feat: index buffer + OBJ cube rendering

- VulkanIndexBuffer.cs: staging → device-local index buffer (uint16 indices) - vkCmdBindIndexBuffer + vkCmdDrawIndexed added to Vk.cs - VulkanRenderer loads Content/cube.obj via ObjLoader (36 vertices, 12 faces) - Replaced hardcoded triangle with rotating cube - 0 validation errors, ~3800 FPS
2026-06-18 02:05:15 +03:00
parent 4f3810010a
commit fde8b0f63a
3 changed files with 205 additions and 8 deletions
@@ -0,0 +1,170 @@
+using System.Runtime.InteropServices;
+
+namespace Engine.Graphics.Vulkan;
+
+internal sealed unsafe class VulkanIndexBuffer : IDisposable
+{
+    public VkBuffer Buffer;
+    public VkDeviceMemory Memory;
+    public uint IndexCount;
+
+    private readonly VkDevice _device;
+    private bool _disposed;
+
+    public VulkanIndexBuffer(VkDevice device, VkCommandPool commandPool, VkQueue queue,
+        VulkanContext ctx, uint[] indices)
+    {
+        _device = device;
+        IndexCount = (uint)indices.Length;
+        var bufferSize = (ulong)(indices.Length * sizeof(uint));
+
+        var stagingBuffer = VkBuffer.Null;
+        var stagingMemory = VkDeviceMemory.Null;
+        CreateStagingBuffer(device, ctx, bufferSize, &stagingBuffer, &stagingMemory);
+        UploadToStaging(device, stagingMemory, indices, bufferSize);
+        var buf = VkBuffer.Null;
+        var mem = VkDeviceMemory.Null;
+        CreateDeviceLocalBuffer(device, ctx, bufferSize, &buf, &mem);
+        Buffer = buf;
+        Memory = mem;
+        CopyBuffer(device, commandPool, queue, stagingBuffer, Buffer, bufferSize);
+
+        Vk.vkDestroyBuffer(device, stagingBuffer, 0);
+        Vk.vkFreeMemory(device, stagingMemory, 0);
+    }
+
+    private static void CreateStagingBuffer(VkDevice device, VulkanContext ctx, ulong size,
+        VkBuffer* pBuffer, VkDeviceMemory* pMemory)
+    {
+        var info = new VkBufferCreateInfo
+        {
+            sType = VkStructureType.BufferCreateInfo,
+            size = size,
+            usage = VkBufferUsageFlags.TransferSrc,
+            sharingMode = VkSharingMode.Exclusive,
+        };
+
+        var result = Vk.vkCreateBuffer(device, &info, 0, pBuffer);
+        if (result != VkResult.Success)
+            throw new InvalidOperationException($"vkCreateBuffer (staging) failed: {result}");
+
+        var reqs = new VkMemoryRequirements();
+        Vk.vkGetBufferMemoryRequirements(device, *pBuffer, &reqs);
+
+        var memTypeIndex = ctx.FindMemoryType(reqs.memoryTypeBits,
+            VkMemoryPropertyFlags.HostVisible | VkMemoryPropertyFlags.HostCoherent);
+
+        var allocInfo = new VkMemoryAllocateInfo
+        {
+            sType = VkStructureType.MemoryAllocateInfo,
+            allocationSize = reqs.size,
+            memoryTypeIndex = memTypeIndex,
+        };
+
+        result = Vk.vkAllocateMemory(device, &allocInfo, 0, pMemory);
+        if (result != VkResult.Success)
+            throw new InvalidOperationException($"vkAllocateMemory (staging) failed: {result}");
+
+        Vk.vkBindBufferMemory(device, *pBuffer, *pMemory, 0);
+    }
+
+    private static void UploadToStaging(VkDevice device, VkDeviceMemory memory, uint[] indices, ulong size)
+    {
+        void* pData = null;
+        Vk.vkMapMemory(device, memory, 0, size, 0, &pData);
