From 20e8a1800914e678255e1ca12021d9f0bc9097db Mon Sep 17 00:00:00 2001
From: ParantezTech <12572227+par274@users.noreply.github.com>
Date: Fri, 2 Oct 2026 19:07:01 +0300
Subject: [PATCH] [Font] Implement sceFontTextSourceInit

Fills the 0x60-byte text source with the text range, the cursor, the parser
callback and its object, and the text size, and leaves the memory after it
untouched.
---
 src/SharpEmu.Libs/Font/FontExports.cs         | 29 ++++++++++++++++++
 .../Font/FontExportsTests.cs                  | 30 +++++++++++++++++++
 2 files changed, 59 insertions(+)

diff --git a/src/SharpEmu.Libs/Font/FontExports.cs b/src/SharpEmu.Libs/Font/FontExports.cs
index 7ef7f3f..36bf98d 100644
--- a/src/SharpEmu.Libs/Font/FontExports.cs
+++ b/src/SharpEmu.Libs/Font/FontExports.cs
@@ -21,6 +21,35 @@ public static class FontExports
     private static readonly ConcurrentDictionary<ulong, float> FontHeights = new();
     private static readonly Lazy<byte[]?> BitmapFont = new(LoadBitmapFont);
 
+    [SysAbiExport(
+        Nid = "oaJ1BpN2FQk",
+        ExportName = "sceFontTextSourceInit",
+        Target = Generation.Gen5,
+        LibraryName = "libSceFont")]
+    public static int TextSourceInit(CpuContext ctx)
+    {
+        var sourceAddress = ctx[CpuRegister.Rdi];
+        var textAddress = ctx[CpuRegister.Rsi];
+        var textSize = (uint)ctx[CpuRegister.Rdx];
+        if (sourceAddress == 0 || textAddress > ulong.MaxValue - textSize)
+        {
+            return SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_INVALID_ARGUMENT);
+        }
+
+        Span<byte> source = stackalloc byte[0x60];
+        source.Clear();
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x08..], textAddress);
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x10..], textAddress == 0 ? 0 : textAddress + textSize);
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x18..], textAddress);
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x20..], ctx[CpuRegister.Rcx]);
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x28..], ctx[CpuRegister.R8]);
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x38..], 0x10);
+        BinaryPrimitives.WriteUInt64LittleEndian(source[0x40..], textSize);
+        return ctx.Memory.TryWrite(sourceAddress, source)
+            ? SetSuccess(ctx)
+            : SetReturn(ctx, OrbisGen2Result.ORBIS_GEN2_ERROR_MEMORY_FAULT);
+    }
+
     [SysAbiExport(
         Nid = "whrS4oksXc4",
         ExportName = "sceFontMemoryInit",
diff --git a/tests/SharpEmu.Libs.Tests/Font/FontExportsTests.cs b/tests/SharpEmu.Libs.Tests/Font/FontExportsTests.cs
index ab5a2ee..eb21982 100644
--- a/tests/SharpEmu.Libs.Tests/Font/FontExportsTests.cs
+++ b/tests/SharpEmu.Libs.Tests/Font/FontExportsTests.cs
@@ -21,6 +21,36 @@ public sealed class FontExportsTests
         _ctx = new CpuContext(_memory, Generation.Gen5);
     }
 
+    [Fact]
+    public void TextSourceInit_WritesParserAndTextRangeWithoutOverwritingNextObject()
+    {
+        const ulong text = Base + 0x300;
+        const ulong parser = Base + 0x400;
+        const ulong parserObject = Base + 0x500;
+        var bytes = new byte[0x68];
+        Array.Fill(bytes, (byte)0xcc);
+        Assert.True(_memory.TryWrite(LayoutAddress, bytes));
+        _ctx[CpuRegister.Rdi] = LayoutAddress;
+        _ctx[CpuRegister.Rsi] = text;
+        _ctx[CpuRegister.Rdx] = 9;
+        _ctx[CpuRegister.Rcx] = parser;
+        _ctx[CpuRegister.R8] = parserObject;
+
+        Assert.Equal(0, FontExports.TextSourceInit(_ctx));
+        Assert.True(_memory.TryRead(LayoutAddress, bytes));
+        Assert.Equal(0UL, BinaryPrimitives.ReadUInt64LittleEndian(bytes));
+        Assert.Equal(text, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x08)));
+        Assert.Equal(text + 9, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x10)));
+        Assert.Equal(text, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x18)));
+        Assert.Equal(parser, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x20)));
+        Assert.Equal(parserObject, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x28)));
+        Assert.Equal(0UL, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x30)));
+        Assert.Equal(0x10UL, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x38)));
+        Assert.Equal(9UL, BinaryPrimitives.ReadUInt64LittleEndian(bytes.AsSpan(0x40)));
+        Assert.All(bytes[0x48..0x60], value => Assert.Equal((byte)0, value));
+        Assert.All(bytes[0x60..], value => Assert.Equal((byte)0xcc, value));
+    }
+
     // SceFontHorizontalLayout is three floats; the sentinel directly after
     // them must survive the call.
     [Fact]