[Reverse-engineering] [th04/th05] Stage enemy structure

Last one of the shared entity types! The TH05 version of the .STD enemy
VM would now be ready for decompilation in one single future push.

Completes P0088, funded by -Tom-.

th02/sprites/cels.h

@@ -0,0 +1 @@
+#define ENEMY_KILL_CELS 8

th02/sprites/cels.inc

@@ -0,0 +1 @@
+ENEMY_KILL_CELS = 8

th04/main/enemy/enemies[bss].asm

@@ -0,0 +1,15 @@
+ENEMY_W = 32
+ENEMY_H = 32
+
+EF_FREE = 0
+EF_ALIVE = 1
+EF_KILLED = 2
+EF_ALIVE_FIRST_FRAME = 3
+EF_KILL_ANIM = 80h
+
+ENEMY_COUNT = 32
+
+ENEMY_POS_RANDOM = (999 shl 4)
+
+public _enemies
+_enemies	enemy_t ENEMY_COUNT dup (<?>)

th04/main/enemy/enemy.hpp

@@ -0,0 +1,90 @@
+#define ENEMY_W 32
+#define ENEMY_H 32
+
+enum enemy_flag_t {
+	EF_FREE = 0,
+	EF_ALIVE = 1,
+	EF_KILLED = 2,
+	EF_ALIVE_FIRST_FRAME = 3,
+
+	// Yes, the kill animation doesn't use the perfectly suitable animation
+	// system, but is implemented in terms of the [flag].
+	EF_KILL_ANIM = 0x80,
+	EF_KILL_ANIM_last = (EF_KILL_ANIM + PAT_ENEMY_KILL - 1)
+};
+
+#if GAME == 4
+struct enemy_t {
+	unsigned char flag;
+	unsigned char age;
+	motion_t pos;
+	unsigned char patnum_base;
+	int8_t unused_1;
+	int hp;
+	int16_t unused_2;
+	int score;
+	unsigned char near *script;
+	int script_ip;
+
+	// Certain instructions are executed once per frame, up to a number of
+	// frames given in some parameter of the instruction, before [script_ip]
+	// is pointed to the next one. This member tracks the current frame of
+	// this enemy's currently running blocking multi-frame instruction.
+	unsigned char cur_instr_frame;
+
+	// Current loop counter for the LOOP instruction. Resets to 0 once the
+	// amount of loops given in the instruction's parameter has been reached,
+	// allowing a new loop to run. Since there's only one such counter, LOOP
+	// instructions can't be nested.
+	unsigned char loop_i;
+
+	Subpixel speed;
+	unsigned char angle;
+
+	// Certain instructions add this to [angle] for every frame they are
+	// executed.
+	unsigned char angle_delta;
+
+	// Clips the enemy once it leaves the playfield. If not clipped along the
+	// X or Y axis, the [script] will continue to run if the enemy has left
+	// the playfield on that axis, and it will continue to take up a slot in
+	// [enemies].
+	bool clip_x;
+	bool clip_y;
+
+	int8_t unused_3;
+	item_type_t item;
+	bool damaged_this_frame;
+
+	// Animation parameters. Final patnum is
+	//	[patnum_base] + (([age] / [anim_frames_per_cel]) % [anim_cels]
+	unsigned char anim_cels;
+	unsigned char anim_frames_per_cel;
+	unsigned char anim_cur_cel; // technically unnecessary
+
+	bool can_be_damaged;
+	bool autofire;
+	bool kills_player_on_collision;
+
+	// Not updated to reflect the current playfield half the enemy is in!
+	bool spawned_in_left_half;
+
+	bullet_template_t bullet_template;
+
+	// If [autofire] is true, the enemy fires bullets, according to its
+	// template, every [autofire_interval] number of frames, with
+	// [autofire_cur_frame] tracking the current one.
+	unsigned char autofire_cur_frame;
+	unsigned char autofire_interval;
+};
+#endif
+
+#define ENEMY_COUNT 32
+
+extern enemy_t enemies[ENEMY_COUNT];
+extern enemy_t near *enemy_cur;
+
+#define ENEMY_POS_RANDOM 999.0f
+
+void pascal near enemies_invalidate(void);
+void pascal near enemies_render(void);

