From f8edc761fc6e621c557f58b83c929344d4a90531 Mon Sep 17 00:00:00 2001
From: gibbed <rick@gibbed.us>
Date: Wed, 9 Aug 2017 02:28:47 -0500
Subject: [PATCH] Vulkan: Do near-exact lookups for the frontbuffer texture
 (may break everything).

---
 src/xenia/gpu/vulkan/texture_cache.cc         | 52 +++++++++++++++++++
 src/xenia/gpu/vulkan/texture_cache.h          |  2 +
 .../gpu/vulkan/vulkan_command_processor.cc    | 15 ++++--
 3 files changed, 66 insertions(+), 3 deletions(-)

diff --git a/src/xenia/gpu/vulkan/texture_cache.cc b/src/xenia/gpu/vulkan/texture_cache.cc
index 7bd5a71f9..3f699a708 100644
--- a/src/xenia/gpu/vulkan/texture_cache.cc
+++ b/src/xenia/gpu/vulkan/texture_cache.cc
@@ -672,6 +672,58 @@ TextureCache::Sampler* TextureCache::Demand(const SamplerInfo& sampler_info) {
   return sampler;
 }
 
+bool TextureFormatIsSimilar(TextureFormat left, TextureFormat right) {
+#define COMPARE_FORMAT(x, y)                                     \
+  if ((left == TextureFormat::x && right == TextureFormat::y) || \
+      (left == TextureFormat::y && right == TextureFormat::x)) { \
+    return true;                                                 \
+  }
+  if (left == right) return true;
+  COMPARE_FORMAT(k_2_10_10_10, k_2_10_10_10_AS_16_16_16_16);
+  return false;
+#undef COMPARE_FORMAT
+}
+
+TextureCache::Texture* TextureCache::Lookup(const TextureInfo& texture_info) {
+  auto texture_hash = texture_info.hash();
+  for (auto it = textures_.find(texture_hash); it != textures_.end(); ++it) {
+    if (it->second->texture_info == texture_info) {
+      return it->second;
+    }
+  }
+  // slow path
+  for (auto it = textures_.begin(); it != textures_.end(); ++it) {
+    const auto& other_texture_info = it->second->texture_info;
+#define COMPARE_FIELD(x) \
+  if (texture_info.x != other_texture_info.x) continue
+    COMPARE_FIELD(guest_address);
+    COMPARE_FIELD(dimension);
+    COMPARE_FIELD(width);
+    COMPARE_FIELD(height);
+    COMPARE_FIELD(depth);
+    COMPARE_FIELD(endianness);
+    COMPARE_FIELD(is_tiled);
+    COMPARE_FIELD(has_packed_mips);
+    COMPARE_FIELD(input_length);
+#undef COMPARE_FIELD
+    if (!TextureFormatIsSimilar(texture_info.texture_format,
+                                other_texture_info.texture_format)) {
+      continue;
+    }
+    /*const auto format_info = texture_info.format_info();
+    const auto other_format_info = other_texture_info.format_info();
+#define COMPARE_FIELD(x) if (format_info->x != other_format_info->x) continue
+    COMPARE_FIELD(type);
+    COMPARE_FIELD(block_width);
+    COMPARE_FIELD(block_height);
+    COMPARE_FIELD(bits_per_pixel);
+#undef COMPARE_FIELD*/
+    return it->second;
+  }
+
+  return nullptr;
+}
+
 TextureCache::Texture* TextureCache::LookupAddress(uint32_t guest_address,
                                                    uint32_t width,
                                                    uint32_t height,
diff --git a/src/xenia/gpu/vulkan/texture_cache.h b/src/xenia/gpu/vulkan/texture_cache.h
index 863d1a2b0..241faed88 100644
--- a/src/xenia/gpu/vulkan/texture_cache.h
+++ b/src/xenia/gpu/vulkan/texture_cache.h
@@ -92,6 +92,8 @@ class TextureCache {
 
   // TODO(benvanik): ReadTexture.
 
+  Texture* Lookup(const TextureInfo& texture_info);
+
   // Looks for a texture either containing or matching these parameters.
   // Caller is responsible for checking if the texture returned is an exact
   // match or just contains the texture given by the parameters.
diff --git a/src/xenia/gpu/vulkan/vulkan_command_processor.cc b/src/xenia/gpu/vulkan/vulkan_command_processor.cc
index a13513004..db3b7ce00 100644
--- a/src/xenia/gpu/vulkan/vulkan_command_processor.cc
+++ b/src/xenia/gpu/vulkan/vulkan_command_processor.cc
@@ -395,10 +395,19 @@ void VulkanCommandProcessor::PerformSwap(uint32_t frontbuffer_ptr,
   }
   auto swap_fb = reinterpret_cast<VkImage>(swap_state_.front_buffer_texture);
 
+  auto& regs = *register_file_;
+  int r = XE_GPU_REG_SHADER_CONSTANT_FETCH_00_0;
+  auto group =
+      reinterpret_cast<const xenos::xe_gpu_fetch_group_t*>(&regs.values[r]);
+  auto& fetch = group->texture_fetch;
+
+  TextureInfo texture_info;
+  if (!TextureInfo::Prepare(group->texture_fetch, &texture_info)) {
+    assert_always();
+  }
+
   // Issue the commands to copy the game's frontbuffer to our backbuffer.
-  auto texture = texture_cache_->LookupAddress(
-      frontbuffer_ptr, xe::round_up(frontbuffer_width, 32),
-      /*xe::round_up(*/ frontbuffer_height /*, 32)*/, TextureFormat::k_8_8_8_8);
+  auto texture = texture_cache_->Lookup(texture_info);
   if (texture) {
     texture->in_flight_fence = current_batch_fence_;