[Decompilation] [th01] Elis: Pattern 1/13

The one where Elis fires 11 (yes, 11) evenly spaced lasers from her
left eye (?) across the whole playfield, from either the left or right
edge to the other one. First pattern you see in the fight.

Part of P0193, funded by Ember2528.

decomp.hpp

@@ -169,6 +169,9 @@ inline void poked_eax(Decomp_GS *sgm, Decomp_DI *off, uint8_t op) {
 #endif
 // ------------------------------------
 
+// Neither WAIT nor FWAIT emit the emulated WAIT we want...
+#define FWAIT_EMU	db 0xCD, 0x3D;
+
 // 32-bit ASM instructions not supported by Turbo C++ 4.0J's built-in
 // assembler. Makes no sense to compile with `#pragma inline` (and thus,
 // require a 16-bit TASM) just for those.

th01/main/boss/b15m.cpp

@@ -1,21 +1,24 @@
 /// Makai Stage 15 Boss - Elis
 /// --------------------------
 
-extern "C" {
 #include <stddef.h>
 #include "platform.h"
+#include "decomp.hpp"
 #include "pc98.h"
 #include "planar.h"
 #include "master.hpp"
 #include "th01/v_colors.hpp"
 #include "th01/math/area.hpp"
+#include "th01/math/dir.hpp"
 #include "th01/math/subpixel.hpp"
+extern "C" {
 #include "th01/hardware/egc.h"
 #include "th01/hardware/graph.h"
 #include "th01/formats/pf.hpp"
 #include "th01/formats/grc.hpp"
 #include "th01/formats/ptn.hpp"
 #include "th01/main/entity.hpp"
+#include "th01/snd/mdrv2.h"
 #include "th01/main/playfld.hpp"
 #include "th01/main/vars.hpp"
 #include "th01/main/boss/entity_a.hpp"
@@ -30,6 +33,7 @@ extern "C" {
 #include "th01/main/particle.hpp"
 #include "th01/main/boss/boss.hpp"
 #include "th01/main/boss/palette.hpp"
+#include "th01/main/bullet/laser_s.hpp"
 #include "th01/main/bullet/missile.hpp"
 #include "th01/main/bullet/pellet.hpp"
 #include "th01/main/hud/hp.hpp"
@@ -48,6 +52,13 @@ static const pixel_t BASE_TOP = (
 );
 // -----------
 
+enum elis_colors_t {
+	COL_FX = 4,
+};
+
+// State
+// -----
+
 #define pattern_state	elis_pattern_state
 #define stars	elis_stars
 #define flash_colors	elis_flash_colors
@@ -59,14 +70,27 @@ extern int invincibility_frame;
 extern bool16 invincible;
 extern bool16 wave_teleport_done;
 extern bool initial_hp_rendered;
+// -----
+
+// Patterns
+// --------
+static const int CHOOSE_NEW = 0;
 
 extern union {
-	int unknown;
+	int speed_multiplied_by_8;
 } pattern_state;
+// --------
 
 // Entities
 // --------
 
+enum elis_form_t {
+	F_GIRL = 0,
+	F_BAT = 1,
+
+	_elis_form_t_FORCE_INT16 = 0x7FFF,
+};
+
 enum elis_entity_t {
 	// "Girl" sprites
 	ENT_STILL_OR_WAVE = 0,
@@ -75,8 +99,10 @@ enum elis_entity_t {
 	ENT_BAT = 2,
 };
 
-enum still_or_wave_cel_t {
+enum elis_entity_cel_t {
+	// ENT_STILL_OR_WAVE
 	C_STILL = 0,
+	C_HAND = 1,
 	C_WAVE_1 = 2,
 	C_WAVE_2 = 3,
 	C_WAVE_3 = 4,
@@ -104,8 +130,34 @@ inline void ent_sync(elis_entity_t dst, elis_entity_t src) {
 		boss_entities[src].cur_left, boss_entities[src].cur_top
 	);
 }
+
+inline void ent_unput_and_put_both(elis_entity_t ent, elis_entity_cel_t cel) {
+	void girl_bg_put(int unncessary_parameter_that_still_needs_to_be_1_or_2);
+
+	graph_accesspage_func(1);
+	girl_bg_put(ent + 1);
+	boss_entities[ent].move_lock_and_put_image_8(cel);
+	graph_accesspage_func(0);
+	ent_still_or_wave.move_lock_and_put_image_8(cel);
+}
 // --------
 
