#ifdef GL_ES #define LOWP lowp #define MED mediump precision lowp float; #else #define LOWP #define MED #endif uniform sampler2D u_texture0; uniform vec2 threshold; varying MED vec2 v_texCoords; void main(){ vec4 tex = texture2D(u_texture0, v_texCoords); vec3 colors = (tex.rgb - threshold.r) * threshold.g * tex.a; gl_FragColor = vec4(colors, tex.a); }