feat: multiple index buffers per mesh support

src/graphics/core/Mesh.hpp

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <vector>
+
 #include "MeshData.hpp"
 
 
@@ -8,25 +10,32 @@ struct MeshStats {
     static int drawCalls;
 };
 
+struct IndexBufferData {
+    const uint32_t* indices;
+    size_t indicesCount;
+};
+
 template <typename VertexStructure>
 class Mesh {
+    struct IndexBuffer {
+        unsigned int ibo;
+        size_t indexCount;
+    };
     unsigned int vao;
     unsigned int vbo;
-    unsigned int ibo;
+    std::vector<IndexBuffer> ibos;
     size_t vertexCount;
-    size_t indexCount;
 public:
     explicit Mesh(const MeshData<VertexStructure>& data);
 
     Mesh(
         const VertexStructure* vertexBuffer,
         size_t vertices,
-        const uint32_t* indexBuffer,
-        size_t indices
+        std::vector<IndexBufferData> indices
     );
 
     Mesh(const VertexStructure* vertexBuffer, size_t vertices)
-        : Mesh<VertexStructure>(vertexBuffer, vertices, nullptr, 0) {};
+        : Mesh<VertexStructure>(vertexBuffer, vertices, {}) {};
 
     ~Mesh();
 
@@ -34,18 +43,21 @@ public:
     /// attributes
     /// @param vertexBuffer vertex data buffer
     /// @param vertexCount number of vertices in new buffer
-    /// @param indexBuffer indices buffer
-    /// @param indexCount number of values in indices buffer
+    /// @param indices indices buffer
     void reload(
         const VertexStructure* vertexBuffer,
         size_t vertexCount,
-        const uint32_t* indexBuffer = nullptr,
-        size_t indexCount = 0
+        const std::vector<IndexBufferData>& indices
     );
 
+    void reload(const VertexStructure* vertexBuffer, size_t vertexCount) {
+        static const std::vector<IndexBufferData> indices {};
+        reload(vertexBuffer, vertexCount, indices);
+    }
+
     /// @brief Draw mesh with specified primitives type
-    /// @param primitive primitives type
-    void draw(unsigned int primitive) const;
+    /// @param iboIndex index of used element buffer
+    void draw(unsigned int primitive, int iboIndex = 0) const;
 
     /// @brief Draw mesh as triangles
     void draw() const;

src/graphics/core/Mesh.inl

@@ -11,13 +11,21 @@ inline constexpr size_t calc_size(const VertexAttribute attrs[]) {
     return vertexSize;
 }
 
+template <typename VertexStructure>
+inline std::vector<IndexBufferData> convert_to_ibd(const MeshData<VertexStructure>& data) {
+    std::vector<IndexBufferData> indices;
+    for (const auto& buffer : data.indices) {
+        indices.push_back(IndexBufferData {buffer.data(), buffer.size()});
+    }
+    return indices;
+}
+
 template <typename VertexStructure>
 Mesh<VertexStructure>::Mesh(const MeshData<VertexStructure>& data)
     : Mesh(
           data.vertices.data(),
           data.vertices.size(),
-          data.indices.data(),
-          data.indices.size()
+          convert_to_ibd<VertexStructure>(data)
       ) {
 }
 
@@ -25,10 +33,9 @@ template <typename VertexStructure>
 Mesh<VertexStructure>::Mesh(
     const VertexStructure* vertexBuffer,
     size_t vertices,
-    const uint32_t* indexBuffer,
-    size_t indices
+    std::vector<IndexBufferData> indices
 )
-    : vao(0), vbo(0), ibo(0), vertexCount(0), indexCount(0) {
+    : vao(0), vbo(0), ibos(), vertexCount(0) {
     static_assert(
         calc_size(VertexStructure::ATTRIBUTES) == sizeof(VertexStructure)
     );
@@ -39,8 +46,9 @@ Mesh<VertexStructure>::Mesh(
     glGenVertexArrays(1, &vao);
     glGenBuffers(1, &vbo);
 
