From f1eecc00f197a97edc4959d8b4bbdd0f59248abb Mon Sep 17 00:00:00 2001
From: Luxferre <lux@ferre>
Date: Sun, 11 Jan 2026 14:27:20 +0200
Subject: [PATCH] Offloaded some NES routines to eznes.h

---
 nes/eznes.h       | 179 +++++++++++++++++++++++++++++++++++++++
 nes/nescoundrel.c | 211 +++++++++-------------------------------------
 2 files changed, 219 insertions(+), 171 deletions(-)
 create mode 100644 nes/eznes.h

diff --git a/nes/eznes.h b/nes/eznes.h
new file mode 100644
index 0000000..eb2f9e5
--- /dev/null
+++ b/nes/eznes.h
@@ -0,0 +1,179 @@
+#ifndef EZNES_H
+#define EZNES_H
+/**
+  EZnes: a set of helpers for easy NES indie development in pure C
+  for CC65 (in text mode)
+
+  Created by Luxferre in 2026, released into public domain
+*/
+
+#include <nes.h>
+#include <joystick.h>
+#include <conio.h>
+
+#define u8 unsigned char
+#define u16 unsigned short
+#define s8 char
+#define s16 short
+
+/* Generic constants */
+
+#define CPU 1789773 /* NTSC */
+
+#define SCREEN_WIDTH  32
+#define SCREEN_HEIGHT 28
+#define SCREEN_CENTER_X (SCREEN_WIDTH >> 1)
+#define SCREEN_CENTER_Y (SCREEN_HEIGHT >> 1)
+
+#define EZJOY_UP 1
+#define EZJOY_DN 2
+#define EZJOY_LT 3
+#define EZJOY_RT 4
+#define EZJOY_A  5
+#define EZJOY_B  6
+#define EZJOY_SL 7
+#define EZJOY_ST 8
+
+#define NES_BLACK  0x0F
+#define NES_WHITE  0x30
+#define NES_RED    0x15
+#define NES_GREEN  0x28
+#define NES_YELLOW 0x2A
+
+/* Graphics section */
+
+void ppu_off() {
+  PPU.mask &= 0xE7;
+}
+
+void ppu_on() {
+  waitvsync();
+  PPU.scroll = 0;
+  PPU.mask |= 0x1A;
+}
+
+int joy_input_wait() {
+  u8 last_joy = 0, joy, pressed;
+  /* wait until the previous key is released */
+  while(joy_read(JOY_1));
+  /* wait for a new press */
+  while(1) {
+    joy = joy_read(JOY_1);
+    pressed = joy & ~last_joy;
+    if(pressed & JOY_UP_MASK) return EZJOY_UP;
+    if(pressed & JOY_DOWN_MASK) return EZJOY_DN;
+    if(pressed & JOY_LEFT_MASK) return EZJOY_LT;
+    if(pressed & JOY_RIGHT_MASK) return EZJOY_RT;
+    if(pressed & JOY_BTN_1_MASK) return EZJOY_A;
+    if(pressed & JOY_BTN_2_MASK) return EZJOY_B;
+    if(pressed & JOY_BTN_3_MASK) return EZJOY_SL;
+    if(pressed & JOY_BTN_4_MASK) return EZJOY_ST;
+    last_joy = joy;
+    waitvsync();
+  }
+}
+
+/* palette loader */
+void init_palette(u8 bg, u8 c1, u8 c2, u8 c3, u8 c4) {
+  u8 i, pal[16] = {0};
+  pal[0] = pal[4] = pal[8] = pal[12] = bg;
+  pal[3] = c1;
+  pal[7] = c2;
