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8bitworkshop/presets/nes/climber.c

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#include <stdlib.h>
#include <string.h>
// include NESLIB header
#include "neslib.h"
// include CC65 NES Header (PPU)
#include <nes.h>
// BCD arithmetic support
#include "bcd.h"
//#link "bcd.c"
// VRAM update buffer
#include "vrambuf.h"
//#link "vrambuf.c"
// link the pattern table into CHR ROM
//#link "chr_generic.s"
// famitone2 library
//#link "famitone2.s"
// music and sfx
//#link "music_dangerstreets.s"
extern char danger_streets_music_data[];
//#link "demosounds.s"
extern char demo_sounds[];
// indices of sound effects (0..3)
typedef enum { SND_START, SND_HIT, SND_COIN, SND_JUMP } SFXIndex;
///// DEFINES
#define COLS 30 // floor width in tiles
#define ROWS 60 // total nametable height in tiles
#define MAX_FLOORS 24 // total # of floors in a stage
#define GAPSIZE 4 // gap size in tiles
#define BOTTOM_FLOOR_Y 2 // offset for bottommost floor
#define MAX_ACTORS 8 // max # of moving actors
#define SCREEN_Y_BOTTOM 208 // bottom of screen in pixels
#define ACTOR_MIN_X 16 // leftmost position of actor
#define ACTOR_MAX_X 228 // rightmost position of actor
#define ACTOR_SCROLL_UP_Y 110 // min Y position to scroll up
#define ACTOR_SCROLL_DOWN_Y 140 // max Y position to scroll down
#define JUMP_VELOCITY 18 // Y velocity when jumping
// constants for various tiles
#define CH_BORDER 0x40
#define CH_FLOOR 0xf4
#define CH_LADDER 0xd4
#define CH_ITEM 0xc4
#define CH_BLANK 0x20
///// GLOBALS
// vertical scroll amount in pixels
static int scroll_pixel_yy = 0;
// vertical scroll amount in tiles
static byte scroll_tile_y = 0;
// last screen Y position of player sprite
static byte player_screen_y = 0;
// score (BCD)
static byte score = 0;
// screen flash animation (virtual bright)
static byte vbright = 4;
// random byte between (a ... b-1)
// use rand() because rand8() has a cycle of 255
byte rndint(byte a, byte b) {
return (rand() % (b-a)) + a;
}
// return nametable address for tile (x,y)
// assuming vertical scrolling (horiz. mirroring)
word getntaddr(byte x, byte y) {
word addr;
if (y < 30) {
addr = NTADR_A(x,y);
} else {
addr = NTADR_C(x,y-30);
}
return addr;
}
// convert nametable address to attribute address
word nt2attraddr(word a) {
return (a & 0x2c00) | 0x3c0 |
((a >> 4) & 0x38) | ((a >> 2) & 0x07);
}
/// METASPRITES
// define a 2x2 metasprite
#define DEF_METASPRITE_2x2(name,code,pal)\
const unsigned char name[]={\
0, 0, (code)+0, pal, \
0, 8, (code)+1, pal, \
8, 0, (code)+2, pal, \
8, 8, (code)+3, pal, \
128};
// define a 2x2 metasprite, flipped horizontally
#define DEF_METASPRITE_2x2_FLIP(name,code,pal)\
const unsigned char name[]={\
8, 0, (code)+0, (pal)|OAM_FLIP_H, \
8, 8, (code)+1, (pal)|OAM_FLIP_H, \
0, 0, (code)+2, (pal)|OAM_FLIP_H, \
0, 8, (code)+3, (pal)|OAM_FLIP_H, \
128};
DEF_METASPRITE_2x2(playerRStand, 0xd8, 0);
DEF_METASPRITE_2x2(playerRRun1, 0xdc, 0);
DEF_METASPRITE_2x2(playerRRun2, 0xe0, 0);
DEF_METASPRITE_2x2(playerRRun3, 0xe4, 0);
