Maybe you’re thinking of the black out style tinting that you see in movies but most people tint to filter out like 5-20% light.

"Transparent material that is installed, affixed or applied to the topmost portion of the windshield if:

(a) The bottom edge of the material is at least twenty-nine inches above the undepressed driver's seat when measured from a point five inches in front of the bottom of the backrest with the driver's seat in its rearmost and lowermost position with the vehicle on a level surface.

(b) The material is not red or amber in color."[0]

and

"Windshields Sunscreening devices must be applied above the AS-1 line. If there is no AS-1 line, sunscreening devices must end five inches below the top of the windshield. Sunscreening devices may not be red, amber, or blue in color. Sunscreening devices, when measured in combination with the original glass, must have a light transmittance value of 25% or more. Sunscreening devices, when measured in combination with the original glass, must have a luminous reflectance value of 25% or less. A clear (un-tinted) UV film is allowed anywhere on the front windshield without a medical exemption being required."[1]

[0] https://www.azleg.gov/ars/28/00959-01.htm

[1] https://www.dps.texas.gov/rsd/vi/consumerinfo/windowTint.htm

Big difference. I'm not aware of anywhere that it's legal to tint your windshield below the top 4-5 inches. (Not saying it isn't but it certainly isn't in AZ or TX)

In my country, you can put a tinted film on the whole windshield, as long as it allows at least 75% of the light to pass (the side and rear windows can be much darker: the film must allow at least 28% of the light). They're a common sight.