From 277893e2b216606b0dca8ee7568072a57e04333e Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvark@fastmail.com>
Date: Fri, 3 Nov 2023 22:04:51 -0700
Subject: [PATCH] Use selection tangent space to pivot the spawning objects

---
 blade-render/src/render/mod.rs |  6 ++++++
 examples/scene/main.rs         | 26 +++++++++++++++++++++-----
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/blade-render/src/render/mod.rs b/blade-render/src/render/mod.rs
index ce138b59..e68664a5 100644
--- a/blade-render/src/render/mod.rs
+++ b/blade-render/src/render/mod.rs
@@ -108,6 +108,8 @@ pub struct SelectionInfo {
     pub std_deviation_history: u32,
     pub custom_index: u32,
     pub depth: f32,
+    pub position: mint::Vector3<f32>,
+    pub normal: mint::Vector3<f32>,
     pub tex_coords: mint::Vector2<f32>,
     pub base_color_texture: Option<blade_asset::Handle<crate::Texture>>,
     pub normal_texture: Option<blade_asset::Handle<crate::Texture>>,
@@ -119,6 +121,8 @@ impl Default for SelectionInfo {
             std_deviation_history: 0,
             custom_index: 0,
             depth: 0.0,
+            position: [0.0; 3].into(),
+            normal: [0.0; 3].into(),
             tex_coords: [0.0; 2].into(),
             base_color_texture: None,
             normal_texture: None,
@@ -1563,6 +1567,8 @@ impl Renderer {
             std_deviation_history: db_v.count,
             custom_index: db_e.custom_index,
             depth: db_e.depth,
+            position: db_e.position.into(),
+            normal: db_e.normal.into(),
             tex_coords: db_e.tex_coords.into(),
             base_color_texture: self
                 .texture_resource_lookup
diff --git a/examples/scene/main.rs b/examples/scene/main.rs
index 6735038f..e6d63552 100644
--- a/examples/scene/main.rs
+++ b/examples/scene/main.rs
@@ -246,7 +246,10 @@ impl Example {
                 depth: 0.0,
             },
             fly_speed: 0.0,
-            debug: blade_render::DebugConfig::default(),
+            debug: blade_render::DebugConfig {
+                draw_flags: blade_render::DebugDrawFlags::SPACE,
+                ..Default::default()
+            },
             track_hot_reloads: false,
             need_accumulation_reset: true,
             is_debug_drawing: false,
@@ -946,6 +949,22 @@ impl Example {
         if self.scene_load_task.is_some() {
             return false;
         }
+
+        let transform = if self.debug.mouse_pos.is_some() {
+            let selection = self.renderer.read_debug_selection_info();
+            //Note: assuming the object is Y-up
+            let rotation = glam::Quat::from_rotation_arc(glam::Vec3::Y, selection.normal.into());
+            let m = glam::Mat4::from_rotation_translation(rotation, selection.position.into())
+                .transpose();
+            gpu::Transform {
+                x: m.x_axis.into(),
+                y: m.y_axis.into(),
+                z: m.z_axis.into(),
+            }
+        } else {
+            gpu::IDENTITY_TRANSFORM
+        };
+
         let (model, model_task) = self.asset_hub.models.load(
             file_path,
             blade_render::model::Meta {
@@ -953,10 +972,7 @@ impl Example {
             },
         );
         self.scene_load_task = Some(model_task.clone());
-        self.objects.push(blade_render::Object {
-            transform: gpu::IDENTITY_TRANSFORM,
-            model,
-        });
+        self.objects.push(blade_render::Object { transform, model });
         self.object_extras.push(ObjectExtra {
             path: file_path.to_owned(),
         });