Index buffer

src/main.cpp

@@ -21,6 +21,42 @@ constexpr i32 HEIGHT = 600;
 
 constexpr i32 MAX_FRAMES_IN_FLIGHT = 2;
 
+struct Vertex {
+  glm::vec2 pos;
+  glm::vec3 color;
+
+  static fn getBindingDescription() -> vk::VertexInputBindingDescription {
+    vk::VertexInputBindingDescription bindingDescription { .binding   = 0,
+                                                           .stride    = sizeof(Vertex),
+                                                           .inputRate = vk::VertexInputRate::eVertex };
+
+    return bindingDescription;
+  }
+
+  static fn getAttributeDescriptions() -> std::array<vk::VertexInputAttributeDescription, 2> {
+    std::array<vk::VertexInputAttributeDescription, 2> attributeDescriptions {};
+
+    attributeDescriptions[0] = {
+      .location = 0, .binding = 0, .format = vk::Format::eR32G32Sfloat, .offset = offsetof(Vertex, pos)
+    };
+
+    attributeDescriptions[1] = {
+      .location = 1, .binding = 0, .format = vk::Format::eR32G32B32Sfloat, .offset = offsetof(Vertex, color)
+    };
+
+    return attributeDescriptions;
+  }
+};
+
+constexpr std::array<Vertex, 4> vertices = {
+  { { { -0.5F, -0.5F }, { 1.0F, 0.0F, 0.0F } },
+   { { 0.5F, -0.5F }, { 0.0F, 1.0F, 0.0F } },
+   { { 0.5F, 0.5F }, { 0.0F, 0.0F, 1.0F } },
+   { { -0.5F, 0.5F }, { 1.0F, 1.0F, 1.0F } } }
+};
+
+constexpr std::array<u16, 6> indices = { 0, 1, 2, 2, 3, 0 };
+
 constexpr std::array<const char*, 1> validationLayers = { "VK_LAYER_KHRONOS_validation" };
 
 #ifdef __APPLE__
@@ -79,43 +115,12 @@ class VulkanApp {
 
   vk::UniqueBuffer       mVertexBuffer;
   vk::UniqueDeviceMemory mVertexBufferMemory;
+  vk::UniqueBuffer       mIndexBuffer;
+  vk::UniqueDeviceMemory mIndexBufferMemory;
 
   bool mFramebufferResized = false;
   u32  mCurrentFrame       = 0;
 
-  struct Vertex {
-    glm::vec2 pos;
-    glm::vec3 color;
-
-    static fn getBindingDescription() -> vk::VertexInputBindingDescription {
-      vk::VertexInputBindingDescription bindingDescription { .binding   = 0,
-                                                             .stride    = sizeof(Vertex),
-                                                             .inputRate = vk::VertexInputRate::eVertex };
-
-      return bindingDescription;
-    }
-
-    static fn getAttributeDescriptions() -> std::array<vk::VertexInputAttributeDescription, 2> {
-      std::array<vk::VertexInputAttributeDescription, 2> attributeDescriptions {};
-
-      attributeDescriptions[0] = {
-        .location = 0, .binding = 0, .format = vk::Format::eR32G32Sfloat, .offset = offsetof(Vertex, pos)
-      };
-
-      attributeDescriptions[1] = {
-        .location = 1, .binding = 0, .format = vk::Format::eR32G32B32Sfloat, .offset = offsetof(Vertex, color)
-      };
-
-      return attributeDescriptions;
-    }
-  };
-
-  const std::vector<Vertex> mVertices = {
-    { { 0.0F, -0.5F }, { 1.0F, 1.0F, 1.0F } },
-    {  { 0.5F, 0.5F }, { 0.0F, 1.0F, 0.0F } },
-    { { -0.5F, 0.5F }, { 0.0F, 0.0F, 1.0F } }
-  };
-
   struct QueueFamilyIndices {
     std::optional<u32> graphics_family;
     std::optional<u32> present_family;
@@ -177,6 +182,7 @@ class VulkanApp {
     createFramebuffers();
     createCommandPool();
     createVertexBuffer();
+    createIndexBuffer();
     createCommandBuffers();
     createSyncObjects();
   }
@@ -307,10 +313,11 @@ class VulkanApp {
   }
 
