[feat]: wire in scene into the simulation engine

1 files changed, 24 insertions, 6 deletions

diff --git a/src/rendering/black_hole_renderer.cpp b/src/rendering/black_hole_renderer.cpp
index e4bc2a4..5916171 100644
--- a/src/rendering/black_hole_renderer.cpp
+++ b/src/rendering/black_hole_renderer.cpp
@@ -42,11 +42,9 @@ namespace Donut
         m_obj_ubo  = device.create_buffer(BufferType::Uniform, 800);
         m_sim_ubo  = device.create_buffer(BufferType::Uniform, 16);
 
-        // The single "object" is the black hole itself (position 0, radius = r_s).
-        std::vector<uint8_t> obj(800, 0);
-        int num_objects = 1;                          std::memcpy(obj.data() +   0, &num_objects, 4);
-        float pos_radius[4] = { 0, 0, 0, SagA_rs };   std::memcpy(obj.data() +  16, pos_radius, 16);
-        float color[4]      = { 0, 0, 0, 1 };         std::memcpy(obj.data() + 272, color, 16);
+        // The hole itself is the hardcoded singularity in the shader; the Objects
+        // UBO carries the Scene's spheres, refilled each frame in render_geodesic.
+        std::vector<uint8_t> obj(800, 0);   // numObjects = 0 until the first frame
         m_obj_ubo->update(obj.data(), obj.size());
 
         {
@@ -80,7 +78,8 @@ namespace Donut
     }
 
     auto BlackHoleRenderer::render_geodesic(RHI::CommandList& cmd, const GeodesicView& view,
-                                            const BlackHoleParams& params, RHI::Texture* cubemap) -> void
+                                            const BlackHoleParams& params,
+                                            const std::vector<SceneObject>& objects, RHI::Texture* cubemap) -> void
     {
         CamUBO cam{};
         cam.pos = view.position; cam.right = view.right; cam.up = view.up; cam.fwd = view.forward;
@@ -113,6 +112,25 @@ namespace Donut
         };
         m_disk_ubo->update(disk, sizeof(disk));
 
+        // Scene objects → the geodesic's Objects UBO (std140: numObjects@0,
+        // objPosRadius[i]@16+16i, objColor[i]@272+16i). They render as spheres the
+        // curved rays intersect, so the hole lenses them. 1 scene unit = 1 r_s.
+        {
+            const float k = SagA_rs / SCENE_UNITS_PER_RS;   // scene units -> metres
+            std::vector<uint8_t> objbuf(800, 0);
+            int n = std::min((int)objects.size(), 16);
+            std::memcpy(objbuf.data(), &n, 4);
+            for (int i = 0; i < n; ++i)
+            {
+                const SceneObject& o = objects[i];
+                float pr[4]  = { o.position.x * k, o.position.y * k, o.position.z * k, o.radius * k };
+                float col[4] = { o.color.r, o.color.g, o.color.b, 1.0f };
+                std::memcpy(objbuf.data() + 16  + 16 * i, pr,  16);
+                std::memcpy(objbuf.data() + 272 + 16 * i, col, 16);
+            }
+            m_obj_ubo->update(objbuf.data(), objbuf.size());
+        }
+
         // Progressive resolution: small target while moving, large once settled.
         RenderTarget* target = view.moving ? m_geo_lo.get() : m_geo_hi.get();
         m_last_target = target;