Merge pull request #10292 from OatmealDome/lodbias-take-two

PixelShaderGen: Use LOD bias when sampling texture on Metal and OpenGL ES

Source/Core/VideoBackends/D3D/D3DMain.cpp

@@ -109,6 +109,7 @@ void VideoBackend::FillBackendInfo()
   g_Config.backend_info.bSupportsPipelineCacheData = false;
   g_Config.backend_info.bSupportsCoarseDerivatives = true;
   g_Config.backend_info.bSupportsTextureQueryLevels = true;
+  g_Config.backend_info.bSupportsLodBiasInSampler = true;
   g_Config.backend_info.bSupportsLogicOp = D3D::SupportsLogicOp(g_Config.iAdapter);
 
   g_Config.backend_info.Adapters = D3DCommon::GetAdapterNames();

Source/Core/VideoBackends/D3D12/VideoBackend.cpp

@@ -85,6 +85,7 @@ void VideoBackend::FillBackendInfo()
   g_Config.backend_info.bSupportsPipelineCacheData = true;
   g_Config.backend_info.bSupportsCoarseDerivatives = true;
   g_Config.backend_info.bSupportsTextureQueryLevels = true;
+  g_Config.backend_info.bSupportsLodBiasInSampler = true;
 
   // We can only check texture support once we have a device.
   if (g_dx_context)

Source/Core/VideoBackends/Null/NullBackend.cpp

@@ -58,6 +58,7 @@ void VideoBackend::InitBackendInfo()
   g_Config.backend_info.bSupportsPipelineCacheData = false;
   g_Config.backend_info.bSupportsCoarseDerivatives = false;
   g_Config.backend_info.bSupportsTextureQueryLevels = false;
+  g_Config.backend_info.bSupportsLodBiasInSampler = false;
 
   // aamodes: We only support 1 sample, so no MSAA
   g_Config.backend_info.Adapters.clear();

Source/Core/VideoBackends/OGL/OGLMain.cpp

@@ -93,6 +93,7 @@ void VideoBackend::InitBackendInfo()
   g_Config.backend_info.bSupportsPartialDepthCopies = true;
   g_Config.backend_info.bSupportsShaderBinaries = false;
   g_Config.backend_info.bSupportsPipelineCacheData = false;
+  g_Config.backend_info.bSupportsLodBiasInSampler = true;
 
   // TODO: There is a bug here, if texel buffers or SSBOs/atomics are not supported the graphics
   // options will show the option when it is not supported. The only way around this would be

Source/Core/VideoBackends/OGL/OGLRender.cpp

@@ -513,6 +513,9 @@ Renderer::Renderer(std::unique_ptr<GLContext> main_gl_context, float backbuffer_
     // ARB_get_texture_sub_image (unlikely, except maybe on NVIDIA), we can use that instead.
     g_Config.backend_info.bSupportsDepthReadback = g_ogl_config.bSupportsTextureSubImage;
 
+    // GL_TEXTURE_LOD_BIAS is not supported on GLES.
+    g_Config.backend_info.bSupportsLodBiasInSampler = false;
+
     if (GLExtensions::Supports("GL_EXT_shader_framebuffer_fetch"))
     {
       g_ogl_config.SupportedFramebufferFetch = EsFbFetchType::FbFetchExt;

Source/Core/VideoBackends/OGL/SamplerCache.cpp

@@ -97,8 +97,10 @@ void SamplerCache::SetParameters(GLuint sampler_id, const SamplerState& params)
   glSamplerParameterf(sampler_id, GL_TEXTURE_MIN_LOD, params.tm1.min_lod / 16.f);
   glSamplerParameterf(sampler_id, GL_TEXTURE_MAX_LOD, params.tm1.max_lod / 16.f);
 
-  if (!static_cast<Renderer*>(g_renderer.get())->IsGLES())
+  if (g_ActiveConfig.backend_info.bSupportsLodBiasInSampler)
+  {
     glSamplerParameterf(sampler_id, GL_TEXTURE_LOD_BIAS, params.tm0.lod_bias / 256.f);
+  }
 
   if (params.tm0.anisotropic_filtering && g_ogl_config.bSupportsAniso)
   {

Source/Core/VideoBackends/Software/SWmain.cpp

@@ -87,6 +87,7 @@ void VideoSoftware::InitBackendInfo()
   g_Config.backend_info.bSupportsBBox = true;
   g_Config.backend_info.bSupportsCoarseDerivatives = false;
   g_Config.backend_info.bSupportsTextureQueryLevels = false;
+  g_Config.backend_info.bSupportsLodBiasInSampler = false;
 