+// Form-relative coordinates
+// -------------------------
+
+inline screen_x_t form_center_x(elis_form_t form) {
+	return (ent_still_or_wave.cur_left + (GIRL_W / 2));
+}
+
+inline screen_x_t girl_lefteye_x(void) {
+	return (ent_still_or_wave.cur_left + 60);
+}
+
+inline screen_y_t girl_lefteye_y(void) {
+	return (ent_still_or_wave.cur_top + 28);
+}
+// -------------------------
+
 // Surround area
 // -------------
 // Common bullet spawn area around Elis.
@@ -320,3 +372,129 @@ bool16 wave_teleport(screen_x_t target_left, screen_y_t target_top)
 
 #define select_for_rank elis_select_for_rank
 #include "th01/main/select_r.cpp"
+
+int pattern_11_lasers_across(void)
+{
+	enum {
+		INTERVAL = 10,
+	};
+
+	#define circle_center_x	form_center_x(F_GIRL)
+	#define circle_center_y	(ent_still_or_wave.cur_top + (GIRL_H / 3))
+
+	#define circle_radius	pattern0_circle_radius
+	#define direction    	pattern0_direction
+
+	extern pixel_t circle_radius;
+	extern bool16 direction; // ACTUAL TYPE: x_direction_t
+	double target_left;
+	double target_y;
+
+	if(boss_phase_frame == 50) {
+		direction = (rand() % 2);
+		ent_unput_and_put_both(ENT_STILL_OR_WAVE, C_HAND);
+		select_for_rank(pattern_state.speed_multiplied_by_8,
+			(to_sp(6.25f) / 2),
+			(to_sp(6.875f) / 2),
+			(to_sp(7.5f) / 2),
+			(to_sp(8.125f) / 2)
+		);
+	} else if(boss_phase_frame == 60) {
+		shape_circle_put(
+			circle_center_x, circle_center_y, (GIRL_W / 4), COL_FX, 0x02
+		);
+		circle_radius = (GIRL_W / 4);
+	} else if(
+		(boss_phase_frame < 120) &&
+		(boss_phase_frame > 60) &&
+		((boss_phase_frame % 2) == 0)
+	) {
+		shape_circle_sloppy_unput(
+			circle_center_x, circle_center_y, circle_radius, 0x02
+		);
+		circle_radius += 8;
+		shape_circle_put(
+			circle_center_x, circle_center_y, circle_radius, COL_FX, (
+				(boss_phase_frame < 100) ? 0x02 :
+				(boss_phase_frame < 110) ? 0x08 :
+				0x20
+			)
+		);
+	} else if(boss_phase_frame == 120) {
+		shape_circle_sloppy_unput(
+			circle_center_x, circle_center_y, circle_radius, 0x20
+		);
+	} else if(boss_phase_frame == 150) {
+		ent_unput_and_put_both(ENT_STILL_OR_WAVE, C_STILL);
+	}
+
+	if((boss_phase_frame >= 70) && ((boss_phase_frame % INTERVAL) == 0)) {
+		#undef RES_Y
+		#define RES_Y *reinterpret_cast<float near*>(0x13ED)
+
+		if(direction == X_RIGHT) {
+			target_left = (PLAYFIELD_LEFT +
+				(((boss_phase_frame - 70) / INTERVAL) * (PLAYFIELD_W / 10))
+			);
+		} else {
+			target_left = (PLAYFIELD_RIGHT -
+				(((boss_phase_frame - 70) / INTERVAL) * (PLAYFIELD_W / 10))
+			);
+		}
+		target_y = RES_Y;
+		shootout_laser_safe(boss_phase_frame / INTERVAL).spawn(
+			girl_lefteye_x(),
+			girl_lefteye_y(),
+			target_left,
+			target_y,
+			pattern_state.speed_multiplied_by_8,
+			V_WHITE,
+			25,
+			4
+		);
+		mdrv2_se_play(6);
+
+		// <= instead of < is why this pattern actually fires 11 lasers rather
+		// than the 10 you might guess from looking at the target calculation
+		// above.
+
+		/* TODO: Proper decompilation, once data can be emitted here:
+		* ----------------------------------------------------------
+		if(
+			((direction == X_RIGHT) && (target_left >= PLAYFIELD_RIGHT)) ||
+			((direction == X_LEFT) && (target_left <= PLAYFIELD_LEFT))
+		)
+		* ----------------------------------------------------------
+		* Performing arithmetic or comparisons between a double (target_left)
+		* and a float (PLAYFIELD_RIGHT) variable always FLDs the float first,
+		* before emitting the corresponding FPU instruction with the double,
+		* which is not what we want here.
+		*/
+		if(direction != X_RIGHT) {
+			goto firing_left;
+		}
+		asm {
+			fld  	qword ptr [bp-8];
+			fcomp	dword ptr [0x13F1];
+			fstsw	word ptr [bp-18];
+			FWAIT_EMU;
+			mov  	ax, word ptr [bp-18];
+			sahf;
+		}
+		if(!FLAGS_CARRY) {
+			goto done;
+		}
+firing_left:
+		if((direction == X_LEFT) && (target_left <= PLAYFIELD_LEFT)) {
+done:
+			boss_phase_frame = 0;
+			return CHOOSE_NEW;
+		}
+	}
+	return 1;
+
+	#undef direction
+	#undef circle_radius
+	#undef circle_center_y
+	#undef circle_center_x
+}

