Ryujinx-uplift/Ryujinx.Graphics/Shader/CodeGen/Glsl/Instructions/InstGenPacking.cs

using Ryujinx.Graphics.Shader.StructuredIr;

using static Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions.InstGenHelper;
using static Ryujinx.Graphics.Shader.StructuredIr.InstructionInfo;

namespace Ryujinx.Graphics.Shader.CodeGen.Glsl.Instructions
{
    static class InstGenPacking
    {
        public static string PackHalf2x16(CodeGenContext context, AstOperation operation)
        {
            IAstNode src0 = operation.GetSource(0);
            IAstNode src1 = operation.GetSource(1);

            string src0Expr = GetSoureExpr(context, src0, GetSrcVarType(operation.Inst, 0));
            string src1Expr = GetSoureExpr(context, src1, GetSrcVarType(operation.Inst, 1));

            return $"packHalf2x16(vec2({src0Expr}, {src1Expr}))";
        }

        public static string UnpackHalf2x16(CodeGenContext context, AstOperation operation)
        {
            IAstNode src = operation.GetSource(0);

            string srcExpr = GetSoureExpr(context, src, GetSrcVarType(operation.Inst, 0));

            return $"unpackHalf2x16({srcExpr}){GetMask(operation.ComponentMask)}";
        }

        private static string GetMask(int compMask)
        {
            string mask = ".";

            for (int index = 0; index < 2; index++)
            {
                if ((compMask & (1 << index)) != 0)
                {
                    mask += "xy".Substring(index, 1);
                }
            }

            return mask;
        }
    }
}