Spectrum Displaying Shader

A spectrum displaying shader.

Use with following code (needs put some Nodes, add SpectrumAnalyzer Effect to AudioBus):

const VU_COUNT:int = 32
const FREQ_MAX:float = 3000.0
const MIN_DB:float = 80.0

var spectrum_shader:ShaderMaterial = null
var analyzer:AudioEffectSpectrumAnalyzerInstance = null

func _ready( ):
	self.analyzer = AudioServer.get_bus_effect_instance( 0, 0 )
	self.spectrum_shader = $ColorRect.material

func _process( delta:float ):
	var prev_hz:float = 0.0

	for i in range( VU_COUNT ):
		var hz:float = ( i + 1 ) * FREQ_MAX / VU_COUNT
		var mag:float = self.analyzer.get_magnitude_for_frequency_range( prev_hz, hz ).length( )
		self.spectrum_shader.set_shader_param( "hz%d" % i, clamp( ( linear2db( mag ) + MIN_DB ) / MIN_DB, 0.0, 1.0 ) )
		prev_hz = hz

 

Shader code
/*
	スペクトラム表示シェーダー by あるる(きのもと 結衣) @arlez80
	Spectrum Displaying Shader by KINOMOTO Yui

	MIT License
*/
shader_type canvas_item;
render_mode unshaded;

uniform sampler2D tex;
uniform float hz0;
uniform float hz1;
uniform float hz2;
uniform float hz3;
uniform float hz4;
uniform float hz5;
uniform float hz6;
uniform float hz7;
uniform float hz8;
uniform float hz9;
uniform float hz10;
uniform float hz11;
uniform float hz12;
uniform float hz13;
uniform float hz14;
uniform float hz15;
uniform float hz16;
uniform float hz17;
uniform float hz18;
uniform float hz19;
uniform float hz20;
uniform float hz21;
uniform float hz22;
uniform float hz23;
uniform float hz24;
uniform float hz25;
uniform float hz26;
uniform float hz27;
uniform float hz28;
uniform float hz29;
uniform float hz30;
uniform float hz31;

void fragment( )
{
	float p = UV.x * 32.0;
	float f = mix( hz0, hz1, clamp( p, 0.0, 1.0 ) );
	f = mix( f, hz2, clamp( p - 1.0, 0.0, 1.0 ) );
	f = mix( f, hz3, clamp( p - 2.0, 0.0, 1.0 ) );
	f = mix( f, hz4, clamp( p - 3.0, 0.0, 1.0 ) );
	f = mix( f, hz5, clamp( p - 4.0, 0.0, 1.0 ) );
	f = mix( f, hz6, clamp( p - 5.0, 0.0, 1.0 ) );
	f = mix( f, hz7, clamp( p - 6.0, 0.0, 1.0 ) );
	f = mix( f, hz8, clamp( p - 7.0, 0.0, 1.0 ) );
	f = mix( f, hz9, clamp( p - 8.0, 0.0, 1.0 ) );
	f = mix( f, hz10, clamp( p - 9.0, 0.0, 1.0 ) );
	f = mix( f, hz11, clamp( p - 10.0, 0.0, 1.0 ) );
	f = mix( f, hz12, clamp( p - 11.0, 0.0, 1.0 ) );
	f = mix( f, hz13, clamp( p - 12.0, 0.0, 1.0 ) );
	f = mix( f, hz14, clamp( p - 13.0, 0.0, 1.0 ) );
	f = mix( f, hz15, clamp( p - 14.0, 0.0, 1.0 ) );
	f = mix( f, hz16, clamp( p - 15.0, 0.0, 1.0 ) );
	f = mix( f, hz17, clamp( p - 16.0, 0.0, 1.0 ) );
	f = mix( f, hz18, clamp( p - 17.0, 0.0, 1.0 ) );
	f = mix( f, hz19, clamp( p - 18.0, 0.0, 1.0 ) );
	f = mix( f, hz20, clamp( p - 19.0, 0.0, 1.0 ) );
	f = mix( f, hz21, clamp( p - 20.0, 0.0, 1.0 ) );
	f = mix( f, hz22, clamp( p - 21.0, 0.0, 1.0 ) );
	f = mix( f, hz23, clamp( p - 22.0, 0.0, 1.0 ) );
	f = mix( f, hz24, clamp( p - 23.0, 0.0, 1.0 ) );
	f = mix( f, hz25, clamp( p - 24.0, 0.0, 1.0 ) );
	f = mix( f, hz26, clamp( p - 25.0, 0.0, 1.0 ) );
	f = mix( f, hz27, clamp( p - 26.0, 0.0, 1.0 ) );
	f = mix( f, hz28, clamp( p - 27.0, 0.0, 1.0 ) );
	f = mix( f, hz29, clamp( p - 28.0, 0.0, 1.0 ) );
	f = mix( f, hz30, clamp( p - 29.0, 0.0, 1.0 ) );
	f = mix( f, hz31, clamp( p - 30.0, 0.0, 1.0 ) );

	COLOR = texture( tex, vec2( UV.x, 0.0 ) ) * float( 1.0 - UV.y < f );
}
Tags
spectrum
The shader code and all code snippets in this post are under MIT license and can be used freely. Images and videos, and assets depicted in those, do not fall under this license. For more info, see our License terms.

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