From b8b4533adf84e3771c4041a3121364b956ec694f Mon Sep 17 00:00:00 2001
From: FreeArtMan <dos21h@gmail.com>
Date: Fri, 27 Aug 2021 23:13:46 +0100
Subject: Added wasm demo for fft

---
 md/writeup/naive_fft_implementation_in_c.md | 123 ++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)

(limited to 'md/writeup')

diff --git a/md/writeup/naive_fft_implementation_in_c.md b/md/writeup/naive_fft_implementation_in_c.md
index e5729ee..d82cc57 100644
--- a/md/writeup/naive_fft_implementation_in_c.md
+++ b/md/writeup/naive_fft_implementation_in_c.md
@@ -16,6 +16,115 @@ MathJax = {
 <script type="text/javascript" id="MathJax-script" async
   src="/js/tex-chtml.js">
 </script>
+<script src="/demo/naive_fft/index.js"></script>
+    <script type='text/javascript'>
+          var Module = {};
+          fetch('/demo/naive_fft/index.wasm')
+            .then(response =>
+              response.arrayBuffer()
+            ).then(buffer => {
+              //Module.canvas = document.getElementById("canvas");
+              Module.wasmBinary = buffer;
+              var script = document.createElement('script');
+              script.src = "/demo/naive_fft/index.js";
+              script.onload = function() {
+                console.log("Emscripten boilerplate loaded.");
+                run_dft         = Module.cwrap("dft",            [],[['float'],['float'],'number','number']);
+                run_fft_shuffle = Module.cwrap("ffti_shuffle_1", [],[['float'],['float'],'number']);
+                run_fft         = Module.cwrap("fft_1",          [],[['float'],['float'],'number','number']);
+
+
+
+                var inputDataI    = document.querySelector('.inputDataI');
+                var inputDataIerr = document.querySelector('.inputDataIerr');
+                var inputDataQ    = document.querySelector('.inputDataQ');
+                var inputDataQerr = document.querySelector('.inputDataQerr');
+                var outputDataI   = document.querySelector('.outputDataI');
+                var outputDataQ   = document.querySelector('.outputDataQ');
+
+                document.querySelector("#calcButton").onclick = function() {
+                      console.log("calc FFT");
+
+                      function cArray(size) {
+                          var offset = Module._malloc(size * 8);
+                          Module.HEAPF64.set(new Float64Array(size), offset / 8);
+                          return {
+                              "data": Module.HEAPF64.subarray(offset / 8, offset / 8 + size),
+                              "offset": offset
+                          }
+                      }
+
+                      function checkArr(inputData,errorOutput) {
+                        var strArr = inputData.value;
+                        
+                        strArr = strArr.replace(/ +(?= )/g,'');
+                        var splArr = strArr.split(" ");
+                        var data = Array(splArr.length).fill(0);
+                        for (let i=0; i<splArr.length;i++) {
+                          try {
+                            var j=splArr[i];
+                            if ( j != parseFloat(j)) throw new Error("ERROR: not float "+splArr[i]+" at index "+i);
+                            data[i] = parseFloat(j)
+                          } catch (err) {
+                            console.log("Error: ",err.message)
+                            errorOutput.innerHTML = err.message;
+                            return {"result":false,"data":[]};
+                          }
+
+                        }
+                        return {"result":true,"data":data};
+                      }
+                      console.log("checkArr");
+                      var arrIok = checkArr(inputDataI,inputDataIerr);
+                      console.log("checkArr");
+                      var arrQok = checkArr(inputDataQ,inputDataQerr);
+                      //max size 8 values, as thats enought for a demo
+                      //https://stackoverflow.com/questions/17883799/how-to-handle-passing-returning-array-pointers-to-emscripten-compiled-code
+                      if (!arrIok.result) return;
+                      if (!arrQok.result) return;
+
+                      var N=8;
+                      var myArray_i = cArray(N);
+                      var myArray_q = cArray(N);
+
+                      //set test data
+                      for(let i=0,j=0;i<N,j<arrIok.data.length;i++,j++) {
+                        myArray_i.data[i] = arrIok.data[j];
+                      }
+                      for(let i=0,j=0;i<N,j<arrQok.data.length;i++,j++) {
+                        myArray_q.data[i] = arrQok.data[j];
+                      }
+                      console.log(myArray_i.data);
+                      console.log(myArray_q.data);
+                      //DFT
+                      run_dft(myArray_i.offset,myArray_q.offset,N,0);
+                      //FFT
+                      //run_fft_shuffle(myArray_i.offset,myArray_q.offset,N);
+                      //run_fft(myArray_i.offset,myArray_q.offset,N,1);
+                      
+                      console.log(myArray_i.data);
+                      console.log(myArray_q.data)
+                      function outputResult(array,output) {
+                        var arr = Array(array.slice(0,N));
+                      
+                        arr = arr.map(function(item){
+                          return item.map(function(num){
+                            return parseFloat(num.toFixed(4));
+                          });
+                        });
+                        output.value = arr;
+                      }
+                      outputResult(myArray_i.data, outputDataI);
+                      outputResult(myArray_q.data, outputDataQ);
+                      
+                  }
+
+              } //end onload
+              document.body.appendChild(script);
+            });
+            
+            
+    </script>
 
 Time to implement DFT/FFT by myself. Just followed Ifeachor book on theory part and 
 IOWA FFT source on implementation side.
@@ -212,6 +321,20 @@ res4 = fft(data4)
 
 ```
 
+### Demo
+
+Here hookedup demo of compiled wasm fft code location of demo source http://git.main.lv/cgit.cgi/NaiveFFT.git/tree/Build/index.html?h=main
+
+Two boxes for input and two boxes for output. Values set as vectors of complex numbers. First box for real
+part, second box for imaginary part or in case of DSP IQ sample values.
+
+Input I:<textarea class="inputDataI">1 1 0</textarea><sup class="inputDataIerr"></sup>  
+Input Q:<textarea class="inputDataQ">0 0 0</textarea><sup class="inputDataQerr"></sup>  
+Output I:<textarea class="outputDataI"></textarea>  
+Output Q:<textarea class="outputDataQ"></textarea>  
+<button id="calcButton" type="button">Cals</button>  
+
+
 ### Source
 
 Source located in main branch of git repo
-- 
cgit v1.2.3