Mouse Input

SNES Mouse support (1-2 mice on ports 1/2) More...

Macros
#define	MOUSE_BUTTON_LEFT   0x01
#define	MOUSE_BUTTON_RIGHT   0x02
#define	MOUSE_SENS_HIGH   2
#define	MOUSE_SENS_LOW   0
#define	MOUSE_SENS_MEDIUM   1

Functions
u8	mouseButtonsHeld (u8 port)
	Get currently held mouse buttons.
u8	mouseButtonsPressed (u8 port)
	Get newly pressed mouse buttons this frame.
u8	mouseGetSensitivity (u8 port)
	Get current mouse sensitivity.
s16	mouseGetX (u8 port)
	Get X displacement since last frame.
s16	mouseGetY (u8 port)
	Get Y displacement since last frame.
u8	mouseInit (u8 port)
	Initialize mouse on given port.
u8	mouseIsConnected (u8 port)
	Check if mouse is connected on port.
void	mouseSetSensitivity (u8 port, u8 sensitivity)
	Set mouse sensitivity.

Detailed Description

SNES Mouse support (1-2 mice on ports 1/2)

The SNES mouse provides 2 buttons and relative X/Y displacement. Displacement is read via bit-bang in the NMI handler after mouseInit().

Usage

// Detect and initialize mouse on port 1
if (mouseInit(0)) {
    // Mouse found!
}
 
// Main loop
while (1) {
    WaitForVBlank();
    s16 dx = mouseGetX(0);
    s16 dy = mouseGetY(0);
    cursor_x += dx;
    cursor_y += dy;
    if (mouseButtonsPressed(0) & MOUSE_BUTTON_LEFT) {
        // Left click!
    }
}

Macro Definition Documentation

MOUSE_BUTTON_LEFT

#define MOUSE_BUTTON_LEFT   0x01

Left mouse button

MOUSE_BUTTON_RIGHT

#define MOUSE_BUTTON_RIGHT   0x02

Right mouse button

MOUSE_SENS_HIGH

#define MOUSE_SENS_HIGH   2

High sensitivity

MOUSE_SENS_LOW

#define MOUSE_SENS_LOW   0

Low sensitivity

MOUSE_SENS_MEDIUM

#define MOUSE_SENS_MEDIUM   1

Medium sensitivity

Function Documentation

mouseButtonsHeld()

u8 mouseButtonsHeld

(

u8

port

)

Get currently held mouse buttons.

Parameters

port	Controller port (0 or 1)

Returns

Button mask (MOUSE_BUTTON_LEFT / MOUSE_BUTTON_RIGHT)

mouseButtonsPressed()

u8 mouseButtonsPressed

(

u8

port

)

Get newly pressed mouse buttons this frame.

Parameters

port	Controller port (0 or 1)

Returns

Button mask of buttons pressed this frame (edge detection)

mouseGetSensitivity()

u8 mouseGetSensitivity

(

u8

port

)

Get current mouse sensitivity.

Parameters

port	Controller port (0 or 1)

Returns

Current sensitivity (MOUSE_SENS_LOW/MEDIUM/HIGH)

mouseGetX()

s16 mouseGetX

(

u8

port

)

Get X displacement since last frame.

Returns signed displacement: positive = right, negative = left. Raw hardware format is sign-magnitude; this function converts it.

Parameters

port	Controller port (0 or 1)

Returns

X displacement (-127 to +127)

mouseGetY()

s16 mouseGetY

(

u8

port

)

Get Y displacement since last frame.

Returns signed displacement: positive = down, negative = up.

Parameters

port	Controller port (0 or 1)

Returns

Y displacement (-127 to +127)

mouseInit()

u8 mouseInit

(

u8

port

)

Initialize mouse on given port.

Detects if a mouse is connected by checking the auto-joypad device signature. If found, cycles sensitivity to fix the Nintendo power-on bug and enables mouse reading in the NMI handler.

Parameters

port	Controller port (0 = port 1, 1 = port 2)

Returns

1 if mouse detected, 0 if not

mouseIsConnected()

u8 mouseIsConnected

(

u8

port

)

Check if mouse is connected on port.

Parameters

port	Controller port (0 or 1)

Returns

1 if connected, 0 if not

mouseSetSensitivity()

void mouseSetSensitivity	(	u8	port,
		u8	sensitivity
	)

Set mouse sensitivity.

Cycles the mouse sensitivity by strobing the controller port. The sensitivity cycles: LOW -> MEDIUM -> HIGH -> LOW -> ...

Parameters

port	Controller port (0 or 1)
sensitivity	Target sensitivity (MOUSE_SENS_LOW/MEDIUM/HIGH)