th04/main/enemy/enemy.inc

@@ -0,0 +1,33 @@
+enemy_t	struc
+	flag	db ?
+	age	db ?
+	pos	motion_t <?>
+	E_patnum_base	db ?
+		db ?
+	E_hp	dw ?
+		db ?
+		db ?
+	E_score	dw ?
+	E_script	dw ?
+	E_script_ip	dw ?
+	E_cur_instr_frame	db ?
+	E_loop_i	db ?
+	E_speed	dw ?
+	E_angle	db ?
+	E_angle_delta	db ?
+	E_clip_x	db ?
+	E_clip_y	db ?
+		db ?
+	E_item	db ?
+	E_damaged_this_frame	db ?
+	E_anim_cels	db ?
+	E_anim_frames_per_cel	db ?
+	E_anim_cur_cel	db ?
+	E_can_be_damaged	db ?
+	E_autofire	db ?
+	E_kills_player_on_collision	db ?
+	E_spawned_in_left_half	db ?
+	E_bullet_template	bullet_template_t <?>
+	E_autofire_cur_frame	db ?
+	E_autofire_interval	db ?
+enemy_t	ends

th04/main/enemy/inv.asm

@@ -0,0 +1,24 @@
+public ENEMIES_INVALIDATE
+enemies_invalidate	proc near
+	push	si
+	push	di
+	mov	_tile_invalidate_box, (ENEMY_W shl 16) or ENEMY_H
+	mov	si, offset _enemies
+	mov	di, ENEMY_COUNT
+
+@@loop:
+	cmp	[si+enemy_t.flag], EF_FREE
+	jz	short @@next
+	cmp	[si+enemy_t.flag], EF_ALIVE_FIRST_FRAME
+	jz	short @@next
+	call	tiles_invalidate_around pascal, large dword ptr [si+enemy_t.pos.prev]
+
+@@next:
+	add	si, size enemy_t
+	dec	di
+	jnz	short @@loop
+	pop	di
+	pop	si
+	retn
+enemies_invalidate	endp
+	even

