What is the way to form a curve with three points P1, P11 and P2, and the curve does not change?

ofPolyline pline;
pline.curveTo(glm::vec3(0.0f, 0.0f, 0.0f));//p0
pline.curveTo(glm::vec3(350.0f, 700.0f, 0.0f));//p1
pline.curveTo(glm::vec3(600.0f, 500.0f, 0.0f));//p2
pline.curveTo(glm::vec3(1920.0f, 1080.0f, 0.0f));//p3
pline.draw();

hello everyone,Please tell me about the sampling line. Now there is a curve from P1 to P2. What is the way to generate a curve from newp1 - newp11 - newp2, and the curve remains unchanged? How can we find these three new points

thanks everyone.

It helps if you explain clearer what is newp1 - newp11 - newp2

but if you want to find specific points in the curve you created you can use
ofPolyline::getPointAtLength
ofPolyline::getPointAtPercent

thanks