nxsand: A GPU grid for falling sand

flowchart LR

subgraph group_runtime["Runtime"]
  node_entry["Platform entry<br/>[main.cpp]"]
  node_app["App frame loop<br/>[app.cpp]"]
  node_game_settings["Game settings<br/>[game_settings.hpp]"]
  node_engine_settings["Engine settings"]
end

subgraph group_simulation["Simulation"]
  node_sim_state["Simulation state<br/>[sim_state.hpp]"]
  node_materials["Materials<br/>[materials.hpp]"]
  node_physics["Physics parameters<br/>[physics_params.hpp]"]
  node_sim_pipeline["GPU simulation<br/>[sim_pipeline.cpp]"]
  node_sim_backend["Simulation backend<br/>[sim_backend.hpp]"]
end

subgraph group_presentation["Presentation"]
  node_render["World renderer"]
  node_shader_program["Shader programs<br/>[shader_program.cpp]"]
  node_font["Font atlas<br/>[font_atlas.cpp]"]
  node_audio["Audio<br/>[tone_audio.cpp]"]
end

subgraph group_interaction["Interaction"]
  node_input["Input handling<br/>[input.cpp]"]
  node_menu["Menus<br/>[menu.cpp]"]
  node_layout["UI layout<br/>[layout.hpp]"]
  node_theme["UI theme<br/>[theme.hpp]"]
end

subgraph group_persistence["Persistence"]
  node_save["World saves<br/>[save.cpp]"]
  node_save_paths["Save storage<br/>[save_paths.cpp]"]
  node_settings_io["Settings storage<br/>[settings_io.cpp]"]
end

node_player(("Player"))

node_player -->|"launches"| node_entry
node_entry -->|"starts"| node_app
node_app -->|"ticks"| node_sim_pipeline
node_app -->|"renders"| node_render
node_app -->|"reads"| node_input
node_app -->|"coordinates"| node_menu
node_app -->|"requests saves"| node_save
node_app -->|"loads settings"| node_settings_io
node_app -->|"applies settings"| node_engine_settings
node_app -->|"uses settings"| node_game_settings
node_app -->|"holds state"| node_sim_state
node_app -->|"holds parameters"| node_physics
node_sim_pipeline -->|"updates grid"| node_sim_state
node_sim_pipeline -->|"simulates materials"| node_materials
node_sim_pipeline -->|"uses parameters"| node_physics
node_sim_pipeline -->|"selects backend"| node_sim_backend
node_render -->|"uses shaders"| node_shader_program
node_render -->|"draws grid"| node_sim_state
node_render -->|"colors materials"| node_materials
node_menu -->|"edits settings"| node_engine_settings
node_menu -->|"uses text"| node_font
node_menu -->|"draws interface"| node_render
node_layout -->|"uses styles"| node_theme
node_input -->|"maps controls"| node_layout
node_audio -->|"reads preferences"| node_game_settings
node_save -.->|"uses storage"| node_save_paths
node_settings_io -->|"uses storage"| node_save_paths
node_engine_settings -->|"persists preferences"| node_settings_io


class node_entry,node_app,node_game_settings,node_engine_settings toneBlue
class node_sim_state,node_materials,node_physics,node_sim_pipeline,node_sim_backend toneAmber
class node_render,node_shader_program,node_font,node_audio toneMint
class node_input,node_menu,node_layout,node_theme toneRose
class node_save,node_save_paths,node_settings_io,node_player toneIndigo