Curves doc improved

public/externalLibs/graphics/CURVES_README.md

@@ -11,7 +11,7 @@ and of the point returned by the Curve as the position
 of your pen on a 2-dimensional plane at the time indicated by the
 argument. We represent the *type* of such Curve functions like this:
 
-Curve: Number → Point
+Curve := Number → Point
 
 where Point is a pair of Numbers. If `C` is a Curve, then the starting
 point of the curve is always `C(0)`, and the ending point is always
@@ -53,12 +53,19 @@ function unit_circle(t) {
 draw_connected_full_view(100)(unit_circle);
 ```
 </a>
-Here, `draw_connected_full_view` is applied to 100, which means that 100+1 points
-are being sampled. The function returns a Curve drawer: A function that turns
-a Curve into a Drawing. When a program evaluates to a Drawing, the Source system
+Here, `draw_connected_full_view` is applied to 100, which means that 100+1 numbers
+between 0 and 1 are being sampled:
+0, 0.01, 0.02, ..., 0.99, 1. 
+The function `draw_connected_full_view` is a Curve drawer:
+A function that takes a number and returns a function that turns
+a Curve into a Drawing.
+
+Drawer := Number → (Curve → Drawing)
+
+When a program evaluates to a Drawing, the Source system
 displays it graphically, in a window, instead of textually.
 
-The functions returned by `draw_connected_full_view` stretches or shrinks
+The functions returned by `draw_connected_full_view` stretch or shrink
 the given Curve to show the full curve and maximize its width and height,
 with some padding.
 

public/externalLibs/graphics/webGLcurve.js

@@ -79,10 +79,10 @@ function generateCurve(scaleMode, drawMode, numPoints, func, isFullView) {
  * displays it graphically, in a window, instead of textually.
  * The parts between (0,0) and (1,1) of the resulting Drawing 
  * are shown in the window.
- * @param {number} num - determines the number of points to be 
+ * @param {Number} num - determines the number of points to be 
  * sampled. Including 0 and 1,
  * there are <CODE>num + 1</CODE> evenly spaced sample points.
- * @return {function} function from Curves to Drawings.
+ * @return {function} function of type Curve → Drawing
  */
 function draw_connected(num) {
   return function(func) {
@@ -98,10 +98,10 @@ function draw_connected(num) {
  * displays it graphically, in a window, instead of textually.
  * The parts between (0,0) and (1,1) of the resulting Drawing 
  * are shown in the window.
- * @param {number} num - determines the number of points to be 
+ * @param {Number} num - determines the number of points to be 
  * sampled. Including 0 and 1,
  * there are <CODE>num + 1</CODE> evenly spaced sample points.
- * @return {function} function from Curves to Drawings.
+ * @return {function} function of type Curve → Drawing
  */
 function draw_points_on(num) {
   return curve => 
@@ -116,10 +116,10 @@ function draw_points_on(num) {
  * displays it graphically, in a window, instead of textually.
  * The Drawing is squeezed such that all its parts are shown in the
  * window.
- * @param {number} num - determines the number of points to be 
+ * @param {Number} num - determines the number of points to be 
  * sampled. Including 0 and 1,
  * there are <CODE>num + 1</CODE> evenly spaced sample points.
- * @return {function} function from Curves to Drawings.
+ * @return {function} function of type Curve → Drawing
  */
 function draw_points_squeezed_to_window(num) {
   return function(func) {
@@ -136,10 +136,10 @@ function draw_points_squeezed_to_window(num) {
  * The Drawing is resized proportionally such that it 
  * is shown as big as possible, and still fits entirely 
  * inside the window.
- * @param {number} num - determines the number of points to be 
+ * @param {Number} num - determines the number of points to be 
  * sampled. Including 0 and 1,
  * there are <CODE>num + 1</CODE> evenly spaced sample points.
- * @return {function} function from Curves to Drawings.
+ * @return {function} function of type Curve → Drawing
  */
 function draw_connected_squeezed_to_window(num) {
   return function(func) {
@@ -156,10 +156,10 @@ function draw_connected_squeezed_to_window(num) {
  * The Drawing is stretched or shrunk
  * to show the full curve
  * and maximize its width and height, with some padding.
- * @param {number} num - determines the number of points to be 
+ * @param {Number} num - determines the number of points to be 
  * sampled. Including 0 and 1,
  * there are <CODE>num + 1</CODE> evenly spaced sample points.
- * @return {function} function from Curves to Drawings.
+ * @return {function} function of type Curve → Drawing
  */
 function draw_connected_full_view(num) {
   return function(func) {
@@ -175,10 +175,10 @@ function draw_connected_full_view(num) {
  * displays it graphically, in a window, instead of textually.
  * The Drawing is scaled proportionally to show the full curve
  * and maximize its size, with some padding.
- * @param {number} num - determines the number of points to be 
+ * @param {Number} num - determines the number of points to be 
  * sampled. Including 0 and 1,
  * there are <CODE>num + 1</CODE> evenly spaced sample points.
