Live Raylib demo · Jolt Wasm experiment

Experiments

EXP-015: C-authored scene

The original signed-scalar scene-selection and input façade documented below.

EXP-016: Jolt-authored scene

The same scene with geometry, colors, and input mapping defined as Jolt command data.

EXP-017: Jolt Flappy Bird →

A recognizable game with per-frame Jolt physics, pipes, collision, scoring, Space/click input, and embedded runtime.

Interactive input façade

Launch the 26 MB experimental runtime, then move the pointer over its canvas and press →. The accent-colored circle follows pointer position; holding ArrowRight visibly changes keyboard state and shifts the rectangle.

Not loaded. Explicit activation avoids starting a pthread worker during page navigation.

What this demonstrates

Observed

Chromium reported crossOriginIsolated and SharedArrayBuffer, canonical Jolt output, scene readiness, real mouse dispatch, and ArrowRight dispatch with no page errors.

Ownership boundary

Jolt selects scalar scene/input state through jolt.ffi. The C façade and Raylib own drawing, input polling, and browser frame scheduling.

Not claimed

This is not the desktop raylib-jlt binding running unchanged, nor per-frame Jolt execution. It is the narrow ABI-proven route documented by EXP-015.

Jolt source used by this build

The published runtime was minted with app.exp015-input-keys. It selects input mode and scene through the proven signed-scalar ABI; drawing and input polling remain in the C-owned Raylib loop.

(ns app.exp015-input-keys
  (:require [jolt.ffi :as ffi]
            [app.witness :as witness]))

;; The C facade owns Raylib's browser frame loop;
;; Jolt selects its initial input mode and scene.
(declare project-set-scene project-set-input-mode)
(ffi/defcfn project-set-scene "project_set_scene" [:int32] :int32)
(ffi/defcfn project-set-input-mode "project_set_input_mode" [:int32] :int32)

(defn -main [& args]
  (when-not (= 1 (project-set-input-mode 1))
    (throw (ex-info "EXP-015 input mode selection failed" {})))
  (when-not (= 2 (project-set-scene 2))
    (throw (ex-info "EXP-015 scene selection failed" {})))
  (apply witness/-main args)
  (println "EXP-015-JOLT-RAYLIB-SCENE-SELECTED"))

The invoked app.witness namespace emits the canonical collection, Unicode, and allocation-pressure output shown by the runtime.

Actual Raylib scene and frame loop

This is the scene implementation linked into the published Wasm module, excerpted from the reproducible EXP-015 C façade patch. It is C—not JavaScript—that polls Raylib input and draws each browser frame.

static int32_t project_scene = 1;
static unsigned int project_frame = 0;
static int32_t project_input_mode = 0;

static int32_t project_set_input_mode(int32_t mode) {
  project_input_mode = mode;
  return project_input_mode;
}

static int32_t project_set_scene(int32_t scene) {
  project_scene = scene;
  return project_scene;
}

static void project_draw_frame(void) {
  int mouse_x = project_input_mode ? GetMouseX() : 180;
  int mouse_y = project_input_mode ? GetMouseY() : 150;
  int key_shift = project_input_mode && IsKeyDown(KEY_RIGHT) ? 100 : 0;
  Color accent = project_scene == 2
    ? (Color){230, 41, 55, 255}
    : (Color){0, 228, 48, 255};

  BeginDrawing();
  ClearBackground((Color){20, 24, 41, 255});
  DrawRectangle(36, 32, 648, 296, (Color){35, 45, 74, 255});
  DrawCircle(mouse_x, mouse_y, 72, accent);
  DrawRectangle(320 + key_shift, 88, 300, 124, accent);
  DrawText("Chez static facade + Raylib", 58, 246, 28, RAYWHITE);
  DrawText(TextFormat(
    "Scene: %d frame: %u mouse: %d,%d key-right: %d",
    project_scene, project_frame, mouse_x, mouse_y, key_shift != 0),
    58, 286, 20, RAYWHITE);
  EndDrawing();

  project_frame++;
  if (project_frame == 1) project_ready(project_scene);
}

static void project_start_raylib(void) {
  SetTraceLogLevel(LOG_ERROR);
  InitWindow(720, 360, "Chez Raylib static facade");
  emscripten_set_main_loop(project_draw_frame, 0, 1);
}

Jolt selects

The Jolt entry calls the registered signed-int32 functions. Mode 1 enables live input and scene 2 selects the red accent.

Raylib updates

GetMouseX/Y moves the circle. IsKeyDown(KEY_RIGHT) adds 100 pixels to the rectangle position while the key is held.

Browser schedules

emscripten_set_main_loop gives browser scheduling to the C/Raylib owner. The first completed frame publishes the readiness marker used by automation.

Verified browser capture

Verified Chromium capture showing the Raylib canvas with green input-controlled shapes and Jolt runtime output.

Sources: EXP-015 findings · raylib-jlt live-Wasm proposal · published artifact hashes.