-    reload(vertexBuffer, vertices, indexBuffer, indices);
+    reload(vertexBuffer, vertices, std::move(indices));
 
+    glBindVertexArray(vao);
     // attributes
     int offset = 0;
     for (int i = 0; attrs[i].count; i++) {
@@ -65,8 +73,8 @@ Mesh<VertexStructure>::~Mesh() {
     MeshStats::meshesCount--;
     glDeleteVertexArrays(1, &vao);
     glDeleteBuffers(1, &vbo);
-    if (ibo != 0) {
-        glDeleteBuffers(1, &ibo);
+    for (int i = ibos.size() - 1; i >= 0; i--) {
+        glDeleteBuffers(1, &ibos[i].ibo);
     }
 }
 
@@ -74,11 +82,9 @@ template <typename VertexStructure>
 void Mesh<VertexStructure>::reload(
     const VertexStructure* vertexBuffer,
     size_t vertexCount,
-    const uint32_t* indexBuffer,
-    size_t indexCount
+    const std::vector<IndexBufferData>& indices
 ) {
     this->vertexCount = vertexCount;
-    this->indexCount = indexCount;
     glBindVertexArray(vao);
     glBindBuffer(GL_ARRAY_BUFFER, vbo);
     if (vertexBuffer != nullptr && vertexCount != 0) {
@@ -92,30 +98,47 @@ void Mesh<VertexStructure>::reload(
         glBufferData(GL_ARRAY_BUFFER, 0, {}, GL_STREAM_DRAW);
     }
 
-    if (indexBuffer != nullptr && indexCount != 0) {
-        if (ibo == 0) glGenBuffers(1, &ibo);
-        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
+    for (int i = indices.size(); i < ibos.size(); i++) {
+        glDeleteBuffers(1, &ibos[i].ibo);
+    }
+    ibos.clear();
+
+    for (int i = 0; i < indices.size(); i++) {
+        const auto& indexBuffer = indices[i];
+        ibos.push_back(IndexBuffer {0, 0});
+        glGenBuffers(1, &ibos[i].ibo);
+        ibos[i].indexCount = indexBuffer.indicesCount;
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibos[i].ibo);
         glBufferData(
             GL_ELEMENT_ARRAY_BUFFER,
-            sizeof(uint32_t) * indexCount,
-            indexBuffer,
+            sizeof(uint32_t) * indexBuffer.indicesCount,
+            indexBuffer.indices,
             GL_STATIC_DRAW
         );
-    } else if (ibo != 0) {
-        glDeleteBuffers(1, &ibo);
     }
+    glBindVertexArray(0);
 }
 
 template <typename VertexStructure>
-void Mesh<VertexStructure>::draw(unsigned int primitive) const {
+void Mesh<VertexStructure>::draw(unsigned int primitive, int iboIndex) const {
     MeshStats::drawCalls++;
-    glBindVertexArray(vao);
-    if (ibo != 0) {
-        glDrawElements(primitive, indexCount, GL_UNSIGNED_INT, nullptr);
-    } else {
+    
+    if (!ibos.empty()) {
+        if (iboIndex < ibos.size()) {
+            glBindVertexArray(vao);
+            glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibos[
+                std::min(static_cast<size_t>(iboIndex), ibos.size())
+            ].ibo);
+            glDrawElements(
+                primitive, ibos.at(0).indexCount, GL_UNSIGNED_INT, nullptr
+            );
+            glBindVertexArray(0);
+        }
+    } else if (vertexCount > 0) {
+        glBindVertexArray(vao);
         glDrawArrays(primitive, 0, vertexCount);
+        glBindVertexArray(0);
     }
-    glBindVertexArray(0);
 }
 
 template <typename VertexStructure>

src/graphics/core/MeshData.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <vector>
 #include <stdexcept>
 
