Made MeshRenderer able to take a matrix transform for each mesh, and we are now able to draw 100 cubes.

Claude OPus helpes with implementation

Assets/source/RootConstants.hlsl

@@ -4,6 +4,7 @@
 cbuffer RootConstants : register(b0, space0)
 {
     row_major float4x4 ViewProjection;
+    row_major float4x4 Model;
     uint     BufferIndex;
     uint     TextureIndex; 
     uint     VertexOffset; // Base vertex for indexed drawing with bindless buffers

Assets/source/Triangle.vert.hlsl

@@ -19,7 +19,7 @@ Output main(uint vertexIndex : SV_VertexID)
     float4 col = asfloat(buffer.Load4(offset + 12));
 
     //output.Position = float4(pos, 1.0f);
-    output.Position = mul(ViewProjection, float4(pos, 1.0f));
+    output.Position = mul(ViewProjection, mul(Model, float4(pos, 1.0f)));
     output.Color = col;
     return output;
 }

Juliet/include/Core/Math/Matrix.h

@@ -8,8 +8,9 @@ namespace Juliet
     struct Matrix
     {
         float m[4][4];
+    };
 
-        static Matrix Identity()
+    [[nodiscard]] inline Matrix MatrixIdentity()
     {
         Matrix result = {};
         result.m[0][0] = 1.0f;
@@ -19,7 +20,16 @@ namespace Juliet
         return result;
     }
 
-        Matrix operator*(const Matrix& rhs) const
+    [[nodiscard]] inline Matrix MatrixTranslation(float x, float y, float z)
+    {
+        Matrix result = MatrixIdentity();
+        result.m[0][3] = x;
+        result.m[1][3] = y;
+        result.m[2][3] = z;
+        return result;
+    }
+
+    [[nodiscard]] inline Matrix operator*(const Matrix& lhs, const Matrix& rhs)
     {
         Matrix result = {};
         for (int i = 0; i < 4; ++i)
@@ -28,13 +38,12 @@ namespace Juliet
             {
                 for (int k = 0; k < 4; ++k)
                 {
-                        result.m[i][j] += m[i][k] * rhs.m[k][j];
+                    result.m[i][j] += lhs.m[i][k] * rhs.m[k][j];
                 }
             }
         }
         return result;
     }
-    };
 
     inline Matrix LookAt(const Vector3& eye, const Vector3& target, const Vector3& up)
     {

Juliet/include/Graphics/Mesh.h

@@ -2,6 +2,7 @@
 
 #include <Core/Common/CoreTypes.h>
 #include <Core/Common/NonNullPtr.h>
+#include <Core/Math/Matrix.h>
 #include <Juliet.h>
 
 namespace Juliet
@@ -16,5 +17,7 @@ namespace Juliet
 
         index_t VertexOffset;
         index_t IndexOffset;
+
+        Matrix Transform = MatrixIdentity();
     };
 } // namespace Juliet

Juliet/include/Graphics/MeshRenderer.h

@@ -43,6 +43,7 @@ namespace Juliet
     struct PushData
     {
         Matrix ViewProjection;
+        Matrix Model;
         uint32 BufferIndex;
     };
 
@@ -55,6 +56,7 @@ namespace Juliet
     // Utils
     [[nodiscard]] JULIET_API MeshID AddCube();
     [[nodiscard]] JULIET_API MeshID AddQuad();
+    JULIET_API void                  SetMeshTransform(MeshID id, const Matrix& transform);
 
 #if ALLOW_SHADER_HOT_RELOAD
     JULIET_API void ReloadMeshRendererShaders();

Juliet/src/Core/HAL/Display/Display.cpp

@@ -123,7 +123,7 @@ namespace Juliet
     {
         // Find and destroy
         VectorArena<Window>& windows = g_CurrentDisplayDevice->Windows;
-        for (index_t idx = windows.Size() - 1; idx != 0; --idx)
+        for (index_t idx = windows.Size(); idx-- > 0;)
         {
             Window& windowRef = windows[idx];
             if (windowRef.ID == window->ID)

Juliet/src/Core/HAL/Display/Win32/Win32DisplayDevice.cpp

@@ -36,7 +36,7 @@ namespace Juliet::Win32
 
             device->PumpEvents = PumpEvents;
 
-            device->Windows.Create(JULIET_DEBUG_ONLY("Display Windows"));
+            device->Windows.Create(arena JULIET_DEBUG_PARAM("Display Windows"));
 
             return device;
         }

Juliet/src/Core/Memory/MemoryArena.cpp

@@ -75,12 +75,12 @@ namespace Juliet
 
     void ArenaRelease(NonNullPtr<Arena> arena)
     {
-        JULIET_DEBUG_ONLY(DebugUnregisterArena(arena);)
+        // Release active blocks (Current chain)
-
         for (Arena *node = arena->Current, *previous = nullptr; node != nullptr; node = previous)
         {
             previous = node->Previous;
 
+            JULIET_DEBUG_ONLY(DebugUnregisterArena(node);)
             JULIET_DEBUG_ONLY(DebugArenaFreeBlock(node);)
 
             Memory::OS_Release(node, node->Reserved);

Juliet/src/Core/Memory/MemoryArenaDebug.cpp

@@ -68,6 +68,8 @@ namespace Juliet
         {
             arena->GlobalNext->GlobalPrev = arena->GlobalPrev;
         }
+        arena->GlobalPrev = nullptr;
+        arena->GlobalNext = nullptr;
     }
 
     void DebugArenaSetDebugName(NonNullPtr<Arena> arena, const char* name)

Juliet/src/Graphics/DebugDisplayRenderer.cpp

@@ -300,15 +300,17 @@ namespace Juliet
         {
             BindGraphicsPipeline(renderPass, g_DebugState.DepthTestedPipeline);
 
