" float line1 = floor((coord.y - y_offset) / double_line_h) * double_line_h + y_offset;\n"
" float line2 = line1 + double_line_h;\n"
" float frac = (line2 - coord.y) / double_line_h;\n"
" gl_FragColor = mix(texture2D(tex, vec2(coord.x, line2)),\n"
" texture2D(tex, vec2(coord.x, line1)),frac);\n";
" float line1 = floor((coord.y - y_offset) / double_line_h) * double_line_h + y_offset;\n"
" float line2 = line1 + double_line_h;\n"
" float frac = (line2 - coord.y) / double_line_h;\n"
" gl_FragColor = mix(texture2D(tex, vec2(coord.x, line2)),\n"
" texture2D(tex, vec2(coord.x, line1)),frac);\n";