Fix for index buffer

- Fix index data offset in Vulkan geometry buffer.
- Normalize vertex colors.
- Add support for drawing from a given index offset.

src/engine/renderer/opengl/renderer_opengl.cc

@@ -26,6 +26,9 @@ constexpr GLenum kGlDataType[eng::kDataType_Max] = {
     GL_UNSIGNED_BYTE, GL_FLOAT,        GL_INT,
     GL_SHORT,         GL_UNSIGNED_INT, GL_UNSIGNED_SHORT};
 
+constexpr GLboolean kGlNormalize[eng::kDataType_Max] = {
+    GL_TRUE, GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE};
+
 const std::string kAttributeNames[eng::kAttribType_Max] = {
     "in_color", "in_normal", "in_position", "in_tex_coord"};
 
@@ -132,11 +135,16 @@ void RendererOpenGL::DestroyGeometry(uint64_t resource_id) {
   geometries_.erase(it);
 }
 
-void RendererOpenGL::Draw(uint64_t resource_id) {
+void RendererOpenGL::Draw(uint64_t resource_id,
+                          uint64_t num_indices,
+                          uint64_t start_offset) {
   auto it = geometries_.find(resource_id);
   if (it == geometries_.end())
     return;
 
+  if (num_indices == 0)
+    num_indices = it->second.num_indices;
+
   // Set up the vertex data.
   if (it->second.vertex_array_id)
     glBindVertexArray(it->second.vertex_array_id);
@@ -152,14 +160,14 @@ void RendererOpenGL::Draw(uint64_t resource_id) {
                             (const GLvoid*)e.vertex_offset);
     }
 
-    if (it->second.num_indices > 0)
+    if (num_indices > 0)
       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, it->second.index_buffer_id);
   }
 
   // Draw the primitive.
-  if (it->second.num_indices > 0)
+  if (num_indices > 0)
-    glDrawElements(it->second.primitive, it->second.num_indices,
+    glDrawElements(it->second.primitive, num_indices, it->second.index_type,
-                   it->second.index_type, NULL);
+                   (void*)(intptr_t)(start_offset * sizeof(unsigned short)));
   else
     glDrawArrays(it->second.primitive, 0, it->second.num_vertices);
 
@@ -446,7 +454,7 @@ bool RendererOpenGL::InitCommon() {
 #if 0
   LOG(0) << "  extensions:";
   for (auto& ext : extensions)
-    LOG(0) << "    " << ext.c_str());
+    LOG(0) << "    " << ext.c_str();
 #endif
 
   // Check for supported texture compression extensions.
@@ -465,7 +473,8 @@ bool RendererOpenGL::InitCommon() {
       extensions.find("GL_ATI_texture_compression_atitc") != extensions.end())
     texture_compression_.atc = true;
 
-  if (extensions.find("GL_OES_vertex_array_object") != extensions.end()) {
+  if (extensions.find("GL_OES_vertex_array_object") != extensions.end() ||
+      extensions.find("GL_ARB_vertex_array_object") != extensions.end()) {
     // This extension seems to be broken on older PowerVR drivers.
     if (!strstr(renderer, "PowerVR SGX 53") &&
         !strstr(renderer, "PowerVR SGX 54") &&
@@ -555,8 +564,9 @@ bool RendererOpenGL::SetupVertexLayout(
     if (use_vao) {
       // This will be saved into the vertex array object.
       glEnableVertexAttribArray(attribute_index);
-      glVertexAttribPointer(attribute_index, num_elements, type, GL_FALSE,
+      glVertexAttribPointer(attribute_index, num_elements, type,
-                            vertex_size, (const GLvoid*)vertex_offset);
+                            kGlNormalize[data_type], vertex_size,
+                            (const GLvoid*)vertex_offset);
     } else {
       // Need to keep this information for when rendering.
       GeometryOpenGL::Element element;

src/engine/renderer/opengl/renderer_opengl.h

@@ -33,7 +33,9 @@ class RendererOpenGL final : public Renderer {
 
   uint64_t CreateGeometry(std::unique_ptr<Mesh> mesh) final;
   void DestroyGeometry(uint64_t resource_id) final;
-  void Draw(uint64_t resource_id) final;
+  void Draw(uint64_t resource_id,
+            uint64_t num_indices = 0,
+            uint64_t start_offset = 0) final;
 
   uint64_t CreateTexture() final;
   void UpdateTexture(uint64_t resource_id, std::unique_ptr<Image> image) final;

src/engine/renderer/renderer.h

@@ -40,7 +40,9 @@ class Renderer {
 
   virtual uint64_t CreateGeometry(std::unique_ptr<Mesh> mesh) = 0;
   virtual void DestroyGeometry(uint64_t resource_id) = 0;
-  virtual void Draw(uint64_t resource_id) = 0;
+  virtual void Draw(uint64_t resource_id,
+                    uint64_t num_indices = 0,
+                    uint64_t start_offset = 0) = 0;
 
