shader: add viewport-index exports and indexed raster state

Co-authored-by: Ettore Sartori <85788613+Ekt0re@users.noreply.github.com>

src/graphics/host_gpu/renderer/debug.cpp

@@ -939,7 +939,8 @@ static bool ScissorClipRuleToIntersectionMask(uint16_t rule, uint8_t* mask) {
 }
 
 ScissorRect calc_final_scissor(const HW::ScreenViewport& vp, const HW::ScanModeControl& smc,
-                               vk::Extent2D extent) {
+                               vk::Extent2D extent, uint32_t viewport_index) {
+	EXIT_IF(viewport_index >= std::size(vp.viewports));
 	ScissorRect screen {vp.screen_scissor_left, vp.screen_scissor_top, vp.screen_scissor_right,
 	                    vp.screen_scissor_bottom};
 	ScissorRect final = screen;
@@ -972,7 +973,7 @@ ScissorRect calc_final_scissor(const HW::ScreenViewport& vp, const HW::ScanModeC
 		final = ScissorRectIntersect(final, generic);
 	}
 
-	const auto& viewport = vp.viewports[0];
+	const auto& viewport = vp.viewports[viewport_index];
 	ScissorRect viewport_scissor {viewport.viewport_scissor_left, viewport.viewport_scissor_top,
 	                              viewport.viewport_scissor_right,
 	                              viewport.viewport_scissor_bottom};

src/graphics/host_gpu/renderer/debug.h

@@ -39,7 +39,7 @@ void                     hw_print(const CommandBuffer& buffer);
 void                     hw_check(const CommandBuffer& buffer);
 void                     LogDrawPhase(const char* draw_name, const char* phase);
 ScissorRect calc_final_scissor(const HW::ScreenViewport& vp, const HW::ScanModeControl& smc,
-                               vk::Extent2D extent);
+                               vk::Extent2D extent, uint32_t viewport_index);
 
 } // namespace Libs::Graphics
 

src/graphics/host_gpu/renderer/pipeline/shaders.cpp

@@ -574,8 +574,6 @@ void CreatePipelineInternal(
 
 	vk::PipelineViewportStateCreateInfo viewport_state {};
 	viewport_state.pNext = &depth_clip_control;
-	viewport_state.viewportCount = 1;
-	viewport_state.scissorCount  = 1;
 
 	vk::CullModeFlags cull_mode = vk::CullModeFlagBits::eNone;
 	if (static_params.cull_back) {
@@ -704,8 +702,8 @@ void CreatePipelineInternal(
 	depth_stencil_info.maxDepthBounds    = static_params.depth_max_bounds;
 
 	const vk::DynamicState dynamic_states[] = {
-	    vk::DynamicState::eViewport,
+	    vk::DynamicState::eViewportWithCount,
-	    vk::DynamicState::eScissor,
+	    vk::DynamicState::eScissorWithCount,
 	    vk::DynamicState::eLineWidth,
 	    vk::DynamicState::eDepthTestEnable,
 	    vk::DynamicState::eDepthWriteEnable,

src/graphics/host_gpu/renderer/renderDraw.cpp

@@ -210,7 +210,7 @@ static void LogDrawTargetState(const char* draw_name, const RenderColorInfo& col
 	    });
 
 	const auto extent = color.Extent();
-	const auto sc     = calc_final_scissor(vp, ctx.GetScanModeControl(), extent);
+	const auto sc     = calc_final_scissor(vp, ctx.GetScanModeControl(), extent, 0);
 
 	LOGF(
 	    "DrawTargetState[%u]: frame=%d %s target=%s addr=0x%010" PRIx64
@@ -315,6 +315,7 @@ static void LogDrawInputState(const CommandBuffer& buffer, const RenderColorInfo
 }
 
 static void SetGraphicsDynamicParams(const CommandBuffer& buffer, vk::CommandBuffer vk_buffer,
+                                     const ShaderVertexInputInfo& vs_input_info,
                                      const RenderColorInfo* colors, uint32_t color_count,
                                      const RenderDepthInfo& depth) {
 	KYTY_PROFILER_FUNCTION();
@@ -333,31 +334,46 @@ static void SetGraphicsDynamicParams(const CommandBuffer& buffer, vk::CommandBuf
 		framebuffer_extent = {limits.maxFramebufferWidth, limits.maxFramebufferHeight};
 	}
 