-            // Pack VP matrix + buffer index into push constants
+            // Pack VP matrix + Model (identity for debug) + buffer index into push constants
             struct
             {
                 Matrix vp;
+                Matrix model;
                 uint32 bufferIndex;
                 uint32 vertexOffset; // Offset in vertices (not bytes)
                 uint32 padding[2];
             } pushData;
             pushData.vp           = Camera_GetViewProjectionMatrix(camera);
+            pushData.model        = MatrixIdentity();
             pushData.bufferIndex  = bufferIndex;
             pushData.vertexOffset = 0; // Depth-tested vertices start at 0
             SetPushConstants(cmdList, ShaderStage::Vertex, 0, sizeof(pushData) / sizeof(uint32), &pushData);
@@ -321,15 +323,17 @@ namespace Juliet
         {
             BindGraphicsPipeline(renderPass, g_DebugState.OverlayPipeline);
 
-            // Pack VP matrix + buffer index into push constants
+            // Pack VP matrix + Model (identity for debug) + buffer index into push constants
             struct
             {
                 Matrix vp;
+                Matrix model;
                 uint32 bufferIndex;
                 uint32 vertexOffset; // Offset in vertices (not bytes)
                 uint32 padding[2];
             } pushData;
             pushData.vp           = Camera_GetViewProjectionMatrix(camera);
+            pushData.model        = MatrixIdentity();
             pushData.bufferIndex  = bufferIndex;
             pushData.vertexOffset = kMaxDebugVertices / 2; // Overlay vertices start at half
             SetPushConstants(cmdList, ShaderStage::Vertex, 0, sizeof(pushData) / sizeof(uint32), &pushData);

Juliet/src/Graphics/MeshRenderer.cpp

@@ -187,12 +187,13 @@ namespace Juliet
         uint32 vertexDescriptorIndex = GetDescriptorIndex(g_MeshRenderer.Device, g_MeshRenderer.VertexBuffer);
 
         pushData.BufferIndex = vertexDescriptorIndex;
-        SetPushConstants(cmdList, ShaderStage::Vertex, 0, sizeof(pushData) / 4, &pushData);
 
         SetIndexBuffer(cmdList, g_MeshRenderer.IndexBuffer, IndexFormat::UInt16, g_MeshRenderer.Indices.Count, 0);
 
         for (Mesh& mesh : g_MeshRenderer.Meshes)
         {
+            pushData.Model = mesh.Transform;
+            SetPushConstants(cmdList, ShaderStage::Vertex, 0, sizeof(pushData) / 4, &pushData);
             DrawIndexedPrimitives(pass, static_cast<uint32>(mesh.IndexCount), 1, static_cast<uint32>(mesh.IndexOffset),
                                   static_cast<uint32>(mesh.VertexOffset), 0);
         }
@@ -292,6 +293,11 @@ namespace Juliet
         return g_MeshRenderer.Meshes.Count - 1;
     }
 
+    void SetMeshTransform(MeshID id, const Matrix& transform)
+    {
+        Assert(id < static_cast<MeshID>(g_MeshRenderer.Meshes.Count), "Invalid MeshID");
+        g_MeshRenderer.Meshes.Data[id].Transform = transform;
+    }
 #if ALLOW_SHADER_HOT_RELOAD
     void ReloadMeshRendererShaders()
     {

JulietApp/main.cpp

@@ -109,7 +109,20 @@ void JulietApplication::Init()
                 Running = false;
             }
 
-            std::ignore = AddCube();
+            constexpr int   kGridSize = 10;
+            constexpr float kSpacing  = 2.5f;
+            constexpr float kOffset   = (kGridSize - 1) * kSpacing * 0.5f;
+
+            for (int row = 0; row < kGridSize; ++row)
+            {
+                for (int col = 0; col < kGridSize; ++col)
+                {
+                    MeshID cube = AddCube();
+                    float  x    = static_cast<float>(col) * kSpacing - kOffset;
+                    float  y    = static_cast<float>(row) * kSpacing - kOffset;
+                    SetMeshTransform(cube, MatrixTranslation(x, y, 0.0f));
+                }
+            }
 
             CommandList* loadCmd = AcquireCommandList(GraphicsDevice);
             LoadMeshesOnGPU(loadCmd);
@@ -275,8 +288,6 @@ void JulietApplication::OnRender(RenderPass* pass, CommandList* cmd)
     pushData.ViewProjection = Camera_GetViewProjectionMatrix(GetDebugCamera());
 
     RenderMeshes(pass, cmd, pushData);
-
-    // SetPushConstants(cmd, ShaderStage::Vertex, 0, sizeof(pushData) / 4, &pushData);
 }
 
 ColorTargetInfo JulietApplication::GetColorTargetInfo(Texture* swapchainTexture)
@@ -308,14 +319,14 @@ Camera JulietApplication::GetDebugCamera()
     float currentOrbitTime = time * orbitSpeed;
 
     // --- Adjusted for 1-Meter Scale ---
-    float baseRadius = 2.5f; // Hover 2.5 meters away (down from 15.0f)
+    float baseRadius = 25.0f; // Increased to see 10x10 cube grid
 
     float radius = baseRadius;
-    /* Uncomment for active zoom
+    //* Uncomment for active zoom
-    float zoomAmplitude = 1.0f; // Oscillate between 1.5m and 3.5m away
+    float zoomAmplitude = 10.0f; // Oscillate between 1.5m and 3.5m away
     float zoomSpeed     = 0.8f;
     radius              = baseRadius + (sinf(time * zoomSpeed) * zoomAmplitude);
-    */
+    //*/
     float zHeight = radius * 0.5f; // Keep a nice downward viewing angle
 
     Camera cam      = {};