DEF_METASPRITE_2x2(playerRJump, 0xe8, 0);
DEF_METASPRITE_2x2(playerRClimb, 0xec, 0);
DEF_METASPRITE_2x2(playerRSad, 0xf0, 0);
DEF_METASPRITE_2x2_FLIP(playerLStand, 0xd8, 0);
DEF_METASPRITE_2x2_FLIP(playerLRun1, 0xdc, 0);
DEF_METASPRITE_2x2_FLIP(playerLRun2, 0xe0, 0);
DEF_METASPRITE_2x2_FLIP(playerLRun3, 0xe4, 0);
DEF_METASPRITE_2x2_FLIP(playerLJump, 0xe8, 0);
DEF_METASPRITE_2x2_FLIP(playerLClimb, 0xec, 0);
DEF_METASPRITE_2x2_FLIP(playerLSad, 0xf0, 0);
//DEF_METASPRITE_2x2(personToSave, 0xba, 1);
const unsigned char personToSave[]={
0, 0, (0xba)+0, 3,
0, 8, (0xba)+2, 0,
8, 0, (0xba)+1, 3,
8, 8, (0xba)+3, 0,
128};
const unsigned char* const playerRunSeq[16] = {
playerLRun1, playerLRun2, playerLRun3,
playerLRun1, playerLRun2, playerLRun3,
playerLRun1, playerLRun2,
playerRRun1, playerRRun2, playerRRun3,
playerRRun1, playerRRun2, playerRRun3,
playerRRun1, playerRRun2,
};
///// GAME LOGIC
// struct definition for a single floor
typedef struct Floor {
byte ypos; // # of tiles from ground
int height:4; // # of tiles to next floor
int gap:4; // X position of gap
int ladder1:4; // X position of first ladder
int ladder2:4; // X position of second ladder
int objtype:4; // item type (FloorItem)
int objpos:4; // X position of object
} Floor;
// various items the player can pick up
typedef enum FloorItem { ITEM_NONE, ITEM_MINE, ITEM_HEART, ITEM_POWER };
// array of floors
Floor floors[MAX_FLOORS];
// is this x (pixel) position within the gap <gap>?
bool is_in_gap(byte x, byte gap) {
if (gap) {
byte x1 = gap*16 + 4;
return (x > x1 && x < x1+GAPSIZE*8-4);
} else {
return false;
}
}
// is this ladder at (tile) position x within the gap?
bool ladder_in_gap(byte x, byte gap) {
return gap && x >= gap && x < gap+GAPSIZE*2;
}
// create floors at start of game
void make_floors() {
byte i;
byte y = BOTTOM_FLOOR_Y;
Floor* prevlev = &floors[0];
for (i=0; i<MAX_FLOORS; i++) {
Floor* lev = &floors[i];
lev->height = rndint(2,5)*2;
do {
// only have gaps in higher floors
lev->gap = i>=5 ? rndint(0,13) : 0;
} while (ladder_in_gap(prevlev->ladder1, lev->gap) ||
ladder_in_gap(prevlev->ladder2, lev->gap));
do {
lev->ladder1 = rndint(1,14);
lev->ladder2 = rndint(1,14);
} while (ladder_in_gap(lev->ladder1, lev->gap) ||
ladder_in_gap(lev->ladder2, lev->gap));
if (i > 0) {
lev->objtype = rndint(1,4);
do {
lev->objpos = rndint(1,14);
} while (ladder_in_gap(lev->objpos, lev->gap));
}
lev->ypos = y;
y += lev->height;
prevlev = lev;
}
// top floor is special
floors[MAX_FLOORS-1].height = 15;
floors[MAX_FLOORS-1].gap = 0;
floors[MAX_FLOORS-1].ladder1 = 0;
floors[MAX_FLOORS-1].ladder2 = 0;
floors[MAX_FLOORS-1].objtype = 0;
}
void create_actors_on_floor(byte floor_index);
// draw a nametable line into the frame buffer at <screen_y>
// 0 == bottom of stage
void draw_floor_line(byte screen_y) {
char buf[COLS];
char attrs[8];
byte floor, i;
byte y = screen_y;
byte rowy;
word addr;
for (floor=0; floor<MAX_FLOORS; floor++) {
Floor* lev = &floors[floor];
byte dy = y - lev->ypos;
if (dy >= 254) dy = 0; // if below BOTTOM_Y_FLOOR
// is this floor visible on-screen?
