1 files changed, 65 insertions, 0 deletions
diff --git a/game/addons/zylann.hterrain/tools/preview_generator.gd b/game/addons/zylann.hterrain/tools/preview_generator.gd
new file mode 100644
index 0000000..4b6e3db
--- /dev/null
+++ b/game/addons/zylann.hterrain/tools/preview_generator.gd
@@ -0,0 +1,65 @@
+@tool
+extends EditorResourcePreviewGenerator
+
+const HTerrainData = preload("../hterrain_data.gd")
+const HT_Errors = preload("../util/errors.gd")
+const HT_Logger = preload("../util/logger.gd")
+
+var _logger = HT_Logger.get_for(self)
+
+
+func _generate(res: Resource, size: Vector2i, metadata: Dictionary) -> Texture2D:
+	if res == null or not (res is HTerrainData):
+		return null
+	var normalmap = res.get_image(HTerrainData.CHANNEL_NORMAL)
+	if normalmap == null:
+		return null
+	return _generate_internal(normalmap, size)
+
+
+func _generate_from_path(path: String, size: Vector2i, metadata: Dictionary) -> Texture2D:
+	if not path.ends_with("." + HTerrainData.META_EXTENSION):
+		return null
+	var data_dir := path.get_base_dir()
+	var normals_fname := str(HTerrainData.get_channel_name(HTerrainData.CHANNEL_NORMAL), ".png")
+	var normals_path := data_dir.path_join(normals_fname)
+	var normals := Image.new()
+	var err := normals.load(normals_path)
+	if err != OK:
+		_logger.error("Could not load '{0}', error {1}" \
+			.format([normals_path, HT_Errors.get_message(err)]))
+		return null
+	return _generate_internal(normals, size)
+
+
+func _handles(type: String) -> bool:
+	return type == "Resource"
+
+
+static func _generate_internal(normals: Image, size: Vector2) -> Texture2D:
+	var im := Image.create(size.x, size.y, false, Image.FORMAT_RGB8)
+
+	var light_dir := Vector3(-1, -0.5, -1).normalized()
+
+	for y in im.get_height():
+		for x in im.get_width():
+
+			var fx := float(x) / float(im.get_width())
+			var fy := float(im.get_height() - y - 1) / float(im.get_height())
+			var mx := int(fx * normals.get_width())
+			var my := int(fy * normals.get_height())
+
+			var n := _decode_normal(normals.get_pixel(mx, my))
+
+			var ndot := -n.dot(light_dir)
+			var gs := clampf(0.5 * ndot + 0.5, 0.0, 1.0)
+			var col := Color(gs, gs, gs, 1.0)
+
+			im.set_pixel(x, y, col)
+
+	var tex := ImageTexture.create_from_image(im)
+	return tex
+
+
+static func _decode_normal(c: Color) -> Vector3:
+	return Vector3(2.0 * c.r - 1.0, 2.0 * c.b - 1.0, 2.0 * c.g - 1.0)