Function clamp [src]

Odd ramp function | _____ | / |/ -------/------- /| _____/ | | Limit val to the inclusive range [lower, upper].

Prototype

pub fn clamp(val: anytype, lower: anytype, upper: anytype) @TypeOf(val, lower, upper)

Example

 test clamp {
    // Within range
    try testing.expect(std.math.clamp(@as(i32, -1), @as(i32, -4), @as(i32, 7)) == -1);
    // Below
    try testing.expect(std.math.clamp(@as(i32, -5), @as(i32, -4), @as(i32, 7)) == -4);
    // Above
    try testing.expect(std.math.clamp(@as(i32, 8), @as(i32, -4), @as(i32, 7)) == 7);

    // Floating point
    try testing.expect(std.math.clamp(@as(f32, 1.1), @as(f32, 0.0), @as(f32, 1.0)) == 1.0);
    try testing.expect(std.math.clamp(@as(f32, -127.5), @as(f32, -200), @as(f32, -100)) == -127.5);

    // Vector
    try testing.expect(@reduce(.And, std.math.clamp(@as(@Vector(3, f32), .{ 1.4, 15.23, 28.3 }), @as(@Vector(3, f32), .{ 9.8, 13.2, 15.6 }), @as(@Vector(3, f32), .{ 15.2, 22.8, 26.3 })) == @as(@Vector(3, f32), .{ 9.8, 15.23, 26.3 })));

    // Mix of comptime and non-comptime
    var i: i32 = 1;
    _ = &i;
    try testing.expect(std.math.clamp(i, 0, 1) == 1);
}

Source

  pub fn clamp(val: anytype, lower: anytype, upper: anytype) @TypeOf(val, lower, upper) {
    const T = @TypeOf(val, lower, upper);
    switch (@typeInfo(T)) {
        .int, .float, .comptime_int, .comptime_float => assert(lower <= upper),
        .vector => |vinfo| switch (@typeInfo(vinfo.child)) {
            .int, .float => assert(@reduce(.And, lower <= upper)),
            else => @compileError("Expected vector of ints or floats, found " ++ @typeName(T)),
        },
        else => @compileError("Expected an int, float or vector of one, found " ++ @typeName(T)),
    }
    return @max(lower, @min(val, upper));
}  