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--- 4rpl:commands:signalgenerator [2019/04/29 11:19] – edits for ctyle and clarity Karsten75
+++ 4rpl:commands:signalgenerator [2024/05/29 15:57] (current) – Grabz
@@ Line 1: / Line 1: @@
-~~NOTOC~~
+<=[[4rpl:start| Index]] \\
+<=[[4rpl:start#math_utility| Math Utility]]
 ====== SignalGenerator ======
-SignalGenerator(<-interval <-sigFrequency <-phaseShift false <-signalType) ->sigValue
+SignalGenerator(<-time <-frequency <-phaseShift <-invert <-signalType) ->sigValue
 ===== Description =====
 Computes the value for a given signal waveform and pushes it to the stack.
-A function to derive the y-coordinate for a given x-co-ordiante on a graph line following one of the indicated wave patterns. Uselful to animate an object or to a given pattern over time. Could be used for instance to vary output from an emitter. Oscillating rightness of light source or beacon; Oscillating strength of an emitter over time - both of these can be thought of as a a use case for this function.
+A function to derive the y-coordinate for a given x-coordinate on a graph line following one of the indicated wave patterns.
-Arguments and type in order:
+Useful to animate an object or to produce a pattern over time. For instance, could be used  to vary the strength of an emitter over time, or to "pulse" (oscillate) the brightness of light source or beacon.
-  - Integer. the X coordinate in the waveform (Eg. time)
-  - Float. Frequency of the waveform
-  - Float. Phase Shift of the waveform
-  - Bool. invert the waveform
-  - Integer. Signal type (0 to 6 in types, below)
-Signal types.
+Arguments and type in order:
-  * 0 = NONE
+  * time: (float) Current step in the waveform. For a wave duration of 10.0, a step of 2.5 is a quarter of the way into a pattern.
-  * 1 = SINE
+  * frequency: (float) The frequency dictates the duration of each repeating pattern. A duration of 10.0 must set the frequency to 0.1 (1/10.0)
-  * 2 = SQUARE
+  * phaseShift: (float) A starting offset, between 0 and 1, where 0 will start the pattern at the beginning, and 1 will start it at the end. For sine wave, 0.25 will begin the wave at the peak, and 0.75 will begin at the valley.
-  * 3 = TRIANGLE
+  * invert: (0/1) inverts the waveform
-  * 4 = SAW-TOOTH
+  * signalType: (0 to 6)
-  * 5 = RANDOM
+     * 0 = NONE
-  * 6 = CONSTANT
+     * 1 = SINE
+     * 2 = SQUARE
+     * 3 = TRIANGLE
+     * 4 = SAW-TOOTH
+     * 5 = RANDOM
+     * 6 = CONSTANT
-=== Notes ===
+The resulting variable sigValue contains a float value between -1 and 1 which represents the current state of the wave at the provided step (time) given its provided frequency and other factors.
-== Phase Shift==
+===== Example =====
-The phase difference or phase shift as it is also called of a Sinusoidal Waveform is the angle Φ (Greek letter Phi), in degrees or radians that the waveform has shifted from a certain reference point along the horizontal zero axis. In other words phase shift is the lateral difference between two or more waveforms along a common axis and sinusoidal waveforms of the same frequency can have a phase difference.
+To create a sine wave that should start at its peak and run for 80 frames until it repeats, we should set the frequency to (1.0/80.0), phase shift to 0.25, start the time value at 0 and add 1 to it every frame.
-The phase difference, Φ of an alternating waveform can vary from between 0 to its maximum time period, T of the waveform during one complete cycle and this can be anywhere along the horizontal axis between, Φ = 0 to 2π (radians) or Φ  = 0 to 360o depending upon the angular units used.
+Play the following example in the editor console to spawn a continuous stream of creeper using the sine wave at the bottom of the map.
