Merge "Blend premultiplied colors" into sc-dev

            + "    vec2 uv = p * in_resolutionScale;\n"

            + "    vec2 densityUv = uv - mod(uv, in_noiseScale);\n"

            + "    float turbulence = turbulence(uv, in_turbulencePhase);\n"

            + "    float sparkle = sparkles(densityUv, in_noisePhase) * ring * alpha "

            + "    float sparkleAlpha = sparkles(densityUv, in_noisePhase) * ring * alpha "

            + "* turbulence;\n"

            + "    float fade = min(fadeIn, 1. - fadeOutRipple);\n"

            + "    float circleAlpha = softCircle(p, center, in_maxRadius * scaleIn, 0.2) * fade;\n"

            + "    vec3 color = mix(in_color.rgb, in_sparkleColor.rgb, sparkle);\n"

            + "    float waveAlpha = softCircle(p, center, in_maxRadius * scaleIn, 0.2) * fade "

            + "* in_color.a;\n"

            + "    vec4 waveColor = vec4(in_color.rgb * waveAlpha, waveAlpha);\n"

            + "    vec4 sparkleColor = vec4(in_sparkleColor.rgb * in_sparkleColor.a, "

            + "in_sparkleColor.a);\n"

            + "    float mask = in_hasMask == 1. ? sample(in_shader, p).a > 0. ? 1. : 0. : 1.;\n"

            + "    float a = (in_color.a * circleAlpha + in_sparkleColor.a * sparkle) * mask;\n"

            + "    return vec4(color * a, a);\n"

            + "    return mix(waveColor, sparkleColor, sparkleAlpha) * mask;\n"

            + "}";

    private static final String SHADER = SHADER_UNIFORMS + SHADER_LIB + SHADER_MAIN;

    private static final double PI_ROTATE_RIGHT = Math.PI * 0.0078125;