[Vulkan] Use vertex_fetch_bitmap instead of vertex_bindings()

Avoids using cached/stale vertex binding indices

src/xenia/gpu/vulkan/vulkan_command_processor.cc

@@ -2516,10 +2516,21 @@ bool VulkanCommandProcessor::IssueDraw(xenos::PrimitiveType prim_type,
   // Ensure vertex buffers are resident.
   // TODO(Triang3l): Cache residency for ranges in a way similar to how texture
   // validity is tracked.
+  //
+  // Use the vertex_fetch_bitmap instead of vertex_bindings() to avoid using
+  // cached/stale vertex binding indices. The bitmap is populated during shader
+  // translation and represents which fetch constant indices the shader actually
+  // references, allowing us to check the current register values at draw time.
+  const Shader::ConstantRegisterMap& constant_map_vertex =
+      vertex_shader->constant_register_map();
   uint64_t vertex_buffers_resident[2] = {};
-  for (const Shader::VertexBinding& vertex_binding :
+  for (uint32_t i = 0; i < xe::countof(constant_map_vertex.vertex_fetch_bitmap);
-       vertex_shader->vertex_bindings()) {
+       ++i) {
-    uint32_t vfetch_index = vertex_binding.fetch_constant;
+    uint32_t vfetch_bits_remaining = constant_map_vertex.vertex_fetch_bitmap[i];
+    uint32_t j;
+    while (xe::bit_scan_forward(vfetch_bits_remaining, &j)) {
+      vfetch_bits_remaining = xe::clear_lowest_bit(vfetch_bits_remaining);
+      uint32_t vfetch_index = i * 32 + j;
       if (vertex_buffers_resident[vfetch_index >> 6] &
           (uint64_t(1) << (vfetch_index & 63))) {
         continue;
@@ -2541,15 +2552,35 @@ bool VulkanCommandProcessor::IssueDraw(xenos::PrimitiveType prim_type,
               vfetch_index, vfetch_constant.dword_0, vfetch_constant.dword_1);
           return false;
         default:
+          // Type is kTexture (2) or kInvalidTexture (3) - completely wrong for
+          // vertex data
+          if (cvars::gpu_allow_invalid_fetch_constants) {
             XELOGW(
-            "Vertex fetch constant {} ({:08X} {:08X}) is completely invalid!",
+                "Vertex fetch constant {} ({:08X} {:08X}) has wrong type {} "
-            vfetch_index, vfetch_constant.dword_0, vfetch_constant.dword_1);
+                "(texture fetch constant in vertex slot) - allowing due to "
+                "--gpu_allow_invalid_fetch_constants=true. This will likely "
+                "crash "
+                "or produce garbage!",
+                vfetch_index, vfetch_constant.dword_0, vfetch_constant.dword_1,
+                static_cast<uint32_t>(vfetch_constant.type));
+            break;
+          }
+          XELOGW(
+              "Vertex fetch constant {} ({:08X} {:08X}) is completely invalid! "
+              "Type={} - this slot contains a texture fetch constant (type 2), "
+              "not a "
+              "vertex fetch constant (type 0). This may indicate the shader is "
+              "reading "
+              "from the wrong fetch constant index, or the game has a bug.",
+              vfetch_index, vfetch_constant.dword_0, vfetch_constant.dword_1,
+              static_cast<uint32_t>(vfetch_constant.type));
           return false;
       }
       if (!shared_memory_->RequestRange(vfetch_constant.address << 2,
                                         vfetch_constant.size << 2)) {
         XELOGE(
-          "Failed to request vertex buffer at 0x{:08X} (size {}) in the shared "
+            "Failed to request vertex buffer at 0x{:08X} (size {}) in the "
+            "shared "
             "memory",
             vfetch_constant.address << 2, vfetch_constant.size << 2);
         return false;
@@ -2557,6 +2588,7 @@ bool VulkanCommandProcessor::IssueDraw(xenos::PrimitiveType prim_type,
       vertex_buffers_resident[vfetch_index >> 6] |= uint64_t(1)
                                                     << (vfetch_index & 63);
     }
+  }
 
   // Synchronize the memory pages backing memory scatter export streams, and
   // calculate the range that includes the streams for the buffer barrier.