How to generate full complete waveform on texture with texture.SetPixel?

Can anyone help me with this ? Actually, I am not good at English and I don't understand how this whole script work even if I read all the answers and guides. I just want to generate waveform on the texture and show it. The waveforms in the pic are what I want and what I get now.

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 
 [RequireComponent(typeof(AudioSource))]
 public class WaveFormTest : MonoBehaviour
 {
     public new AudioSource audio;
 
     public RawImage image;
 
     int resolution = 60;
 
     float[] waveForm;
     float[] samples;
 
     Texture2D texture;
 
     private void Start()
     {
         texture = new Texture2D(900, 100, TextureFormat.RGBA32, false);
         CreateWaveForm();
     }
 
     // This two are from unity answer (I mixed up)
     public void CreateWaveForm()
     {
         resolution = audio.clip.frequency / resolution;
 
         samples = new float[audio.clip.samples * audio.clip.channels];
         audio.clip.GetData(samples, 0);
 
         int s = 0;
         while (s < samples.Length)
         {
             samples[s] = samples[s] * 0.5F;
             ++s;
         }
         audio.clip.SetData(samples, 0);
 
         waveForm = new float[(samples.Length / resolution)];
 
         for (int i = 0; i < waveForm.Length; i++)
         {
             waveForm[i] = 0;
 
             for (int ii = 0; ii < resolution; ii++)
             {
                 waveForm[i] += Mathf.Abs(samples[(i * resolution) + ii]);
             }
 
             waveForm[i] /= resolution;
         }
 
         MakeTexture(900, 100, waveForm, Color.yellow);
     }
 
     public void MakeTexture(int width, int height, float[] waveform, Color col)
     {
         texture = new Texture2D(width, height, TextureFormat.RGBA32, false);
 
         for (int x = 0; x < width; x++)
         {
             for (int y = 0; y < height; y++)
             {
                 texture.SetPixel(x, y, Color.black);
             }
         }
 
         for (int x = 0; x < waveform.Length; x++)
         {
             for (int y = 0; y <= waveform[x] * ((float)height * .75f); y++)
             {
                 texture.SetPixel(x, (height / 2) + y, col);
                 texture.SetPixel(x, (height / 2) - y, col);
             }
         }
 
         texture.Apply();
 
         image.texture = texture;
     }
 
     void Update()
     {
         //script from unity doc.
         float[] spectrum = new float[1024];
 
         AudioListener.GetSpectrumData(spectrum, 0, FFTWindow.Rectangular);
 
         for (int i = 1; i < spectrum.Length - 1; i++)
         {
             Debug.DrawLine(new Vector3(i - 1, spectrum[i] + 10, 0), new Vector3(i, spectrum[i + 1] + 10, 0), Color.red);
             Debug.DrawLine(new Vector3(i - 1, Mathf.Log(spectrum[i - 1]) + 10, 2), new Vector3(i, Mathf.Log(spectrum[i]) + 10, 2), Color.cyan);
             Debug.DrawLine(new Vector3(Mathf.Log(i - 1), spectrum[i - 1] - 10, 1), new Vector3(Mathf.Log(i), spectrum[i] - 10, 1), Color.green);
             Debug.DrawLine(new Vector3(Mathf.Log(i - 1), Mathf.Log(spectrum[i - 1]), 3), new Vector3(Mathf.Log(i), Mathf.Log(spectrum[i]), 3), Color.blue);
         }
 
         //script from unity answer
         for (int i = 0; i < waveForm.Length - 1; i++)
         {
             Vector3 sv = new Vector3(i * .01f, waveForm[i] * 10, 0);
             Vector3 ev = new Vector3(i * .01f, -waveForm[i] * 10, 0);
 
             Debug.DrawLine(sv, ev, Color.yellow);
         }
 
         int current = audio.timeSamples / resolution;
         current *= 2;
 
         Vector3 c = new Vector3(current * .01f, 0, 0);
 
         Debug.DrawLine(c, c + Vector3.up * 10, Color.white);
     }
 }