Zephyr: Renderer: handle changes in vertex and index count

ZephyrEngine · May 2, 2024 · 91da51e · 91da51e
1 parent 910c383
commit 91da51e
Show file tree

Hide file tree

Showing 4 changed files with 21 additions and 5 deletions.
diff --git a/app/next/CMakeLists.txt b/app/next/CMakeLists.txt
@@ -12,6 +12,6 @@ find_package(SDL2 REQUIRED)
 
 add_executable(zephyr-next ${SOURCES} ${HEADERS})
 
-target_link_libraries(zephyr-next PRIVATE zephyr)
+target_link_libraries(zephyr-next PRIVATE zephyr nlohmann_json)
 target_include_directories(zephyr-next PRIVATE include)
 target_include_directories(zephyr-next PRIVATE src)
diff --git a/zephyr/renderer/include/zephyr/renderer/backend/render_backend.hpp b/zephyr/renderer/include/zephyr/renderer/backend/render_backend.hpp
@@ -34,6 +34,9 @@ namespace zephyr {
   class RenderGeometry {
     public:
       virtual ~RenderGeometry() = default;
+
+      [[nodiscard]] virtual size_t GetNumberOfVertices() const = 0;
+      [[nodiscard]] virtual size_t GetNumberOfIndices() const = 0;
   };
 
   struct RenderObject {

diff --git a/zephyr/renderer/src/backend/opengl/render_backend.cpp b/zephyr/renderer/src/backend/opengl/render_backend.cpp
@@ -64,6 +64,14 @@ namespace zephyr {
         return render_geometry;
       }
 
+      [[nodiscard]] size_t GetNumberOfVertices() const override {
+        return m_number_of_vertices;
+      }
+
+      [[nodiscard]] size_t GetNumberOfIndices() const override {
+        return m_number_of_indices;
+      }
+
       void UpdateIndices(std::span<const u8> data) {
         // @todo: validation
         glNamedBufferSubData(m_gl_ibo.value(), 0u, (GLsizeiptr)data.size_bytes(), data.data());

diff --git a/zephyr/renderer/src/engine/geometry_cache.cpp b/zephyr/renderer/src/engine/geometry_cache.cpp
@@ -62,10 +62,15 @@ namespace zephyr {
       const Geometry* geometry = upload_task.geometry;
       RenderGeometry* render_geometry = m_render_geometry_table[geometry];
 
-      if(!render_geometry) {
-        render_geometry = m_render_backend->CreateRenderGeometry(
-          upload_task.layout, upload_task.number_of_vertices, upload_task.number_of_indices);
-        m_render_geometry_table[upload_task.geometry] = render_geometry;
+      const size_t new_number_of_vertices = upload_task.number_of_vertices;
+      const size_t new_number_of_indices  = upload_task.number_of_indices;
+
+      if(!render_geometry || new_number_of_vertices != render_geometry->GetNumberOfVertices() || new_number_of_indices != render_geometry->GetNumberOfIndices()) {
+        if(render_geometry) {
+          m_render_backend->DestroyRenderGeometry(render_geometry);
+        }
+        render_geometry = m_render_backend->CreateRenderGeometry(upload_task.layout, new_number_of_vertices, new_number_of_indices);
+        m_render_geometry_table[geometry] = render_geometry;
       }
 
       m_render_backend->UpdateRenderGeometryVertices(render_geometry, upload_task.raw_vbo_data);