#if defined(GL_OES_blend_subtract)
    glBlendEquationOES(GL_FUNC_REVERSE_SUBTRACT_OES);
    #elif defined(TARGET_PANDORA)
    if (glBlendEquationOES)
        glBlendEquationOES(GL_FUNC_REVERSE_SUBTRACT_OES);
    #else
    if(GLEW_EXT_blend_equation_separate && GLEW_ARB_imaging) {
        glBlendEquation(GL_FUNC_REVERSE_SUBTRACT);
    } else {
        const int max_color = std::max(water_color[0], std::max(water_color[1], water_color[2]));
        water_color[0] = (max_color - water_color[0])/8;
        water_color[1] = (max_color - water_color[1])/8;
        water_color[2] = (max_color - water_color[2])/8;
    }
    #endif