+  pal[11] = c3;
+  pal[15] = c4;
+  PPU.vram.address = 0x3F;
+  PPU.vram.address = 0;
+  for(i=0; i<16; i++) PPU.vram.data = pal[i];
+}
+
+/* 4x4 char block colorization method (palette is 0 to 3) */
+void colorxy(u8 x, u8 y, u8 palette) {
+  unsigned int addr;
+  u8 attr_byte;
+  addr = 0x23C0 + ((y >> 2) << 3) + (x >> 2);
+  attr_byte = palette | (palette << 2) | (palette << 4) | (palette << 6);
+  waitvsync();
+  PPU.vram.address = (u8) (addr >> 8);
+  PPU.vram.address = (u8) (addr & 255);
+  PPU.vram.data = attr_byte;
+}
+
+/* Sound section */
+
+unsigned int get_timer_by_freq(int freq) {
+  return (unsigned int) ((CPU / 16 / freq) - 1);
+}
+
+void play_pulse(u8 idx, unsigned int freq, u8 len) {
+  unsigned int tm = get_timer_by_freq(freq);
+  if(len > 31) len = 31;
+  if(idx > 1) idx = 0;
+  APU.pulse[idx].period_low = tm & 255;
+  APU.pulse[idx].len_period_high = (tm >> 8) | (len << 3);
+}
+
+void play_jingle(unsigned int n1f1,
+  unsigned int n1f2,
+  unsigned int n2f1,
+  unsigned int n2f2,
+  unsigned int n3f1,
+  unsigned int n3f2) {
+  unsigned int i, dl = 2000;
+  play_pulse(0, n1f1, 2);
+  play_pulse(1, n1f2, 2);
+  for(i=0;i<dl;++i);
+  play_pulse(0, n2f1, 2);
+  play_pulse(1, n2f2, 2);
+  for(i=0;i<dl;++i);
+  play_pulse(0, n3f1, 2);
+  play_pulse(1, n3f2, 2);
+}
+
+void init_sound() {
+  APU.status = 3;
+  APU.pulse[0].ramp = 0x8;
+  APU.pulse[1].ramp = 0x8;
+  APU.pulse[0].control = 0x9F;
+  APU.pulse[1].control = 0x9F;
+  waitvsync();
+}
+
+/* Game initialization section */
+
+void init_game(u8 bg, u8 c1, u8 c2, u8 c3, u8 c4) {
+#ifdef _randomize
+  _randomize();
+#endif
+  init_sound();
+  bgcolor(COLOR_BLACK);
+  textcolor(0);
+  init_palette(bg, c1, c2, c3, c4);
+  joy_install(joy_static_stddrv);
+  clrscr();
+}
+
+/* wait until Start is pressed */
+void wait_for_start() {
+  u8 joy;
+  while(1) {
+    joy = joy_read(JOY_1);
+    if(JOY_START(joy)) break;
+    waitvsync();
+  }
+}
+
+/* randomize until Start is pressed */
+void wait_for_start_rand() {
+  u8 joy;
+  unsigned int entropy = rand();
+  while(1) {
+    ++entropy;
+    joy = joy_read(JOY_1);
+    if(JOY_START(joy)) break;
+    waitvsync();
+  }
+  srand(entropy);
+}
+
+#endif
+
diff --git a/nes/nescoundrel.c b/nes/nescoundrel.c
index 1273a5c..df68a0d 100644
--- a/nes/nescoundrel.c
+++ b/nes/nescoundrel.c
@@ -4,135 +4,20 @@
   Created by Luxferre in 2026, released into public domain
 */
 
