refactor

src/lib.rs

@@ -10,42 +10,6 @@ static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
 pub type DrawResult<T> = Result<T, Box<dyn std::error::Error>>;
 
-// Creates and does the math for creating all the rectangles under the graph
-#[inline(always)]
-fn integral_rectangles(
-    min_x: f32, step: f32, num_interval: usize, func: &dyn Fn(f64) -> f64,
-) -> (Vec<(f32, f32, f32)>, f32) {
-    let data2: Vec<(f32, f32, f32)> = (0..num_interval)
-        .map(|e| {
-            let x: f32 = ((e as f32) * step) + min_x;
-
-            // Makes sure rectangles are properly handled on x values below 0
-            let x2: f32 = match x > 0.0 {
-                true => x + step,
-                false => x - step,
-            };
-
-            let tmp1: f32 = func(x as f64) as f32;
-            let tmp2: f32 = func(x2 as f64) as f32;
-
-            // Chooses the y value who's absolute value is the smallest
-            let y: f32 = match tmp2.abs() > tmp1.abs() {
-                true => tmp1,
-                false => tmp2,
-            };
-
-            if !y.is_nan() {
-                (x, x2, y)
-            } else {
-                (0.0, 0.0, 0.0)
-            }
-        })
-        .filter(|ele| ele != &(0.0, 0.0, 0.0))
-        .collect();
-    let area: f32 = data2.iter().map(|(_, _, y)| y * step).sum(); // sum of all rectangles' areas
-    (data2, area)
-}
-
 /// Result of screen to chart coordinates conversion.
 #[wasm_bindgen]
 pub struct Point {
@@ -145,8 +109,7 @@ impl ChartManager {
                 None => panic!("use_front_cache is true, but front_cache is None!"),
             },
             false => {
-                let output: (Vec<(f32, f32, f32)>, f32) =
+                let output: (Vec<(f32, f32, f32)>, f32) = self.integral_rectangles(step, &func);
-                    integral_rectangles(self.min_x, step, self.num_interval, &func);
                 self.front_cache = Some(output.clone());
                 output
             }
@@ -212,6 +175,42 @@ impl ChartManager {
 
         Ok(chart)
     }
+
+    // Creates and does the math for creating all the rectangles under the graph
+    #[inline(always)]
+    fn integral_rectangles(
+        &self, step: f32, func: &dyn Fn(f64) -> f64,
+    ) -> (Vec<(f32, f32, f32)>, f32) {
+        let data2: Vec<(f32, f32, f32)> = (0..self.num_interval)
+            .map(|e| {
+                let x: f32 = ((e as f32) * step) + self.min_x;
+
+                // Makes sure rectangles are properly handled on x values below 0
+                let x2: f32 = match x > 0.0 {
+                    true => x + step,
+                    false => x - step,
+                };
+
+                let tmp1: f32 = func(x as f64) as f32;
+                let tmp2: f32 = func(x2 as f64) as f32;
+
+                // Chooses the y value who's absolute value is the smallest
+                let y: f32 = match tmp2.abs() > tmp1.abs() {
+                    true => tmp1,
+                    false => tmp2,
+                };
+
+                if !y.is_nan() {
+                    (x, x2, y)
+                } else {
+                    (0.0, 0.0, 0.0)
+                }
+            })
+            .filter(|ele| ele != &(0.0, 0.0, 0.0))
+            .collect();
+        let area: f32 = data2.iter().map(|(_, _, y)| y * step).sum(); // sum of all rectangles' areas
+        (data2, area)
+    }
 }
 
 #[wasm_bindgen]