   fn createLogicalDevice() -> void {
-    QueueFamilyIndices indices = findQueueFamilies(mPhysicalDevice);
+    QueueFamilyIndices qfIndices = findQueueFamilies(mPhysicalDevice);
 
     std::vector<vk::DeviceQueueCreateInfo> queueCreateInfos;
-    std::set<u32> uniqueQueueFamilies = { indices.graphics_family.value(), indices.present_family.value() };
+    std::set<u32>                          uniqueQueueFamilies = { qfIndices.graphics_family.value(),
+                                                                   qfIndices.present_family.value() };
 
     f32 queuePriority = 1.0F;
 
@@ -331,8 +338,8 @@ class VulkanApp {
                                       .pEnabledFeatures        = &deviceFeatures };
 
     mDevice        = mPhysicalDevice.createDeviceUnique(createInfo);
-    mGraphicsQueue = mDevice->getQueue(indices.graphics_family.value(), 0);
+    mGraphicsQueue = mDevice->getQueue(qfIndices.graphics_family.value(), 0);
-    mPresentQueue  = mDevice->getQueue(indices.present_family.value(), 0);
+    mPresentQueue  = mDevice->getQueue(qfIndices.present_family.value(), 0);
   }
 
   fn createSwapChain() -> void {
@@ -348,9 +355,9 @@ class VulkanApp {
         imageCount > swapChainSupport.capabilities.maxImageCount)
       imageCount = swapChainSupport.capabilities.maxImageCount;
 
-    QueueFamilyIndices indices            = findQueueFamilies(mPhysicalDevice);
+    QueueFamilyIndices qfIndices          = findQueueFamilies(mPhysicalDevice);
-    std::array<u32, 2> queueFamilyIndices = { indices.graphics_family.value(),
+    std::array<u32, 2> queueFamilyIndices = { qfIndices.graphics_family.value(),
-                                              indices.present_family.value() };
+                                              qfIndices.present_family.value() };
 
     vk::SwapchainCreateInfoKHR createInfo {
       .surface          = mSurface.get(),
@@ -360,11 +367,12 @@ class VulkanApp {
       .imageExtent      = extent,
       .imageArrayLayers = 1,
       .imageUsage       = vk::ImageUsageFlagBits::eColorAttachment,
-      .imageSharingMode = indices.graphics_family != indices.present_family ? vk::SharingMode::eConcurrent
+      .imageSharingMode = qfIndices.graphics_family != qfIndices.present_family ? vk::SharingMode::eConcurrent
                                                                                 : vk::SharingMode::eExclusive,
-      .queueFamilyIndexCount = static_cast<u32>(indices.graphics_family != indices.present_family ? 2 : 0),
+      .queueFamilyIndexCount =
+        static_cast<u32>(qfIndices.graphics_family != qfIndices.present_family ? 2 : 0),
       .pQueueFamilyIndices =
-        indices.graphics_family != indices.present_family ? queueFamilyIndices.data() : nullptr,
+        qfIndices.graphics_family != qfIndices.present_family ? queueFamilyIndices.data() : nullptr,
       .preTransform   = swapChainSupport.capabilities.currentTransform,
       .compositeAlpha = vk::CompositeAlphaFlagBitsKHR::eOpaque,
       .presentMode    = presentMode,
@@ -578,7 +586,7 @@ class VulkanApp {
   }
 
   fn createVertexBuffer() -> void {
-    vk::DeviceSize bufferSize = sizeof(mVertices[0]) * mVertices.size();
+    vk::DeviceSize bufferSize = sizeof(vertices[0]) * vertices.size();
 
     vk::UniqueBuffer       stagingBuffer;
     vk::UniqueDeviceMemory stagingBufferMemory;
@@ -592,7 +600,7 @@ class VulkanApp {
     );
 
     void* data = mDevice->mapMemory(stagingBufferMemory.get(), 0, bufferSize);
-    memcpy(data, mVertices.data(), static_cast<usize>(bufferSize));
+    memcpy(data, vertices.data(), static_cast<usize>(bufferSize));
     mDevice->unmapMemory(stagingBufferMemory.get());
 
     createBuffer(
@@ -609,6 +617,38 @@ class VulkanApp {
     stagingBufferMemory.reset();
   }
 
