[Decompilation] [th05] Stage 5 midboss: Rendering

15 lines of code, and still not quirk-free.

Completes P0225, funded by Enderwolf, Blue Bolt, 32th System, and Yanga.

Makefile.mak

@@ -149,7 +149,7 @@ bin\th05\op.exe: th05\op010.cpp bin\th05\op.obj th05\op011.cpp th05\m_char.cpp b
 $**
 |
 
-bin\th05\main.exe: bin\th05\main.obj bin\th04\slowdown.obj th05\demo.cpp th05\ems.cpp bin\th05\cfg_lres.obj th05\main010.cpp th05\f_dialog.cpp th05\dialog.cpp th05\playfld.cpp bin\th04\mb_inv.obj bin\th04\boss_bd.obj th05\boss_bg.cpp th05\p_common.cpp th05\p_reimu.cpp th05\p_marisa.cpp th05\p_mima.cpp th05\p_yuuka.cpp bin\th05\player.obj bin\th05\hud_bar.obj bin\th05\scoreupd.obj th05\hud_ovrl.cpp bin\th04\player_p.obj bin\th04\vector2n.obj bin\th05\spark_a.obj th05\bullet_p.cpp bin\th04\grcg_3.obj th05\player_a.cpp bin\th05\bullet_1.obj th05\bullet_c.cpp bin\th03\vector2.obj bin\th03\hfliplut.obj bin\th04\snd_pmdr.obj bin\th04\snd_mmdr.obj bin\th04\snd_mode.obj bin\th05\bullet.obj th05\bullet_t.cpp bin\th04\cdg_p_na.obj bin\th04\snd_se_r.obj bin\th04\snd_se.obj bin\th05\cdg_put.obj bin\th04\exit.obj bin\th05\vector.obj bin\th05\snd_load.obj bin\th05\snd_kaja.obj bin\th05\initmain.obj bin\th05\input_s.obj bin\th05\inp_h_w.obj bin\th05\frmdelay.obj bin\th04\cdg_load.obj bin\th04\scrolly3.obj bin\th04\motion_3.obj th05\gather.cpp th05\main032.cpp th05\midboss.cpp bin\th04\hud_hp.obj th05\mb_dft.cpp th05\laser_sc.cpp th05\cheeto_u.cpp bin\th04\it_spl_u.obj th05\bullet_u.cpp th05\midboss1.cpp th05\boss_4.cpp th05\boss_6.cpp th05\boss_x.cpp th05\boss.cpp th05\main014.cpp
+bin\th05\main.exe: bin\th05\main.obj bin\th04\slowdown.obj th05\demo.cpp th05\ems.cpp bin\th05\cfg_lres.obj th05\main010.cpp th05\f_dialog.cpp th05\dialog.cpp th05\playfld.cpp bin\th04\mb_inv.obj bin\th04\boss_bd.obj th05\boss_bg.cpp th05\p_common.cpp th05\p_reimu.cpp th05\p_marisa.cpp th05\p_mima.cpp th05\p_yuuka.cpp bin\th05\player.obj bin\th05\hud_bar.obj bin\th05\scoreupd.obj th05\midboss5.cpp th05\hud_ovrl.cpp bin\th04\player_p.obj bin\th04\vector2n.obj bin\th05\spark_a.obj th05\bullet_p.cpp bin\th04\grcg_3.obj th05\player_a.cpp bin\th05\bullet_1.obj th05\bullet_c.cpp bin\th03\vector2.obj bin\th03\hfliplut.obj bin\th04\snd_pmdr.obj bin\th04\snd_mmdr.obj bin\th04\snd_mode.obj bin\th05\bullet.obj th05\bullet_t.cpp bin\th04\cdg_p_na.obj bin\th04\snd_se_r.obj bin\th04\snd_se.obj bin\th05\cdg_put.obj bin\th04\exit.obj bin\th05\vector.obj bin\th05\snd_load.obj bin\th05\snd_kaja.obj bin\th05\initmain.obj bin\th05\input_s.obj bin\th05\inp_h_w.obj bin\th05\frmdelay.obj bin\th04\cdg_load.obj bin\th04\scrolly3.obj bin\th04\motion_3.obj th05\gather.cpp th05\main032.cpp th05\midboss.cpp bin\th04\hud_hp.obj th05\mb_dft.cpp th05\laser_sc.cpp th05\cheeto_u.cpp bin\th04\it_spl_u.obj th05\bullet_u.cpp th05\midboss1.cpp th05\boss_4.cpp th05\boss_6.cpp th05\boss_x.cpp th05\boss.cpp th05\main014.cpp
 	$(CC) $(CFLAGS) $(LARGE_LFLAGS) -3 -Z -DGAME=5 -DBINARY='M' -nbin\th05\ -eMAIN.EXE @&&|
 $**
 |

