8bitworkshop/presets/sms-sms-libcv/climber.c

#include <stdlib.h>
#include <string.h>
#include <cv.h>
#include <cvu.h>

#include "common.h"
//#link "common.c"

//#link "chr_generic.c"
extern const unsigned char CHR_GENERIC[8192];

#define XOFS		-16 // sprite horiz. offset
#define LADDER_DELTA_X	8

#define BGCOL CV_COLOR_BLUE

#define CH_BORDER 	0x8f
#define CH_FLOOR	0xf4
#define CH_LADDER	0xd4
#define CH_ITEM		0xc8
#define CH_PLAYER	0xd8

/*{pal:222,n:16}*/
const char PALETTE0[16] = {
  0x30, 0x38, 0x3E, 0x3F,
  0x30, 0x38, 0x3E, 0x3F,
  0x30, 0x38, 0x3E, 0x3F,
  0x30, 0x38, 0x3E, 0x3F,
};

/*{pal:222,n:16}*/
const char PALETTE1[16] = {
  0x30, 0x00, 0x3F, 0x03,
  0x30, 0x38, 0x3E, 0x3F,
  0x30, 0x38, 0x3E, 0x3F,
  0x30, 0x38, 0x3E, 0x3F,
};

#define NUM_SPRITE_PATTERNS 5
#define NUM_SPRITE_STATES 4

///

typedef struct Level {
  byte ypos;
  byte height; // TODO: why does bitmask not work?
  byte gap:4;
  byte ladder1:4;
  byte ladder2:4;
  byte objtype:4;
  byte objpos:4;
} Level;

#define MAX_LEVELS 32
#define GAPSIZE 3

Level levels[MAX_LEVELS];

bool is_in_gap(byte x, byte gap) {
  if (gap) {
    byte x1 = gap*16 + 26 - XOFS;
    return (x > x1 && x < x1+GAPSIZE*8-4);
  } else {
    return false;
  }
}

bool ladder_in_gap(byte x, byte gap) {
  return gap && x >= gap && x < gap+GAPSIZE*2;
}

void make_levels() {
  byte i;
  byte y=0;
  Level* prevlev = &levels[0];
  for (i=0; i<MAX_LEVELS; i++) {
    Level* lev = &levels[i];
    lev->height = rndint(4,7);
    lev->ladder1 = rndint(1,14);
    lev->ladder2 = rndint(1,14);
    do {
      lev->gap = i>0 ? rndint(0,13) : 0;
    } while (ladder_in_gap(prevlev->ladder1, lev->gap) || 
             ladder_in_gap(prevlev->ladder2, lev->gap));
    lev->objtype = rndint(1,2);
    lev->objpos = rndint(1,14);
    lev->ypos = y;
    y += lev->height;
    prevlev = lev;
  }
  // top level is special
  levels[MAX_LEVELS-1].height = 15;
  levels[MAX_LEVELS-1].gap = 0;
  levels[MAX_LEVELS-1].ladder1 = 0;
  levels[MAX_LEVELS-1].ladder2 = 0;
  levels[MAX_LEVELS-1].objtype = 0;
}

static byte scroll_y = 0;

void create_actors_on_level(byte i);

void draw_level_line(byte screen_y) {
  char buf[COLS*2];
  byte i;
  byte y = screen_y + scroll_y;
  for (i=0; i<MAX_LEVELS; i++) {
    Level* lev = &levels[i];
    byte dy = y - lev->ypos;
    // is this level visible on-screen?
    if (dy < lev->height) {
      if (dy == 0) {
        // draw floor
        memset(buf, CH_FLOOR, sizeof(buf));
        // draw the gap
	if (lev->gap)
          memset(buf+lev->gap*2, 0, GAPSIZE*2);
      } else {
        // draw empty space
        memset(buf, 0, sizeof(buf));
        // draw walls
        if (i < MAX_LEVELS-1) {
          buf[0] = CH_FLOOR;
          buf[COLS*2-1] = CH_FLOOR;
        }
        // draw ladders
        if (lev->ladder1) {
          buf[lev->ladder1*4] = CH_LADDER;
          buf[lev->ladder1*4+2] = CH_LADDER+2;
        }
        if (lev->ladder2) {
          buf[lev->ladder2*4] = CH_LADDER;
          buf[lev->ladder2*4+2] = CH_LADDER+2;
        }
      }
      // draw object, if it exists
      if (lev->objtype) {
        byte ch = lev->objtype*4 + CH_ITEM;
        if (dy == 1) {
          buf[lev->objpos*2] = ch+1;
          buf[lev->objpos*2+2] = ch+3;
        }
        else if (dy == 2) {
          buf[lev->objpos*2] = ch;
          buf[lev->objpos*2+2] = ch+2;
        }
      }
      // copy line to screen buffer
      cvu_memtovmemcpy(IMAGE + COLS*2*(ROWS-1) - COLS*2*screen_y, buf, sizeof(buf));
      // create actors on this level, if needed
      // (only when drawing top and bottom of screen)
      if (screen_y == 0 || screen_y == ROWS-1)
        create_actors_on_level(i);
      break;
    }
  }
}

void draw_screen() {
  byte y;
  for (y=0; y<ROWS; y++) {
    draw_level_line(y);
  }
}

word get_floor_yy(byte level) {
  return levels[level].ypos * 8 + 8;
}

word get_ceiling_yy(byte level) {
  return (levels[level].ypos + levels[level].height) * 8 + 8;
}