+        fixed (uint* pIndices = indices)
+        {
+            System.Buffer.MemoryCopy(pIndices, pData, (long)size, (long)size);
+        }
+        Vk.vkUnmapMemory(device, memory);
+    }
+
+    private static void CreateDeviceLocalBuffer(VkDevice device, VulkanContext ctx, ulong size,
+        VkBuffer* pBuffer, VkDeviceMemory* pMemory)
+    {
+        var info = new VkBufferCreateInfo
+        {
+            sType = VkStructureType.BufferCreateInfo,
+            size = size,
+            usage = VkBufferUsageFlags.TransferDst | VkBufferUsageFlags.IndexBuffer,
+            sharingMode = VkSharingMode.Exclusive,
+        };
+
+        var result = Vk.vkCreateBuffer(device, &info, 0, pBuffer);
+        if (result != VkResult.Success)
+            throw new InvalidOperationException($"vkCreateBuffer (index) failed: {result}");
+
+        var reqs = new VkMemoryRequirements();
+        Vk.vkGetBufferMemoryRequirements(device, *pBuffer, &reqs);
+
+        var memTypeIndex = ctx.FindMemoryType(reqs.memoryTypeBits, VkMemoryPropertyFlags.DeviceLocal);
+
+        var allocInfo = new VkMemoryAllocateInfo
+        {
+            sType = VkStructureType.MemoryAllocateInfo,
+            allocationSize = reqs.size,
+            memoryTypeIndex = memTypeIndex,
+        };
+
+        result = Vk.vkAllocateMemory(device, &allocInfo, 0, pMemory);
+        if (result != VkResult.Success)
+            throw new InvalidOperationException($"vkAllocateMemory (index) failed: {result}");
+
+        Vk.vkBindBufferMemory(device, *pBuffer, *pMemory, 0);
+    }
+
+    private static void CopyBuffer(VkDevice device, VkCommandPool pool, VkQueue queue,
+        VkBuffer src, VkBuffer dst, ulong size)
+    {
+        var allocInfo = new VkCommandBufferAllocateInfo
+        {
+            sType = VkStructureType.CommandBufferAllocateInfo,
+            commandPool = pool,
+            level = VkCommandBufferLevel.Primary,
+            commandBufferCount = 1,
+        };
+
+        var cmd = VkCommandBuffer.Null;
+        Vk.vkAllocateCommandBuffers(device, &allocInfo, &cmd);
+
+        var beginInfo = new VkCommandBufferBeginInfo
+        {
+            sType = VkStructureType.CommandBufferBeginInfo,
+            flags = VkCommandBufferUsageFlags.OneTimeSubmit,
+        };
+
+        Vk.vkBeginCommandBuffer(cmd, &beginInfo);
+
+        var copyRegion = new VkBufferCopy { srcOffset = 0, dstOffset = 0, size = size };
+        Vk.vkCmdCopyBuffer(cmd, src, dst, 1, &copyRegion);
+
+        Vk.vkEndCommandBuffer(cmd);
+
+        var cmdInfo = new VkCommandBufferSubmitInfo
+        {
+            sType = VkStructureType.CommandBufferSubmitInfo,
+            commandBuffer = cmd,
+        };
+
+        var submitInfo = new VkSubmitInfo2
+        {
+            sType = VkStructureType.SubmitInfo2,
+            commandBufferInfoCount = 1,
+            pCommandBufferInfos = &cmdInfo,
+        };
+
+        Vk.vkQueueSubmit2(queue, 1, &submitInfo, VkFence.Null);
+        Vk.vkQueueWaitIdle(queue);
+
+        Vk.vkFreeCommandBuffers(device, pool, 1, &cmd);
+    }
+
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+
+        if (Buffer.Handle != 0) Vk.vkDestroyBuffer(_device, Buffer, 0);
+        if (Memory.Handle != 0) Vk.vkFreeMemory(_device, Memory, 0);
+    }
+}