main.c File Reference

Single controller input display. More...

#include <snes.h>
#include <snes/text.h>
#include <snes/gameloop.h>

Functions
int	main (void)
	Entry point — gameLoopRun never returns.
static void	on_init (void)
	One-time setup. Static labels then screen on.
static void	on_update (void)
	Per-frame: read joypad, paint the held button name.

Detailed Description

Single controller input display.

Reads the SNES controller and displays which button is currently held. The simplest possible input example — one controller, one text line, real-time feedback. This is the starting point for understanding how SNES games read player input.

The SNES joypad has 12 buttons: 4 face buttons (A, B, X, Y), 2 shoulder buttons (L, R), a D-pad (4 directions), START, and SELECT. The NMI handler reads the joypad automatically every VBlank. Your code just calls padHeld(0) to get the current state as a 16-bit bitmask.

Ported from PVSnesLib "controller" example by alekmaul.

SNES Concepts

• padHeld(0) — 16-bit bitmask of currently held buttons
• KEY_A, KEY_B, KEY_X, KEY_Y, KEY_L, KEY_R — button constants
• KEY_UP, KEY_DOWN, KEY_LEFT, KEY_RIGHT — D-pad constants
• KEY_START, KEY_SELECT — system button constants
• NMI handler reads joypads automatically (padUpdate is a no-op)

What to Observe

• Press any button — its name appears on screen immediately
• Release — the display clears
• Try pressing multiple buttons — only one is shown (first match)
• The response is instant (1 frame = 16ms latency)

Modules Used

console, sprite, dma, background, text, input

See also

input.h

Function Documentation

main()

int main

(

void

)

Entry point — gameLoopRun never returns.

on_init()

static void on_init ( void  )

static

One-time setup. Static labels then screen on.

on_update()

static void on_update ( void  )

static

Per-frame: read joypad, paint the held button name.

padHeld() returns the bitmask of currently-pressed buttons (latched by the NMI handler this frame). The if/else cascade prints the first match — multiple-button combinations only show one.