From d7dfb681aa1f771172f314677e23d1447899cdf4 Mon Sep 17 00:00:00 2001
From: raven02 <jacky.kktsui@yahoo.com.hk>
Date: Wed, 24 Jun 2015 08:25:22 -0700
Subject: [PATCH] gl4: implement texture max anisotropy

---
 src/xenia/gpu/gl4/texture_cache.cc | 29 +++++++++++++++++++++++++++--
 src/xenia/gpu/sampler_info.cc      |  4 ++++
 src/xenia/gpu/sampler_info.h       |  4 +++-
 src/xenia/gpu/xenos.h              |  3 ++-
 4 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/xenia/gpu/gl4/texture_cache.cc b/src/xenia/gpu/gl4/texture_cache.cc
index 2c582da01..a3c409983 100644
--- a/src/xenia/gpu/gl4/texture_cache.cc
+++ b/src/xenia/gpu/gl4/texture_cache.cc
@@ -362,8 +362,33 @@ TextureCache::SamplerEntry* TextureCache::LookupOrInsertSampler(
   glSamplerParameteri(entry->handle, GL_TEXTURE_MIN_FILTER, min_filter);
   glSamplerParameteri(entry->handle, GL_TEXTURE_MAG_FILTER, mag_filter);
 
-  // TODO(benvanik): anisotropic filtering.
-  // GL_TEXTURE_MAX_ANISOTROPY_EXT
+  GLfloat aniso;
+  switch (sampler_info.aniso_filter) {
+    case ucode::ANISO_FILTER_DISABLED:
+      aniso = 0.0f;
+      break;
+    case ucode::ANISO_FILTER_MAX_1_1:
+      aniso = 1.0f;
+      break;
+    case ucode::ANISO_FILTER_MAX_2_1:
+      aniso = 2.0f;
+      break;
+    case ucode::ANISO_FILTER_MAX_4_1:
+      aniso = 4.0f;
+      break;
+    case ucode::ANISO_FILTER_MAX_8_1:
+      aniso = 8.0f;
+      break;
+    case ucode::ANISO_FILTER_MAX_16_1:
+      aniso = 16.0f;
+      break;
+    default:
+      assert_unhandled_case(aniso);
+      return nullptr;
+  }
+
+  if (aniso)
+    glSamplerParameterf(entry->handle, GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso);
 
   // Add to map - map takes ownership.
   auto entry_ptr = entry.get();
diff --git a/src/xenia/gpu/sampler_info.cc b/src/xenia/gpu/sampler_info.cc
index 5140db71d..6bef01ae0 100644
--- a/src/xenia/gpu/sampler_info.cc
+++ b/src/xenia/gpu/sampler_info.cc
@@ -30,6 +30,10 @@ bool SamplerInfo::Prepare(const xenos::xe_gpu_texture_fetch_t& fetch,
   out_info->clamp_u = fetch.clamp_x;
   out_info->clamp_v = fetch.clamp_y;
   out_info->clamp_w = fetch.clamp_z;
+  out_info->aniso_filter = static_cast<ucode::instr_aniso_filter_t>(
+      fetch_instr.aniso_filter == 7 ? fetch.aniso_filter
+                                    : fetch_instr.aniso_filter);
+
   return true;
 }
 
diff --git a/src/xenia/gpu/sampler_info.h b/src/xenia/gpu/sampler_info.h
index c89b582ea..4cc310731 100644
--- a/src/xenia/gpu/sampler_info.h
+++ b/src/xenia/gpu/sampler_info.h
@@ -23,6 +23,7 @@ struct SamplerInfo {
   uint32_t clamp_u;
   uint32_t clamp_v;
   uint32_t clamp_w;
+  ucode::instr_aniso_filter_t aniso_filter;
 
   static bool Prepare(const xenos::xe_gpu_texture_fetch_t& fetch,
                       const ucode::instr_fetch_tex_t& fetch_instr,
@@ -32,7 +33,8 @@ struct SamplerInfo {
   bool operator==(const SamplerInfo& other) const {
     return min_filter == other.min_filter && mag_filter == other.mag_filter &&
            mip_filter == other.mip_filter && clamp_u == other.clamp_u &&
-           clamp_v == other.clamp_v && clamp_w == other.clamp_w;
+           clamp_v == other.clamp_v && clamp_w == other.clamp_w &&
+           aniso_filter == other.aniso_filter;
   }
 };
 
diff --git a/src/xenia/gpu/xenos.h b/src/xenia/gpu/xenos.h
index 927cc62fb..e910d9002 100644
--- a/src/xenia/gpu/xenos.h
+++ b/src/xenia/gpu/xenos.h
@@ -342,7 +342,8 @@ XEPACKEDUNION(xe_gpu_texture_fetch_t, {
     uint32_t mag_filter : 2;
     uint32_t min_filter : 2;
     uint32_t mip_filter : 2;
-    uint32_t unk3_2 : 6;
+    uint32_t aniso_filter : 3;      // correct ?
+    uint32_t arbitrary_filter : 3;  // correct ?
     uint32_t border : 1;
     uint32_t unk4_0 : 2;  // dword_4
     uint32_t mip_min_level : 4;