#ifdef GL_ES precision lowp float; #endif varying vec4 v_fragmentColor; varying vec2 v_texCoord; void main() { vec4 col = texture2D(CC_Texture0, v_texCoord); float grey = dot(col.rgb, vec3(0.299, 0.587, 0.114)); float alpha = v_fragmentColor.a; gl_FragColor = vec4(grey * alpha, grey * alpha, grey * alpha, col.a * alpha); }