if (dy < lev->height) {
if (dy <= 1) {
// draw floor
for (i=0; i<COLS; i+=2) {
if (dy) {
buf[i] = CH_FLOOR;
buf[i+1] = CH_FLOOR+2;
} else {
buf[i] = CH_FLOOR+1;
buf[i+1] = CH_FLOOR+3;
}
}
// draw the gap
if (lev->gap)
memset(buf+lev->gap*2, 0, GAPSIZE);
} else {
// draw empty space
memset(buf, 0, sizeof(buf));
// draw walls
if (floor < MAX_FLOORS-1) {
buf[0] = CH_FLOOR+1;
buf[COLS-1] = CH_FLOOR;
}
// draw ladders
if (lev->ladder1) {
buf[lev->ladder1*2] = CH_LADDER;
buf[lev->ladder1*2+1] = CH_LADDER+1;
}
if (lev->ladder2) {
buf[lev->ladder2*2] = CH_LADDER;
buf[lev->ladder2*2+1] = CH_LADDER+1;
}
}
// draw object, if it exists
if (lev->objtype) {
byte ch = lev->objtype*4 + CH_ITEM;
if (dy == 2) {
buf[lev->objpos*2] = ch+1;
buf[lev->objpos*2+1] = ch+3;
}
else if (dy == 3) {
buf[lev->objpos*2] = ch+0;
buf[lev->objpos*2+1] = ch+2;
}
}
// compute row in name buffer and address
rowy = (ROWS-1) - (screen_y%60);
addr = getntaddr(1, rowy);
// copy attribute table (every 4th row)
if ((addr & 0x60) == 0) {
byte a;
if (dy==1)
a = 0x05;
else if (dy==3)
a = 0x50;
else
a = 0x00;
memset(attrs, a, 8);
vrambuf_put(nt2attraddr(addr), attrs, 8);
}
// copy line to screen buffer
vrambuf_put(addr, buf, COLS);
// create actors on this floor, if needed
// TODO: maybe this happens too early?
if (dy == 0 && (floor >= 2)) {
create_actors_on_floor(floor);
}
break;
}
}
}
// draw entire stage at current scroll position
// filling up entire name table
void draw_entire_stage() {
byte y;
for (y=0; y<ROWS; y++) {
draw_floor_line(y);
// allow buffer to flush, delaying a frame
vrambuf_flush();
}
}
// get Y pixel position for a given floor
word get_floor_yy(byte floor) {
return floors[floor].ypos * 8 + 16;
}
// get Y ceiling position for a given floor
word get_ceiling_yy(byte floor) {
return (floors[floor].ypos + floors[floor].height) * 8 + 16;
}
// set scrolling position
void set_scroll_pixel_yy(int yy) {
// draw an offscreen line, every 8 pixels
if ((yy & 7) == 0) {
// scrolling upward or downward?
if (yy > scroll_pixel_yy)
draw_floor_line(scroll_tile_y+30);
else
draw_floor_line(scroll_tile_y-30);
}
scroll_pixel_yy = yy;
scroll_tile_y = yy >> 3; // divide by 8
scroll(0, 479 - ((yy + 224) % 480));
}
// redraw a floor when object picked up
void refresh_floor(byte floor) {
byte y = floors[floor].ypos;
draw_floor_line(y+2);
draw_floor_line(y+3);
}
///// ACTORS
typedef enum ActorState {
INACTIVE, STANDING, WALKING, CLIMBING, JUMPING, FALLING, PACING
};
typedef enum ActorType {
ACTOR_PLAYER, ACTOR_ENEMY, ACTOR_RESCUE
};
typedef struct Actor {
word yy; // Y position in pixels (16 bit)
byte x; // X position in pixels (8 bit)
byte floor; // floor index
byte state; // ActorState
int name:2; // ActorType
int dir:1; // direction (0=right, 1=left)
int onscreen:1; // is actor onscreen?
