Implement OpImageQueryLod

src/Pipeline/SamplerCore.cpp

@@ -83,7 +83,7 @@ namespace sw
 			cubeFace(face, uuuu, vvvv, u, v, w, M);
 		}
 
-		if(function == Implicit || function == Bias || function == Grad)
+		if(function == Implicit || function == Bias || function == Grad || function == Query)
 		{
 			if(state.textureType != TEXTURE_3D)
 			{
@@ -124,8 +124,27 @@ namespace sw
 		if(function != Base && function != Fetch)
 		{
 			lod += *Pointer<Float>(sampler + OFFSET(vk::Sampler, mipLodBias));
+
+			if(function == Query)
+			{
+				c.y = Float4(lod);  // Unclamped LOD.
+			}
+
 			lod = Max(lod, *Pointer<Float>(sampler + OFFSET(vk::Sampler, minLod)));
 			lod = Min(lod, *Pointer<Float>(sampler + OFFSET(vk::Sampler, maxLod)));
+
+			if(function == Query)
+			{
+				if(state.mipmapFilter == MIPMAP_POINT)
+				{
+					lod = Round(lod);  // TODO: Preferred formula is ceil(lod + 0.5) - 1
+				}
+
+				c.x = lod;
+			//	c.y contains unclamped LOD.
+
+				return c;
+			}
 		}
 
 		bool force32BitFiltering = state.highPrecisionFiltering && !hasYuvFormat() && (state.textureFilter != FILTER_POINT);

src/Pipeline/SamplerCore.hpp

@@ -35,7 +35,8 @@ namespace sw
 		Grad,      // Use provided gradients.
 		Fetch,     // Use provided integer coordinates.
 		Base,      // Sample base level.
-		SAMPLER_METHOD_LAST = Base,
+		Query,     // Return implicit LOD.
+		SAMPLER_METHOD_LAST = Query,
 	};
 
 	enum SamplerOption

src/Pipeline/SpirvShader.cpp

@@ -13,8 +13,8 @@
 // limitations under the License.
 
 #include "SpirvShader.hpp"
-#include "SamplerCore.hpp"
 
+#include "SamplerCore.hpp"
 #include "Reactor/Coroutine.hpp"
 #include "System/Math.hpp"
 #include "Vulkan/VkBuffer.hpp"
@@ -919,8 +919,9 @@ namespace sw
 			case spv::OpImageSampleProjDrefImplicitLod:
 			case spv::OpImageSampleProjDrefExplicitLod:
 			case spv::OpImageFetch:
-			case spv::OpImageQuerySize:
 			case spv::OpImageQuerySizeLod:
+			case spv::OpImageQuerySize:
+			case spv::OpImageQueryLod:
 			case spv::OpImageQueryLevels:
 			case spv::OpImageQuerySamples:
 			case spv::OpImageRead:
@@ -2471,11 +2472,14 @@ namespace sw
 		case spv::OpImageFetch:
 			return EmitImageFetch(insn, state);
 
+		case spv::OpImageQuerySizeLod:
+			return EmitImageQuerySizeLod(insn, state);
+
 		case spv::OpImageQuerySize:
 			return EmitImageQuerySize(insn, state);
 
-		case spv::OpImageQuerySizeLod:
-			return EmitImageQuerySizeLod(insn, state);
+		case spv::OpImageQueryLod:
+			return EmitImageQueryLod(insn, state);
 
 		case spv::OpImageQueryLevels:
 			return EmitImageQueryLevels(insn, state);
@@ -4839,12 +4843,12 @@ namespace sw
 		return EmitResult::Continue;
 	}
 
-	SpirvShader::EmitResult SpirvShader::EmitImageQuerySize(InsnIterator insn, EmitState *state) const
+	SpirvShader::EmitResult SpirvShader::EmitImageQuerySizeLod(InsnIterator insn, EmitState *state) const
 	{
 		auto &resultTy = getType(Type::ID(insn.word(1)));
 		auto resultId = Object::ID(insn.word(2));
 		auto imageId = Object::ID(insn.word(3));
-		auto lodId = Object::ID(0);
+		auto lodId = Object::ID(insn.word(4));
 
 		auto &dst = state->routine->createIntermediate(resultId, resultTy.sizeInComponents);
 		GetImageDimensions(state->routine, resultTy, imageId, lodId, dst);
@@ -4852,12 +4856,12 @@ namespace sw
 		return EmitResult::Continue;
 	}
 
