Ripple.glsl

#include "Uniforms.glsl"
#include "Samplers.glsl"
#include "Transform.glsl"
#include "ScreenPos.glsl"

#ifdef COMPILEPS
uniform float cElapsedTime;
#endif

uniform sampler2D tex;

varying vec2 vScreenPos;

void VS()
{
    mat4 modelMatrix = iModelMatrix;
    vec3 worldPos = GetWorldPos(modelMatrix);
    gl_Position = GetClipPos(worldPos);
    vScreenPos = GetScreenPosPreDiv(gl_Position);    
}

void PS()
{
	float t = clamp(cElapsedTime / 6., 0., 1.);

	vec2 coords = vScreenPos.st;
	vec2 dir = coords - vec2(.5);
	
	float dist = distance(coords, vec2(.5));
	vec2 offset = dir * (sin(dist * 80. - cElapsedTime*15.) + .5) / 30.;

	vec2 texCoord = coords + offset;
	vec4 diffuse = texture2D(sDiffMap, texCoord);

	vec4 mixin = texture2D(tex, texCoord);

 	gl_FragColor = mixin * t + diffuse * (1. - t);
}