[Maintenance] Declare 8-bit pixel delta and length types

Part of P0242, funded by Yanga.

pc98.h

@@ -12,6 +12,8 @@
 // Display-space widths, heights, and object-space coordinates
 typedef int pixel_t;
 typedef unsigned int upixel_t;
+typedef int8_t pixel_delta_8_t;
+typedef uint8_t pixel_length_8_t;
 
 // A version of master.lib's Point without the constructor, even in C++
 struct point_t {

th01/main/boss/b10j.cpp

@@ -98,7 +98,7 @@ bool meteor_active = true;
 uint8_t spreadin_interval = 4;
 
 // Sprite pixels to spread in per frame, in one half of Mima's sprite
-uint8_t spreadin_speed = 8;
+pixel_length_8_t spreadin_speed = 8;
 // -----
 
 // Entities

th01/math/subpixel.hpp

@@ -102,8 +102,8 @@ struct SPPoint : public SPPointBase<Subpixel> {
 };
 
 // 8-bit (Q4.4)
-typedef SubpixelBase<subpixel_length_8_t, subpixel_length_8_t> SubpixelLength8;
-typedef SubpixelBase<char, char> Subpixel8;
+typedef SubpixelBase<subpixel_length_8_t, pixel_length_8_t> SubpixelLength8;
+typedef SubpixelBase<char, pixel_delta_8_t> Subpixel8;
 typedef SPPointBase<Subpixel8> SPPoint8;
 // -------------------------------------------------------------------------
 

th02/main/player/bomb.cpp

@@ -64,7 +64,7 @@ void near bomb_update_and_render(void)
 }
 
 // ZUN bloat: Needed to circumvent 16-bit promotion in a single comparison.
-inline int8_t bomb_particle_h(void) {
+inline pixel_delta_8_t bomb_particle_h(void) {
 	return BOMB_PARTICLE_H;
 }
 
@@ -74,7 +74,7 @@ void pascal near bomb_circle_point_put(screen_x_t left, screen_y_t top)
 	#define first_bit_mirrored	_DX
 
 	register const bomb_particle_dots_t near* sprite;
-	int8_t y;
+	pixel_delta_8_t y;
 	unsigned int first_bit;
 
 	if(!overlap_xy_ltrb_lt_gt(

th02/main/scroll.hpp

@@ -6,7 +6,7 @@ extern vram_y_t scroll_line;
 #if (GAME == 2)
 	// Amount of pixels to be added to [scroll_line] on every scrolling
 	// operation.
-	extern uint8_t scroll_speed;
+	extern pixel_length_8_t scroll_speed;
 
 	extern uint8_t scroll_cycle;
 

th02/main/tile/tile.cpp

@@ -24,7 +24,7 @@ typedef dots_t(TILE_W) tile_line_dots_t;
 // State
 // -----
 
-extern int8_t tile_line_at_top;
+extern pixel_delta_8_t tile_line_at_top;
 extern vram_offset_t tile_image_vos[TILE_IMAGE_COUNT];
 extern pixel_t tile_copy_lines_top;
 extern pixel_t tile_copy_lines_h;
@@ -178,7 +178,7 @@ void pascal near tile_grcg_clear_8(vram_offset_t vo_topleft)
 }
 
 // Enforces signed 8-bit comparisons in one place. MODDERS: Just remove this.
-inline int8_t tile_line_0(void) { return 0; }
+inline pixel_delta_8_t tile_line_0(void) { return 0; }
 
 bool16 pascal tiles_scroll_and_egc_render_both(pixel_t speed)
 {

th05/main/bullet/laser.cpp

@@ -153,9 +153,9 @@ void near lasers_render(void)
 
 		// ZUN bloat: Only needed because we mutate [coords] for rendering the
 		// inner ray.
-		uint8_t width_orig = laser->coords.width.nonshrink;
+		pixel_length_8_t width_orig = laser->coords.width.nonshrink;
 
-		uint8_t radius = laser->coords.width.nonshrink;
+		pixel_length_8_t radius = laser->coords.width.nonshrink;
 
 		vector2_at(
 			drawpoint,

th05/main/bullet/laser.hpp

@@ -38,20 +38,19 @@ struct laser_coords_t {
 
 	unsigned char angle;
 
-	// In pixels.
 	union {
 		// ZUN landmine: LF_FIXED_SHRINK and LF_FIXED_SHRINK_AND_WAIT_TO_GROW
 		// are effectively limited to a maximum width of 127 pixels due to an
 		// implementation convenience in their update code. For larger values,
 		// their shrink animation wouldn't play, and the laser will transition
 		// to its next flag immediately.
-		int8_t shrink;
+		pixel_delta_8_t shrink;
 
 		// Other types have no limit besides the 8-bit one inherent to the
 		// type. Shootout lasers should probably still be kept below
 		// LASER_SHOOTOUT_DECAY_WIDTH_MAX though, as any larger value would
 		// skip the decay animation.
-		uint8_t nonshrink;
+		pixel_length_8_t nonshrink;
 	} width;
 };
 
@@ -77,9 +76,11 @@ struct Laser {
 	// [age] at which a fixed laser should transition from LF_FIXED_ACTIVE to
 	// LF_FIXED_SHRINK.
 	int shrink_at_age;
+
 	// [width] (in pixels) at which a fixed laser should transition from
 	// LF_FIXED_GROW to LF_FIXED_ACTIVE.
-	uint8_t grow_to_width;
+	pixel_length_8_t grow_to_width;
+
 	uint8_t padding[3];
 
 	void fixed_init(const PlayfieldPoint &origin) {