-#include <nes.h>
-#include <joystick.h>
-#include <conio.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include "eznes.h"
 
 /* Constants section */
 
-#define SCREEN_WIDTH  32
-#define SCREEN_HEIGHT 28
-#define SCREEN_CENTER_X (SCREEN_WIDTH >> 1)
-#define SCREEN_CENTER_Y (SCREEN_HEIGHT >> 1)
-
-#define KEY_UP 1
-#define KEY_DN 2
-#define KEY_LT 3
-#define KEY_RT 4
-#define KEY_A  5
-#define KEY_B  6
-#define KEY_SL 7
-#define KEY_ST 8
-
 #define GAME_WHITE 0
 #define GAME_RED 1
 #define GAME_YELLOW 2
 #define GAME_GREEN 3
 
-/* Graphics section */
-
-void ppu_off() {
-  PPU.mask &= 0xE7;
-}
-
-void ppu_on() {
-  waitvsync();
-  PPU.scroll = 0;
-  PPU.mask |= 0x1A;
-}
-
-int joy_input_wait() {
-  unsigned char last_joy = 0, joy, pressed;
-  /* wait until the previous key is released */
-  while(joy_read(JOY_1));
-  /* wait for a new press */
-  while(1) {
-    joy = joy_read(JOY_1);
-    pressed = joy & ~last_joy;
-    if(pressed & JOY_UP_MASK) return KEY_UP;
-    if(pressed & JOY_DOWN_MASK) return KEY_DN;
-    if(pressed & JOY_LEFT_MASK) return KEY_LT;
-    if(pressed & JOY_RIGHT_MASK) return KEY_RT;
-    if(pressed & JOY_BTN_1_MASK) return KEY_A;
-    if(pressed & JOY_BTN_2_MASK) return KEY_B;
-    if(pressed & JOY_BTN_3_MASK) return KEY_SL;
-    if(pressed & JOY_BTN_4_MASK) return KEY_ST;
-    last_joy = joy;
-    waitvsync();
-  }
-}
-
-/* palette loader */
-void init_palette() {
-  unsigned char i;
-  const unsigned char my_palette[16] = {
-    0x0f, 0, 0, 0x30, /* white */
-    0x0f, 0, 0, 0x15, /* red */
-    0x0f, 0, 0, 0x28, /* yellow */
-    0x0f, 0, 0, 0x2A  /* green */
-  };
-  PPU.vram.address = 0x3F;
-  PPU.vram.address = 0;
-  for(i=0; i<16; i++) PPU.vram.data = my_palette[i];
-}
-
-/* 4x4 char block colorization method (palette is 0 to 3) */
-void colorxy(unsigned char x, unsigned char y, unsigned char palette) {
-  unsigned int addr;
-  unsigned char attr_byte;
-  addr = 0x23C0 + ((y >> 2) << 3) + (x >> 2);
-  attr_byte = palette | (palette << 2) | (palette << 4) | (palette << 6);
-  waitvsync();
-  PPU.vram.address = (unsigned char) (addr >> 8);
-  PPU.vram.address = (unsigned char) (addr & 255);
-  PPU.vram.data = attr_byte;
-}
-
 /* Sound section */
 
-#define CPU 1789773 /* NTSC */
-
-unsigned int get_timer(int freq) {
-  return (unsigned int) ((CPU / 16 / freq) - 1);
-}
-
-void play_pulse(unsigned char idx, unsigned int freq, unsigned char len) {
-  unsigned int tm = get_timer(freq);
-  if(len > 31) len = 31;
-  if(idx > 1) idx = 0;
-  APU.pulse[idx].period_low = tm & 255;
-  APU.pulse[idx].len_period_high = (tm >> 8) | (len << 3);
-}
-
-void play_jingle(unsigned int n1f1,
-  unsigned int n1f2,
-  unsigned int n2f1,
-  unsigned int n2f2,
-  unsigned int n3f1,
-  unsigned int n3f2) {
-  unsigned int i, dl = 2000;
-  play_pulse(0, n1f1, 2);
-  play_pulse(1, n1f2, 2);
-  for(i=0;i<dl;++i);
-  play_pulse(0, n2f1, 2);
-  play_pulse(1, n2f2, 2);
-  for(i=0;i<dl;++i);
-  play_pulse(0, n3f1, 2);
-  play_pulse(1, n3f2, 2);
-}
-
-void init_sound() {
-  APU.status = 3;
-  APU.pulse[0].ramp = 0x8;
-  APU.pulse[1].ramp = 0x8;
-  APU.pulse[0].control = 0x9F;
-  APU.pulse[1].control = 0x9F;
-  waitvsync();
-}
-
 void beep_start() {
   play_jingle(220, 440, 440, 660, 660, 880);
 }
@@ -152,7 +37,7 @@ void beep_run() {
   play_jingle(660, 880, 440, 660, 220, 440);
 }
 void beep_win() {
-  unsigned short i;
+  u16 i;
   play_jingle(55, 110, 110, 220, 220, 440);
   for(i=0;i<4000;++i);
   play_jingle(440, 660, 660, 880, 880, 1760);
@@ -160,7 +45,7 @@ void beep_win() {
   play_jingle(880, 660, 660, 880, 880, 1760);
 }
 void beep_lose() {
-  unsigned short i;
+  u16 i;
   play_jingle(110, 55, 220, 110, 110, 55);
   for(i=0;i<4000;++i);
   play_jingle(110, 55, 110, 55, 110, 55);
@@ -172,21 +57,12 @@ void beep_err() {
 /* Main game logic */
 
