Fix dynamic rendering implicit clears with multiview

Applied the same fix that had been previously applied to
CmdClearAttachment::execute() to CmdBeginRendering::execute().
Also, multiview is set when viewMask > 0, so the logic was
modified to take that into account.

Tests: dEQP-VK.multiview.dynamic_rendering.readback_implicit_clear.*
Bug: b/204502119
Change-Id: I98fddd81ebf82412bd5f5e13ce8a9fe645905e41
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/63288
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
Commit-Queue: Alexis Hétu <sugoi@google.com>

src/Pipeline/PixelProgram.cpp

diff --git a/src/Pipeline/PixelProgram.cpp b/src/Pipeline/PixelProgram.cpp
index 42fefc1..d6cbe0a 100644
--- a/src/Pipeline/PixelProgram.cpp
+++ b/src/Pipeline/PixelProgram.cpp
@@ -98,7 +98,7 @@
 	routine.helperInvocation = ~maskAny(cMask, samples);
 	routine.windowSpacePosition[0] = x + SIMD::Int(0, 1, 0, 1);
 	routine.windowSpacePosition[1] = y + SIMD::Int(0, 0, 1, 1);
-	routine.viewID = *Pointer<Int>(data + OFFSET(DrawData, viewID));
+	routine.layer = *Pointer<Int>(data + OFFSET(DrawData, layer));
 
 	// PointCoord formula reference: https://www.khronos.org/registry/vulkan/specs/1.2/html/vkspec.html#primsrast-points-basic
 	// Note we don't add a 0.5 offset to x and y here (like for fragCoord) because pointCoordX/Y have 0.5 subtracted as part of the viewport transform.
@@ -108,7 +108,7 @@
 
 	routine.setInputBuiltin(spirvShader, spv::BuiltInViewIndex, [&](const SpirvShader::BuiltinMapping &builtin, Array<SIMD::Float> &value) {
 		assert(builtin.SizeInComponents == 1);
-		value[builtin.FirstComponent] = As<SIMD::Float>(SIMD::Int(routine.viewID));
+		value[builtin.FirstComponent] = As<SIMD::Float>(SIMD::Int(routine.layer));
 	});
 
 	routine.setInputBuiltin(spirvShader, spv::BuiltInFragCoord, [&](const SpirvShader::BuiltinMapping &builtin, Array<SIMD::Float> &value) {

src/Pipeline/SpirvShader.hpp

diff --git a/src/Pipeline/SpirvShader.hpp b/src/Pipeline/SpirvShader.hpp
index 6aab7a7..1641d83 100644
--- a/src/Pipeline/SpirvShader.hpp
+++ b/src/Pipeline/SpirvShader.hpp
@@ -1509,7 +1509,7 @@
 	// Give careful consideration to the runtime performance loss before adding
 	// more state here.
 	std::array<SIMD::Int, 2> windowSpacePosition;
-	Int viewID;  // slice offset into input attachments for multiview, even if the shader doesn't use ViewIndex
+	Int layer;  // slice offset into input attachments for multiview, even if the shader doesn't use ViewIndex
 	Int instanceID;
 	SIMD::Int vertexIndex;
 	std::array<SIMD::Float, 4> fragCoord;

src/Pipeline/SpirvShaderDebugger.cpp

diff --git a/src/Pipeline/SpirvShaderDebugger.cpp b/src/Pipeline/SpirvShaderDebugger.cpp
index 0d3704b..0f25a32 100644
--- a/src/Pipeline/SpirvShaderDebugger.cpp
+++ b/src/Pipeline/SpirvShaderDebugger.cpp
@@ -2633,7 +2633,7 @@
 		case spv::ExecutionModelFragment:
 			{
 				auto fragment = globals + OFFSET(Globals, fragment);
-				store(fragment + OFFSET(Globals::Fragment, viewIndex), routine->viewID);
+				store(fragment + OFFSET(Globals::Fragment, viewIndex), routine->layer);
 				store(fragment + OFFSET(Globals::Fragment, fragCoord), routine->fragCoord);
 				store(fragment + OFFSET(Globals::Fragment, pointCoord), routine->pointCoord);
 				store(fragment + OFFSET(Globals::Fragment, windowSpacePosition), routine->windowSpacePosition);
@@ -2643,7 +2643,7 @@
 		case spv::ExecutionModelVertex:
 			{
 				auto vertex = globals + OFFSET(Globals, vertex);
-				store(vertex + OFFSET(Globals::Vertex, viewIndex), routine->viewID);
+				store(vertex + OFFSET(Globals::Vertex, viewIndex), routine->layer);
 				store(vertex + OFFSET(Globals::Vertex, instanceIndex), routine->instanceID);
 				store(vertex + OFFSET(Globals::Vertex, vertexIndex), routine->vertexIndex);
 			}

src/Pipeline/SpirvShaderImage.cpp

diff --git a/src/Pipeline/SpirvShaderImage.cpp b/src/Pipeline/SpirvShaderImage.cpp
index d66a1a2..7a9b1dd 100644
--- a/src/Pipeline/SpirvShaderImage.cpp
+++ b/src/Pipeline/SpirvShaderImage.cpp
@@ -684,7 +684,7 @@
 	if(dim == spv::DimSubpassData)
 	{
 		// Multiview input attachment access is to the layer corresponding to the current view
-		ptrOffset += SIMD::Int(state->routine->viewID) * slicePitch;
+		ptrOffset += SIMD::Int(state->routine->layer) * slicePitch;
 	}
 
 	if(instruction.sample)

src/Pipeline/VertexProgram.cpp

diff --git a/src/Pipeline/VertexProgram.cpp b/src/Pipeline/VertexProgram.cpp
index ca1aad3..7583b12 100644
--- a/src/Pipeline/VertexProgram.cpp
+++ b/src/Pipeline/VertexProgram.cpp
@@ -36,12 +36,12 @@
 
 	// TODO(b/146486064): Consider only assigning these to the SpirvRoutine iff
 	// they are ever going to be read.
-	routine.viewID = *Pointer<Int>(data + OFFSET(DrawData, viewID));
+	routine.layer = *Pointer<Int>(data + OFFSET(DrawData, layer));
 	routine.instanceID = *Pointer<Int>(data + OFFSET(DrawData, instanceID));
 
 	routine.setInputBuiltin(spirvShader, spv::BuiltInViewIndex, [&](const SpirvShader::BuiltinMapping &builtin, Array<SIMD::Float> &value) {
 		assert(builtin.SizeInComponents == 1);
-		value[builtin.FirstComponent] = As<SIMD::Float>(SIMD::Int(routine.viewID));
+		value[builtin.FirstComponent] = As<SIMD::Float>(SIMD::Int(routine.layer));
 	});
 
 	routine.setInputBuiltin(spirvShader, spv::BuiltInInstanceIndex, [&](const SpirvShader::BuiltinMapping &builtin, Array<SIMD::Float> &value) {