union {
struct { // when jumping...
sbyte yvel; // Y velocity
sbyte xvel; // X velocity
} jumping;
} u;
} Actor;
Actor actors[MAX_ACTORS];
void create_actors_on_floor(byte floor_index) {
byte actor_index = (floor_index % (MAX_ACTORS-1)) + 1;
struct Actor* a = &actors[actor_index];
if (!a->onscreen) {
Floor *floor = &floors[floor_index];
a->state = STANDING;
a->name = ACTOR_ENEMY;
a->x = rand8();
a->yy = get_floor_yy(floor_index);
a->floor = floor_index;
a->onscreen = 1;
// rescue person on top of the building
if (floor_index == MAX_FLOORS-1) {
a->name = ACTOR_RESCUE;
a->state = PACING;
a->x = 0;
}
}
}
byte draw_actor(byte oam_id, byte i) {
struct Actor* a = &actors[i];
bool dir;
const unsigned char* meta;
byte x,y; // sprite variables
int screen_y = SCREEN_Y_BOTTOM - a->yy + scroll_pixel_yy;
if (screen_y > 192+8 || screen_y < -18) {
a->onscreen = 0;
return oam_id; // offscreen vertically
}
dir = a->dir;
switch (a->state) {
case INACTIVE:
a->onscreen = 0;
return oam_id; // inactive, offscreen
case STANDING:
meta = dir ? playerLStand : playerRStand;
break;
case WALKING:
meta = playerRunSeq[((a->x >> 1) & 7) + (dir?0:8)];
break;
case JUMPING:
meta = dir ? playerLJump : playerRJump;
break;
case FALLING:
meta = dir ? playerLSad : playerRSad;
break;
case CLIMBING:
meta = (a->yy & 4) ? playerLClimb : playerRClimb;
break;
case PACING:
meta = personToSave;
break;
}
// set sprite values
x = a->x;
y = screen_y;
oam_id = oam_meta_spr(x, y, oam_id, meta);
// is this actor 0? (player sprite)
if (i == 0) {
player_screen_y = y; // last screen Y position
// set special palette for the player's sprites
// directly in OAM buffer
OAMBUF[0].attr |= 3;
OAMBUF[1].attr |= 3;
OAMBUF[2].attr |= 3;
OAMBUF[3].attr |= 3;
}
a->onscreen = 1;
return oam_id;
}
byte draw_scoreboard(byte oam_id) {
oam_id = oam_spr(24+0, 24, '0'+(score >> 4), 2, oam_id);
oam_id = oam_spr(24+8, 24, '0'+(score & 0xf), 2, oam_id);
return oam_id;
}
void refresh_sprites() {
byte i;
// draw all actors
byte oam_id = 0;
for (i=0; i<MAX_ACTORS; i++)
oam_id = draw_actor(oam_id, i);
// draw scoreboard
oam_id = draw_scoreboard(oam_id);
// hide rest of actors
oam_hide_rest(oam_id);
}
byte is_ladder_close(byte actor_x, byte ladder_pos) {
byte ladder_x;
if (ladder_pos == 0)
return 0;
ladder_x = ladder_pos * 16;
return ((byte)(actor_x - ladder_x) < 16) ? ladder_x : 0;
}
byte get_closest_ladder(byte player_x, byte floor_index) {
Floor* floor = &floors[floor_index];
byte x;
if (floor_index >= MAX_FLOORS) return 0;
x = is_ladder_close(player_x, floor->ladder1);
if (x) return x;
x = is_ladder_close(player_x, floor->ladder2);
if (x) return x;
return 0;
}
byte mount_ladder(Actor* player, signed char floor_adjust) {
byte x = get_closest_ladder(player->x, player->floor + floor_adjust);
