From ce4ae025c699acb163e4be610b00a043f311581a Mon Sep 17 00:00:00 2001
From: Matthew Stanley <1379tech@gmail.com>
Date: Tue, 6 Oct 2026 23:48:08 -0700
Subject: [PATCH] Support identified scene motion in shared draw replay

---
 runtime/include/render_pass_replay.hpp | 35 +++++++++++++++++---------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/runtime/include/render_pass_replay.hpp b/runtime/include/render_pass_replay.hpp
index fa3dff83..c707eab7 100644
--- a/runtime/include/render_pass_replay.hpp
+++ b/runtime/include/render_pass_replay.hpp
@@ -21,6 +21,7 @@ class PSXDrawReplay {
     uint8_t scratch[1024]{};
     uint32_t start = 0, stop = 0, previous_tick = 0;
     bool captured = false, ready = false, have_tick = false;
+    bool projections = true;
     PSXProjectionHistory* history = nullptr;
 public:
     PSXProjectionStats stats{};
@@ -30,26 +31,34 @@ public:
         captured = ready = have_tick = false; ticks = 0;
         psx_projection_invalidate(history);
     }
-    void capture(CPUState* cpu, uint32_t first, uint32_t last) {
+    // Titles with known actor/camera layouts can apply their motion sets after
+    // restore, instead of matching final GTE projections. Both routes share the
+    // same draw-entry snapshot and machine sandbox.
+    void capture(CPUState* cpu, uint32_t first, uint32_t last,
+                 bool capture_projections = true) {
         if (g_psx_render_pass_active) return;
         if (captured) invalidate(); // previous drawing section never completed
-        if (!history) history = psx_projection_create(65536);
-        if (!history || first >= last || ((first | last) & 3)) return;
+        projections = capture_projections;
+        if (projections && !history) history = psx_projection_create(65536);
+        if ((projections && !history) || first >= last || ((first | last) & 3)) return;
         entry = *cpu; start = first; stop = last;
         ram.resize(memory_get_ram_bytes());
         std::memcpy(ram.data(), memory_get_ram_ptr(), ram.size());
         std::memcpy(scratch, memory_get_scratchpad_ptr(), sizeof scratch);
         captured = true; ready = false;
-        psx_projection_capture_begin(history);
+        if (projections) psx_projection_capture_begin(history);
     }
-    bool prepare(uint32_t tick) {
+    bool prepare(uint32_t tick, bool motion_ready = false) {
         if (!captured) { invalidate(); return false; }
         captured = false;
         ticks = have_tick ? tick - previous_tick : 0;
         previous_tick = tick; have_tick = true;
-        psx_projection_capture_end(history, ticks, 512.0);
-        psx_projection_stats(history, &stats);
-        ready = ticks && ticks <= 8 && stats.changed && !stats.overflow;
+        if (projections) {
+            psx_projection_capture_end(history, ticks, 512.0);
+            psx_projection_stats(history, &stats);
+        }
+        ready = ticks && ticks <= 8 && (projections
+            ? stats.changed && !stats.overflow : motion_ready);
         return ready;
     }
     bool restore(CPUState* cpu, uint32_t alpha) {
@@ -60,14 +69,16 @@ public:
         // shadows are stale; the pass checkpoint restores them afterwards.
         pgxp_invalidate_all();
         *cpu = entry;
-        psx_projection_replay_begin(history, alpha);
+        if (projections) psx_projection_replay_begin(history, alpha);
         return true;
     }
     bool draw(CPUState* cpu) {
         const bool reached = psx_mod_run_guest_span(cpu, start, stop) != 0;
-        psx_projection_replay_end(history);
-        psx_projection_stats(history, &stats);
-        return reached && stats.replayed != 0;
+        if (projections) {
+            psx_projection_replay_end(history);
+            psx_projection_stats(history, &stats);
+        }
+        return reached && (!projections || stats.replayed != 0);
     }
     static uint32_t call(CPUState* cpu, uint32_t function, uint32_t a0=0, uint32_t a1=0) {
         const CPUState saved = *cpu;