[Reverse-engineering] [th04/th05] Bullet template structure

Turns out that angles are more clearly expressed in hex after all. And
if we use negative values for everything greater than 80h, we still
remove those from the PI calculation.

*Really* not sure about using that delta union in the TH04 one though.
Might be saner to just hide the complexity of the technically two
separate types after all… Let's see.

Part of P0075, funded by Myles and -Tom-.

th04/bullet/bullet.hpp

@@ -114,3 +114,31 @@ int pascal near bullet_patnum_for_angle(unsigned char angle);
 extern bullet_t bullets[BULLET_COUNT];
 #define pellets (&bullets[0])
 #define bullets16 (&bullets[PELLET_COUNT])
+
+struct bullet_template_t {
+	uint8_t spawn_type;
+	unsigned char patnum;	// TH05: 0 = pellet
+	SPPoint origin;
+#if GAME == 5
+	bullet_pattern_t pattern;
+	bullet_special_motion_t special_motion;
+	unsigned char spread;
+	unsigned char spread_angle_delta;
+	unsigned char stack;
+	SubpixelLength8 stack_speed_delta;
+	unsigned char angle;
+	SubpixelLength8 speed;
+#else
+	SPPoint velocity;
+	bullet_pattern_t pattern;
+	unsigned char angle;
+	SubpixelLength8 speed;
+	unsigned char count;
+	bullet_template_delta_t delta;
+	uint8_t unused_1;
+	bullet_special_motion_t special_motion;
+	uint8_t unused_2;
+#endif
+};
+
+extern bullet_template_t bullet_template;

th04/bullet/pattypes.h

@@ -1,5 +1,12 @@
 #pragma option -b-
 
+typedef union {
+	unsigned char spread_angle;
+	// In subpixels, obviously, but pre-C++11 doesn't let us use any of the
+	// Subpixel classes with their custom assignment operators in a union...
+	unsigned char stack_speed;
+} bullet_template_delta_t;
+
 // All _AIMED patterns define the 0° [angle] as the current player position,
 // relative to the bullet origin.
 typedef enum {

th04/bullet/template[bss].asm

@@ -1,5 +1,34 @@
+if GAME eq 4
+	bullet_template_delta_t union
+		spread_angle	db ?
+		stack_speed 	db ?
+	bullet_template_delta_t ends
+endif
+
 bullet_template_t struc
+	spawn_type	db ?
+	patnum	db ?
+	BT_origin	Point <?>
+if GAME eq 5
 	pattern	db ?
+	BT_special_motion	db ?
+	spread	db ?
+	spread_angle_delta	db ?
+	BT_stack	db ?
+	stack_speed_delta	db ?
+	BT_angle	db ?
+	speed	db ?
+else
+	BT_velocity	Point <?>
+	pattern	db ?
+	BT_angle	db ?
+	speed	db ?
+	count	db ?
+	BT_delta	bullet_template_delta_t <?>
+		db ?
+	BT_special_motion	db ?
+		db ?
+endif
 bullet_template_t ends
 
 public _bullet_template