th04/main/enemy/render.asm

@@ -0,0 +1,98 @@
+public ENEMIES_RENDER
+enemies_render	proc near
+
+@@patnum	= byte ptr -5
+@@top   	= word ptr -4
+@@i     	= word ptr -2
+
+	enter	6, 0
+	push	si
+	push	di
+	mov	si, offset _enemies
+	mov	[bp+@@i], 0
+	jmp	@@more?
+; ---------------------------------------------------------------------------
+
+@@loop:
+	cmp	byte ptr [si+enemy_t.flag], EF_ALIVE
+	jz	short @@outside_playfield?
+	cmp	byte ptr [si+enemy_t.flag], EF_KILL_ANIM
+	jb	@@next
+
+@@outside_playfield?:
+	cmp	[si+enemy_t.pos.prev.y], (-(ENEMY_H / 2) shl 4)
+	jle	@@next
+	cmp	[si+enemy_t.pos.prev.y], ((PLAYFIELD_H + (ENEMY_H / 2)) shl 4)
+	jge	@@next
+	mov	al, [si+enemy_t.E_patnum_base]
+	mov	[bp+@@patnum], al
+	cmp	[si+enemy_t.E_anim_cels], 1
+	jbe	short @@put
+	mov	al, [si+enemy_t.age]
+	mov	ah, 0
+	mov	dl, [si+enemy_t.E_anim_frames_per_cel]
+	mov	dh, 0
+	push	dx
+	cwd
+	pop	bx
+	idiv	bx
+	or	dx, dx
+	jnz	short @@still_same_cel
+	inc	[si+enemy_t.E_anim_cur_cel]
+	mov	al, [si+enemy_t.E_anim_cur_cel]
+	cmp	al, [si+enemy_t.E_anim_cels]
+	jb	short @@still_same_cel
+	mov	[si+enemy_t.E_anim_cur_cel], 0
+
+@@still_same_cel:
+	mov	al, [si+enemy_t.E_anim_cur_cel]
+	add	[bp+@@patnum], al
+
+@@put:
+	mov	ax, [si+enemy_t.cur.pos.x]
+	sar	ax, 4
+	add	ax, (PLAYFIELD_X - (ENEMY_W / 2))
+	mov	di, ax
+	call	scroll_subpixel_y_to_vram_seg1 pascal, [si+enemy_t.pos.cur.y]
+	mov	[bp+@@top], ax
+	or	di, di
+	jle	short @@next
+	cmp	di, PLAYFIELD_RIGHT
+	jge	short @@next
+	cmp	[si+enemy_t.pos.cur.y], (-(ENEMY_H / 2) shl 4)
+	jle	short @@next
+	cmp	[si+enemy_t.pos.cur.y], ((PLAYFIELD_H + (ENEMY_H / 2)) shl 4)
+	jge	short @@next
+	cmp	[si+enemy_t.E_damaged_this_frame], 0
+	jnz	short @@damaged
+	push	di
+	push	ax
+	mov	al, [bp+@@patnum]
+	mov	ah, 0
+	push	ax
+	call	super_roll_put
+	jmp	short @@next
+; ---------------------------------------------------------------------------
+
+@@damaged:
+	push	di
+	push	[bp+@@top]
+	mov	al, [bp+@@patnum]
+	mov	ah, 0
+	push	ax
+	pushd	PLANE_PUT or GC_BRGI
+	call	super_roll_put_1plane
+	mov	[si+enemy_t.E_damaged_this_frame], 0
+
+@@next:
+	inc	[bp+@@i]
+	add	si, size enemy_t
+
+@@more?:
+	cmp	[bp+@@i], ENEMY_COUNT
+	jl	@@loop
+	pop	di
+	pop	si
+	leave
+	retn
+enemies_render	endp

th04/main/item/items.hpp

@@ -1,4 +1,8 @@
 enum item_type_t {
+#if GAME == 5
+	IT_NONE = -2,
+#endif
+	IT_ENEMY_DROP_NEXT = -1,
 	IT_POWER = 0,
 	IT_POINT = 1,
 	IT_DREAM = 2,

th04/main/item/items[bss].asm

@@ -1,4 +1,8 @@
 ; item_type_t
+if GAME eq 5
+	IT_NONE = -2
+endif
+IT_ENEMY_DROP_NEXT = -1
 IT_POWER = 0
 IT_POINT = 1
 IT_DREAM = 2

th04/sprites/cels.h

@@ -1,5 +1,7 @@
 /// Animation frame counts
 /// ----------------------
+#include "th02/sprites/cels.h"
+
 #define HITSHOT_CELS 4
 #define BULLET_CLOUD_CELS 4
 #define BULLET_DECAY_CELS 4

th04/sprites/cels.inc

@@ -1,3 +1,5 @@
+include th02/sprites/cels.inc
+
 HITSHOT_CELS = 4
 BULLET_CLOUD_CELS = 4
 BULLET_DECAY_CELS = 4

th04/sprites/main_pat.h

@@ -7,6 +7,8 @@
 typedef enum {
 	// miko32.bft
 	// ----------
+	PAT_ENEMY_KILL = 4,
+	PAT_ENEMY_KILL_last = (PAT_ENEMY_KILL + ENEMY_KILL_CELS - 1),
 	PAT_CLOUD_BULLET16_BLUE = 20,
 	PAT_CLOUD_BULLET16_BLUE_last = (PAT_CLOUD_BULLET16_BLUE + BULLET_CLOUD_CELS - 1),
 	PAT_CLOUD_BULLET16_RED,