if (x) {
player->x = x + 8;
player->state = CLIMBING;
player->floor += floor_adjust;
return 1;
} else
return 0;
}
void check_scroll_up() {
if (player_screen_y < ACTOR_SCROLL_UP_Y) {
set_scroll_pixel_yy(scroll_pixel_yy + 1);
}
}
void check_scroll_down() {
if (player_screen_y > ACTOR_SCROLL_DOWN_Y && scroll_pixel_yy > 0) {
set_scroll_pixel_yy(scroll_pixel_yy - 1);
}
}
void fall_down(struct Actor* actor) {
actor->floor--;
actor->state = FALLING;
actor->u.jumping.xvel = 0;
actor->u.jumping.yvel = 0;
}
void move_actor(struct Actor* actor, byte joystick, bool scroll) {
switch (actor->state) {
case STANDING:
case WALKING:
// left/right has priority over climbing
if (joystick & PAD_A) {
actor->state = JUMPING;
actor->u.jumping.xvel = 0;
actor->u.jumping.yvel = JUMP_VELOCITY;
if (joystick & PAD_LEFT) actor->u.jumping.xvel = -1;
if (joystick & PAD_RIGHT) actor->u.jumping.xvel = 1;
// play sound for player
if (scroll) sfx_play(SND_JUMP,0);
} else if (joystick & PAD_LEFT) {
actor->x--;
actor->dir = 1;
actor->state = WALKING;
} else if (joystick & PAD_RIGHT) {
actor->x++;
actor->dir = 0;
actor->state = WALKING;
} else if (joystick & PAD_UP) {
mount_ladder(actor, 0); // state -> CLIMBING
} else if (joystick & PAD_DOWN) {
mount_ladder(actor, -1); // state -> CLIMBING, floor -= 1
} else {
actor->state = STANDING;
}
if (scroll) {
check_scroll_up();
check_scroll_down();
}
break;
case CLIMBING:
if (joystick & PAD_UP) {
if (actor->yy >= get_ceiling_yy(actor->floor)) {
actor->floor++;
actor->state = STANDING;
} else {
actor->yy++;
}
} else if (joystick & PAD_DOWN) {
if (actor->yy <= get_floor_yy(actor->floor)) {
actor->state = STANDING;
} else {
actor->yy--;
}
}
if (scroll) {
check_scroll_up();
check_scroll_down();
}
break;
case FALLING:
if (scroll) {
check_scroll_up();
check_scroll_down();
}
case JUMPING:
actor->x += actor->u.jumping.xvel;
actor->yy += actor->u.jumping.yvel/4;
actor->u.jumping.yvel -= 1;
if (actor->yy <= get_floor_yy(actor->floor)) {
actor->yy = get_floor_yy(actor->floor);
actor->state = STANDING;
}
break;
}
// don't allow player to travel past left/right edges of screen
if (actor->x > ACTOR_MAX_X) actor->x = ACTOR_MAX_X; // we wrapped around right edge
if (actor->x < ACTOR_MIN_X) actor->x = ACTOR_MIN_X;
// if player lands in a gap, they fall (switch to JUMPING state)
if (actor->state <= WALKING &&
is_in_gap(actor->x, floors[actor->floor].gap)) {
fall_down(actor);
}
}
void pickup_object(Actor* actor) {
Floor* floor = &floors[actor->floor];
byte objtype = floor->objtype;
if (objtype && actor->state <= WALKING) {
byte objx = floor->objpos * 16;
if (actor->x >= objx && actor->x < objx+16) {
// clear the item from the floor and redraw
floor->objtype = 0;
refresh_floor(actor->floor);
// did we hit a mine?
