From 3636733ef8257ac2eec7f58b587c664d0d01ba15 Mon Sep 17 00:00:00 2001
From: Cory Petkovsek <632766+TokisanGames@users.noreply.github.com>
Date: Sun, 29 Oct 2023 17:51:00 +0700
Subject: [PATCH] Add get_texture_id()

---
 src/terrain_3d_storage.cpp | 22 ++++++++++++++++++++++
 src/terrain_3d_storage.h   |  1 +
 2 files changed, 23 insertions(+)

diff --git a/src/terrain_3d_storage.cpp b/src/terrain_3d_storage.cpp
index e89f9239..cd8d0c9d 100644
--- a/src/terrain_3d_storage.cpp
+++ b/src/terrain_3d_storage.cpp
@@ -447,6 +447,27 @@ Color Terrain3DStorage::get_color(Vector3 p_global_position) {
 	return clr;
 }
 
+/**
+ * Returns:
+ * X = base index
+ * Y = overlay index
+ * Z = percentage blend between X and Y. Limited to the fixed values in RANGE.
+ * Interpretation of this data is up to the gamedev. Unfortunately due to blending, this isn't
+ * pixel perfect. I would have your player print this location as you walk around to see how the
+ * blending values look, then consider that the overlay texture is visible starting at a blend
+ * value of .3-.5, otherwise it's the base texture.
+ **/
+Vector3 Terrain3DStorage::get_texture_id(Vector3 p_global_position) {
+	// Get bit field from pixel
+	uint32_t bits;
+	*(real_t *)&bits = get_pixel(TYPE_CONTROL, p_global_position).r;
+	uint32_t base_index = bits >> 27u & 0x1Fu;
+	uint32_t overlay_index = bits >> 22u & 0x1Fu;
+	uint32_t blend_index = bits >> 19u & 0x7u;
+	real_t blend = RANGE[blend_index];
+	return Vector3(real_t(base_index), real_t(overlay_index), blend);
+}
+
 /**
  * Returns sanitized maps of either a region set or a uniform set
  * Verifies size, vailidity, and format of maps
@@ -975,6 +996,7 @@ void Terrain3DStorage::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_color", "global_position"), &Terrain3DStorage::get_color);
 	ClassDB::bind_method(D_METHOD("get_control", "global_position"), &Terrain3DStorage::get_control);
 	ClassDB::bind_method(D_METHOD("get_roughness", "global_position"), &Terrain3DStorage::get_roughness);
+	ClassDB::bind_method(D_METHOD("get_texture_id", "global_position"), &Terrain3DStorage::get_texture_id);
 	ClassDB::bind_method(D_METHOD("force_update_maps", "map_type"), &Terrain3DStorage::force_update_maps, DEFVAL(TYPE_MAX));
 
 	ClassDB::bind_static_method("Terrain3DStorage", D_METHOD("load_image", "file_name", "cache_mode", "r16_height_range", "r16_size"), &Terrain3DStorage::load_image, DEFVAL(ResourceLoader::CACHE_MODE_IGNORE), DEFVAL(Vector2(0, 255)), DEFVAL(Vector2i(0, 0)));
diff --git a/src/terrain_3d_storage.h b/src/terrain_3d_storage.h
index 2a46122c..6a54c845 100644
--- a/src/terrain_3d_storage.h
+++ b/src/terrain_3d_storage.h
@@ -147,6 +147,7 @@ class Terrain3DStorage : public Resource {
 	inline Color get_color(Vector3 p_global_position);
 	inline Color get_control(Vector3 p_global_position) { return get_pixel(TYPE_CONTROL, p_global_position); }
 	inline real_t get_roughness(Vector3 p_global_position) { return get_pixel(TYPE_COLOR, p_global_position).a; }
+	Vector3 get_texture_id(Vector3 p_global_position);
 	TypedArray<Image> sanitize_maps(MapType p_map_type, const TypedArray<Image> &p_maps);
 	void force_update_maps(MapType p_map = TYPE_MAX);