Do ALL HotD versions flash when you shoot ?
- Thread starter Djidjo
- Start date
According to the lightgun patents, the screen MUST flash so it can find out where it's pointing at.
I'm not sure if all lightguns work according to that patents, but I don't remember a single lightgun game EVER that didn't flash when you shoot. When the screen flashes white, the gun waits for light intensity changes at the point it's aiming at. Since the TV has a fixed refresh rate, it's possible to calculate the approximate screen position for a pixel based on how long it took to fill it with a different color.
There are games that show a target where you're aiming at (Jurassic Park, Gun Blade NY). I have no idea how that works.
I'm not sure if all lightguns work according to that patents, but I don't remember a single lightgun game EVER that didn't flash when you shoot. When the screen flashes white, the gun waits for light intensity changes at the point it's aiming at. Since the TV has a fixed refresh rate, it's possible to calculate the approximate screen position for a pixel based on how long it took to fill it with a different color.
There are games that show a target where you're aiming at (Jurassic Park, Gun Blade NY). I have no idea how that works.
The intensity change doesn't exist because of the color change, but because of the movement of the electron beam. This is why light guns don't work on LCD/Plasma (no beam to detect) and projection screens (beams hit internal CRTs only). Flashing white just amplifies the beam, making the detection more reliable as antime said. Arcade games like JP can probably afford nicer sensors that are reliable without flashing, and I'm pretty sure Gunblade's guns work by sensing the tilt (they're on a fixed mount, and below the player's POV anyway so it doesn't need to be very accurate at all).
So the gun only needs to measure how long it took for screen pixels under it's aim to get "beamed"? Makes sense. If that's so, it's possible for it to figure out where it's aiming (with less accuracy) at even under a still image without any flash.
It's a damn accurate sensor they got in there, heh?
The tilting thing might be true... but I remember the aim crosshair is properly emulated in the Nebula Model 2 editon.
Also, now that I think about it... I am not sure if GunBlade flashed the screen at all. After all you had a heavty machinegun. If the screen flashed for every single projectile, it would cause major seizures to whoever played it.
Probably it's gun works like the JP one, and the sensor works all the time.
It's a damn accurate sensor they got in there, heh?
The tilting thing might be true... but I remember the aim crosshair is properly emulated in the Nebula Model 2 editon.
Also, now that I think about it... I am not sure if GunBlade flashed the screen at all. After all you had a heavty machinegun. If the screen flashed for every single projectile, it would cause major seizures to whoever played it.
Probably it's gun works like the JP one, and the sensor works all the time.
Not even that. It just needs to let the system know when it happens; at that point the CPU grabs the current raster position from the video hardware.
What I'm saying is that "aiming" is irrelevant with this kind of gun as long as it looks approximately correct. From an emulation standpoint I doubt it's much different from an analog joystick, and if you know where the translated X/Y values are stored in RAM you could just write to them directly and bypass emulating the gun input altogether.
