Add infinite lines.

src/lines.rs

@@ -1,3 +1,5 @@
+use sys::ImPlotInfLinesFlags__ImPlotInfLinesFlags_Horizontal;
+
 use crate::sys;
 use std::ffi::CString;
 use std::os::raw::c_char;
@@ -35,6 +37,19 @@ impl PlotLine {
 		}
 	}
 
+	pub fn plot_inf(&self, x: f64) {
+		unsafe {
+			sys::ImPlot_PlotInfLines_doublePtr(
+				self.label.as_ptr() as *const c_char,
+				&x,
+				1,
+				ImPlotInfLinesFlags__ImPlotInfLinesFlags_Horizontal as i32,
+				0,
+				8, /* sizeof(double) */
+			);
+		}
+	}
+
 	pub fn plot(&self, x: &[f64], y: &[f64]) {
 		if x.len().min(y.len()) == 0 {
 			return;