changed parameter name

docs/lib-shape_trapezium.md

@@ -14,7 +14,7 @@ Returns shape points of an isosceles trapezoid. They can be used with xxx_extrud
 	include <shape_trapezium.scad>;
 
 	polygon(
-		shape_trapezium([20, 10], 
+		shape_trapezium([40, 20], 
 		h = 20,
 		corner_r = 2)
 	);
@@ -31,7 +31,7 @@ Returns shape points of an isosceles trapezoid. They can be used with xxx_extrud
 	width = 2;
 
 	shape_pts = shape_trapezium(
-		[20, 10], 
+		[40, 20], 
 		h = 20, 
 		corner_r = 2
 	);

src/__private__/__half_trapezium.scad

@@ -1,20 +1,18 @@
-function __half_trapezium(radius, h, round_r) =
+function __half_trapezium(length, h, round_r) =
     let(
-        is_vt = __is_vector(radius),
-        r1 = is_vt ? radius[0] : radius,
-        r2 = is_vt ? radius[1] : radius,
+        is_vt = __is_vector(length),
+        l1 = is_vt ? length[0] : length,
+        l2 = is_vt ? length[1] : length,
         frags = __frags(round_r),
-        b_ang = atan2(h, r1 - r2),
+        b_ang = atan2(h, l1 - l2),
         b_sector_angle = 180 - b_ang,
-        b_leng = r1 - round_r / tan(b_ang / 2),
+        b_leng = l1 - round_r / tan(b_ang / 2),
         b_round_frags = frags * b_sector_angle / 360,
         b_end_angle = -90 + b_sector_angle,
         t_sector_angle = b_ang,
-        t_leng = r2 - round_r * tan(t_sector_angle / 2),
+        t_leng = l2 - round_r * tan(t_sector_angle / 2),
         t_round_frags = frags * t_sector_angle / 360,
-        
         half_h = h / 2,
-        
         br_corner = [
             for(pt = __pie_for_rounding(round_r, -90, b_end_angle, b_round_frags))
                 [pt[0] + b_leng, pt[1] + round_r - half_h]

src/__private__/__trapezium.scad

@@ -1,6 +1,6 @@
-function __trapezium(radius, h, round_r) =
+function __trapezium(length, h, round_r) =
     let(
-        r_half_trapezium = __half_trapezium(radius, h, round_r),
+        r_half_trapezium = __half_trapezium(length / 2, h, round_r),
         to = len(r_half_trapezium) - 1,
         l_half_trapezium = [
             for(i = [0:to]) 

src/rounded_square.scad

@@ -21,12 +21,9 @@ module rounded_square(size, corner_r, center = false) {
     is_vt = __is_vector(size);
     x = is_vt ? size[0] : size;
     y = is_vt ? size[1] : size;       
-
-    half_x = x / 2;
-    half_y = y / 2;
     
-    translate(center ? [0, 0] : [half_x, half_y]) polygon(__trapezium(
-        radius = half_x, 
+    translate(center ? [0, 0] : [x / 2, y / 2]) polygon(__trapezium(
+        length = x, 
         h = y, 
         round_r = corner_r
     ));

src/shape_square.scad

@@ -25,7 +25,7 @@ function shape_square(size, corner_r = 0) =
         y = is_vt ? size[1] : size        
     )
     __trapezium(
-        radius = x / 2, 
+        length = x, 
         h = y, 
         round_r = corner_r
     );

src/shape_trapezium.scad

@@ -18,9 +18,9 @@ include <__private__/__pie_for_rounding.scad>;
 include <__private__/__half_trapezium.scad>;
 include <__private__/__trapezium.scad>;
 
-function shape_trapezium(radius, h, corner_r = 0) = 
+function shape_trapezium(length, h, corner_r = 0) = 
     __trapezium(
-        radius = radius, 
+        length = length, 
         h = h, 
         round_r = corner_r
     );