const FRAG_SRC: &str = "#ifdef GL_ES\n precision mediump float;\n#endif\n\nuniform sampler2D u_sampler;\n\n#if NEW_SHADER_INTERFACE\n in vec4 v_rgba_in_gamma;\n in vec2 v_tc;\n out vec4 f_color;\n // a dirty hack applied to support webGL2\n #define gl_FragColor f_color\n #define texture2D texture\n#else\n varying vec4 v_rgba_in_gamma;\n varying vec2 v_tc;\n#endif\n\n// 0-1 sRGB gamma from 0-1 linear\nvec3 srgb_gamma_from_linear(vec3 rgb) {\n bvec3 cutoff = lessThan(rgb, vec3(0.0031308));\n vec3 lower = rgb * vec3(12.92);\n vec3 higher = vec3(1.055) * pow(rgb, vec3(1.0 / 2.4)) - vec3(0.055);\n return mix(higher, lower, vec3(cutoff));\n}\n\n// 0-1 sRGBA gamma from 0-1 linear\nvec4 srgba_gamma_from_linear(vec4 rgba) {\n return vec4(srgb_gamma_from_linear(rgba.rgb), rgba.a);\n}\n\nvoid main() {\n#if SRGB_TEXTURES\n vec4 texture_in_gamma = srgba_gamma_from_linear(texture2D(u_sampler, v_tc));\n#else\n vec4 texture_in_gamma = texture2D(u_sampler, v_tc);\n#endif\n\n // We multiply the colors in gamma space, because that\'s the only way to get text to look right.\n gl_FragColor = v_rgba_in_gamma * texture_in_gamma;\n}\n";