Merge pull request #7070 from FernandoS27/want-you-bad

Vulkan Rasterizer: Correct DepthBias/PolygonOffset on Vulkan.

1 files changed, 14 insertions, 2 deletions

diff --git a/src/video_core/renderer_vulkan/vk_rasterizer.cpp b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
index 3bcd6d6cc..30b47a7a0 100644
--- a/src/video_core/renderer_vulkan/vk_rasterizer.cpp
+++ b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
@@ -627,9 +627,21 @@ void RasterizerVulkan::UpdateDepthBias(Tegra::Engines::Maxwell3D::Regs& regs) {
     if (!state_tracker.TouchDepthBias()) {
         return;
     }
-    scheduler.Record([constant = regs.polygon_offset_units, clamp = regs.polygon_offset_clamp,
+    float units = regs.polygon_offset_units / 2.0f;
+    const bool is_d24 = regs.zeta.format == Tegra::DepthFormat::S8_UINT_Z24_UNORM ||
+                        regs.zeta.format == Tegra::DepthFormat::D24X8_UNORM ||
+                        regs.zeta.format == Tegra::DepthFormat::D24S8_UNORM ||
+                        regs.zeta.format == Tegra::DepthFormat::D24C8_UNORM;
+    if (is_d24 && !device.SupportsD24DepthBuffer()) {
+        // the base formulas can be obtained from here:
+        //   https://docs.microsoft.com/en-us/windows/win32/direct3d11/d3d10-graphics-programming-guide-output-merger-stage-depth-bias
+        const double rescale_factor =
+            static_cast<double>(1ULL << (32 - 24)) / (static_cast<double>(0x1.ep+127));
+        units = static_cast<float>(static_cast<double>(units) * rescale_factor);
+    }
+    scheduler.Record([constant = units, clamp = regs.polygon_offset_clamp,
                       factor = regs.polygon_offset_factor](vk::CommandBuffer cmdbuf) {
-        cmdbuf.SetDepthBias(constant, clamp, factor / 2.0f);
+        cmdbuf.SetDepthBias(constant, clamp, factor);
     });
 }