Add more README improvements

README.md

@@ -3,11 +3,11 @@
 Perlin Explorer is a mod for Minetest to allow to test and experiment around with Perlin noises.
 
 This is especially useful for game and mod developers who want to fine-tune the noises in an
-efficient manner. It's also useful to discover useful noise parameters for the various
+efficient manner. It’s also useful to discover useful noise parameters for the various
 mapgen settings in Minetest.
 
-This mod uses Minetest's builtin Perlin noise, so the same rules apply here.
+This mod uses Minetest’s builtin Perlin noise, so the same rules apply here.
-Refer to Minetest's documentation to learn about noise parameters.
+Refer to Minetest’s documentation to learn about noise parameters.
 
 ## /!\ WARNING WARNING WARNING /!\
 
@@ -26,7 +26,7 @@ security-tested yet.
 	* Color denotes value, cutoff points can be customized
 	* Choose between solid nodes, transparent grid nodes, and tiny climbable cube nodes
 * Generate a small portion of the noise as map at a given area
-* Enable "mapgen mode" to automatically generate a map as you move around
+* Enable “mapgen mode” to automatically generate a map as you move around
 * Load predefined Perlin noises from the Minetest configuration
 * Save noise parameters into profiles for later use
 * Mathematical and statistical analysis of noises
@@ -67,6 +67,19 @@ This document is *not* an introduction to Perlin noises
 and noise parameters. Please refer to the Minetest Lua API
 documentation to learn more.
 
+### Active noise
+This tool heavily relies on something called the “active noise”
+(or “active noise parameters”). These are the noise parameters
+and options that the mod will use for various operations, like
+getting values, generating nodes, using mapgen mode, etc. The “Apply” button
+in the Perlin Noise Creator tool sets the active noise.
+There can only be one active noise parameters. Also, the active
+noise is always valid; if you enter invalid noise parameters,
+the mod refuses them for the active noise.
+
+Initially, there are no active noise parameters, you you have
+to push the “Apply” button mentioned before first.
+
 ### The tools
 This section explains the various tools you have at your disposal.
 These tools are items, so check out your Creative Inventory
@@ -102,7 +115,7 @@ The bottom part contains the actual noise parameters.
 
 Please refer to Minetest Lua API documentation for a definition.
 Node this mod will enforce sanity check on some for the values,
-i.e. octaves can't be lower than 1.
+i.e. octaves can’t be lower than 1.
 
 HINT: If you hit “Enter” while the focus is on any of the noise
 parameters, this is the same as if you clicked “Accept” or “Accept
@@ -112,9 +125,10 @@ tweak a particular value.
 The little dice button randomizes the seed, it’s a simple
 convenience.
 
-The "Analyze" button shows you some basic info about the current
+The “Analyze” button shows you some basic info about the
-noise parameters. First, the minimum and maximum possible value
+noise parameters as displayed in the form. First, the
-throughout the entire noise. Then, the "wavelengths" for each
+minimum and maximum possible value
+throughout the entire noise. Then, the “wavelengths” for each
 axis. This means across how many nodes (roughly) the noise is
 stretched out, specified for each octave, beginning with the first.
 If any wavelength reaches a number lower than 1, it will be
@@ -122,6 +136,9 @@ shown in red because the official Lua documentation discourages
 this. If this happens, either increase the spread, the octaves
 or the lacunarity.
 
+**Note**: The Analyze feature uses the noise parameters currently
+in the form, *not* the *active* noise parameters.
+
 ###### Profiles
 A profile is just noise parameters that you can load for later use.
 It’s a convenience feature.
@@ -172,11 +189,13 @@ can do 3 things here:
   if the column says “31.4%”, “0.0” for “Max.” and “-4.2” for “Min.” that means
   that 31.4% of all values that were calculated were greater than or equal
   to -4.2, but smaller than 0.
-  The statistics always distributes the values into 10 “buckets” of
+  The statistics always distributes the values into “buckets” of
   equal sizes, beginning with the lowest theoretical value and
   ending with the highest one.
   The statistics are useful if you want to make sure certain values
   occur with a certain probability.
+  **Note**: This button will calculate statistics of the noise settings
+  as displayed in the form, it does *not* use the active noise.
 
 ##### Node generation
 
@@ -226,11 +245,11 @@ and ends at the ”High color at” setting.
 
 For example, if 0 is the midpoint, and the “low/high color”
 settings are -1 and 1, respectively, all values below 0 (the
-midpoint) will use the 'low values' color gradient and all
+midpoint) will use the ‘low values’ color gradient and all
-values above 0 will use the 'high values' color gradient.
+values above 0 will use the ‘high values’ color gradient.
-All values at -1 and below will have the "extreme low"
+All values at -1 and below will have the “extreme low”
 color (dark blue) and all values at 1 or above will have the
-"extreme high" (orange) color.
+“extreme high” (orange) color.
 Note that the colors only serve as a visual aid and
 given the limited palette, is only an estimation
 of the noise values. You can always use the Perlin Value