+  fn createIndexBuffer() -> void {
+    vk::DeviceSize bufferSize = sizeof(indices[0]) * indices.size();
+
+    vk::UniqueBuffer       stagingBuffer;
+    vk::UniqueDeviceMemory stagingBufferMemory;
+
+    createBuffer(
+      bufferSize,
+      vk::BufferUsageFlagBits::eTransferSrc,
+      vk::MemoryPropertyFlagBits::eHostVisible | vk::MemoryPropertyFlagBits::eHostCoherent,
+      stagingBuffer,
+      stagingBufferMemory
+    );
+
+    void* data = mDevice->mapMemory(stagingBufferMemory.get(), 0, bufferSize);
+    memcpy(data, indices.data(), static_cast<usize>(bufferSize));
+    mDevice->unmapMemory(stagingBufferMemory.get());
+
+    createBuffer(
+      bufferSize,
+      vk::BufferUsageFlagBits::eIndexBuffer | vk::BufferUsageFlagBits::eTransferDst,
+      vk::MemoryPropertyFlagBits::eDeviceLocal,
+      mIndexBuffer,
+      mIndexBufferMemory
+    );
+
+    copyBuffer(stagingBuffer.get(), mIndexBuffer.get(), bufferSize);
+
+    stagingBuffer.reset();
+    stagingBufferMemory.reset();
+  }
+
   fn createBuffer(
     vk::DeviceSize          deviceSize,
     vk::BufferUsageFlags    bufferUsageFlags,
@@ -720,7 +760,9 @@ class VulkanApp {
 
     commandBuffer.bindVertexBuffers(0, mVertexBuffer.get(), { 0 });
 
-    commandBuffer.draw(static_cast<u32>(mVertices.size()), 1, 0, 0);
+    commandBuffer.bindIndexBuffer(mIndexBuffer.get(), 0, vk::IndexType::eUint16);
+
+    commandBuffer.drawIndexed(static_cast<u32>(indices.size()), 1, 0, 0, 0);
 
     commandBuffer.endRenderPass();
 
@@ -867,7 +909,7 @@ class VulkanApp {
   }
 
   fn isDeviceSuitable(vk::PhysicalDevice device) -> bool {
-    QueueFamilyIndices indices = findQueueFamilies(device);
+    QueueFamilyIndices qfIndices = findQueueFamilies(device);
 
     bool extensionsSupported = checkDeviceExtensionSupport(device);
 
@@ -878,7 +920,7 @@ class VulkanApp {
       swapChainAdequate = !swapChainSupport.formats.empty() && !swapChainSupport.present_modes.empty();
     }
 
-    return indices.isComplete() && extensionsSupported && swapChainAdequate;
+    return qfIndices.isComplete() && extensionsSupported && swapChainAdequate;
   }
 
   static fn checkDeviceExtensionSupport(vk::PhysicalDevice device) -> bool {
@@ -893,24 +935,24 @@ class VulkanApp {
   }
 
   fn findQueueFamilies(vk::PhysicalDevice device) -> QueueFamilyIndices {
-    QueueFamilyIndices indices;
+    QueueFamilyIndices qfIndices;
 
     std::vector<vk::QueueFamilyProperties> queueFamilies = device.getQueueFamilyProperties();
 
     for (u32 i = 0; i < queueFamilies.size(); i++) {
       if (queueFamilies[i].queueFlags & vk::QueueFlagBits::eGraphics)
-        indices.graphics_family = i;
+        qfIndices.graphics_family = i;
 
       vk::Bool32 queuePresentSupport = device.getSurfaceSupportKHR(i, mSurface.get());
 
       if (queuePresentSupport)
-        indices.present_family = i;
+        qfIndices.present_family = i;
 
-      if (indices.isComplete())
+      if (qfIndices.isComplete())
         break;
     }
 
-    return indices;
+    return qfIndices;
   }
 
   static fn getRequiredExtensions() -> std::vector<const char*> {