Miyoo SDL2/OpenGL Benchmarks

SDL2 benchmark programs for the Miyoo Mini. The project is used to exercise rendering, audio, OpenGL ES, and SDL2 backend behaviour against a custom SDL2 build for the device.

The generated package is written to app-dist/sdl_bench/.

AI disclosure: there's been a substantial usage of various LLM in this project to both write the code & maintain the repo itself.

Screenshots

Requirements

• Docker, for the cross-compilation container used by mm-buildbot.
• Git, used to obtain mm-buildbot when it is not already checked out.
• A Miyoo Mini SD card or deployment target for running the packaged app.

The build is delegated to the current main branch of XK9274/mm-buildbot. mm-buildbot owns the Miyoo toolchain, SDL2 core, Neon helper, and SDL2 add-on builds. The benchmark repository only builds the benchmark sources and stages the application.

Build

Build all benchmark binaries and prepare the distribution package:

./build.sh

Use verbose output when diagnosing build issues:

./build.sh --verbose

The build process:

• locates or clones a local mm-buildbot checkout;
• builds or reuses the shared SDL2 provider packages;
• compiles the benchmark binaries with the project Makefile;
• copies the resulting ARM binaries and provider runtime libraries into app-dist/sdl_bench/.

The root build.sh script is the main entry point.

Local Build

For local development, point the build at an existing mm-buildbot checkout:

MM_BUILDBOT_DIR=/path/to/mm-buildbot ./build.sh

Already-built provider bundles can be supplied for faster local iteration:

MM_BUILDBOT_DIR=/path/to/mm-buildbot \
MMIYOO_SDL2_PREFIX=/path/to/sdl2-mmiyoo-lib/bundle \
MMIYOO_SDL2_ADDONS_PREFIX=/path/to/sdl2-mmiyoo-addons/bundle \
./build.sh

If no checkout is supplied, build.sh looks for ../mm-buildbot and then clones mm-buildbot/main into ../.mm-buildbot-cache/mm-buildbot. Override the cache path with MM_BUILDBOT_CACHE_DIR.

MM_BUILDBOT_CACHE_DIR=/path/to/cache ./build.sh

The buildbot providers supply SDL2, SDL2_ttf, SDL2_gfx, SDL2_image, EGL/GLES, and the Neon helper consistently for the benchmark and other applications.

Installation

Copy the generated app directory to the Miyoo Mini SD card:

app-dist/sdl_bench/ -> /mnt/SDCARD/App/sdl_bench/

Then restart MainUI or reboot the device. The app appears under Apps as SDL Benchmark.

When launched normally, app-dist/sdl_bench/launch.sh starts sdl2_title, the themed launcher/title screen, from which you pick and configure a suite to run. Each suite run writes its own log under app-dist/sdl_bench/logs/.

The launcher also has two diagnostic entry points:

./launch.sh --gdb <binary-name> [port]
./launch.sh --geometry <tag> [duration_s]
./launch.sh --obj-model <tag> [duration_s]

--gdb starts one binary under gdbserver. --geometry runs the render suite's geometry scene only and tags its periodic FPS output for A/B testing. --obj-model runs sdl2_obj_model_loader standalone and tags its periodic per-stage timing output the same way.

Benchmarks

• sdl2_title

  • Themed launcher/title screen shown when the app starts.
  • Lets you pick a suite, configure resolution/vsync/frame-limit/input, and launches the selected binary; shows live battery/backend status.

• sdl2_bench_double_buf

  • Combined stress scene: a rotating polyhedron, a particle field, and animated fill-rect bands running simultaneously.
  • Shape, particle, and fill workloads are each independently togglable in-app for isolated measurement.

• sdl2_render_suite

  • Runs a broader 2D rendering workload set.
  • Includes fill, line, texture, geometry, scaling, memory, and pixel scenes.

• sdl2_gl_fbo_effects

  • Renders 15 shader-based effects offscreen into a hidden window's FBO and reads the pixels back with glReadPixels, composited via the ordinary 2D SDL_Renderer. Does not exercise a real on-screen GL swap chain.

• sdl2_audio_bench

  • Exercises SDL2 audio device setup and buffer behaviour.
  • Includes waveform and sample playback related checks.

• sdl2_space_bench

  • Runs an interactive space shooter style benchmark.
  • Exercises sprites, particles, projectiles, drones, anomalies, GL effects, overlay rendering, and runtime metrics.

• sdl2_sprite_bench

  • Fullscreen bouncing/morphing sprite stress test, deliberately without vsync, to isolate the render/present path's own throughput.

• sdl2_gfx_bench

  • Cycles antialiased shapes, rounded rects, polygons, bezier curves, and thick lines via SDL2_gfx's software primitive renderer.
  • Exercises CPU-side rasterization independent of the hardware-accelerated SDL_Renderer path the other suites use.

