# Composites the v4 mask-fitted marks into the Quaternius base-color texture:
# maps each gen-v4 result back into UV space (inverse of prep.gd's transform),
# extracts ink by luminance, multiplies it onto skin inside the part mask, then
# dilates 4px into unpainted texels so UV-seam bilinear/mip sampling never shows
# a bare gutter line. Backs up the previous bake to baked_body_v3.png once.
# Run headless (after _gen-marks-v4.ps1):
#   tinqs.console.exe --headless --path tattoo-test -s res://composite.gd
extends SceneTree

const SKIN_TEX_PATH := "C:/Users/CAN/tinqs-ltd/ariki-game/assets/quaternius/source-models/T_Regular_Male_Dark_BaseColor_png.png"
const MASK_DIR := "C:/Users/CAN/tinqs-ltd/tattoo-test/masks/"
const GEN_DIR := "C:/Users/CAN/tinqs-ltd/tattoo-test/gen-v4/"
const OUT_PATH := "C:/Users/CAN/tinqs-ltd/tattoo-test/baked_body.png"
const BACKUP_PATH := "C:/Users/CAN/tinqs-ltd/tattoo-test/baked_body_v3.png"

const INK_COLOR := Color(0.10, 0.085, 0.08)
const INK_OPACITY := 0.88
const DILATE := 4

const JOBS := [
	{"part": "arm_r", "mark": "chiefs-mark"},
	{"part": "arm_l", "mark": "iron-spine"},
	{"part": "leg_r", "mark": "voyagers-current"},
	{"part": "leg_l", "mark": "storm-bearer"},
	{"part": "chest", "mark": "star-eye"},
	{"part": "back", "mark": "hearth-warmth"},
]

func _init() -> void:
	var prep := load("res://prep.gd")
	if FileAccess.file_exists(OUT_PATH) and not FileAccess.file_exists(BACKUP_PATH):
		DirAccess.copy_absolute(OUT_PATH, BACKUP_PATH)
		print("backed up previous bake -> ", BACKUP_PATH)

	var img := Image.load_from_file(SKIN_TEX_PATH)
	img.convert(Image.FORMAT_RGBA8)
	var size := img.get_width()
	var painted := PackedByteArray()
	painted.resize(size * size)

	var missing := 0
	for job in JOBS:
		var gen_path: String = GEN_DIR + "v4_" + job["part"] + "_" + job["mark"] + ".png"
		if not FileAccess.file_exists(gen_path):
			push_error("missing gen result: " + gen_path + " (run _gen-marks-v4.ps1 first)")
			missing += 1
			continue
		var mask := Image.load_from_file(MASK_DIR + "mask_" + job["part"] + ".png")
		var gen := Image.load_from_file(gen_path)
		gen.convert(Image.FORMAT_RGBA8)
		var t: Dictionary = prep.transform_for(mask)
		var rect: Rect2i = t["rect"]
		var s: float = t["scale"]
		var off: Vector2 = t["offset"]
		var out_scale := float(gen.get_width()) / float(prep.CANVAS)
		var mask_scale := float(mask.get_width()) / float(size)
		var count := 0
		for py in range(rect.position.y, rect.end.y):
			for px in range(rect.position.x, rect.end.x):
				var mx := int(px * mask_scale)
				var my := int(py * mask_scale)
				if mask.get_pixel(mx, my).r < 0.5:
					continue
				var cx := ((px - rect.position.x) + 0.5) * s + off.x
				var cy := ((py - rect.position.y) + 0.5) * s + off.y
				var c := _sample_bilinear(gen, cx * out_scale, cy * out_scale)
				var ink := 1.0 - smoothstep(0.45, 0.80, (c.r + c.g + c.b) / 3.0)
				var alpha := ink * INK_OPACITY
				if alpha > 0.003:
					img.set_pixel(px, py, img.get_pixel(px, py).lerp(INK_COLOR, alpha))
					count += 1
				painted[py * size + px] = 1  # whole mask counts as painted (bare skin is intentional)
		print("%s %s painted px: %d" % [job["part"], job["mark"], count])

	if missing == JOBS.size():
		push_error("no gen results found - nothing composited")
		quit(1)
		return

	# edge padding: pull composited colors DILATE px outward into unpainted texels
	for pass_i in DILATE:
		var grown := PackedInt32Array()
		for y in size:
			for x in size:
				if painted[y * size + x] == 1:
					continue
				var acc := Color(0, 0, 0)
				var n := 0
				for d in [[1, 0], [-1, 0], [0, 1], [0, -1]]:
					var nx: int = x + d[0]
					var ny: int = y + d[1]
					if nx < 0 or nx >= size or ny < 0 or ny >= size:
						continue
					if painted[ny * size + nx] == 1:
						acc += img.get_pixel(nx, ny)
						n += 1
				if n > 0:
					img.set_pixel(x, y, acc / n)
					grown.append(y * size + x)
		for p in grown:
			painted[p] = 1

	img.save_png(OUT_PATH)
	print("saved: ", OUT_PATH)
	quit()

func _sample_bilinear(img: Image, x: float, y: float) -> Color:
	var w := img.get_width()
	var h := img.get_height()
	var fx := clampf(x - 0.5, 0.0, w - 1.001)
	var fy := clampf(y - 0.5, 0.0, h - 1.001)
	var x0 := int(fx)
	var y0 := int(fy)
	var x1 := mini(x0 + 1, w - 1)
	var y1 := mini(y0 + 1, h - 1)
	var tx := fx - x0
	var ty := fy - y0
	return img.get_pixel(x0, y0).lerp(img.get_pixel(x1, y0), tx) \
		.lerp(img.get_pixel(x0, y1).lerp(img.get_pixel(x1, y1), tx), ty)