GameState Struct Reference

Centralized game state structure. More...

Public Attributes
s16	bg1_scroll_x
s16	bg1_scroll_y
s16	bg2_scroll_x
s16	bg2_scroll_y
Entity	bullets [8]
Entity	enemies [8]
u8	fire_cd
u16	frame
s16	player_x
s16	player_y
u16	prng
u16	scroll_y

Detailed Description

Centralized game state structure.

Note

IMPORTANT COMPILER PATTERN: Using a global struct with s16 types is the REQUIRED pattern for sprite coordinates in OpenSNES. The following patterns FAIL:

// BAD - causes LEFT/RIGHT movement to fail while UP/DOWN works:
static u16 player_x;
static u16 player_y;
 
// GOOD - all movement directions work correctly:
typedef struct { s16 x, y; } Player;
Player player = {100, 100};

This is due to a compiler quirk where separate static u16 variables generate different (broken) code compared to struct member access. See .claude/KNOWLEDGE.md for detailed documentation.

See also

animated_sprite example for reference implementation

Member Data Documentation

bg1_scroll_x

s16 GameState::bg1_scroll_x

BG1 horizontal scroll offset

bg1_scroll_y

s16 GameState::bg1_scroll_y

BG1 vertical scroll offset

bg2_scroll_x

s16 GameState::bg2_scroll_x

BG2 horizontal scroll offset (parallax)

bg2_scroll_y

s16 GameState::bg2_scroll_y

BG2 vertical scroll offset

bullets

Entity GameState::bullets[8]

enemies

Entity GameState::enemies[8]

fire_cd

u8 GameState::fire_cd

frame

u16 GameState::frame

player_x

s16 GameState::player_x

Player X position (screen coords) - MUST be s16

player_y

s16 GameState::player_y

Player Y position (screen coords) - MUST be s16

prng

u16 GameState::prng

scroll_y

u16 GameState::scroll_y

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The documentation for this struct was generated from the following files:

• /home/runner/work/opensnes/opensnes/examples/games/shmup_1942/main.c
• /home/runner/work/opensnes/opensnes/examples/scrolling/continuous_scroll/main.c