th01/main/player/orb.cpp

@@ -17,9 +17,6 @@ inline double gravity_for(const double& force)
 	asm { mov 	[bp-2], ax; } \
 	asm { fild	word ptr [bp-2]; } \
 	asm { fadd	force; } \
-
-// Neither WAIT nor FWAIT emit the emulated WAIT we want...
-#define FWAIT db 0xCD, 0x3D;
 /// ----------------------------------
 
 int orb_velocity_y_update(void)
@@ -45,7 +42,7 @@ int orb_velocity_y_update(void)
 		fld  	orb_velocity_y;
 		fcomp	ORB_VELOCITY_Y_MAX;
 		fstsw	[bp-2];
-		FWAIT;
+		FWAIT_EMU;
 		mov  	ax, [bp-2];
 		sahf;
 		jbe  	min_velocity_check;
@@ -57,7 +54,7 @@ int orb_velocity_y_update(void)
 		fld 	ORB_VELOCITY_Y_MIN;
 set_velocity:
 		fstp	orb_velocity_y;
-		FWAIT;
+		FWAIT_EMU;
 	}
 	return gravity_for(orb_force);
 }
@@ -99,7 +96,7 @@ void orb_force_new(double immediate, orb_force_t force)
 			fdiv	ORB_FORCE_2_0;
 			fadd	ORB_FORCE_SHOT_BASE;
 			fstp	orb_force;
-			FWAIT;
+			FWAIT_EMU;
 		}
 	}
 	if(force == OF_IMMEDIATE) {

th01/main_011.cpp

@@ -5,11 +5,12 @@
 
 #pragma option -zPmain_01
 
-extern "C" {
 #include "platform.h"
+#include "decomp.hpp"
 #include "pc98.h"
 #include "planar.h"
 #include "master.hpp"
+extern "C" {
 #include "th01/hardware/egc.h"
 #include "th01/main/playfld.hpp"
 #include "th01/main/player/player.hpp"