-	const auto final_scissor = calc_final_scissor(vp, ctx.GetScanModeControl(), framebuffer_extent);
+	const auto& outputs = vs_input_info.stage.program->info.outputs;
-
+	const bool  indexed_viewports =
-	vk::Viewport viewport {};
+	    std::any_of(outputs.begin(), outputs.end(), [](const auto& output) {
+		    return output.kind == ShaderRecompiler::IR::StageOutputKind::ViewportIndex;
+	    });
+	constexpr uint32_t viewport_slots = std::size(HW::ScreenViewport {}.viewports);
+	std::array<vk::Viewport, viewport_slots> viewports {};
+	std::array<vk::Rect2D, viewport_slots>   scissors {};
+	const uint32_t viewport_count = indexed_viewports ? viewport_slots : 1;
+	for (uint32_t i = 0; i < viewport_count; i++) {
+		const auto& guest    = vp.viewports[i];
+		auto&       viewport = viewports[i];
 		if (ctx.GetClipControl().clip_disable) {
 			const auto& limits = buffer.GetGraphics().GetPhysicalDeviceProperties().limits;
-		viewport.x         = 0.0f;
-		viewport.y         = 0.0f;
 			viewport.width  = static_cast<float>(std::min(limits.maxViewportDimensions[0], 16384u));
 			viewport.height = static_cast<float>(std::min(limits.maxViewportDimensions[1], 16384u));
 		} else {
-		viewport.x      = vp.viewports[0].xoffset - vp.viewports[0].xscale;
+			viewport.x      = guest.xoffset - guest.xscale;
-		viewport.y      = vp.viewports[0].yoffset - vp.viewports[0].yscale;
+			viewport.y      = guest.yoffset - guest.yscale;
-		viewport.width  = vp.viewports[0].xscale * 2.0f;
+			viewport.width  = guest.xscale * 2.0f;
-		viewport.height = vp.viewports[0].yscale * 2.0f;
+			viewport.height = guest.yscale * 2.0f;
 		}
-	viewport.minDepth = vp.viewports[0].zoffset -
+		viewport.minDepth =
-	                    (ctx.GetClipControl().dx_clip_space ? 0.0f : vp.viewports[0].zscale);
+		    guest.zoffset - (ctx.GetClipControl().dx_clip_space ? 0.0f : guest.zscale);
-	viewport.maxDepth = vp.viewports[0].zscale + vp.viewports[0].zoffset;
+		viewport.maxDepth = guest.zscale + guest.zoffset;
-	vk_buffer.setViewport(0, 1, &viewport);
 
-	vk::Rect2D scissor {};
+		const auto final_scissor =
+		    calc_final_scissor(vp, ctx.GetScanModeControl(), framebuffer_extent, i);
+		auto& scissor  = scissors[i];
 		scissor.offset = {final_scissor.left, final_scissor.top};
 		scissor.extent = {static_cast<uint32_t>(final_scissor.right - final_scissor.left),
 		                  static_cast<uint32_t>(final_scissor.bottom - final_scissor.top)};
-	vk_buffer.setScissor(0, 1, &scissor);
+		if (viewport.width == 0.0f) {
+			// Keep empty slots at their guest index; Vulkan requires a positive viewport width.
+			viewport.width = 1.0f;
+			scissor.extent = {0, 0};
+		}
+	}
+	vk_buffer.setViewportWithCount(viewport_count, viewports.data());
+	vk_buffer.setScissorWithCount(viewport_count, scissors.data());
 
 	float line_width = ctx.GetLineWidth();
 	if (line_width != 1.0f) {
@@ -1125,8 +1141,8 @@ void RenderExecutor::ExecutePreparedDraw(uint64_t submit_id, CommandBuffer& buff
 		CommitIndexBuffer(vk_buffer, index_binding);
 	}
 
