rf) { Matrix3 m = { rf.bx.x, rf.bx.y, rf.bx.z, -dotvec3(rf.bx, rf.p), rf.by.x, rf.by.y, rf.by.z, -dotvec3(rf.by, rf.p), rf.bz.x, rf.bz.y, rf.bz.z, -dotvec3(rf.bz, rf.p), 0, 0, 0, 1, }; return xform3(p, m); } Point2 invrframexform(Point2 p, RFrame rf) { Matrix m = { rf.bx.x, rf.bx.y, -dotvec2(rf.bx, rf.p), rf.by.x, rf.by.y, -dotvec2(rf.by, rf.p), 0, 0, 1, }; invm(m); return xform(p, m); } Point3 invrframexform3(Point3 p, RFrame3 rf) { Matrix3 m = { rf.bx.x, rf.bx.y, rf.bx.z, -dotvec3(rf.bx, rf.p), rf.by.x, rf.by.y, rf.by.z, -dotvec3(rf.by, rf.p), rf.bz.x, rf.bz.y, rf.bz.z, -dotvec3(rf.bz, rf.p), 0, 0, 0, 1, }; invm3(m); return xform3(p, m); }