#5912: Extend IGeometryStore interface by resizeData() method to be a…

…ble to trim the stored data.
codereader · Mar 4, 2022 · ac5ba82 · ac5ba82
1 parent d0dc716
commit ac5ba82
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Showing 3 changed files with 47 additions and 0 deletions.
diff --git a/include/igeometrystore.h b/include/igeometrystore.h
@@ -53,6 +53,11 @@ class IGeometryStore
     virtual void updateSubData(Slot slot, std::size_t vertexOffset, const std::vector<ArbitraryMeshVertex>& vertices,
         std::size_t indexOffset, const std::vector<unsigned int>& indices) = 0;
 
+    /**
+     * Called in case the stored data in the given slot should just be cut off at the end.
+     */
+    virtual void resizeData(Slot slot, std::size_t vertexSize, std::size_t indexSize) = 0;
+
     virtual void deallocateSlot(Slot slot) = 0;
 
     // The render parameters suitable for rendering surfaces using gl(Multi)DrawElements

diff --git a/radiantcore/rendersystem/backend/GeometryStore.h b/radiantcore/rendersystem/backend/GeometryStore.h
@@ -141,6 +141,18 @@ class GeometryStore :
         });
     }
 
+    void resizeData(Slot slot, std::size_t vertexSize, std::size_t indexSize) override
+    {
+        auto& current = getCurrentBuffer();
+
+        current.vertices.resizeData(GetVertexSlot(slot), vertexSize);
+        current.indices.resizeData(GetIndexSlot(slot), indexSize);
+
+        _transactionLog.emplace_back(detail::BufferTransaction{
+            slot, detail::BufferTransaction::Type::Update
+        });
+    }
+
     void deallocateSlot(Slot slot) override
     {
         auto& current = getCurrentBuffer();

diff --git a/test/ContinuousBuffer.cpp b/test/ContinuousBuffer.cpp
@@ -208,6 +208,36 @@ TEST(ContinuousBufferTest, ReplaceSubDataOverflow)
     EXPECT_THROW(buffer.setSubData(handle, 4, five), std::logic_error);
 }
 
+TEST(ContinuousBufferTest, ResizeData)
+{
+    auto eight = std::vector<int>({ 0,1,2,3,4,5,6,7 });
+
+    render::ContinuousBuffer<int> buffer(24);
+
+    auto handle = buffer.allocate(eight.size());
+    buffer.setData(handle, eight);
+
+    EXPECT_EQ(buffer.getNumUsedElements(handle), eight.size());
+
+    buffer.resizeData(handle, 5);
+    EXPECT_TRUE(checkData(buffer, handle, eight)) << "Data should not have changed";
+    EXPECT_EQ(buffer.getNumUsedElements(handle), 5) << "Used Element Count should be 5 now";
+}
+
+TEST(ContinuousBufferTest, ResizeDataOverflow)
+{
+    auto eight = std::vector<int>({ 0,1,2,3,4,5,6,7 });
+
+    render::ContinuousBuffer<int> buffer(24);
+
+    auto handle = buffer.allocate(eight.size());
+    buffer.setData(handle, eight);
+
+    EXPECT_EQ(buffer.getNumUsedElements(handle), eight.size());
+
+    EXPECT_THROW(buffer.resizeData(handle, eight.size() + 1), std::logic_error);
+}
+
 TEST(ContinuousBufferTest, BufferGrowth)
 {
     auto sixteen = std::vector<int>({ 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 });