 #include "typedefs.hpp"
@@ -40,7 +41,7 @@ struct VertexAttribute {
 template<typename VertexStructure>
 struct MeshData {
     util::Buffer<VertexStructure> vertices;
-    util::Buffer<uint32_t> indices;
+    std::vector<util::Buffer<uint32_t>> indices;
     util::Buffer<VertexAttribute> attrs;
 
     MeshData() = default;
@@ -50,7 +51,7 @@ struct MeshData {
     /// @param attrs vertex attribute sizes (must be null-terminated) 
     MeshData(
         util::Buffer<VertexStructure> vertices,
-        util::Buffer<uint32_t> indices,
+        std::vector<util::Buffer<uint32_t>> indices,
         util::Buffer<VertexAttribute> attrs
     ) : vertices(std::move(vertices)),
         indices(std::move(indices)),

src/graphics/render/BlocksRenderer.cpp

@@ -706,6 +706,7 @@ void BlocksRenderer::build(const Chunk* chunk, const Chunks* chunks) {
     vertexCount = 0;
     vertexOffset = 0;
     indexCount = 0;
+    denseRender = settings.graphics.denseRender.get();
 
     render(voxels, beginEnds);
 }
@@ -714,7 +715,7 @@ ChunkMeshData BlocksRenderer::createMesh() {
     return ChunkMeshData{
         MeshData(
             util::Buffer(vertexBuffer.get(), vertexCount),
-            util::Buffer(indexBuffer.get(), indexCount),
+            std::vector<util::Buffer<uint32_t>> {util::Buffer(indexBuffer.get(), indexCount)},
             util::Buffer(
                 ChunkVertex::ATTRIBUTES, sizeof(ChunkVertex::ATTRIBUTES) / sizeof(VertexAttribute)
             )
@@ -727,7 +728,8 @@ ChunkMesh BlocksRenderer::render(const Chunk *chunk, const Chunks *chunks) {
     build(chunk, chunks);
 
     return ChunkMesh{std::make_unique<Mesh<ChunkVertex>>(
-        vertexBuffer.get(), vertexCount, indexBuffer.get(), indexCount
+        vertexBuffer.get(), vertexCount, 
+        std::vector<IndexBufferData> {IndexBufferData {indexBuffer.get(), indexCount}}
     ), std::move(sortingMesh)};
 }
 

src/graphics/render/BlocksRenderer.hpp

@@ -33,6 +33,7 @@ class BlocksRenderer {
     int voxelBufferPadding = 2;
     bool overflow = false;
     bool cancelled = false;
+    bool denseRender = false;
     const Chunk* chunk = nullptr;
     std::unique_ptr<VoxelsVolume> voxelsBuffer;
 
@@ -137,7 +138,7 @@ class BlocksRenderer {
         }
         if ((variant.culling == CullingMode::DISABLED ||
              (variant.culling == CullingMode::OPTIONAL &&
-              settings.graphics.denseRender.get())) &&
+             denseRender)) &&
             vox.id == def.rt.id) {
             return true;
         }

src/graphics/render/ChunksRenderer.cpp

@@ -89,8 +89,7 @@ ChunksRenderer::ChunksRenderer(
     logger.info() << "created " << threadPool.getWorkersCount() << " workers";
 }
 
-ChunksRenderer::~ChunksRenderer() {
-}
+ChunksRenderer::~ChunksRenderer() = default;
 
 const Mesh<ChunkVertex>* ChunksRenderer::render(
     const std::shared_ptr<Chunk>& chunk, bool important

src/graphics/render/commons.hpp

@@ -47,7 +47,7 @@ struct ChunkMeshData {
 };
 
 struct ChunkMesh {
-    std::unique_ptr<Mesh<ChunkVertex> > mesh;
+    std::unique_ptr<Mesh<ChunkVertex>> mesh;
     SortingMeshData sortingMeshData;
     std::unique_ptr<Mesh<ChunkVertex> > sortedMesh = nullptr;
 };