//! Blending modes for drawing (for render states)

// Enums
pub const Factor = enum(c_int) {
    zero,
    one,
    srcColor,
    oneMinusSrcColor,
    dstColor,
    oneMinusDstColor,
    srcAlpha,
    oneMinusSrcAlpha,
    dstAlpha,
    oneMinusDstAlpha 
};

pub const Equation = enum(c_int) {
    add,
    subtract,
    reverseSubtract
};

const BlendMode = @This();

// Preset blend modes
pub const BlendAlpha = BlendMode{
    .color_src_factor = .srcAlpha,
    .color_dst_factor = .oneMinusSrcAlpha,
    .color_equation = .add,
    .alpha_src_factor = .one,
    .alpha_dst_factor = .oneMinusSrcAlpha,
    .alpha_equation = .add
};

pub const BlendAdd = BlendMode{
    .color_src_factor = .srcAlpha,
    .color_dst_factor = .one,
    .color_equation = .add,
    .alpha_src_factor = .one,
    .alpha_dst_factor = .one,
    .alpha_equation = .add
};

pub const BlendMultiply = BlendMode{
    .color_src_factor = .dstColor,
    .color_dst_factor = .zero,
    .color_equation = .add,
    .alpha_src_factor = .dstColor,
    .alpha_dst_factor = .zero,
    .alpha_equation = .add
};

pub const BlendMin = BlendMode{
    .color_src_factor = .one,
    .color_dst_factor = .one,
    .color_equation = .min,
    .alpha_src_factor = .one,
    .alpha_dst_factor = .one,
    .alpha_equation = .min
};

pub const BlendMax = BlendMode{
    .color_src_factor = .one,
    .color_dst_factor = .one,
    .color_equation = .max,
    .alpha_src_factor = .one,
    .alpha_dst_factor = .one,
    .alpha_equation = .max
};

pub const BlendNone = BlendMode{
    .color_src_factor = .one,
    .color_dst_factor = .zero,
    .color_equation = .add,
    .alpha_src_factor = .one,
    .alpha_dst_factor = .zero,
    .alpha_equation = .add
};

const sfBlendMode = @import("../sfml_import.zig").c.sfBlendMode;
/// Bitcasts this blendmode to the csfml struct
/// For inner workings
pub fn _toCSFML(self: BlendMode) sfBlendMode {
    return @bitCast(sfBlendMode, self);
}

color_src_factor: Factor,
color_dst_factor: Factor,
color_equation: Equation,
alpha_src_factor: Factor,
alpha_dst_factor: Factor,
alpha_equation: Equation