[Vulkan] Color exponent bias and gamma conversion

src/xenia/gpu/vulkan/vulkan_command_processor.cc

@@ -3267,6 +3267,13 @@ void VulkanCommandProcessor::UpdateSystemConstantValues(
   auto pa_cl_vte_cntl = regs.Get<reg::PA_CL_VTE_CNTL>();
   int32_t vgt_indx_offset = int32_t(regs[XE_GPU_REG_VGT_INDX_OFFSET].u32);
 
+  // Get the color info register values for each render target.
+  reg::RB_COLOR_INFO color_infos[xenos::kMaxColorRenderTargets];
+  for (uint32_t i = 0; i < xenos::kMaxColorRenderTargets; ++i) {
+    color_infos[i] = regs.Get<reg::RB_COLOR_INFO>(
+        reg::RB_COLOR_INFO::rt_register_indices[i]);
+  }
+
   bool dirty = false;
 
   // Flags.
@@ -3288,6 +3295,14 @@ void VulkanCommandProcessor::UpdateSystemConstantValues(
   if (pa_cl_vte_cntl.vtx_w0_fmt) {
     flags |= SpirvShaderTranslator::kSysFlag_WNotReciprocal;
   }
+  // Gamma writing.
+  // TODO(Triang3l): Gamma as sRGB check.
+  for (uint32_t i = 0; i < xenos::kMaxColorRenderTargets; ++i) {
+    if (color_infos[i].color_format ==
+        xenos::ColorRenderTargetFormat::k_8_8_8_8_GAMMA) {
+      flags |= SpirvShaderTranslator::kSysFlag_ConvertColor0ToGamma << i;
+    }
+  }
   dirty |= system_constants_.flags != flags;
   system_constants_.flags = flags;
 
@@ -3356,6 +3371,29 @@ void VulkanCommandProcessor::UpdateSystemConstantValues(
     }
   }
 
+  // Color exponent bias.
+  for (uint32_t i = 0; i < xenos::kMaxColorRenderTargets; ++i) {
+    reg::RB_COLOR_INFO color_info = color_infos[i];
+    // Exponent bias is in bits 20:25 of RB_COLOR_INFO.
+    int32_t color_exp_bias = color_info.color_exp_bias;
+    if (render_target_cache_->GetPath() ==
+            RenderTargetCache::Path::kHostRenderTargets &&
+        (color_info.color_format == xenos::ColorRenderTargetFormat::k_16_16 &&
+             !render_target_cache_->IsFixedRG16TruncatedToMinus1To1() ||
+         color_info.color_format ==
+                 xenos::ColorRenderTargetFormat::k_16_16_16_16 &&
+             !render_target_cache_->IsFixedRGBA16TruncatedToMinus1To1())) {
+      // Remap from -32...32 to -1...1 by dividing the output values by 32,
+      // losing blending correctness, but getting the full range.
+      color_exp_bias -= 5;
+    }
+    float color_exp_bias_scale;
+    *reinterpret_cast<int32_t*>(&color_exp_bias_scale) =
+        UINT32_C(0x3F800000) + (color_exp_bias << 23);
+    dirty |= system_constants_.color_exp_bias[i] != color_exp_bias_scale;
+    system_constants_.color_exp_bias[i] = color_exp_bias_scale;
+  }
+
   if (dirty) {
     current_graphics_descriptor_set_values_up_to_date_ &=
         ~(UINT32_C(1) << SpirvShaderTranslator::kDescriptorSetSystemConstants);

src/xenia/gpu/vulkan/vulkan_render_target_cache.cc

@@ -784,11 +784,10 @@ bool VulkanRenderTargetCache::Resolve(const Memory& memory,
   bool draw_resolution_scaled = IsDrawResolutionScaled();
 
   draw_util::ResolveInfo resolve_info;
-  // TODO(Triang3l): Truncation of fixed16 (but not fixed16 as float16) range to
-  // -1 to 1.
   if (!draw_util::GetResolveInfo(
           register_file(), memory, trace_writer_, draw_resolution_scale_x(),
-          draw_resolution_scale_y(), false, false, resolve_info)) {
+          draw_resolution_scale_y(), IsFixedRG16TruncatedToMinus1To1(),
+          IsFixedRGBA16TruncatedToMinus1To1(), resolve_info)) {
     return false;
   }
 

src/xenia/gpu/vulkan/vulkan_render_target_cache.h

@@ -128,6 +128,20 @@ class VulkanRenderTargetCache final : public RenderTargetCache {
     return last_update_framebuffer_;
   }
 
+  // Using R16G16[B16A16]_SNORM, which are -1...1, not the needed -32...32.
+  // Persistent data doesn't depend on this, so can be overriden by per-game
+  // configuration.
+  bool IsFixedRG16TruncatedToMinus1To1() const {
+    // TODO(Triang3l): Not float16 condition.
+    return GetPath() == Path::kHostRenderTargets &&
+           !cvars::snorm16_render_target_full_range;
+  }
+  bool IsFixedRGBA16TruncatedToMinus1To1() const {
+    // TODO(Triang3l): Not float16 condition.
+    return GetPath() == Path::kHostRenderTargets &&
+           !cvars::snorm16_render_target_full_range;
+  }
+
   bool depth_float24_round() const { return depth_float24_round_; }
 
   bool msaa_2x_attachments_supported() const {