+<code 4RPL>
+$time:0
+$duration:80.0
+$phaseShift:0.25
+$invert:0
+$signalType:1
-===== Examples =====
+SignalGenerator(<-time <-frequency <-phaseShift <-invert <-signalType) ->sigValue
+<-time 1 add ->time
+#Let's use the result to spawn some creeper in a range of cells:
+AddCreeper(<-time <-mapX mod, <-sigValue 20.0 mul 20 add, 1)
+:Once
+.0 <-duration div ->frequency
+   GetMapSize ->mapZ ->mapX
+</code>
+===== Patterns =====
+[{{cw4_signalgenerator_1.png|1 - SINE, Pattern repeated every 60 cells}}] \\
+[{{cw4_signalgenerator_2.png|2 - SQUARE, Pattern repeated every 60 cells}}]
+[{{cw4_signalgenerator_3.png|3 - TRIANGLE, Pattern repeated every 60 cells}}] \\
+[{{cw4_signalgenerator_4.png|4 - SAW-TOOTH, Pattern repeated every 60 cells}}]
+[{{cw4_signalgenerator_5.png|5 - RANDOM, Pattern repeated every 5 cells}}] \\
+===== Extra Notes =====
+This is how each wave is produced in the game's source code:
+==== Sine wave function ====
+<code C#>
+float t = frequency * time + phase;
+value = (float)Mathf.Sin(2f * Mathf.PI * t);
+</code>
+==== Square wave function ====
+<code c#>
+value = Mathf.Sign(Mathf.Sin(2f * Mathf.PI * t));
+</code>
+==== For triangle wave function ====
+<code c#>
+value = 1f - 4f * (float)Mathf.Abs(Mathf.Round(t - 0.25f) - (t - 0.25f));
+</code>
+==== Saw-tooth wave function ====
+<code c#>
+value = 2f * (t - (float)Mathf.Floor(t + 0.5f));
+</code>
+==== Random wave function ====
+The function will output the same number for a given interval.  Interval is 1/frequency.  It only changes to a new value on the next interval.  Hence a random number per interval, or a random number at a given frequency.  Otherwise, just use the rand functions to get a new value on each call.
+<code c#>
+float interval = 1 / frequency;
+int slot = (int)(time / interval) ;
+slot = (slot * 1431655781) + (slot * 1183186591) + (slot * 622729787) + (slot * 338294347);
+if (slot < 0) slot = -slot;
+value = (float)GameSpace.instance.RandDoubleInput(randSeed + slot)*2-1;
+</code>
+===== Extra examples =====
+==== Sine Wave Creeper on Terrain ====
 <code 4rpl>
-#  On a map with terrain of 200 in X direction and at least 150 in Z direction (3D coordinates)
+# On a map with terrain of 200 in X direction and at least 150 in Z direction (3D coordinates)
 # generate a sine wave of creeper across the map.
-    ->numFrames
+# On a map with terrain of 200 in X direction and at least 150 in Z direction (3D coordinates)
-      ->frequency (1 div (AsFloat (<-numFrames)))
+# generate a sine wave of creeper across the map.
-     ->phaseShift
+ ->numFrames 			# at 30 frames a sec, cycle every 6 seconds.
+<-numFrames asFloat div ->frequency	#stepsize
+->phaseShift
 false ->invert
-     ->signalType #sine
+->signalType 				#sine
-do  (<-numFrames 0)
+do (<-numFrames 0)
-    SignalGenerator(I <-frequency <-phaseShift <-invert <-signalType )  ->sigValue
+    SignalGenerator(I <-frequency <-phaseShift <-invert <-signalType) ->sigValue
-    round (<-sigValue) 2) ->sigValue
+    Round(<-sigValue 2) ->sigValue
-    print3 (I " : " <-sigValue )
+    TraceAllSp (I " : " <-sigValue)
-    SetCreeper(I 75 add (<-sigValue mul (50)) 15 true)
+    SetCreeper(I 75 add(<-sigValue mul(50)) 15 true)
 loop
 </code>
+The above command generated this sinusoidal creeper pattern on a map
+{{sine_creeper.png?450}}
+==== Make a Unit Move or "Float" Above Terrain ====
+<code 4RPL>
+# Oscillate
+$UID:1
+GetUnitMoveCell(<-UID) ->cellZ ->cellX
+if (<-cellz  -1 EQ)
+	SignalGenerator(<-time , <-frequency , <-phaseShift , <-invert , <-signaltype) ->sigValue
+	<-time 1 + ->time
+	<-sigvalue 1 + <-scale * ->sigvalue
+	GetUnitPosition(<-UID) ->pos
+	GetExactTerrain(<-pos.X <-pos.Z false) ->exactTerrainHeight
+	SetUnitPosition(<-UID V3(<-pos.x , <-exactTerrainHeight <-sigvalue + , <-pos.z))	# Buil-in unit
+	# SetObjPosition(2  "" V3(0 <-sigValue 0) false)          							# for custom unit
+else
+->time
+endIf
+:Once
+	# Parameters for SignalGenerator
+.0  180 / ->frequency  		# we cycle over 180 frames
+.0 ->phaseShift 			# offset from zero-time
+	false ->invert 				# Invert the waveform
+->signalType				# type of signal generated
+.5 ->scale				# control the maximum size of movement
+</code>
+<=[[4rpl:start| Index]]

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