4 files changed, 23 insertions, 3 deletions

diff --git a/src/video_core/engines/maxwell_3d.cpp b/src/video_core/engines/maxwell_3d.cpp
index 88483eab9..d64a5080b 100644
--- a/src/video_core/engines/maxwell_3d.cpp
+++ b/src/video_core/engines/maxwell_3d.cpp
@@ -144,6 +144,16 @@ void Maxwell3D::CallMethod(const GPU::MethodCall& method_call) {
             dirty_flags.color_buffer |= 1u << static_cast<u32>(rt_index);
         }
 
+        // Zeta buffer
+        constexpr u32 registers_in_zeta = sizeof(regs.zeta) / sizeof(u32);
+        if (method_call.method == MAXWELL3D_REG_INDEX(zeta_enable) ||
+            method_call.method == MAXWELL3D_REG_INDEX(zeta_width) ||
+            method_call.method == MAXWELL3D_REG_INDEX(zeta_height) ||
+            (method_call.method >= MAXWELL3D_REG_INDEX(zeta) &&
+             method_call.method < MAXWELL3D_REG_INDEX(zeta) + registers_in_zeta)) {
+            dirty_flags.zeta_buffer = true;
+        }
+
         // Shader
         constexpr u32 shader_registers_count =
             sizeof(regs.shader_config[0]) * Regs::MaxShaderProgram / sizeof(u32);
diff --git a/src/video_core/engines/maxwell_3d.h b/src/video_core/engines/maxwell_3d.h
index 8d0e18d80..1f76aa670 100644
--- a/src/video_core/engines/maxwell_3d.h
+++ b/src/video_core/engines/maxwell_3d.h
@@ -1090,6 +1090,7 @@ public:
 
     struct DirtyFlags {
         u8 color_buffer = 0xFF;
+        bool zeta_buffer = true;
 
         bool shaders = true;
 
@@ -1098,6 +1099,7 @@ public:
 
         void OnMemoryWrite() {
             color_buffer = 0xFF;
+            zeta_buffer = true;
             shaders = true;
             vertex_array = 0xFFFFFFFF;
         }
diff --git a/src/video_core/renderer_opengl/gl_rasterizer_cache.cpp b/src/video_core/renderer_opengl/gl_rasterizer_cache.cpp
index 0059b336a..d26a5f4de 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer_cache.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer_cache.cpp
@@ -919,9 +919,16 @@ Surface RasterizerCacheOpenGL::GetTextureSurface(const Tegra::Texture::FullTextu
 }
 
 Surface RasterizerCacheOpenGL::GetDepthBufferSurface(bool preserve_contents) {
-    const auto& regs{Core::System::GetInstance().GPU().Maxwell3D().regs};
+    auto& gpu{Core::System::GetInstance().GPU().Maxwell3D()};
+    const auto& regs{gpu.regs};
+
+    if (!gpu.dirty_flags.zeta_buffer) {
+        return last_depth_buffer;
+    }
+    gpu.dirty_flags.zeta_buffer = false;
+
     if (!regs.zeta.Address() || !regs.zeta_enable) {
-        return {};
+        return last_depth_buffer = {};
     }
 
     SurfaceParams depth_params{SurfaceParams::CreateForDepthBuffer(
@@ -929,7 +936,7 @@ Surface RasterizerCacheOpenGL::GetDepthBufferSurface(bool preserve_contents) {
         regs.zeta.memory_layout.block_width, regs.zeta.memory_layout.block_height,
         regs.zeta.memory_layout.block_depth, regs.zeta.memory_layout.type)};
 
-    return GetSurface(depth_params, preserve_contents);
+    return last_depth_buffer = GetSurface(depth_params, preserve_contents);
 }
 
 Surface RasterizerCacheOpenGL::GetColorBufferSurface(std::size_t index, bool preserve_contents) {
diff --git a/src/video_core/renderer_opengl/gl_rasterizer_cache.h b/src/video_core/renderer_opengl/gl_rasterizer_cache.h
index 3bdd141a7..37611c4fc 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer_cache.h
+++ b/src/video_core/renderer_opengl/gl_rasterizer_cache.h
@@ -398,6 +398,7 @@ private:
     OGLBuffer copy_pbo;
 
     std::array<Surface, Tegra::Engines::Maxwell3D::Regs::NumRenderTargets> last_color_buffers;
+    Surface last_depth_buffer;
 };
 
 } // namespace OpenGL