Added mouse picking for selecting entities

- Added entity id uniform to the gbuffer
- Added entity id to RenderList
- Added selecting when clicking on an entity

Editor/resources/Shaders/gbuffer.shader

@@ -53,6 +53,7 @@ uniform sampler2D m_Roughness;
 uniform sampler2D m_AO;
 uniform sampler2D m_Normal;
 uniform sampler2D m_Displacement;
+uniform int u_EntityID;
 
 layout(std140, binding = 32) uniform u_MaterialUniform
 {
@@ -104,5 +105,5 @@ void main()
     gMaterial.g = finalAO;
     gMaterial.b = finalRoughness;
 
-    gEntityID = int(gAlbedo.r * 255.0);
+    gEntityID = int(u_EntityID);
 }

Editor/src/Windows/EditorInterface.cpp

@@ -231,11 +231,29 @@ namespace Nuake {
                     tc.SetGlobalTransform(transform);
                 }
             }
+
+            if (m_IsHoveringViewport && Input::IsMouseButtonPressed(GLFW_MOUSE_BUTTON_1) && !ImGuizmo::IsUsing())
+            {
+                const auto windowPosNuake = Vector2(windowPos.x, windowPos.y);
+                auto& gbuffer = Engine::GetCurrentScene()->mSceneRenderer->GetGBuffer();
+                auto pixelPos = Input::GetMousePosition() - windowPosNuake;
+                pixelPos.y = gbuffer.GetSize().y - pixelPos.y; // imgui coords are inverted on the Y axis
+
+                gbuffer.Bind();
+
+                if (const int result = gbuffer.ReadPixel(3, pixelPos); result >= 0)
+                {
+                    Selection = EditorSelection(Entity{ (entt::entity)result, Engine::GetCurrentScene().get() });
+                }
+
+                gbuffer.Unbind();
+            }
         }
         else
         {
             ImGui::PopStyleVar();
         }
+
         ImGui::End();
     }
 

Nuake/src/Rendering/RenderList.h

@@ -12,6 +12,7 @@ namespace Nuake
 	{
 		Ref<Mesh> Mesh;
 		Matrix4 transform;
+		uint32_t entityId;
 	};
 
 	class RenderList
@@ -22,14 +23,14 @@ namespace Nuake
 			this->m_RenderList = std::map<Ref<Material>, std::vector<RenderMesh>>();
 		}
 
-		void AddToRenderList(Ref<Mesh> mesh, Matrix4 transform)
+		void AddToRenderList(Ref<Mesh> mesh, Matrix4 transform, const uint32_t entityId = -1)
 		{
 			Ref<Material> material = mesh->GetMaterial();
 
 			if (m_RenderList.find(material) == m_RenderList.end())
 				m_RenderList[material] = std::vector<RenderMesh>();
 
-			m_RenderList[material].push_back({mesh, transform});
+			m_RenderList[material].push_back({mesh, transform, entityId});
 		}
 
 		void Flush(Shader* shader, bool depthOnly = false)
@@ -43,6 +44,7 @@ namespace Nuake
 				for (auto& m : i.second)
 				{
 					shader->SetUniformMat4f("u_Model", m.transform);
+					shader->SetUniform1i("u_EntityID", m.entityId);
 					m.Mesh->Draw(shader, false);
 				}
 			}

Nuake/src/Rendering/Renderer.cpp

@@ -108,14 +108,14 @@ namespace Nuake
     {
     }
 
-    void Renderer::SubmitMesh(Ref<Mesh> mesh, Matrix4 transform)
+    void Renderer::SubmitMesh(Ref<Mesh> mesh, Matrix4 transform, const uint32_t entityId)
     {
-        m_RenderList.AddToRenderList(mesh, transform);
+        m_RenderList.AddToRenderList(mesh, transform, entityId);
     }
 
     void Renderer::SubmitCube(Matrix4 transform)
     {
-        m_RenderList.AddToRenderList(CubeMesh, transform);
+        m_RenderList.AddToRenderList(CubeMesh, transform, -1);
     }
 
     void Renderer::Flush(Shader* shader, bool depthOnly)

Nuake/src/Rendering/Renderer.h

@@ -60,7 +60,7 @@ namespace Nuake
 		static void LoadShaders();
 
 		static void BeginScene();
-		static void SubmitMesh(Ref<Mesh> mesh, Matrix4 transform);
+		static void SubmitMesh(Ref<Mesh> mesh, Matrix4 transform, const uint32_t entityId = -1);
 		static void SubmitCube(Matrix4 transform);
 		static void Flush(Shader* shader, bool depthOnly = false);
 

Nuake/src/Rendering/SceneRenderer.cpp

@@ -223,7 +223,9 @@ namespace Nuake {
 				if (mesh.ModelResource && visibility.Visible)
 				{
 					for (auto& m : mesh.ModelResource->GetMeshes())
-						Renderer::SubmitMesh(m, transform.GetGlobalTransform());
+					{
+						Renderer::SubmitMesh(m, transform.GetGlobalTransform(), (uint32_t)e);
+					}
 				}
 			}
 
@@ -240,7 +242,9 @@ namespace Nuake {
 					continue;
 
 				for (auto& b : model.Meshes)
-					Renderer::SubmitMesh(b, transform.GetGlobalTransform());
+				{
+					Renderer::SubmitMesh(b, transform.GetGlobalTransform(), (uint32_t)e);
+				}
 			}
 			Renderer::Flush(gBufferShader, false);
 		}