fix(agc): rect-list/NGG strips, Index8 expand, and GE_INDX_OFFSET

NGG single-rect UI needs triangle-strip expansion; Prospero Index8 must expand to host u16; glyphs need base vertex from GE_INDX_OFFSET. Skip param-less rect-lists instead of inventing colour draws. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-08-01 15:39:47 +08:00 · 2026-07-23 01:46:52 +01:00
parent 83745325c3
commit 4b9d2cafac
9 changed files with 606 additions and 94 deletions
@@ -0,0 +1,95 @@
+// Copyright (C) 2026 SharpEmu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+using System.Buffers.Binary;
+using SharpEmu.Libs.Agc;
+using Xunit;
+
+namespace SharpEmu.Libs.Tests.Agc;
+
+/// <summary>
+/// Regression coverage for the AGC UI path: index8 expansion and rect-list
+/// vertex counts / topology selection.
+/// </summary>
+public sealed class AgcRectListIndexHelpersTests
+{
+    [Theory]
+    [InlineData(0u, 0u, 2)] // Index16
+    [InlineData(1u, 1u, 4)] // Index32
+    [InlineData(2u, 2u, 1)] // Index8
+    [InlineData(0x402u, 2u, 1)] // UC 0x400|size -> Index8
+    public void IndexType_DecodeAndStride_MatchProspero(uint raw, uint expected, int stride)
+    {
+        var decoded = AgcIndexHelpers.Decode(raw);
+        Assert.Equal((AgcIndexHelpers.ProsperoIndexType)expected, decoded);
+        Assert.Equal(stride, AgcIndexHelpers.GetGuestStrideBytes(decoded));
+    }
+
+    [Fact]
+    public void ExpandIndex8ToU16_PreservesValues()
+    {
+        ReadOnlySpan<byte> source = [0x00, 0x01, 0xFF, 0x7F];
+        Span<byte> destination = stackalloc byte[8];
+        AgcIndexHelpers.ExpandIndex8ToU16(source, destination);
+        Assert.Equal(0, BinaryPrimitives.ReadUInt16LittleEndian(destination[..2]));
+        Assert.Equal(1, BinaryPrimitives.ReadUInt16LittleEndian(destination.Slice(2, 2)));
+        Assert.Equal(255, BinaryPrimitives.ReadUInt16LittleEndian(destination.Slice(4, 2)));
+        Assert.Equal(127, BinaryPrimitives.ReadUInt16LittleEndian(destination.Slice(6, 2)));
+    }
+
+    [Theory]
+    // NGG single-rect UI (DualSense): expand even when VBs are present
+    [InlineData(7u, 3u, false, true, 4u)]
+    [InlineData(7u, 1u, false, false, 4u)]
+    [InlineData(7u, 4u, false, true, 4u)]
+    // Indexed / multi-vert auto: keep guest count (loading video)
+    [InlineData(7u, 3u, true, false, 3u)]
+    [InlineData(7u, 6u, false, true, 6u)]
+    [InlineData(7u, 4u, true, true, 4u)]
+    [InlineData(0x11u, 3u, false, false, 4u)]
+    [InlineData(0x11u, 6u, false, false, 6u)]
+    [InlineData(4u, 3u, false, false, 3u)]
+    public void RectListDrawVertexCount_MatchesExpansion(
+        uint primitiveType,
+        uint vertexCount,
+        bool indexed,
+        bool hasVertexBuffers,
+        uint expected)
+    {
+        Assert.Equal(
+            expected,
+            AgcPrimitiveHelpers.GetRectListDrawVertexCount(
+                primitiveType,
+                vertexCount,
+                indexed,
+                hasVertexBuffers));
+    }
+
+    [Theory]
+    [InlineData(7u, false, 3u, true, true)]
+    [InlineData(7u, false, 6u, true, false)]
+    [InlineData(7u, true, 3u, false, false)]
+    [InlineData(0x11u, false, 3u, true, true)]
+    [InlineData(0x11u, true, 3u, false, false)]
+    public void RectListTriangleStrip_MatchesGuards(
+        uint primitiveType,
+        bool indexed,
+        uint vertexCount,
+        bool hasVertexBuffers,
+        bool expected) =>
+        Assert.Equal(
+            expected,
+            AgcPrimitiveHelpers.ShouldDrawRectListAsTriangleStrip(
+                primitiveType,
+                indexed,
+                vertexCount,
+                hasVertexBuffers));
+
+    [Theory]
+    [InlineData(7u, (uint)AgcPrimitiveHelpers.GsOutputPrimitiveType.Rectangle2D)]
+    [InlineData(0x11u, (uint)AgcPrimitiveHelpers.GsOutputPrimitiveType.RectList)]
+    [InlineData(4u, (uint)AgcPrimitiveHelpers.GsOutputPrimitiveType.Triangles)]
+    [InlineData(1u, (uint)AgcPrimitiveHelpers.GsOutputPrimitiveType.Points)]
+    public void PrimitiveTypeToGsOut_MatchesProspero(uint primitiveType, uint expected) =>
+        Assert.Equal(expected, AgcPrimitiveHelpers.PrimitiveTypeToGsOut(primitiveType));
+}