master.hpp

@@ -708,5 +708,16 @@ void MASTER_RET vsync_end(void);
 			));
 		}
 	};
+
+	#ifdef PC98_H
+		// Generates a super_roll_put_1plane [plane_put] constant for blitting
+		// the sprite in the single given color.
+		inline uint16_t super_plane(uint8_t col, bool erase = false) {
+			return (
+				(erase ? PLANE_ERASE : (0xFF00 | GC_RMW)) +
+				((COLOR_COUNT - 1) - col)
+			);
+		}
+	#endif
 #endif
 /// ------------------

th02/main/playfld.hpp

@@ -52,6 +52,14 @@
 		}
 
 		#ifdef SCROLL_HPP
+			vram_y_t to_vram_top_scrolled_seg1(
+				pixel_t sprite_h_if_centered
+			) const {
+				return scroll_subpixel_y_to_vram_seg1(
+					y + (PLAYFIELD_TOP - (sprite_h_if_centered / 2))
+				);
+			}
+
 			vram_y_t to_vram_top_scrolled_seg3(
 				pixel_t sprite_h_if_centered
 			) const {

th04/main/midboss/midboss.hpp

@@ -61,6 +61,20 @@ inline int midboss_hittest_shots_invincible(
 	return midboss_hittest_shots_damage(radius_x, radius_y, 10);
 }
 
+// ZUN quirk: This is the place where [damage_this_frame] is reset, but this
+// function is typically not called during PHASE_EXPLODE_BIG. As a result, the
+// nonzero [damage_this_frame] value that caused the midboss to be defeated in
+// the first place is carried over to the next midboss, causing it to flash
+// white during the first frame that calls this function.
+#define midboss_put_generic(left, top, patnum) { \
+	if(midboss.damage_this_frame == 0) { \
+		super_roll_put(left, top, patnum); \
+	} else { \
+		super_roll_put_1plane(left, top, patnum, 0, super_plane(V_WHITE)); \
+		midboss.damage_this_frame = 0; \
+	} \
+}
+
 // Updates the defeat animation during PHASE_EXPLODE_BIG, and resets the boss
 // during any other phase. TH04's version also takes ownership of
 // [midboss.phase_frame], incrementing it on every call.

th04/main/scroll.hpp

@@ -17,7 +17,7 @@ extern bool scroll_active;
 
 // Transforms [y] to its corresponding VRAM line, adding the current
 // [scroll_line] or 0 if scrolling is disabled.
-vram_y_t pascal near scroll_subpixel_y_to_vram_seg1(subpixel_t y);
+extern "C" vram_y_t pascal near scroll_subpixel_y_to_vram_seg1(subpixel_t y);
 vram_y_t pascal near scroll_subpixel_y_to_vram_seg3(subpixel_t y);
 // Like the one above, but always adds [scroll_line], even if scrolling is
 // disabled.

