Increase size of output vertex buffer

QTProject/subdivision.cpp

@@ -723,10 +723,12 @@ Subdivision::Result Subdivision::runShader(Input input, Tables &tables) {
     f->glBufferData(GL_SHADER_STORAGE_BUFFER, tables.edge_indices.size() * sizeof(GLuint), tables.edge_indices.data(), GL_DYNAMIC_DRAW);
 
     // Create an output buffer
+    // the new vertex buffer contains the old vertices + the new edge vertices + the modified non-edge vertices
+    unsigned int output_size = input.vertex_buffer.size() + tables.edge_indices.size() / 4 + (tables.vertex_offsets.size() - 1);
     GLuint output_handle;
     f->glGenBuffers(1, &output_handle);
     f->glBindBuffer(GL_SHADER_STORAGE_BUFFER, output_handle);
-    f->glBufferData(GL_SHADER_STORAGE_BUFFER, (input.vertex_buffer.size() + tables.edge_indices.size() / 4) * sizeof(Vertex), NULL, GL_DYNAMIC_DRAW);
+    f->glBufferData(GL_SHADER_STORAGE_BUFFER, output_size * sizeof(Vertex), NULL, GL_DYNAMIC_DRAW);
     result.vb_handle = output_handle;
 
     f->glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);