Implement Bullet Bill model visibility and cockpit recentering improvements

- Added support for hiding model arrays in the rendering pipeline to optimize performance during VR gameplay.
- Introduced new functions in `gx_model_visibility` to manage hidden model arrays and their visibility based on game state.
- Enhanced cockpit recentering logic to ensure accurate seat measurements and eye positioning during gameplay.
- Updated `FirstPersonState` to track cockpit height and forward direction, improving VR experience.
- Added tests for Bullet Bill model visibility and cockpit height adjustments to ensure functionality and stability.
- Refactored existing code to accommodate new features and improve overall code organization.

aurora-main/tests/model_visibility_test.cpp

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#include "gx_test_common.hpp"
+#include "gx/model_visibility.hpp"
+#include <aurora/aurora.h>
+
+namespace {
+class HiddenModelTest : public GXFifoTest {
+protected:
+  void SetUp() override {
+    GXFifoTest::SetUp();
+    flush_and_capture();
+    aurora::gx::hiddenModelArrays.clear();
+    aurora::gx::hiddenModelDraws = 0;
+    aurora::gx::hiddenModelLastDraws = 0;
+    auto& state = gxState();
+    state.lastVtxFmt = GX_VTXFMT0;
+    state.lastVtxSize = 1;
+    state.projType = GX_PERSPECTIVE;
+    state.vtxDesc[GX_VA_POS] = GX_INDEX8;
+    state.arrays[GX_VA_POS].data = source.data();
+    state.arrays[GX_VA_POS].size = source.size();
+    state.arrays[GX_VA_POS].stride = 12;
+    std::memcpy(pos(), matrix.data(), sizeof(float) * 12);
+    state.stateDirty = true;
+    aurora_hide_model_array(source.data(), matrix.data());
+  }
+  void TearDown() override { aurora_clear_hidden_model_arrays(); }
+  float* pos() { return reinterpret_cast<float*>(&gxState().pnMtx[0].pos); }
+  void draw() { decode_fifo({static_cast<u8>(GX_TRIANGLES), 0, 3, 0, 1, 2}); }
+  std::array<uint8_t, 36> source{};
+  std::array<float, 12> matrix{1, 0, 0, 10, 0, 1, 0, 20, 0, 0, 1, 30};
+};
+
+TEST_F(HiddenModelTest, LocalBodyIsSkippedBeforeVertexUploadAndClearRestoresIt) {
+  draw();
+  EXPECT_TRUE(aurora::gfx::testing::last_pushed_vertices().empty());
+  aurora_clear_hidden_model_arrays();
+  EXPECT_EQ(aurora_hidden_model_draw_count(), 1u);
+  draw();
+  EXPECT_FALSE(aurora::gfx::testing::last_pushed_vertices().empty());
+}
+
+TEST_F(HiddenModelTest, OpponentUsingSameArrayIsDrawn) {
+  pos()[3] += 100;
+  draw();
+  EXPECT_FALSE(aurora::gfx::testing::last_pushed_vertices().empty());
+  EXPECT_EQ(aurora::gx::hiddenModelDraws, 0u);
+}
+
+TEST_F(HiddenModelTest, ArmsAndIndexedJointsAreKept) {
+  std::array<uint8_t, 36> arms{};
+  gxState().arrays[GX_VA_POS].data = arms.data();
+  EXPECT_FALSE(aurora::gx::model_array_hidden());
+  gxState().arrays[GX_VA_POS].data = source.data();
+  gxState().vtxDesc[GX_VA_PNMTXIDX] = GX_DIRECT;
+  EXPECT_FALSE(aurora::gx::model_array_hidden());
+}
+
+TEST_F(HiddenModelTest, DirectPositionsOrthographicAndInvalidMatricesAreKept) {
+  gxState().vtxDesc[GX_VA_POS] = GX_DIRECT;
+  EXPECT_FALSE(aurora::gx::model_array_hidden());
+  gxState().vtxDesc[GX_VA_POS] = GX_INDEX8;
+  gxState().projType = GX_ORTHOGRAPHIC;
+  EXPECT_FALSE(aurora::gx::model_array_hidden());
+  gxState().projType = GX_PERSPECTIVE;
+  pos()[0] = __builtin_nanf("");
+  EXPECT_FALSE(aurora::gx::model_array_hidden());
+}
+
+TEST_F(HiddenModelTest, RawBridgeDrawAlsoSkipsLocalBody) {
+  const std::array<uint8_t, 3> vertices{0, 1, 2};
+  ASSERT_TRUE(aurora::gx::fifo::submit_raw_draw(GX_TRIANGLES, GX_VTXFMT0, vertices.data(), 3, vertices.size()));
+  EXPECT_TRUE(aurora::gfx::testing::last_pushed_vertices().empty());
+  EXPECT_EQ(aurora::gx::hiddenModelDraws, 1u);
+}
+} // namespace