if (objtype == ITEM_MINE) {
fall_down(actor);
sfx_play(SND_HIT,0);
vbright = 8; // flash
} else {
score = bcd_add(score, 1);
sfx_play(SND_COIN,0);
}
}
}
}
void move_player() {
byte joy = pad_poll(0);
move_actor(&actors[0], joy, true);
pickup_object(&actors[0]);
}
byte iabs(int x) {
return x >= 0 ? x : -x;
}
bool check_collision(Actor* a) {
byte i;
byte afloor = a->floor;
// can't fall through basement
if (afloor == 0) return false;
// can't fall if already falling
if (a->state == FALLING) return false;
// iterate through entire list of actors
for (i=1; i<MAX_ACTORS; i++) {
Actor* b = &actors[i];
// actors must be on same floor and within 8 pixels
if (b->onscreen &&
afloor == b->floor &&
iabs(a->yy - b->yy) < 8 &&
iabs(a->x - b->x) < 8) {
return true;
}
}
return false;
}
///
const char* RESCUE_TEXT =
"Is this a rescue?\n"
"I am just hanging out\n"
"on top of this building.\n"
"Get lost!!!";
void type_message(const char* charptr) {
char ch;
byte x,y;
x = 2;
// compute message y position relative to scroll
y = ROWS*3 + 39 - scroll_tile_y;
while ((ch = *charptr++)) {
while (y >= 60) y -= 60;
if (ch == '\n') {
x = 2;
y++;
} else {
vrambuf_put(getntaddr(x, y), &ch, 1);
x++;
}
// flush buffer and wait a few frames
vrambuf_flush();
delay(5);
}
}
void rescue_scene() {
// make player face to the left
actors[0].dir = 1;
actors[0].state = STANDING;
refresh_sprites();
type_message(RESCUE_TEXT);
// wait 2 seconds
delay(100);
}
void play_scene() {
byte i;
memset(actors, 0, sizeof(actors));
actors[0].state = STANDING;
actors[0].name = ACTOR_PLAYER;
actors[0].x = 64;
actors[0].floor = 0;
actors[0].yy = get_floor_yy(0);
set_scroll_pixel_yy(0);
draw_entire_stage();
while (actors[0].floor != MAX_FLOORS-1) {
//set_scroll_pixel_yy(scroll_pixel_yy+1);
vrambuf_flush();
refresh_sprites();
move_player();
// move all the actors
for (i=1; i<MAX_ACTORS; i++) {
move_actor(&actors[i], rand8(), false);
}
// see if the player hit another actor
if (check_collision(&actors[0])) {
fall_down(&actors[0]);
sfx_play(SND_HIT,0);
vbright = 8; // flash
}
if (vbright > 4) {
pal_bright(--vbright);
}
}
rescue_scene();
}
/*{pal:"nes",layout:"nes"}*/
const char PALETTE[32] = {
0x03, // background color
0x11,0x30,0x27, 0x0, // ladders and pickups
0x1c,0x20,0x2c, 0x0, // floor blocks
0x00,0x10,0x20, 0x0,
0x06,0x16,0x26, 0x0,
0x16,0x35,0x24, 0x0, // enemy sprites
0x00,0x37,0x25, 0x0, // rescue person
0x0d,0x2d,0x3a, 0x0,
0x0d,0x27,0x2a // player sprites
};
void setup_graphics() {
ppu_off();
oam_clear();
pal_all(PALETTE);
vram_adr(0x2000);
vram_fill(CH_BLANK, 0x1000);
vrambuf_clear();
set_vram_update(updbuf);
ppu_on_all();
}
void setup_sounds() {
famitone_init(danger_streets_music_data);
sfx_init(demo_sounds);
nmi_set_callback(famitone_update);
}
void main() {
setup_sounds();
while (1) {
setup_graphics();
sfx_play(SND_START,0);
make_floors();
music_play(0);
play_scene();
}
}
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