1 files changed, 27 insertions, 4 deletions
diff --git a/Gen/GenTrig.swift b/Gen/GenTrig.swift
index 84bf9cf..cc4abb5 100644
--- a/Gen/GenTrig.swift
+++ b/Gen/GenTrig.swift
@@ -5,6 +5,8 @@
 //  Created by Jacky Jack on 26/10/2024.
 //
 
+import Foundation
+
 /// Generate sin function as float array
 /// - Parameters:
 ///   - sample_rate: sample rate, how many samples per second
@@ -14,8 +16,19 @@
 ///   - sample_num: number of samples to generate
 /// - Returns: Array of floats within range [-ampl ... apml]
 ///
-func genSin(_ sample_rate: Int,_ freq: Float,_ ampl: Float,_ phase: Float,_ sample_num: Float) -> Array<Float> {
-    return [0.0]
+func genSin(_ sample_rate: Int,_ freq: Int,_ ampl: Float,_ phase: Float,_ sample_num: Int) -> Array<Float32> {
+    
+    //let one_sec = sample_num/sample_rate
+    let sample_per_hz:Float32 = Float32(sample_rate)/Float32(freq)
+    let hz_step: Float32 = 2*Float32.pi/sample_per_hz
+    var out_signal:[Float32] = Array(repeating: Float(0.0), count: sample_num)
+    var start = phase
+    for i in 0..<sample_num {
+        out_signal[i] = ampl * sin(start)
+        start += hz_step
+    }
+    
+    return out_signal
 }
 
 /// Generate Cos function as float array
@@ -27,7 +40,17 @@ func genSin(_ sample_rate: Int,_ freq: Float,_ ampl: Float,_ phase: Float,_ samp
 ///   - sample_num: number of samples to generate
 /// - Returns: Array of floats within range [-ampl ... apml]
 ///
-func genCos(_ sample_rate: Int,_ freq: Float,_ ampl: Float,_ phase: Float,_ sample_num: Float) -> Array<Float> {
-    return [0.0]
+func genCos(_ sample_rate: Int,_ freq: Float,_ ampl: Float,_ phase: Float,_ sample_num: Int) -> Array<Float32> {
+    //let one_sec = sample_num/sample_rate
+    let sample_per_hz:Float32 = Float32(sample_rate)/Float32(freq)
+    let hz_step: Float32 = 2*Float32.pi/sample_per_hz
+    var out_signal:[Float32] = Array(repeating: Float32(0.0), count: sample_num)
+    var start = phase
+    for i in 0...sample_num {
+        out_signal[i] = ampl * cos(start)
+        start += hz_step
+    }
+    
+    return out_signal
 }