Replicate shadertoy example in SFML? - c++

Question

I would like to replicate this in SFML, so I wrote this:
Main.cpp
#include <SFML/Graphics.hpp>
#define WIDTH 800
int main() {
sf::RenderWindow window(sf::VideoMode(WIDTH, WIDTH), "Test");
sf::Shader shader, buffer;
shader.loadFromFile("shader.frag", sf::Shader::Fragment);
buffer.loadFromFile("buffer.frag", sf::Shader::Fragment);
sf::Shader *shaders[] = {&shader, &buffer};
sf::Texture texture;
texture.create(WIDTH, WIDTH);
sf::RenderTexture renderTexture;
sf::Vector2f mousePos = sf::Vector2f(-1.f, -1.f);
for(auto &shader : shaders) {
shader->setUniform("iChannel0", texture);
shader->setUniform("iResolution", sf::Glsl::Vec2(WIDTH, WIDTH));
}
auto time = sf::Clock();
sf::Sprite sprite(texture);
while(window.isOpen()) {
sf::Event currEvent;
while(window.pollEvent(currEvent)) {
switch(currEvent.type) {
case(sf::Event::Closed): window.close(); break;
case(sf::Event::MouseMoved):
mousePos = sf::Vector2f(
currEvent.mouseMove.x, currEvent.mouseMove.y);
break;
}
}
buffer.setUniform("iTime", time.getElapsedTime().asSeconds());
buffer.setUniform("iMouse", sf::Glsl::Vec2(
mousePos.x, WIDTH - mousePos.y));
sf::RenderStates states;
states.blendMode = sf::BlendAdd;
states.shader = &buffer;
renderTexture.clear(sf::Color::Transparent);
renderTexture.draw(sf::Sprite(texture), states);
renderTexture.display();
sprite.setTexture(renderTexture.getTexture());
window.clear(sf::Color::Black);
window.draw(sprite, &shader);
window.display();
}
}
Buffer.frag
#version 140
out vec4 out_Colour;
uniform sampler2D iChannel0;
uniform vec2 iResolution;
uniform vec2 iMouse;
uniform float iTime;
void main(void){
vec2 mouse = iMouse.xy;
if(mouse.x <= 0.)
mouse = vec2(iResolution.x * (sin(iTime)+1.)/2., iResolution.y/2.);
vec3 blob = vec3(.11-clamp(
length((
gl_FragCoord.xy-mouse.xy)/iResolution.x),0.,.11))*2.;
vec3 stack = texture(
iChannel0,gl_FragCoord.xy/iResolution.xy).xyz * vec3(0.99,.982,.93);
out_Colour = vec4(stack + blob, 1.0);
}
Shader.frag
#version 140
out vec4 out_Colour;
uniform sampler2D iChannel0;
uniform vec2 iResolution;
void main(void){
out_Colour = vec4(texture(
iChannel0, gl_FragCoord.xy / iResolution.xy).xyz, 1.0);
}
I am probably missing something with the buffers.
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shadertoy to SFML