th05/main/midboss/m5.cpp

@@ -0,0 +1,45 @@
+/// Stage 5 midboss
+/// ---------------
+
+#pragma option -zCmain_0_TEXT
+
+#include "platform.h"
+#include "pc98.h"
+#include "master.hpp"
+#include "th02/v_colors.hpp"
+#include "th04/math/motion.hpp"
+#include "th01/math/subpixel.hpp"
+#include "th04/main/phase.hpp"
+#include "th04/main/scroll.hpp"
+#include "th04/main/playfld.hpp"
+#include "th04/main/midboss/midboss.hpp"
+
+// Constants
+// ---------
+
+static const pixel_t MIDBOSS5_W = 64;
+static const pixel_t MIDBOSS5_H = 64;
+// ---------
+
+// Rendering
+// ---------
+
+void pascal near midboss5_render(void)
+{
+	if(midboss.phase < PHASE_EXPLODE_BIG) {
+		// ZUN quirk: Should refer to the correct height of the midboss rather
+		// than hardcoding a wrong 32 pixels. As a result, this midboss plops
+		// into view rather suddenly during its initial entrance from the top
+		// of the playfield. Fixed in uth05win.
+		if(midboss.pos.cur.y < to_sp(PLAYFIELD_TOP - (32 / 2))) {
+			return;
+		}
+
+		screen_x_t left = midboss.pos.cur.to_screen_left(MIDBOSS5_W);
+		vram_y_t top = midboss.pos.cur.to_vram_top_scrolled_seg1(MIDBOSS5_H);
+		midboss_put_generic(left, top, midboss.sprite);
+	} else if(midboss.phase == PHASE_BOSS_EXPLODE_BIG) {
+		midboss_defeat_render();
+	}
+}
+// ---------

th05/main/player/bombanim.cpp

@@ -76,7 +76,7 @@ extern union {
 		star->topleft.screen_y.to_pixel_slow(), \
 		PAT_PLAYCHAR_BOMB, \
 		0, \
-		(PLANE_ERASE | ((COLOR_COUNT - 1) - col)) \
+		super_plane(col, true) \
 	);
 
 void pascal near reimu_stars_update_and_render(void)

th05/midboss5.cpp

@@ -0,0 +1 @@
+#include "th05/main/midboss/m5.cpp"

th05_main.asm

@@ -6878,63 +6878,6 @@ loc_11862:
 		leave
 		retn
 @exalice_fg_render$qv	endp
-
-
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-public @MIDBOSS5_RENDER$QV
-@midboss5_render$qv	proc near
-		push	bp
-		mov	bp, sp
-		push	si
-		push	di
-		cmp	_midboss_phase, PHASE_EXPLODE_BIG
-		jnb	short loc_118C3
-		cmp	_midboss_pos.cur.y, 0
-		jl	short loc_118CD
-		mov	ax, _midboss_pos.cur.x
-		sar	ax, 4
-		mov	si, ax
-		mov	ax, _midboss_pos.cur.y
-		add	ax, (-16 shl 4)
-		call	scroll_subpixel_y_to_vram_seg1 pascal, ax
-		mov	di, ax
-		cmp	_midboss_damage_this_frame, 0
-		jnz	short loc_118A9
-		push	si
-		push	ax
-		mov	al, _midboss_sprite
-		mov	ah, 0
-		push	ax
-		call	super_roll_put
-		jmp	short loc_118CD
-; ---------------------------------------------------------------------------
-
-loc_118A9:
-		push	si
-		push	di
-		mov	al, _midboss_sprite
-		mov	ah, 0
-		push	ax
-		pushd	PLANE_PUT or GC_BRGI
-		call	super_roll_put_1plane
-		mov	_midboss_damage_this_frame, 0
-		jmp	short loc_118CD
-; ---------------------------------------------------------------------------
-
-loc_118C3:
-		cmp	_midboss_phase, PHASE_EXPLODE_BIG
-		jnz	short loc_118CD
-		call	@midboss_defeat_render$qv
-
-loc_118CD:
-		pop	di
-		pop	si
-		pop	bp
-		retn
-@midboss5_render$qv	endp
 main_0_TEXT	ends
 
 HUD_OVRL_TEXT	segment	byte public 'CODE' use16