FlowMapShader.tres

[gd_resource type="ShaderMaterial" load_steps=3 format=2]

[ext_resource path="res://FlowMap.png" type="Texture" id=1]

[sub_resource type="Shader" id=1]
code = "shader_type canvas_item;

// Set textures to repeat if texture and flow map size differ

uniform sampler2D flowMap;

uniform float timeScale = 0.25;
uniform float flowMapScale = 0.5;

vec4 lerp(vec4 a, vec4 b, float val) {
	
	return (1.0 - val) * a + val * b;
}

void fragment() {
	vec4 flow = texture(flowMap, UV * flowMapScale);
	
	// distortion from flow map
	// fract bc of time
	float time = TIME * timeScale;
	float timeDistortion1 = fract(time);
	float timeDistortion2 = fract(time + 0.5);
	
	vec2 textureDistortion = (vec2(flow.r, flow.g) - 0.5) * 2.0;
	
	// flow distortion 
	//  * or +
	vec2 distortion1 = timeDistortion1 * textureDistortion;
	vec2 distortion2 = timeDistortion2 * textureDistortion;
	
	// set texture with distortion
	vec4 color1 = texture(TEXTURE, UV * distortion1);
	vec4 color2 = texture(TEXTURE, UV * distortion2);
	
	float lerpValue = (fract(time) - 0.5 ) * 2.0;
	lerpValue = abs(lerpValue);
	vec4 finalColor = lerp(color1, color2, lerpValue);
	COLOR = finalColor;
	COLOR = mix(color1, color2, lerpValue);
//	COLOR = flow;
//	COLOR = vec4(lerpValue);
}"
custom_defines = ""

[resource]
shader = SubResource( 1 )
shader_param/timeScale = 0.15
shader_param/flowMapScale = 0.5
shader_param/flowMap = ExtResource( 1 )