-	SetGraphicsDynamicParams(buffer, vk_buffer, state.color_info, state.color_count,
+	SetGraphicsDynamicParams(buffer, vk_buffer, state.vs_input_info, state.color_info,
-	                         state.depth_info);
+	                         state.color_count, state.depth_info);
 
 	LogDrawPhase(draw.name, "BeginRendering");
 	if (set_auto_debug) {

src/graphics/presentation/window/vulkanWindow.cpp

@@ -69,6 +69,7 @@ vk::PhysicalDeviceVulkan12Features WindowContext::RequiredVulkan12Features() noe
 	features.samplerMirrorClampToEdge  = VK_TRUE;
 	features.timelineSemaphore         = VK_TRUE;
 	features.shaderOutputLayer         = VK_TRUE;
+	features.shaderOutputViewportIndex = VK_TRUE;
 	features.bufferDeviceAddress       = VK_TRUE;
 	features.shaderBufferInt64Atomics  = VK_TRUE;
 	return features;
@@ -276,6 +277,11 @@ static void VulkanFindPhysicalDevice(vk::Instance instance, vk::SurfaceKHR surfa
 			LOGF("shaderOutputLayer is not supported\n");
 			skip_device = true;
 		}
+		if (required_features12.shaderOutputViewportIndex == VK_TRUE &&
+		    features12.shaderOutputViewportIndex != VK_TRUE) {
+			LOGF("shaderOutputViewportIndex is not supported\n");
+			skip_device = true;
+		}
 		if (required_features12.bufferDeviceAddress == VK_TRUE &&
 		    features12.bufferDeviceAddress != VK_TRUE) {
 			LOGF("bufferDeviceAddress is not supported\n");
@@ -320,6 +326,10 @@ static void VulkanFindPhysicalDevice(vk::Instance instance, vk::SurfaceKHR surfa
 			LOGF("largePoints is not supported\n");
 			skip_device = true;
 		}
+		if (device_features2.features.multiViewport != VK_TRUE) {
+			LOGF("multiViewport is not supported\n");
+			skip_device = true;
+		}
 		if (device_features2.features.fragmentStoresAndAtomics != VK_TRUE) {
 			LOGF("fragmentStoresAndAtomics is not supported\n");
 			skip_device = true;
@@ -636,10 +646,13 @@ static vk::Device VulkanCreateDevice(vk::PhysicalDevice physical_device, const V
 	EXIT_NOT_IMPLEMENTED(supported_features2.features.shaderClipDistance != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(supported_features2.features.shaderCullDistance != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(supported_features2.features.largePoints != VK_TRUE);
+	EXIT_NOT_IMPLEMENTED(supported_features2.features.multiViewport != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(supported_features2.features.shaderInt64 != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(supported_features2.features.vertexPipelineStoresAndAtomics != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(required_features12.shaderOutputLayer == VK_TRUE &&
 	                     supported_features12.shaderOutputLayer != VK_TRUE);
+	EXIT_NOT_IMPLEMENTED(required_features12.shaderOutputViewportIndex == VK_TRUE &&
+	                     supported_features12.shaderOutputViewportIndex != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(required_features12.bufferDeviceAddress == VK_TRUE &&
 	                     supported_features12.bufferDeviceAddress != VK_TRUE);
 	EXIT_NOT_IMPLEMENTED(required_features12.shaderBufferInt64Atomics == VK_TRUE &&
@@ -663,6 +676,7 @@ static vk::Device VulkanCreateDevice(vk::PhysicalDevice physical_device, const V
 	device_features.shaderClipDistance                   = VK_TRUE;
 	device_features.shaderCullDistance                   = VK_TRUE;
 	device_features.largePoints                          = VK_TRUE;
+	device_features.multiViewport                        = VK_TRUE;
 	device_features.vertexPipelineStoresAndAtomics       = VK_TRUE;
 	graphics.sample_rate_shading_enabled                 = true;
 	device_features.shaderInt64 = VK_TRUE;