#define MAX_ACTORS 5

typedef enum ActorState {
  INACTIVE, WALKING, CLIMBING, JUMPING, FALLING
};

typedef struct Actor {
  word yy;
  byte x;
  byte name;
  byte color1:4;
  byte color2:4;
  byte level;
  byte state:4;
  byte dir:1;
  byte onscreen:1;
  union {
    struct {
      sbyte yvel;
      sbyte xvel;
    } jumping;
  } u;
} Actor;

Actor actors[MAX_ACTORS];

void create_actors_on_level(byte level_index) {
  byte actor_index = (level_index % (MAX_ACTORS-1)) + 1;
  struct Actor* a = &actors[actor_index];
  if (!a->onscreen) {
    Level *level = &levels[level_index];
    a->state = WALKING;
    a->color1 = level->ladder1;
    a->color2 = level->ladder2;
    a->name = CH_PLAYER;
    a->x = level->ladder1 ^ (level->ladder2<<3) ^ (level->gap<<6);
    a->yy = get_floor_yy(level_index);
    a->level = level_index;
  }
}

void draw_actor(byte i) {
  struct Actor* a = &actors[i];
  struct cvu_sprite4 sprite;
  int screen_y = 168 - a->yy + scroll_y*8;
  if (screen_y > 192+8 || screen_y < -18) {
    a->onscreen = 0;
    return; // offscreen vertically
  }
  sprite.name = a->name;
  switch (a->state) {
    case INACTIVE:
      a->onscreen = 0;
      return; // inactive, offscreen
    case WALKING:
      sprite.name += (a->x & 4) ? 12 : 16;
      break;
    case JUMPING:
      sprite.name += 4;
      break;
    case FALLING:
      sprite.name += 24;
      break;
    case CLIMBING:
      // TODO: animation
      sprite.name += 20;
      break;
  }
  sprite.x = a->x;
  sprite.y = screen_y;
  //sprite.tag = a->color1 | 0x80;
  sprite.x += XOFS;
  cvu_set_sprite4(SPRITES, i*2, &sprite);
  //sprite.tag ^= a->color1 ^ a->color2;
  sprite.x += 8;
  sprite.name += 2;
  cvu_set_sprite4(SPRITES, i*2+1, &sprite);
  a->onscreen = 1;
}

void refresh_actors() {
  byte i;
  for (i=0; i<MAX_ACTORS; i++)
    draw_actor(i);
}

void refresh_screen() {
  wait_vsync();
  draw_screen();
  refresh_actors();
}

byte is_ladder_close(byte actor_x, byte ladder_pos) {
  byte ladder_x;
  if (ladder_pos == 0)
    return 0;
  ladder_x = ladder_pos * 16 + LADDER_DELTA_X;
  return ((byte)(actor_x - ladder_x) < 16) ? ladder_x : 0;
}

byte get_closest_ladder(byte player_x, byte level_index) {
  Level* level = &levels[level_index];
  byte x;
  if (level_index >= MAX_LEVELS) return 0;
  x = is_ladder_close(player_x, level->ladder1);
  if (x) return x;
  x = is_ladder_close(player_x, level->ladder2);
  if (x) return x;
  return 0;
}

byte mount_ladder(Actor* player, signed char level_adjust) {
  byte x = get_closest_ladder(player->x, player->level + level_adjust);
  if (x) {
    player->x = x + 8;
    player->state = CLIMBING;
    player->level += level_adjust;
    return 1;
  } else
    return 0;
}

void check_scroll_up() {
  byte player_screen_y = cvu_vinb(SPRITES + 0); // sprite Y pos
  if (player_screen_y < 192/2-4) {
    scroll_y++;
    refresh_screen();
    check_scroll_up();
  }
}

void check_scroll_down() {
  byte player_screen_y = cvu_vinb(SPRITES + 0); // sprite Y pos
  if (player_screen_y > 192/2+4 && scroll_y > 0) {
    scroll_y--;
    refresh_screen();
    check_scroll_down();
  }
}

void fall_down(struct Actor* actor) {
  actor->level--;
  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 WALKING:
      // left/right has priority over climbing
      if (joystick & CV_FIRE_0) {
        actor->state = JUMPING;
        actor->u.jumping.xvel = 0;
        actor->u.jumping.yvel = 15;
        if (joystick & CV_LEFT) actor->u.jumping.xvel = -1;
        if (joystick & CV_RIGHT) actor->u.jumping.xvel = 1;
      } else if (joystick & CV_LEFT) {
        actor->x--;
        actor->dir = 1;
      } else if (joystick & CV_RIGHT) {
        actor->x++;
        actor->dir = 0;
      } else if (joystick & CV_UP) {
        mount_ladder(actor, 0); // state -> CLIMBING
        if (scroll) check_scroll_up();
      } else if (joystick & CV_DOWN) {
        mount_ladder(actor, -1); // state -> CLIMBING, level -= 1
        if (scroll) check_scroll_down();
      }
      break;
      