 void game_startup() {
-  unsigned int entropy;
-  unsigned char joy, i, j;
-#ifdef _randomize
-  _randomize();
-#endif
-  entropy = rand();
-  init_sound();
-  bgcolor(COLOR_BLACK);
-  textcolor(0);
-  init_palette();
-  clrscr();
+  u8 i, j, x = 0;
+  init_game(NES_BLACK, NES_WHITE, NES_RED, NES_GREEN, NES_YELLOW);
   ppu_off();
   for(j=0;j<24;j+=4)
     for(i=3;i<32;i+=4)
-      colorxy(i, j, 1 + ((++entropy) % 3));
+      colorxy(i, j, 1 + ((++x) % 3));
   gotoxy(0, 2);
   cputs( \
 "    _______ _______ _______ \r\n"  \
@@ -215,22 +91,15 @@ void game_startup() {
   cputsxy(SCREEN_CENTER_X - 6, SCREEN_HEIGHT - 4, "Press Start");
   cputsxy(1, SCREEN_HEIGHT - 2, "Luxferre");
   cputsxy(SCREEN_WIDTH-5, SCREEN_HEIGHT - 2, "2026");
-  joy_install(joy_static_stddrv);
   ppu_on();
-  while(1) {
-    ++entropy;
-    joy = joy_read(JOY_1);
-    if(JOY_START(joy)) break;
-    waitvsync();
-  }
-  srand(entropy);
+  wait_for_start_rand();
   beep_start();
   clrscr();
 }
 
 /* Win screen display */
-void win_screen(int score) {
-  unsigned char i, j;
+void win_screen(s16 score) {
+  u8 i, j;
   clrscr();
   ppu_off();
   for(j=0;j<12;j+=4)
@@ -253,7 +122,7 @@ void win_screen(int score) {
   ppu_on();
   waitvsync();
   beep_win();
-  while(joy_input_wait() != KEY_ST);
+  wait_for_start();
 }
 
 /* UI choices */
@@ -286,7 +155,7 @@ static char deck[44], room[] = {0, 0, 0, 0};
 static char status_msg[(SCREEN_WIDTH-1)];
 
 /* tracking variables */
-static short deck_idx = 0, hp = 20, rooms_cleared = 0,
+static s16 deck_idx = 0, hp = 20, rooms_cleared = 0,
   weapon = 0, durability = 0, can_run = 1,
   engaged = 0, potion_drank = 0, last_potion_val = 0;
 
@@ -294,18 +163,18 @@ static short deck_idx = 0, hp = 20, rooms_cleared = 0,
 /* up 1, left 2, right 3, down 4, a run, start quit */
 char get_choice() {
   switch(joy_input_wait()) {
-    case KEY_UP: return CH1;
-    case KEY_LT: return CH2;
-    case KEY_RT: return CH3;
-    case KEY_DN: return CH4;
-    case KEY_ST: return CH_Q;
+    case EZJOY_UP: return CH1;
+    case EZJOY_LT: return CH2;
+    case EZJOY_RT: return CH3;
+    case EZJOY_DN: return CH4;
+    case EZJOY_ST: return CH_Q;
     default: return CH_R;
   }
 }
 
 /* Draw a room character according to the index and value */
-void render_room_item(short i, short v) {
-  unsigned char color,
+void render_room_item(s16 i, s16 v) {
+  u8 color,
         topleft_x, topleft_y,
         topright_x, bottomleft_y,
         text_x, text_y, cheight=7, cwidth=8, left_offset = 9;
@@ -362,7 +231,7 @@ void render_room_item(short i, short v) {
 
