XrBlendFactorFB(3) Manual Page

// Provided by XR_FB_composition_layer_alpha_blend
typedef enum XrBlendFactorFB {
    XR_BLEND_FACTOR_ZERO_FB = 0,
    XR_BLEND_FACTOR_ONE_FB = 1,
    XR_BLEND_FACTOR_SRC_ALPHA_FB = 2,
    XR_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA_FB = 3,
    XR_BLEND_FACTOR_DST_ALPHA_FB = 4,
    XR_BLEND_FACTOR_ONE_MINUS_DST_ALPHA_FB = 5,
    XR_BLEND_FACTOR_MAX_ENUM_FB = 0x7FFFFFFF
} XrBlendFactorFB;