   // aamodes
   g_Config.backend_info.AAModes = {1};

Source/Core/VideoBackends/Vulkan/VulkanContext.cpp

@@ -289,6 +289,7 @@ void VulkanContext::PopulateBackendInfo(VideoConfig* config)
   config->backend_info.bSupportsFramebufferFetch = false;          // Dependent on OS and features.
   config->backend_info.bSupportsCoarseDerivatives = true;          // Assumed support.
   config->backend_info.bSupportsTextureQueryLevels = true;         // Assumed support.
+  config->backend_info.bSupportsLodBiasInSampler = false;          // Dependent on OS.
 }
 
 void VulkanContext::PopulateBackendInfoAdapters(VideoConfig* config, const GPUList& gpu_list)
@@ -316,6 +317,13 @@ void VulkanContext::PopulateBackendInfoFeatures(VideoConfig* config, VkPhysicalD
   config->backend_info.bSupportsSSAA = (features.sampleRateShading == VK_TRUE);
   config->backend_info.bSupportsLogicOp = (features.logicOp == VK_TRUE);
 
+#ifdef __APPLE__
+  // Metal doesn't support this.
+  config->backend_info.bSupportsLodBiasInSampler = false;
+#else
+  config->backend_info.bSupportsLodBiasInSampler = true;
+#endif
+
   // Disable geometry shader when shaderTessellationAndGeometryPointSize is not supported.
   // Seems this is needed for gl_Layer.
   if (!features.shaderTessellationAndGeometryPointSize)

Source/Core/VideoCommon/PixelShaderGen.cpp

@@ -648,7 +648,19 @@ uint WrapCoord(int coord, uint wrap, int size) {{
               "  float3 coords = float3(float(uv.x) / size_s, float(uv.y) / size_t, layer);\n");
     if (api_type == APIType::OpenGL || api_type == APIType::Vulkan)
     {
-      out.Write("  return iround(255.0 * texture(tex, coords));\n}}\n");
+      if (!host_config.backend_sampler_lod_bias)
+      {
+        out.Write("  uint texmode0 = samp_texmode0(texmap);\n"
+                  "  float lod_bias = {} / 256.0f;\n"
+                  "  return iround(255.0 * texture(tex, coords, lod_bias));\n",
+                  BitfieldExtract<&SamplerState::TM0::lod_bias>("texmode0"));
+      }
+      else
+      {
+        out.Write("  return iround(255.0 * texture(tex, coords));\n");
+      }
+
+      out.Write("}}\n");
     }
     else if (api_type == APIType::D3D)
     {

Source/Core/VideoCommon/ShaderGenCommon.cpp

@@ -42,6 +42,7 @@ ShaderHostConfig ShaderHostConfig::GetCurrent()
   bits.manual_texture_sampling = !g_ActiveConfig.bFastTextureSampling;
   bits.manual_texture_sampling_custom_texture_sizes =
       g_ActiveConfig.ManualTextureSamplingWithHiResTextures();
+  bits.backend_sampler_lod_bias = g_ActiveConfig.backend_info.bSupportsLodBiasInSampler;
   return bits;
 }
 

Source/Core/VideoCommon/ShaderGenCommon.h

@@ -172,6 +172,7 @@ union ShaderHostConfig
   BitField<23, 1, bool, u32> enable_validation_layer;
   BitField<24, 1, bool, u32> manual_texture_sampling;
   BitField<25, 1, bool, u32> manual_texture_sampling_custom_texture_sizes;
+  BitField<26, 1, bool, u32> backend_sampler_lod_bias;
 
   static ShaderHostConfig GetCurrent();
 };

Source/Core/VideoCommon/VideoConfig.h

@@ -233,6 +233,7 @@ struct VideoConfig final
     bool bSupportsPipelineCacheData = false;
     bool bSupportsCoarseDerivatives = false;
     bool bSupportsTextureQueryLevels = false;
+    bool bSupportsLodBiasInSampler = false;
   } backend_info;
 
   // Utility