[Feat] (MG_Backend/DirectVulkan): vertex input state builder

CMakeLists.txt

@@ -214,6 +214,7 @@ set(SOURCE_FILES
     MobileGL/MG_Backend/DirectVulkan/Renderer/SwapchainObject.cpp
     MobileGL/MG_Backend/DirectVulkan/Renderer/FrameContext.cpp
     MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.cpp
+    MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateBuilder.cpp
     MobileGL/MG_Backend/DirectVulkan/Renderer/VkBufferObject.cpp
 
     MobileGL/MG_State/GLState/Core.cpp

MobileGL/MG_Backend/DirectVulkan/DirectVulkan.cpp

@@ -85,6 +85,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
     void DrawArrays(GLenum mode, GLint first, GLsizei count) {
         MOBILEGL_ASSERT(pVulkanRenderer, "DirectVulkan::DrawArrays called with null VulkanRenderer");
+        MOBILEGL_ASSERT(MG_State::pGLContext, "DirectVulkan::DrawArrays called with null GL context");
 
         if (first < 0) {
             MGLOG_W("DrawArrays skipped: first (%d) must be non-negative", first);
@@ -105,7 +106,39 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             return;
         }
 
-        pVulkanRenderer->DrawArrays(mode, first, count);
+        DrawArrayPayload payload{};
+        payload.mode = mode;
+        payload.first = first;
+        payload.count = count;
+
+        const auto vao = MG_State::pGLContext->GetBoundVertexArray();
+        if (vao) {
+            const auto& attr0 = vao->GetAttribute(0);
+            if (attr0.Enabled && attr0.Buffer) {
+                const auto positionData = attr0.Buffer->GetDataReadOnly();
+                if (positionData && !positionData->empty()) {
+                    payload.hasPositionStream = true;
+                    payload.positionData = positionData->data();
+                    payload.positionDataSizeBytes = attr0.Buffer->GetSize();
+                    payload.positionOffsetBytes = attr0.Offset;
+                    payload.positionStrideBytes = attr0.Stride > 0 ? static_cast<SizeT>(attr0.Stride) : 0;
+                    payload.positionSize = attr0.Size;
+                    payload.positionNormalized = attr0.Normalized;
+
+                    switch (attr0.Type) {
+                    case DataType::Float32:
+                        payload.positionType = GL_FLOAT;
+                        break;
+                    default:
+                        payload.positionType = GL_FLOAT;
+                        payload.hasPositionStream = false;
+                        break;
+                    }
+                }
+            }
+        }
+
+        pVulkanRenderer->DrawArrays(payload);
     }
 } // namespace MobileGL::MG_Backend::DirectVulkan
 

MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateBuilder.cpp

@@ -0,0 +1,56 @@
+// MobileGL - MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateBuilder.cpp
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#include "VertexInputStateBuilder.h"
+
+namespace MobileGL::MG_Backend::DirectVulkan {
+    VertexInputStateBuilder::VertexInputStateBuilder() {
+        Reset();
+    }
+
+    void VertexInputStateBuilder::Reset() {
+        m_bindings.clear();
+        m_attributes.clear();
+
+        m_state = {};
+        m_state.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
+        m_state.vertexBindingDescriptionCount = 0;
+        m_state.pVertexBindingDescriptions = nullptr;
+        m_state.vertexAttributeDescriptionCount = 0;
+        m_state.pVertexAttributeDescriptions = nullptr;
+    }
+
+    VertexInputStateBuilder& VertexInputStateBuilder::AddBinding(
+        Uint32 binding, Uint32 stride, VkVertexInputRate inputRate) {
+        VkVertexInputBindingDescription desc{};
+        desc.binding = binding;
+        desc.stride = stride;
+        desc.inputRate = inputRate;
+        m_bindings.push_back(desc);
+        return *this;
+    }
+
+    VertexInputStateBuilder& VertexInputStateBuilder::AddAttribute(
+        Uint32 location, Uint32 binding, VkFormat format, Uint32 offset) {
+        VkVertexInputAttributeDescription desc{};
+        desc.location = location;
+        desc.binding = binding;
+        desc.format = format;
+        desc.offset = offset;
+        m_attributes.push_back(desc);
+        return *this;
+    }
+
+    const VkPipelineVertexInputStateCreateInfo& VertexInputStateBuilder::Build() {
+        m_state.vertexBindingDescriptionCount = static_cast<Uint32>(m_bindings.size());
+        m_state.pVertexBindingDescriptions = m_bindings.empty() ? nullptr : m_bindings.data();
+        m_state.vertexAttributeDescriptionCount = static_cast<Uint32>(m_attributes.size());
+        m_state.pVertexAttributeDescriptions = m_attributes.empty() ? nullptr : m_attributes.data();
+        return m_state;
+    }
+} // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateBuilder.h