    case CLIMBING:
      if (joystick & CV_UP) {
      	if (actor->yy >= get_ceiling_yy(actor->level)) {
          actor->level++;
          actor->state = WALKING;
          if (scroll) check_scroll_up();
        } else {
          actor->yy++;
        }
      } else if (joystick & CV_DOWN) {
        if (actor->yy <= get_floor_yy(actor->level)) {
          actor->state = WALKING;
          if (scroll) check_scroll_down();
        } else {
          actor->yy--;
        }
      }
      break;
      
    case JUMPING:
    case FALLING:
      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->level)) {
	actor->yy = get_floor_yy(actor->level);
        actor->state = WALKING;
        if (scroll) check_scroll_down();
      }
      break;
  }
  // don't allow player to travel past left/right edges of screen
  if (actor->x == 0) actor->x = 255; // we wrapped around right edge
  if (actor->x < 24) actor->x = 24;
  // if player lands in a gap, they fall (switch to JUMPING state)
  if (actor->state == WALKING && 
      is_in_gap(actor->x, levels[actor->level].gap)) {
    fall_down(actor);
  }
}

void pickup_object(Actor* actor) {
  Level* level = &levels[actor->level];
  byte objtype = level->objtype;
  if (objtype && actor->state == WALKING) {
    byte objx = level->objpos * 16 + 24 - XOFS;
    if (actor->x >= objx && actor->x < objx+16) {
      level->objtype = 0;
      refresh_screen();
    }
  }
}

void move_player() {
  struct cv_controller_state ctrl;
  cv_get_controller_state(&ctrl, 0);
  move_actor(&actors[0], ctrl.joystick, true);
  pickup_object(&actors[0]);
}

inline byte iabs(int x) {
  return x >= 0 ? x : -x;
}

bool check_collision(Actor* a) {
  byte i;
  for (i=1; i<MAX_ACTORS; i++) {
    Actor* b = &actors[i];
    // actors must be on same level
    // no need to apply XOFS because both sprites are offset
    if (a->level == b->level && 
        iabs(a->yy - b->yy) < 8 && 
        iabs(a->x - b->x) < 8) {
      return true;
    }
  }
  return false;
}

///

void preview_stage() {
  scroll_y = levels[MAX_LEVELS-1].ypos;
  while (scroll_y > 0) {
    wait_vsync();
    refresh_screen();
    refresh_actors();
    scroll_y--;
  }
}

void draw_blimp(struct cvu_sprite4* sprite) {
  sprite->name = 48;
  wait_vsync();
  cvu_set_sprite4(SPRITES, 28, sprite);
  sprite->name += 4;
  sprite->x += 16;
  cvu_set_sprite4(SPRITES, 29, sprite);
  sprite->name += 4;
  sprite->x += 16;
  cvu_set_sprite4(SPRITES, 30, sprite);
  sprite->name += 4;
  sprite->x += 16;
  cvu_set_sprite4(SPRITES, 31, sprite);
  refresh_actors();
}

void blimp_pickup_scene() {
  struct cvu_sprite4 sprite;
  byte player_screen_y = cvu_vinb(SPRITES + 0); // sprite Y pos
  sprite.x = actors[0].x-14;
  sprite.y = 240;
  //sprite.tag = 0x8f;
  while (sprite.y != player_screen_y-16) {
    draw_blimp(&sprite);
    sprite.x -= 48;
    sprite.y++;
  }
  while (sprite.y != 240) {
    draw_blimp(&sprite);
    sprite.x -= 48;
    sprite.y--;
    actors[0].yy++;
  }
}

void play_scene() {
  byte i;
  
  memset(actors, 0, sizeof(actors));
  actors[0].state = WALKING;
  actors[0].color1 = 0xf;
  actors[0].color2 = 0xb;
  actors[0].name = CH_PLAYER;
  actors[0].x = 64;
  actors[0].yy = 8;
  actors[0].level = 0;
  
  create_actors_on_level(2);
  refresh_screen();
  
  while (actors[0].level != MAX_LEVELS-1) {
    wait_vsync();
    refresh_actors();
    move_player();
    // move all the actors
    for (i=1; i<MAX_ACTORS; i++) {
      move_actor(&actors[i], rand(), false);
    }
    // see if the player hit another actor
    if (cv_get_sprite_collission()) {
      if (actors[0].level > 0 && check_collision(&actors[0])) {
        fall_down(&actors[0]);
      }
    }
  }
  
  blimp_pickup_scene();
}

void setup_graphics() {
  cvu_memtovmemcpy(PATTERN, CHR_GENERIC, sizeof(CHR_GENERIC));
  cvu_memtocmemcpy(0xc000, PALETTE0, 16);
  cvu_memtocmemcpy(0xc010, PALETTE1, 16);
}

void main() {
  vdp_setup();
  setup_graphics();
  cv_set_screen_active(true);
  cv_set_vint_handler(&vint_handler);  
  make_levels();
  play_scene();
}