src/graphics/shader/recompiler/backend/spirv/spirvEmitterFlow.cpp

@@ -338,8 +338,9 @@ void EmitAuxPositionExport(ValueEmitContext& ctx, uint32_t data, const IR::Expor
 		}
 		const auto output = IR::DecodePositionExportComponent(
 		    state.input_info.vertex->pa_cl_vs_out_cntl, exp.index, component);
-		if (output.layer) {
+		if (output.layer || output.viewport) {
 			const auto raw = ExportRawComponent(ctx, data, component);
+			if (output.layer) {
 				const auto layer = state.builder.AllocateId();
 				state.builder.AddFunction({OpBitwiseAnd, TypeU32(state), layer, raw,
 				                           ConstantU32(state, 0x7ffu)});
@@ -347,6 +348,14 @@ void EmitAuxPositionExport(ValueEmitContext& ctx, uint32_t data, const IR::Expor
 				                         ? MeshOutputPointer(state, IR::StageOutputKind::Layer)
 				                         : state.layer_variable;
 				state.builder.AddFunction({OpStore, pointer, layer});
+			}
+			if (output.viewport) {
+				// GFX10 MISC.z packs the viewport index in bits 16..19 alongside the layer.
+				const auto viewport = state.builder.AllocateId();
+				state.builder.AddFunction({OpBitFieldUExtract, TypeU32(state), viewport, raw,
+				                           ConstantU32(state, 16), ConstantU32(state, 4)});
+				state.builder.AddFunction({OpStore, state.viewport_index_variable, viewport});
+			}
 			continue;
 		}
 		if (!output.point_size && output.clip_distance == UINT32_MAX &&

src/graphics/shader/recompiler/backend/spirv/spirvEmitterInternal.h

@@ -52,6 +52,7 @@ enum : uint32_t {
 	CapabilityGroupNonUniformBallot          = 64,
 	CapabilityGroupNonUniformShuffle         = 65,
 	CapabilityShaderLayer                    = 69,
+	CapabilityShaderViewportIndex            = 70,
 	CapabilitySignedZeroInfNanPreserve       = 4466,
 	CapabilityFragmentBarycentricKHR         = 5284,
 	CapabilityComputeDerivativeGroupQuadsKHR = 5288,
@@ -91,6 +92,7 @@ enum : uint32_t {
 	BuiltInClipDistance              = 3,
 	BuiltInCullDistance              = 4,
 	BuiltInLayer                     = 9,
+	BuiltInViewportIndex              = 10,
 	BuiltInFragCoord                 = 15,
 	BuiltInFrontFacing               = 17,
 	BuiltInSampleId                  = 18,
@@ -391,6 +393,7 @@ struct EmitterState {
 	uint32_t                   clip_distance_variable                = 0;
 	uint32_t                   cull_distance_variable                = 0;
 	uint32_t                   layer_variable                        = 0;
+	uint32_t                   viewport_index_variable               = 0;
 	uint32_t                   clip_distance_count                   = 0;
 	uint32_t                   cull_distance_count                   = 0;
 	uint32_t                   depth_variable                        = 0;

