precision mediump float;
varying vec2 v_texCoord;
uniform sampler2D u_texture;
uniform vec2 u_resolution;
uniform float u_intensity; // 0-3
uniform int   u_mode;      // 0=sobel line art, 1=overlay, 2=edges only

float lum(vec3 c) {
  return dot(c, vec3(0.299, 0.587, 0.114));
}

void main() {
  vec2 ps = 1.0 / u_resolution;

precision mediump float;
#define GLSLIFY 1
// Common uniforms
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
uniform float u_frame;

// Texture uniforms
uniform sampler2D u_texture;

// Texture varyings
varying vec2 v_uv;