th04/sprites/main_pat.inc

@@ -1,5 +1,6 @@
 include th04/sprites/cels.inc
 
+PAT_ENEMY_KILL = 4
 PAT_CLOUD_BULLET16_BLUE = 20
 PAT_CLOUD_BULLET16_RED = 24
 PAT_OPTION_REIMU = 38

th05/main/enemy/enemy.hpp

@@ -0,0 +1,47 @@
+#define ENEMY_CLIP_NONE 0x00
+#define ENEMY_CLIP_X 0x01
+#define ENEMY_CLIP_Y 0x10
+
+// See TH04's version for documentation on the fields that originated in that
+// game.
+struct enemy_t {
+	unsigned char flag;
+	unsigned char age;
+	motion_t pos;
+	int hp;
+	int score;
+	unsigned char near *script;
+	int script_ip;
+	SubpixelLength8 speed;
+	unsigned char patnum_base;
+	unsigned char cur_instr_frame;
+	unsigned char loop_i;
+	unsigned char angle;
+	unsigned char angle_delta;
+	unsigned char anim_cels;
+	unsigned char anim_frames_per_cel;
+	unsigned char anim_cur_cel; // still technically unnecessary
+
+	char clip;
+
+	item_type_t item;
+	bool damaged_this_frame;
+	bool can_be_damaged;
+	bool autofire;
+	bool kills_player_on_collision;
+	bool spawned_in_left_half;
+	unsigned char autofire_cur_frame;
+	unsigned char autofire_interval;
+	bullet_template_t bullet_template;
+
+	// Custom type ID, set in the spawn parameters. Can be used to parametrize
+	// scripts via conditional jumps based on this value.
+	unsigned char subtype;
+
+	int8_t unused_1;
+	int16_t unused_2;
+	int8_t unused_3;
+	int8_t padding[5];
+};
+
+#include "th04/main/enemy/enemy.hpp"

th05/main/enemy/enemy.inc

@@ -0,0 +1,33 @@
+ENEMY_CLIP_X = 01h
+ENEMY_CLIP_Y = 10h
+
+enemy_t	struc
+	flag	db ?
+	age	db ?
+	pos	motion_t <?>
+	E_hp	dw ?
+	E_score	dw ?
+	E_script	dw ?
+	E_script_ip	dw ?
+	E_speed	db ?
+	E_patnum_base	db ?
+	E_cur_instr_frame	db ?
+	E_loop_i	db ?
+	E_angle	db ?
+	E_angle_delta	db ?
+	E_anim_cels	db ?
+	E_anim_frames_per_cel	db ?
+	E_anim_cur_cel	db ?
+	E_clip	db ?
+	E_item	db ?
+	E_damaged_this_frame	db ?
+	E_can_be_damaged	db ?
+	E_autofire	db ?
+	E_kills_player_on_collision	db ?
+	E_spawned_in_left_half	db ?
+	E_autofire_cur_frame	db ?
+	E_autofire_interval	db ?
+	E_bullet_template	bullet_template_t <?>
+	E_subtype	db ?
+		db 9 dup(?)
+enemy_t	ends

th05/sprites/main_pat.h

@@ -10,7 +10,9 @@
 typedef enum {
 	// miko32.bft
 	// ----------
-	PAT_CLOUD_BULLET16_BLUE = 12,
+	PAT_ENEMY_KILL = 4,
+	PAT_ENEMY_KILL_last = (PAT_ENEMY_KILL + ENEMY_KILL_CELS - 1),
+	PAT_CLOUD_BULLET16_BLUE,
 	PAT_CLOUD_BULLET16_BLUE_last = (PAT_CLOUD_BULLET16_BLUE + BULLET_CLOUD_CELS - 1),
 	PAT_CLOUD_BULLET16_RED,
 	// ----------

th05/sprites/main_pat.inc

@@ -3,6 +3,7 @@ include th04/sprites/cels.inc
 PARTICLE_CELS = 4
 B4BALL_CELS = 4
 
+PAT_ENEMY_KILL = 4
 PAT_CLOUD_BULLET16_BLUE = 12
 PAT_CLOUD_BULLET16_RED = 16
 PAT_SHOT_SUB = 22