src/graphics/shader/recompiler/backend/spirv/spirvEmitterModule.cpp

@@ -490,6 +490,10 @@ void AllocateOutputVariables(EmitterState& state) {
 			case IR::StageOutputKind::Layer:
 				binding.variable_id = AllocateSharedOutputVariable(state, state.layer_variable);
 				break;
+			case IR::StageOutputKind::ViewportIndex:
+				binding.variable_id =
+				    AllocateSharedOutputVariable(state, state.viewport_index_variable);
+				break;
 			case IR::StageOutputKind::Depth:
 				binding.variable_id = AllocateSharedOutputVariable(state, state.depth_variable);
 				break;
@@ -583,6 +587,7 @@ void AddOutputAnnotationsAndNames(EmitterState& state) {
 	AddBuiltIn(state.clip_distance_variable, "gl_ClipDistance", BuiltInClipDistance);
 	AddBuiltIn(state.cull_distance_variable, "gl_CullDistance", BuiltInCullDistance);
 	AddBuiltIn(state.layer_variable, "gl_Layer", BuiltInLayer);
+	AddBuiltIn(state.viewport_index_variable, "gl_ViewportIndex", BuiltInViewportIndex);
 	if (state.depth_variable != 0) {
 		state.builder.AddName(state.depth_variable, "gl_FragDepth");
 		state.builder.AddAnnotation(
@@ -712,6 +717,10 @@ void DefineModule(EmitterState& state) {
 		state.builder.RequireVersion(0x00010500u);
 		state.builder.RequireCapability(CapabilityShaderLayer);
 	}
+	if (state.viewport_index_variable != 0) {
+		state.builder.RequireVersion(0x00010500u);
+		state.builder.RequireCapability(CapabilityShaderViewportIndex);
+	}
 	if (InputVariableForKind(state, IR::StageInputKind::SampleId) != 0) {
 		state.builder.RequireCapability(CapabilitySampleRateShading);
 	}
@@ -874,6 +883,11 @@ void DefineModule(EmitterState& state) {
 		    state.layer_variable, TypePointer(state, StorageClassOutput, TypeU32(state)),
 		    StorageClassOutput);
 	}
+	if (state.viewport_index_variable != 0) {
+		state.builder.DefineGlobalVariable(
+		    state.viewport_index_variable, TypePointer(state, StorageClassOutput, TypeU32(state)),
+		    StorageClassOutput);
+	}
 	for (const auto& binding: state.outputs) {
 		if (binding.kind == IR::StageOutputKind::Parameter ||
 		    binding.kind == IR::StageOutputKind::Mrt) {

src/graphics/shader/recompiler/ir/ShaderIR.h

@@ -181,7 +181,8 @@ enum class StageOutputKind {
 	PointSize,
 	ClipDistance,
 	CullDistance,
-	Layer
+	Layer,
+	ViewportIndex
 };
 
 struct PositionExportComponent {

src/graphics/shader/recompiler/ir/passes/ShaderInfoCollection.cpp

@@ -324,7 +324,7 @@ void CollectOutputs(const Program& program, const ShaderVertexInputInfo* vertex,
 						const auto output = DecodePositionExportComponent(
 						    vertex->pa_cl_vs_out_cntl, export_info.index, component);
 						if (output.viewport) {
-							return Fail("vertex viewport-index export is unsupported");
+							AddOutput(info, StageOutputKind::ViewportIndex, 0, 0, "gl_ViewportIndex");
 						}
 						if (output.point_size) {
 							AddOutput(info, StageOutputKind::PointSize, 0, 0, "gl_PointSize");

tests/shaderCfgTests.cpp

@@ -37,6 +37,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <deque>
+#include <initializer_list>
 #include <iterator>
 #include <span>
 #include <sstream>
@@ -907,12 +908,12 @@ SpirvStoredBuiltInElements(const std::vector<uint32_t> &binary,
   return elements;
 }
 
-bool SpirvBuiltInStoreUsesAndConstant(const std::vector<uint32_t> &binary,
+bool SpirvBuiltInStoreUsesOperation(const std::vector<uint32_t> &binary,
-                                      uint32_t builtin,
+                                    uint32_t builtin, uint32_t operation,
-                                      uint32_t constant) {
+                                    std::initializer_list<uint32_t> literals) {
   std::unordered_set<uint32_t> variables;
   std::unordered_map<uint32_t, uint32_t> constants;
-  std::unordered_map<uint32_t, std::array<uint32_t, 2>> bitwise_ands;
+  std::unordered_map<uint32_t, std::vector<uint32_t>> operations;
   std::unordered_map<uint32_t, uint32_t> stores;
   for (size_t i = 5; i < binary.size();) {
     const uint32_t opcode = binary[i] & 0xffffu;
@@ -925,8 +926,8 @@ bool SpirvBuiltInStoreUsesAndConstant(const std::vector<uint32_t> &binary,
       variables.insert(binary[i + 1]);
     } else if (opcode == 43u && count >= 4u) {
       constants[binary[i + 2]] = binary[i + 3];
-    } else if (opcode == 199u && count == 5u) {
+    } else if (opcode == operation && count == 4u + literals.size()) {
-      bitwise_ands[binary[i + 2]] = {binary[i + 3], binary[i + 4]};
+      operations[binary[i + 2]] = {binary.begin() + i + 4, binary.begin() + i + count};
     } else if (opcode == 62u && count >= 3u) {
       stores[binary[i + 1]] = binary[i + 2];
     }
@@ -937,17 +938,18 @@ bool SpirvBuiltInStoreUsesAndConstant(const std::vector<uint32_t> &binary,
     if (store == stores.end()) {
       continue;
     }
-    const auto value = bitwise_ands.find(store->second);
+    const auto value = operations.find(store->second);
-    if (value == bitwise_ands.end()) {
+    if (value == operations.end()) {
       continue;
     }
-    for (const auto operand : value->second) {
+    if (std::equal(value->second.begin(), value->second.end(), literals.begin(),
-      const auto literal = constants.find(operand);
+                   [&](uint32_t id, uint32_t expected) {
-      if (literal != constants.end() && literal->second == constant) {
+                     const auto literal = constants.find(id);
+                     return literal != constants.end() && literal->second == expected;
+                   })) {
       return true;
     }
   }
-  }
   return false;
 }
 
