Super Scope Input

SNES Super Scope support (port 2 only). More...

Macros
#define	SSC_CURSOR   0x4000
#define	SSC_FIRE   0x8000
#define	SSC_NOISE   0x0100
#define	SSC_OFFSCREEN   0x0200
#define	SSC_PAUSE   0x1000
#define	SSC_TURBO   0x2000

Functions
u16	scopeButtonsDown (void)
	Get currently held buttons.
u16	scopeButtonsHeld (void)
	Get buttons held past the hold delay threshold.
u16	scopeButtonsPressed (void)
	Get newly pressed buttons this frame.
void	scopeCalibrate (void)
u16	scopeGetRawX (void)
	Get raw (uncalibrated) H position from PPU.
u16	scopeGetRawY (void)
	Get raw (uncalibrated) V position from PPU.
u16	scopeGetX (void)
	Get calibration-adjusted H position.
u16	scopeGetY (void)
	Get calibration-adjusted V position.
u8	scopeInit (void)
	Detect Super Scope on port 2.
u8	scopeIsConnected (void)
	Check if Super Scope is connected.
void	scopeSetHoldDelay (u16 frames)
void	scopeSetRepeatDelay (u16 frames)
	Set repeat delay (frames between repeat fires after hold).
u16	scopeSinceShot (void)
	Get frames since last detected shot.

Variables
u16	scope_centerh
u16	scope_centerv
u16	scope_holddelay
	Set hold delay (frames before hold triggers).
u16	scope_shothraw
	Calibrate aim from a center-screen shot.
u16	scope_shotvraw

Detailed Description

SNES Super Scope support (port 2 only).

The Super Scope is a light gun that uses the PPU H/V counter latch to determine aim position. It provides 4 buttons and 2 status flags.

Usage

// Detect and initialize Super Scope
if (scopeInit()) {
    // Super Scope found on port 2!
}
 
// Calibration: ask user to fire at screen center
// Wait for fire...
scopeCalibrate();
 
// Main loop
while (1) {
    WaitForVBlank();
    u16 x = scopeGetX();
    u16 y = scopeGetY();
    if (scopeButtonsPressed() & SSC_FIRE) {
        // Shot fired!
    }
}

Macro Definition Documentation

SSC_CURSOR

#define SSC_CURSOR   0x4000

Cursor button

SSC_FIRE

#define SSC_FIRE   0x8000

Fire button (trigger)

SSC_NOISE

#define SSC_NOISE   0x0100

Noise flag (no signal)

SSC_OFFSCREEN

#define SSC_OFFSCREEN   0x0200

Off-screen flag

SSC_PAUSE

#define SSC_PAUSE   0x1000

Pause button

SSC_TURBO

#define SSC_TURBO   0x2000

Turbo switch

Function Documentation

scopeButtonsDown()

u16 scopeButtonsDown

(

void

)

Get currently held buttons.

Returns

Button mask (SSC_FIRE, SSC_CURSOR, SSC_TURBO, SSC_PAUSE, SSC_OFFSCREEN, SSC_NOISE)

scopeButtonsHeld()

u16 scopeButtonsHeld

(

void

)

Get buttons held past the hold delay threshold.

After holding a button for holddelay frames, it triggers as "held". Then it re-triggers every repdelay frames.

Returns

Button mask of held buttons

scopeButtonsPressed()

u16 scopeButtonsPressed

(

void

)

Get newly pressed buttons this frame.

Returns

Button mask of buttons pressed this frame (edge detection)

scopeCalibrate()

void scopeCalibrate ( void )

inline

scopeGetRawX()

u16 scopeGetRawX

(

void

)

Get raw (uncalibrated) H position from PPU.

Returns

Raw X coordinate from PPU H counter

scopeGetRawY()

u16 scopeGetRawY

(

void

)

Get raw (uncalibrated) V position from PPU.

Returns

Raw Y coordinate from PPU V counter

scopeGetX()

u16 scopeGetX

(

void

)

Get calibration-adjusted H position.

Returns

Adjusted X coordinate (0-255 visible range)

scopeGetY()

u16 scopeGetY

(

void

)

Get calibration-adjusted V position.

Returns

Adjusted Y coordinate (0-223 visible range)

scopeInit()

u8 scopeInit

(

void

)

Detect Super Scope on port 2.

Checks the auto-joypad device signature on port 2. If a Super Scope is found, enables reading in the NMI handler and sets default hold/repeat delays (60/20 frames).

Returns

1 if Super Scope detected, 0 if not

scopeIsConnected()

u8 scopeIsConnected

(

void

)

Check if Super Scope is connected.

Returns

1 if connected, 0 if not

scopeSetHoldDelay()

void scopeSetHoldDelay ( u16 frames )

inline

scopeSetRepeatDelay()

void scopeSetRepeatDelay

(

u16

frames

)

Set repeat delay (frames between repeat fires after hold).

Parameters

frames

Number of frames (default: 20)

scopeSinceShot()

u16 scopeSinceShot

(

void

)

Get frames since last detected shot.

Returns

Number of frames since last PPU latch (shot detection)

Variable Documentation

scope_centerh

u16 scope_centerh

extern

scope_centerv

u16 scope_centerv

scope_holddelay

u16 scope_holddelay

extern

Set hold delay (frames before hold triggers).

Parameters

frames

Number of frames (default: 60 = 1 second at 60Hz) Inlined for zero-call-overhead access.

scope_shothraw

u16 scope_shothraw

extern

Calibrate aim from a center-screen shot.

Call this after the user fires at the center of the screen (128, 112). Computes calibration offsets: centerh = 128 - rawX, centerv = 112 - rawY. The NMI handler applies these offsets to all subsequent readings.

Inlined for zero-call-overhead access.

scope_shotvraw

u16 scope_shotvraw