''===================================================================== '' bass_webviz.bi -- Web Audio bridge for BASS analysis calls '' '' Supplies bodies for the BASS functions the fbjs web shim doesn't '' implement, using the browser's AnalyserNode: '' BASS_ChannelGetData (FFT2048 + float waveform) '' BASS_ChannelIsActive '' BASS_ChannelGetLength / GetPosition (fake "bytes" = milliseconds) '' BASS_ChannelBytes2Seconds (ms / 1000) '' BASS_ErrorGetCode '' '' Include AFTER fb_samples_init.bas (needs bass.bi's declares/constants), '' only in the js build: '' #if defined(__FB_JS__) or defined(WEBBUILD) '' #include "bass_webviz.bi" '' #endif ''===================================================================== #ifndef BASS_WEBVIZ_BI #define BASS_WEBVIZ_BI #ifndef BASS_DATA_FLOAT #error "bass_webviz.bi must be included after bass.bi" #endif '' the Mysoft toolchain may already have included emscripten.bi '' (it has no include guard of its own, so only pull it in if needed) #ifndef EMSCRIPTEN_KEEPALIVE #include "emscripten.bi" #endif ''--------------------------------------------------------------------- '' one-time page hook (runs at include point, before any playMusic): '' wrap Audio creation so every element the shim makes is routed '' through a shared AnalyserNode (fftSize 2048 -> 1024 bins, same as '' BASS_DATA_FFT2048) ''--------------------------------------------------------------------- Scope Dim As String js = _ "if(!window.__bviz){var V=window.__bviz={ctx:null,an:null,cur:null};" & _ "V.hook=function(el){try{if(el.__bv)return;" & _ "if(!V.ctx)V.ctx=new(window.AudioContext||window.webkitAudioContext)();" & _ "if(!V.an){V.an=V.ctx.createAnalyser();V.an.fftSize=2048;" & _ "V.an.smoothingTimeConstant=0.45;V.an.connect(V.ctx.destination);}" & _ "V.ctx.createMediaElementSource(el).connect(V.an);el.__bv=1;V.cur=el;" & _ "console.log('bviz: hooked',el.src||el);" & _ "el.addEventListener('play',function(){V.cur=el;" & _ "if(V.ctx.state!=='running')V.ctx.resume();});" & _ "}catch(e){console.log('bviz hook:',e);}};" & _ "['click','keydown','touchstart'].forEach(function(ev){" & _ "document.addEventListener(ev,function(){" & _ "if(V.ctx&&V.ctx.state!=='running')V.ctx.resume();},true);});" & _ "var OP=HTMLMediaElement.prototype.play;" & _ "HTMLMediaElement.prototype.play=function(){V.hook(this);V.cur=this;" & _ "if(V.ctx&&V.ctx.state!=='running')V.ctx.resume();" & _ "return OP.apply(this,arguments);};" & _ "var OA=window.Audio;" & _ "window.Audio=function(u){var el=(u===undefined)?new OA():new OA(u);" & _ "V.hook(el);return el;};" & _ "window.Audio.prototype=OA.prototype;" & _ "var CE=document.createElement.bind(document);" & _ "document.createElement=function(t){var el=CE(t);" & _ "if((''+t).toLowerCase()==='audio')V.hook(el);return el;};" & _ "document.querySelectorAll('audio').forEach(V.hook);}" emscripten_run_script(StrPtr(js)) End Scope Extern "C" ''--------------------------------------------------------------------- Function BASS_ChannelGetData(ByVal handle As DWORD, _ ByVal buffer As Any Ptr, _ ByVal flags As DWORD) As DWORD Dim As String js Dim As UInteger p = Cast(UInteger, buffer) If flags = BASS_DATA_FFT2048 Then '' AnalyserNode gives dB; convert to linear magnitude like BASS js = "(function(p){var V=window.__bviz;if(!V||!V.an)return 0;" & _ "var H=(typeof HEAPF32!=='undefined')?HEAPF32:Module.HEAPF32;" & _ "if(!H)return 0;" & _ "var n=V.an.frequencyBinCount,a=new Float32Array(n);" & _ "V.an.getFloatFrequencyData(a);" & _ "var m=(n<1024)?n:1024;for(var i=0;i>2)+i]=" & _ "(isFinite(d)&&d>-120)?Math.pow(10,d/20):0;}" & _ "return m*4;})(" & p & ")" Return emscripten_run_script_int(StrPtr(js)) ElseIf (flags And BASS_DATA_FLOAT) <> 0 Then '' time-domain floats; analyser is mono, duplicate into L/R pairs Dim As Integer nf = (flags And &h0FFFFFFF) \ 4 js = "(function(p,nf){var V=window.__bviz;if(!V||!V.an)return 0;" & _ "var H=(typeof HEAPF32!=='undefined')?HEAPF32:Module.HEAPF32;" & _ "if(!H)return 0;" & _ "var a=new Float32Array(V.an.fftSize);" & _ "V.an.getFloatTimeDomainData(a);" & _ "var fr=nf>>1;for(var i=0;i>2)+2*i]=v;" & _ "H[(p>>2)+2*i+1]=v;}" & _ "return nf*4;})(" & p & "," & nf & ")" Return emscripten_run_script_int(StrPtr(js)) End If Return 0 End Function ''--------------------------------------------------------------------- Function BASS_ChannelIsActive(ByVal handle As DWORD) As DWORD Dim As String js = _ "(function(){var V=window.__bviz;if(!V||!V.cur)return -1;" & _ "return V.cur.ended?0:(V.cur.paused?3:1);})()" Dim As Long r = emscripten_run_script_int(StrPtr(js)) If r < 0 Then Return 1 '' nothing hooked yet: report playing Return r '' 0 stopped / 1 playing / 3 paused End Function ''--------------------------------------------------------------------- '' positions: we use milliseconds as the "byte" unit, so '' Bytes2Seconds is simply /1000 and everything stays consistent ''--------------------------------------------------------------------- Function BASS_ChannelGetLength(ByVal handle As DWORD, _ ByVal mode As DWORD) As QWORD Dim As String js = _ "(function(){var V=window.__bviz;if(!V||!V.cur)return 0;" & _ "var d=V.cur.duration;" & _ "return isFinite(d)?Math.floor(d*1000):0;})()" Return emscripten_run_script_int(StrPtr(js)) End Function Function BASS_ChannelGetPosition(ByVal handle As DWORD, _ ByVal mode As DWORD) As QWORD Dim As String js = _ "(function(){var V=window.__bviz;if(!V||!V.cur)return 0;" & _ "return Math.floor(V.cur.currentTime*1000);})()" Return emscripten_run_script_int(StrPtr(js)) End Function Function BASS_ChannelBytes2Seconds(ByVal handle As DWORD, _ ByVal posbytes As QWORD) As Double Return posbytes / 1000.0 End Function ''--------------------------------------------------------------------- Function BASS_ErrorGetCode() As Long Return 0 End Function End Extern #endif '' BASS_WEBVIZ_BI