-	SpirvShader::EmitResult SpirvShader::EmitImageQuerySizeLod(InsnIterator insn, EmitState *state) const
+	SpirvShader::EmitResult SpirvShader::EmitImageQuerySize(InsnIterator insn, EmitState *state) const
 	{
 		auto &resultTy = getType(Type::ID(insn.word(1)));
 		auto resultId = Object::ID(insn.word(2));
 		auto imageId = Object::ID(insn.word(3));
-		auto lodId = Object::ID(insn.word(4));
+		auto lodId = Object::ID(0);
 
 		auto &dst = state->routine->createIntermediate(resultId, resultTy.sizeInComponents);
 		GetImageDimensions(state->routine, resultTy, imageId, lodId, dst);
@@ -4865,6 +4869,11 @@ namespace sw
 		return EmitResult::Continue;
 	}
 
+	SpirvShader::EmitResult SpirvShader::EmitImageQueryLod(InsnIterator insn, EmitState *state) const
+	{
+		return EmitImageSample({None, Query}, insn, state);
+	}
+
 	void SpirvShader::GetImageDimensions(SpirvRoutine const *routine, Type const &resultTy, Object::ID imageId, Object::ID lodId, Intermediate &dst) const
 	{
 		auto &image = getObject(imageId);

src/Pipeline/SpirvShader.hpp

@@ -480,7 +480,7 @@ namespace sw
 		// OpImageSample variants
 		enum Variant
 		{
-			None,
+			None,  // No Dref or Proj. Also used by OpImageFetch and OpImageQueryLod.
 			Dref,
 			Proj,
 			ProjDref,
@@ -938,8 +938,9 @@ namespace sw
 		EmitResult EmitImageSampleExplicitLod(Variant variant, InsnIterator insn, EmitState *state) const;
 		EmitResult EmitImageFetch(InsnIterator insn, EmitState *state) const;
 		EmitResult EmitImageSample(ImageInstruction instruction, InsnIterator insn, EmitState *state) const;
-		EmitResult EmitImageQuerySize(InsnIterator insn, EmitState *state) const;
 		EmitResult EmitImageQuerySizeLod(InsnIterator insn, EmitState *state) const;
+		EmitResult EmitImageQuerySize(InsnIterator insn, EmitState *state) const;
+		EmitResult EmitImageQueryLod(InsnIterator insn, EmitState *state) const;
 		EmitResult EmitImageQueryLevels(InsnIterator insn, EmitState *state) const;
 		EmitResult EmitImageQuerySamples(InsnIterator insn, EmitState *state) const;
 		EmitResult EmitImageRead(InsnIterator insn, EmitState *state) const;

src/Pipeline/SpirvShaderSampling.cpp

@@ -89,8 +89,6 @@ SpirvShader::ImageSampler *SpirvShader::emitSamplerFunction(ImageInstruction ins
 		Pointer<SIMD::Float> out = function.Arg<3>();
 		Pointer<Byte> constants = function.Arg<4>();
 
-		SamplerCore s(constants, samplerState);
-
 		SIMD::Float uvw[4];
 		SIMD::Float q;
 		SIMD::Float lodOrBias;  // Explicit level-of-detail, or bias added to the implicit level-of-detail (depending on samplerMethod).
@@ -149,6 +147,7 @@ SpirvShader::ImageSampler *SpirvShader::emitSamplerFunction(ImageInstruction ins
 			}
 		}
 
+		SamplerCore s(constants, samplerState);
 		Vector4f sample = s.sampleTexture(texture, sampler, uvw[0], uvw[1], uvw[2], q, lodOrBias, dsx, dsy, offset, samplerFunction);
 
 		Pointer<SIMD::Float> rgba = out;