arek
81a1b26842
Rendering used to clear the whole canvas and redraw every cell on every frame callback (~60 fps) even though the simulation ticks at 20 tps and starts paused, keeping CPU usage at ~85% while idle. Split simulation timing out of redraw() into the event loop and render only when displayed content can have changed (tick, painting, pattern placement, preview movement, grid-line toggle, resize); idle frames commit only a new frame callback. Repaint incrementally by diffing the grid against a rendered-state snapshot per row and redrawing just the changed cells, with damage limited to the repainted bounding box. Idle CPU drops to ~1% of one core; running frames render at tick rate (~20 fps) at microsecond cost. Adds grid_copy() snapshot helper with tests and archives the optimize-render-on-demand change with the new on-demand-rendering spec.
2.6 KiB
2.6 KiB
Tasks
1. Event-driven rendering (stage 1)
- 1.1 Move simulation tick timing (dt accumulation,
simulation_tick()calls) out ofredraw()into the main dispatch loop; verify withctest --test-dir buildand by running./build/wlgolthat animation still advances when unpaused - 1.2 Add
screen_dirty/full_redrawflags set from all content sources (tick, paint drag, click placement, pointer motion with active tool, tool select/rotate, grid-line toggle,need_resize); verify each source produces a repaint by exercising it in the app - 1.3 Rework
wl_callack_done/loop so a clean frame commits only a new frame callback (no attach, no damage) and a dirty frame renders only when the buffer isreleased, otherwise defers to the next callback; verify withtopthat paused idle CPU is ~0% and that unpausing at 20 tps renders without visual glitches - 1.4 Update the FPS log line to report rendered frames per second and verify the printed values match expected render counts (≈20 while running, 0 while idle)
2. Incremental repaint (stage 2)
- 2.1 Add a
grid_renderedsnapshot buffer sized/moved together withgridincanvas_resize(helper ingrid.c/grid.his acceptable), and verify it survives a window resize without out-of-bounds access - 2.2 Implement the per-row diff between
gridandgrid_renderedand arepaint_cell()that draws background, grid-line fragments on all four edges, and the cell body for each changed cell; verify by stepping (ACTION_STEP) a single-cell change and inspecting that only that cell's pixels change and shared edges stay intact - 2.3 Track last-frame preview cells (and whether the preview was shown) and add them to the repaint set alongside the diff, drawing the new preview last; verify the preview leaves no smearing when moving the cursor and rotates/selects cleanly
- 2.4 Copy
gridintogrid_renderedat the end of each rendered frame and report damage as the bounding box of repainted cells (whole canvas onfull_redraw); verify withWAYLAND_DEBUG=1 ./build/wlgolthat damage rects match changed cells - 2.5 Extend grid tests in
tests/test_grid.cfor the snapshot helper (resize copy bounds, snapshot/diff round-trip) and verify withctest --test-dir build
3. Integration verification
- 3.1 Full visual pass vs the pre-change renderer: paused idle, painting while paused, pattern placement and rotation, grid-line toggle, resize with fractional scale, unpause at min/max speed — confirm no visual differences; measure CPU with
topin each state and record before/after numbers