 /* Render main game screen */
 void render_main_scene() {
-  unsigned char i, deck_count = 0, statbase = 17,
+  u8 i, deck_count = 0, statbase = 17,
     room_start_x = 1,
     room_start_y = 1,
     room_end_x = statbase - 8,
@@ -404,8 +273,8 @@ void render_main_scene() {
 }
 
 /* Confirmation method */
-unsigned char confirm(char *prompt) {
-  unsigned char res = 2, statbase = SCREEN_WIDTH - 7;
+u8 confirm(char *prompt) {
+  u8 res = 2, statbase = SCREEN_WIDTH - 7;
   snprintf(status_msg, sizeof(status_msg), "%s", prompt);
   render_main_scene();
   gotoxy(statbase, SCREEN_HEIGHT-5);
@@ -414,8 +283,8 @@ unsigned char confirm(char *prompt) {
   cprintf("B=NO");
   while(res > 1) {
     switch(joy_input_wait()) {
-      case KEY_A: res = 1; break;
-      case KEY_B: res = 0; break;
+      case EZJOY_A: res = 1; break;
+      case EZJOY_B: res = 0; break;
       default: res = 2;
     }
   }
@@ -431,11 +300,11 @@ void print_msg(char *s) {
 }
 
 /* Array shuffle method */
-void shuffle(char *array, unsigned int n) {
-  unsigned int i, j, t;
+void shuffle(char *array, u16 n) {
+  u16 i, j, t;
   if(n > 1) {
     for(i=n-1;i>0;i--) {
-      j = (unsigned int) (rand()%(i+1));
+      j = (u16) (rand()%(i+1));
       t = array[j];
       array[j] = array[i];
       array[i] = t;
@@ -445,12 +314,12 @@ void shuffle(char *array, unsigned int n) {
 
 /* Room item handling methods */
 
-int handle_monster(int val) {
-  int healthlost = val;
+s16 handle_monster(s16 val) {
+  s16 healthlost = val;
   char monster_msg[(SCREEN_WIDTH-1)];
   beep_enemy();
   if(weapon > 0 && val <= durability) {
-    int weapondiff = val - weapon;
+    s16 weapondiff = val - weapon;
     if(weapondiff < 0) weapondiff = 0;
     snprintf(monster_msg, sizeof(status_msg), "%d-level monster: use weapon?", val);
     if(confirm(monster_msg)) {
@@ -469,14 +338,14 @@ int handle_monster(int val) {
   return val;
 }
 
-void handle_weapon(int val) {
+void handle_weapon(s16 val) {
   weapon = val;
   snprintf(status_msg, sizeof(status_msg), "You equip a %d-level weapon.", weapon);
   durability = 14; /* reset durability to max limit */
   beep_weapon();
 }
 
-void handle_potion(unsigned char val) {
+void handle_potion(u8 val) {
   if(potion_drank) {
     print_msg("Already drank a potion here.");
     beep_err();
@@ -492,11 +361,11 @@ void handle_potion(unsigned char val) {
 }
 
 /* Main gameplay */
-int game() {
-  unsigned int i;
-  int score = -208; /* score storage */
-  int item, room_sum; /* true item value */
-  int last_room = 0, last_room_clr = 0; /* last room markers */
+s16 game() {
+  u16 i;
+  s16 score = -208; /* score storage */
+  s16 item, room_sum; /* true item value */
+  s16 last_room = 0, last_room_clr = 0; /* last room markers */
   char ch;
   deck_idx = 0; /* reset the deck index */
   /* Prefill the deck */
@@ -557,7 +426,7 @@ int game() {
     } else if(ch == CH_R) { /* run mechanics */
       /* Compact and rearrange the deck */
       char temp_deck[sizeof(deck)];
-      int t_idx = 0;
+      s16 t_idx = 0;
 
       /* 1. Collect all valid remaining cards from deck */
       for(i=0; i<sizeof(deck); i++) {
@@ -630,9 +499,9 @@ int game() {
   return score;
 }
 
-/* Entry point */
-int main() {
-  int score;
+/* Entry pos16 */
+s16 main() {
+  s16 score;
   game_startup();
   while(1) {
     score = game();