• sdl2_obj_model_loader (WIP)

  • Loads low-poly Wavefront OBJ/MTL models from assets/models/ (falling back to a built-in placeholder cube if none is bundled), with L2/R2 cycling between every bundled model at runtime and manual orbit/zoom/ wireframe controls.
  • Exercises OBJ/MTL parsing (via tinyobjloader-c) and texture loading entirely separately from a hand-written CPU-side model/view/projection, near-plane clipping, backface culling, and multi-light flat-shading pipeline, drawn through SDL_RenderGeometry -- no OpenGL is used for this suite's 3D rendering.

• sdl2_messagebox_probe

  • Runs three SDL_ShowMessageBox dialogs back to back: a fixed explainer of how the call reaches the driver, a randomized box using the driver's default theme, and a randomized box with a custom SDL_MessageBoxColorScheme.
  • Exercises the Miyoo SDL2 driver's SDL_ShowMessageBox implementation -- button focus/confirm/cancel, box growth for wrapped text, and the colorScheme override path.

Title Menu Categories

sdl2_title groups individual scenes/effects into launchable entries under five categories (L1/R1 switches category, UP/DOWN moves within it):

Category	Entries
Geometry & 3D	Turntable Model: Sheep, Turntable Model: Miyoo, Rotating Mesh (NEON)
2D Rendering	Geo / Particles / Fill, Solid Fill Rate, Texture Blit Throughput, Line & Shape Drawing, Resolution Scaling, Memory Management, Pixel Operations, Sprite Blit Stress Test, AA Shapes (SDL2_gfx), Rounded Rects (SDL2_gfx), Polygons (SDL2_gfx), Bezier Curves (SDL2_gfx), Thick Lines (SDL2_gfx)
Shader Effects	All 15 sdl2_gl_fbo_effects effects, one entry each
Audio	Audio Playback Visualizer
Interactive	Space Shooter Stress Test, Message Box Probe

Most entries launch a suite binary pinned to one internal scene/effect via an env var (e.g. RS_FORCE_SCENE, GB_FORCE_SCENE, RSGL_FORCE_EFFECT, OBJ_MODEL_NAME) with that suite's auto-cycle disabled; a few entries (the double buffer test, the audio visualizer, the space shooter) launch their suite as-is since their internal variations are cosmetic rather than distinct workloads, and stay togglable in-app.

Build Flow

./build.sh
  -> locate or clone mm-buildbot/main
  -> build sdl2-mmiyoo-lib and sdl2-mmiyoo-addons through mm-buildbot
  -> compile the benchmark source against those provider bundles
  -> stage binaries, assets, and runtime libraries

The generated app-dist/sdl_bench/lib/ directory contains the runtime libraries staged by the buildbot SDL providers.

Known Bugs

• Memory management in render_suite is broken/regressed.
• The overlay has a blending issue in most suites, visible in the obj model loader.
• The overlay's own render/update frequency measurably costs framerate; needs throttling instead of running every frame.
• Issue with culling.

Directory Layout

miyoo_sdl2_benchmarks/
|-- build.sh                       # Standalone mm-buildbot-backed build entry point
|-- Makefile                       # Benchmark build configuration
|-- README.md
|-- TODO.md
|-- app-dist/
|   `-- sdl_bench/                 # Device package
|       |-- assets/                # Runtime assets
|       |-- bin/                   # Built benchmark binaries
|       |-- lib/                   # Runtime libraries bundled with the app
|       |-- logs/                  # Runtime-generated benchmark logs
|       |-- config.json
|       `-- launch.sh
|-- assets/                        # README screenshots
|-- build/                         # Local/generated build output
|-- include/                       # Shared headers and GLES headers
|-- src/
|   |-- audio_bench/
|   |-- common/
|   |-- double_buf/
|   |-- gfx_bench/
|   |-- gl_fbo_effects/
|   |-- obj_model_loader/
|   |-- render_suite/
|   |-- space_bench/
|   |-- sprite_bench/
|   `-- title/                     # Launcher/title screen (sdl2_title)
`-- ../.mm-buildbot-cache/         # Default mm-buildbot checkout cache (sibling dir)

Asset Credits

• app-dist/sdl_bench/assets/bgm.wav: Audio Test by NoCopyrightSound633.
• app-dist/sdl_bench/assets/ThaleahFat.ttf: Free Pixel Font Thaleah by Tiny Worlds.
• app-dist/sdl_bench/assets/Metrophobic-Regular.ttf: Metrophobic by The Metrophobic Project Authors, licensed SIL OFL 1.1 (see the accompanying OFL.txt).
• app-dist/sdl_bench/icon.png: Pixel Skill Icons Pack - 250 Warrior Abilities by batareya.
• app-dist/sdl_bench/assets/models/sheep/: Cartoon Low Poly Sheep via Free3D.
• app-dist/sdl_bench/assets/models/miyoo/: model from Thingiverse thing 6118345, licensed CC BY 4.0.