@@ -0,0 +1,29 @@
+// MobileGL - MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateBuilder.h
+// Copyright (c) 2025-2026 MobileGL-Dev
+// Licensed under the GNU Lesser General Public License v3.0:
+//   https://www.gnu.org/licenses/gpl-3.0.txt
+//   https://www.gnu.org/licenses/lgpl-3.0.txt
+// SPDX-License-Identifier: LGPL-3.0-only
+// End of Source File Header
+
+#pragma once
+#include <Includes.h>
+
+namespace MobileGL::MG_Backend::DirectVulkan {
+    class VertexInputStateBuilder {
+    public:
+        VertexInputStateBuilder();
+
+        void Reset();
+        VertexInputStateBuilder& AddBinding(
+            Uint32 binding, Uint32 stride, VkVertexInputRate inputRate = VK_VERTEX_INPUT_RATE_VERTEX);
+        VertexInputStateBuilder& AddAttribute(Uint32 location, Uint32 binding, VkFormat format, Uint32 offset);
+
+        const VkPipelineVertexInputStateCreateInfo& Build();
+
+    private:
+        VkPipelineVertexInputStateCreateInfo m_state{};
+        Vector<VkVertexInputBindingDescription> m_bindings;
+        Vector<VkVertexInputAttributeDescription> m_attributes;
+    };
+} // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.cpp

@@ -7,6 +7,7 @@
 // End of Source File Header
 
 #include "VulkanRenderer.h"
+#include "VertexInputStateBuilder.h"
 
 #include "MG_State/GLState/ProgramState/ProgramObject.h"
 
@@ -112,9 +113,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         dynamicState.dynamicStateCount = static_cast<uint32_t>(std::size(s_dynamicStates));
         dynamicState.pDynamicStates = s_dynamicStates;
 
-        VkPipelineVertexInputStateCreateInfo vertexInput{VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO};
+        VertexInputStateBuilder vertexInputBuilder;
-        vertexInput.vertexBindingDescriptionCount = 0;
+        const auto& vertexInput = vertexInputBuilder.Build();
-        vertexInput.vertexAttributeDescriptionCount = 0;
 
         VkPipelineInputAssemblyStateCreateInfo ia{VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO};
         ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
@@ -444,7 +444,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_frameContext.EndCommandRecording();
     }
 
-    void VulkanRenderer::DrawArrays(GLenum mode, GLint first, GLsizei count) {
+    void VulkanRenderer::DrawArrays(const DrawArrayPayload& payload) {
+        if (payload.mode != GL_TRIANGLES) {
+            MGLOG_W("DrawArrays skipped: primitive mode %u is not supported yet", payload.mode);
+            return;
+        }
+
         EnsureFrameRecordingStarted();
         auto& frame = m_frameContext.GetCurrent();
         if (!frame.isCommandRecording || !m_isMainRenderPassActive) {
@@ -471,7 +476,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         scissor.extent = swapchainExtent;
         vkCmdSetScissor(commandBuffer, 0, 1, &scissor);
 
-        vkCmdDraw(commandBuffer, static_cast<Uint32>(count), 1, static_cast<Uint32>(first), 0);
+        vkCmdDraw(commandBuffer, static_cast<Uint32>(payload.count), 1, static_cast<Uint32>(payload.first), 0);
     }
 
     void VulkanRenderer::DrawElements(GLenum type, GLsizei count, const void* indexData, SizeT indexDataSizeBytes) {

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -19,6 +19,20 @@
 #include "../VkIncludes.h"
 
 namespace MobileGL::MG_Backend::DirectVulkan {
+    struct DrawArrayPayload {
+        GLenum mode = GL_TRIANGLES;
+        GLint first = 0;
+        GLsizei count = 0;
+        Bool hasPositionStream = false;
+        const void* positionData = nullptr;
+        SizeT positionDataSizeBytes = 0;
+        SizeT positionStrideBytes = 0;
+        SizeT positionOffsetBytes = 0;
+        GLenum positionType = GL_FLOAT;
+        GLint positionSize = 0;
+        Bool positionNormalized = false;
+    };
+
     class VulkanRenderer {
     public:
         VulkanRenderer(NativeWindowType window, const VulkanRendererConfig& cfg = {});
@@ -30,7 +44,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void RequestClear(GLbitfield mask, const FloatVec4& color, Float depth, Uint32 stencil);
         Bool ConsumePendingColorClear(VkClearColorValue& outClearColor);
         void EnsureFrameRecordingStarted();
-        void DrawArrays(GLenum mode, GLint first, GLsizei count);
+        void DrawArrays(const DrawArrayPayload& payload);
         void DrawElements(GLenum type, GLsizei count, const void* indexData, SizeT indexDataSizeBytes);
         void Render();
         void Present();