@@ -9722,7 +9724,7 @@ void TestNewShaderRecompilerAuxPositionExports() {
   const auto all_source = DisassembleSpirvBinary(all.spirv);
   Check(all.spirv[1] == 0x00010500u &&
             !Common::ContainsStr(all_source, "SPV_EXT_shader_viewport_index_layer") &&
-            SpirvBuiltInStoreUsesAndConstant(all.spirv, 9u, 0x7ffu),
+            SpirvBuiltInStoreUsesOperation(all.spirv, 9u, 199u, {0x7ffu}),
         "layer export module version or GFX10 layer mask is incorrect");
   const auto positions = std::count_if(
       all.program.info.outputs.begin(), all.program.info.outputs.end(),
@@ -9776,25 +9778,23 @@ void TestNewShaderRecompilerAuxPositionExports() {
                 ShaderRecompiler::IR::StageOutputKind::Position,
         "unmapped auxiliary position export was not ignored");
 
-#if KYTY_PLATFORM != KYTY_PLATFORM_WINDOWS
+  // R-Type Final 3 packs a dynamic viewport index into POS1.z bits 16..19.
-  const auto rejects = [](uint32_t control, uint32_t en,
+  // The same component can carry an independent render-target layer in bits 0..10.
-                          const char *message) {
+  for (const uint32_t control : {0x01280000u, 0x012c0000u}) {
-    const uint32_t shader[] = {
+    const auto indexed = compile(unmapped, control);
-        EncodeExp0(0x0c, 0xf, false), EncodeExp1(0, 1, 2, 3),
+    CheckSpirvBinaryValidates(indexed.spirv);
-        EncodeExp0(0x0d, en), EncodeExp1(4, 5, 6, 7),
+    Check(indexed.spirv[1] == 0x00010500u &&
-        0xbf810000u,
+              SpirvContainsCapability(indexed.spirv, 70u) &&
-    };
+              SpirvBuiltInStoreUsesOperation(indexed.spirv, 10u, 203u, {16u, 4u}),
-    ShaderVertexInputInfo vertex{};
+          "viewport export did not store the GFX10 four-bit index");
-    vertex.pa_cl_vs_out_cntl = control;
+    const bool layered = (control & (1u << 18u)) != 0;
-    auto options = MakeCompileOptions(ShaderType::Vertex);
+    Check(SpirvBuiltInStoreUsesOperation(indexed.spirv, 9u, 199u, {0x7ffu}) == layered,
-    options.input_info.vertex = &vertex;
+          "packed layer/viewport export dropped or invented a layer store");
-    ExpectFatal([&] { (void)RecompileForTest(shader, options); },
+    Check(std::ranges::any_of(indexed.program.info.outputs, [](const auto &output) {
-                message);
+            return output.kind == ShaderRecompiler::IR::StageOutputKind::ViewportIndex;
-  };
+          }),
-  rejects(0x00280000u, 0x4u,
+          "viewport export was omitted from shader reflection");
-          "viewport-index auxiliary position export did not terminate "
+  }
-          "compilation");
-#endif
 
   ShaderVertexInputInfo key0{};
   ShaderVertexInputInfo key1{};