   virtual uint64_t CreateTexture() = 0;
   virtual void UpdateTexture(uint64_t resource_id,

src/engine/renderer/vulkan/renderer_vulkan.cc

@@ -155,10 +155,10 @@ constexpr VkPrimitiveTopology kVkPrimitiveType[eng::kPrimitive_Max] = {
 
 constexpr VkFormat kVkDataType[eng::kDataType_Max][4] = {
     {
-        VK_FORMAT_R8_UINT,
+        VK_FORMAT_R8_UNORM,
-        VK_FORMAT_R8G8_UINT,
+        VK_FORMAT_R8G8_UNORM,
-        VK_FORMAT_R8G8B8_UINT,
+        VK_FORMAT_R8G8B8_UNORM,
-        VK_FORMAT_R8G8B8A8_UINT,
+        VK_FORMAT_R8G8B8A8_UNORM,
     },
     {
         VK_FORMAT_R32_SFLOAT,
@@ -400,7 +400,8 @@ uint64_t RendererVulkan::CreateGeometry(std::unique_ptr<Mesh> mesh) {
   if (mesh->GetIndices()) {
     geometry.num_indices = mesh->num_indices();
     geometry.index_type = GetIndexType(mesh->index_description());
-    index_data_size = mesh->GetIndexSize() * geometry.num_indices;
+    geometry.index_type_size = mesh->GetIndexSize();
+    index_data_size = geometry.index_type_size * geometry.num_indices;
   }
   size_t data_size = vertex_data_size + index_data_size;
 
@@ -414,10 +415,10 @@ uint64_t RendererVulkan::CreateGeometry(std::unique_ptr<Mesh> mesh) {
                                         std::get<0>(geometry.buffer), 0,
                                         mesh->GetVertices(), vertex_data_size));
   if (geometry.num_indices > 0) {
-    geometry.indices_offset = vertex_data_size;
+    geometry.index_data_offset = vertex_data_size;
-    task_runner_.PostTask(
+    task_runner_.PostTask(HERE, std::bind(&RendererVulkan::UpdateBuffer, this,
-        HERE, std::bind(&RendererVulkan::UpdateBuffer, this,
+                                          std::get<0>(geometry.buffer),
-                        std::get<0>(geometry.buffer), geometry.indices_offset,
+                                          geometry.index_data_offset,
                                           mesh->GetIndices(), index_data_size));
   }
   task_runner_.PostTask(HERE,
@@ -442,20 +443,27 @@ void RendererVulkan::DestroyGeometry(uint64_t resource_id) {
   geometries_.erase(it);
 }
 
-void RendererVulkan::Draw(uint64_t resource_id) {
+void RendererVulkan::Draw(uint64_t resource_id,
+                          uint64_t num_indices,
+                          uint64_t start_offset) {
   auto it = geometries_.find(resource_id);
   if (it == geometries_.end())
     return;
 
+  uint64_t data_offset = start_offset * it->second.index_type_size;
+  if (num_indices == 0)
+    num_indices = it->second.num_indices;
+
   VkDeviceSize offset = 0;
   vkCmdBindVertexBuffers(frames_[current_frame_].draw_command_buffer, 0, 1,
                          &std::get<0>(it->second.buffer), &offset);
-  if (it->second.num_indices > 0) {
+  if (num_indices > 0) {
     vkCmdBindIndexBuffer(frames_[current_frame_].draw_command_buffer,
                          std::get<0>(it->second.buffer),
-                         it->second.indices_offset, it->second.index_type);
+                         it->second.index_data_offset + data_offset,
-    vkCmdDrawIndexed(frames_[current_frame_].draw_command_buffer,
+                         it->second.index_type);
-                     it->second.num_indices, 1, 0, 0, 0);
+    vkCmdDrawIndexed(frames_[current_frame_].draw_command_buffer, num_indices,
+                     1, 0, 0, 0);
   } else {
     vkCmdDraw(frames_[current_frame_].draw_command_buffer,
               it->second.num_vertices, 1, 0, 0);

src/engine/renderer/vulkan/renderer_vulkan.h

@@ -35,7 +35,9 @@ class RendererVulkan final : public Renderer {
 
   uint64_t CreateGeometry(std::unique_ptr<Mesh> mesh) final;
   void DestroyGeometry(uint64_t resource_id) final;
-  void Draw(uint64_t resource_id) final;
+  void Draw(uint64_t resource_id,
+            uint64_t num_indices = 0,
+            uint64_t start_offset = 0) final;
 
   uint64_t CreateTexture() final;
   void UpdateTexture(uint64_t resource_id, std::unique_ptr<Image> image) final;
@@ -101,7 +103,8 @@ class RendererVulkan final : public Renderer {
     Buffer<VkBuffer> buffer;
     uint32_t num_vertices = 0;
     uint32_t num_indices = 0;
-    uint64_t indices_offset = 0;
+    uint64_t index_data_offset = 0;
+    uint64_t index_type_size = 0;
     VkIndexType index_type = VK_INDEX_TYPE_UINT16;
   };