- * @return {function} function from Curves to Drawings.
+ * @return {function} function of type Curve → Drawing
  */
 function draw_connected_full_view_proportional(num) {
   return function(func) {
@@ -188,8 +188,8 @@ function draw_connected_full_view_proportional(num) {
 
 /**
  * makes a Point with given x and y coordinates
- * @param {number} x - x-coordinate of new point
- * @param {number} y - y-coordinate of new point
+ * @param {Number} x - x-coordinate of new point
+ * @param {Number} y - y-coordinate of new point
  * @returns {Point} with x and y as coordinates
  */
 function make_point(x, y) {
@@ -199,7 +199,7 @@ function make_point(x, y) {
 /**
  * retrieves the x-coordinate a given Point
  * @param {Point} p - given point
- * @returns {number} x-coordinate of the Point
+ * @returns {Number} x-coordinate of the Point
  */
 function x_of(pt) {
   return pt[0]
@@ -208,7 +208,7 @@ function x_of(pt) {
 /**
  * retrieves the y-coordinate a given Point
  * @param {Point} p - given point
- * @returns {number} y-coordinate of the Point
+ * @returns {Number} y-coordinate of the Point
  */
 function y_of(pt) {
   return pt[1]

public/externalLibs/graphics/webGLhi_graph.js

@@ -64,7 +64,7 @@ function unit_line(t) {
  * only points with the given y-coordinate.
  * 
  * @param {number} t - fraction between 0 and 1
- * @returns {curve} horizontal Curve 
+ * @returns {Curve} horizontal Curve 
  */
 function unit_line_at(y) {
   return function(t) {
@@ -188,15 +188,14 @@ function deriv_t(n) {
 }
 
 /**
- * this function returns a unary Curve operator: 
- * It takes scaling factors <CODE>a</CODE> and <CODE>b</CODE> as arguments 
+ * this function takes scaling factors <CODE>a</CODE> and <CODE>b</CODE> as arguments 
  * and returns a unary Curve operator that
  * scales a given Curve by <CODE>a</CODE> in x-direction and by <CODE>b</CODE> 
  * in y-direction.
  * 
  * @param {number} a - scaling factor in x-direction
  * @param {number} b - scaling factor in y-direction
- * @returns {function} unary Curve operator
+ * @returns {unary_Curve_operator} function that takes a Curve and returns a Curve
  */
 function scale_x_y(a, b) {
   return curve => 
@@ -207,13 +206,12 @@ function scale_x_y(a, b) {
 }
 
 /**
- * this function returns a unary Curve operator: 
- * It takes a scaling factor s argument and returns a
+ * this function takes a scaling factor s argument and returns a
  * unary Curve operator that
  * scales a given Curve by s in x and y direction.
  * 
  * @param {number} s - scaling factor
- * @returns {function} unary Curve operator
+ * @returns {unary_Curve_operator} function that takes a Curve and returns a Curve
  */
 function scale(s) {
   return scale_x_y(s, s)
@@ -422,7 +420,7 @@ function show_connected_gosper(level) {
  * applying an angle given by the given angle-producing function
  * @param {number} level - number of repeated applications of gosperize to the curve
  * @param {function} angle_at - function that determines the angle at each level
- * @returns {curve} 
+ * @returns {Curve} 
  */
 function param_gosper(level, angle_at) {
   if (level === 0) {
@@ -433,11 +431,10 @@ function param_gosper(level, angle_at) {
 }
 
 /**
- * this function returns a unary Curve operator: 
- * It takes an angle theta and returns a Curve operator:
+ * this function takes an angle theta and returns a unary Curve operator:
  * A function that takes a Curve as argument and returns
  * a new Curve, according to the Gosper operation, modified
- * with the given angle
+ * with the given angle theta
  * 
  * @param {Curve} curve - given Curve
  * @returns {Curve} result Curve

public/externalLibs/video/video_lib.js

@@ -374,9 +374,10 @@ VD.handleUpdateDimensions = function(w, h) {
 
 // upside-down
 
-const WIDTH = get_video_width();
-const HEIGHT = get_video_height();
+
 function upside_down(src, dest) {
+    const WIDTH = get_video_width();
+    const HEIGHT = get_video_height();
     for (let x=0; x<WIDTH; x = x + 1) {
         for (let y=0; y<HEIGHT; y = y + 1) {
             copy_pixel(
@@ -390,17 +391,16 @@ function upside_down(src, dest) {
 apply_filter(upside_down);
 
 // sine distortion
-
-const wave_length = 5 * (2 * math_PI);
-const distortion = 10;
-
-const WIDTH = get_video_width();
-const HEIGHT = get_video_height();
-
-const mid_x = WIDTH/2;
-const mid_y = HEIGHT/2;
 
 function sine_distortion(src, dest) {
+    const wave_length = 5 * (2 * math_PI);
+    const distortion = 10;
+
+    const WIDTH = get_video_width();
+    const HEIGHT = get_video_height();
+
+    const mid_x = WIDTH/2;
+    const mid_y = HEIGHT/2;
     for (let x=0; x<WIDTH; x = x + 1){
         for (let y=0; y<HEIGHT; y = y + 1){
             const d_x = math_abs(mid_x - x);
@@ -421,10 +421,10 @@ apply_filter(sine_distortion);
 
 // inversion filter
 
-const WIDTH = get_video_width();
-const HEIGHT = get_video_height();
-
 function invert(src, dest) {
+    const WIDTH = get_video_width();
+    const HEIGHT = get_video_height();
+
     for (let x=0; x<WIDTH; x = x + 1){
         for (let y=0; y<HEIGHT; y = y + 1){
             dest[x][y] = [255 - red_of(src[x][y]),