test(graphics): implement end-to-end graphics surface and activity window integration test

crates/molotov-core/tests/graphics_surface_test.rs

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use molotov_core::graphics::c_api::*;
+use molotov_core::graphics::surface::GraphicsSurface;
+use molotov_core::graphics::types::{ANativeWindow_Buffer, WindowFormat};
+use molotov_core::jni::activity::ActivityRunner;
+
+#[test]
+fn test_end_to_end_graphics_surface_and_activity_binding() {
+    let mut runner = ActivityRunner::new();
+    let surface = Box::new(GraphicsSurface::new(1280, 720, WindowFormat::Rgba8888));
+    let window_handle = Box::into_raw(surface) as *mut ();
+
+    unsafe {
+        // 1. Notify activity that native window was created
+        runner.trigger_window_created(window_handle as *mut _);
+
+        // 2. Engine queries window geometry
+        assert_eq!(ANativeWindow_getWidth(window_handle), 1280);
+        assert_eq!(ANativeWindow_getHeight(window_handle), 720);
+
+        // 3. Engine renders frame
+        let mut buf = std::mem::MaybeUninit::<ANativeWindow_Buffer>::uninit();
+        assert_eq!(ANativeWindow_lock(window_handle, buf.as_mut_ptr(), std::ptr::null_mut()), 0);
+
+        let buffer = buf.assume_init();
+        // Write solid color into buffer (RGBA = 255, 0, 0, 255)
+        let pixel_count = (buffer.width * buffer.height) as usize;
+        let pixels = std::slice::from_raw_parts_mut(buffer.bits as *mut u32, pixel_count);
+        pixels.fill(0xff00_00ff);
+
+        assert_eq!(ANativeWindow_unlockAndPost(window_handle), 0);
+
+        // 4. Notify activity on window destroy
+        runner.trigger_window_destroyed(window_handle as *mut _);
+        ANativeWindow_release(window_handle);
+    }
+}