diff options
| author | Pokechu22 <Pokechu022@gmail.com> | 2023-01-02 19:23:31 -0800 |
|---|---|---|
| committer | Pokechu22 <Pokechu022@gmail.com> | 2023-01-04 10:42:00 -0800 |
| commit | cefcd9c93c2d76074c3be7a6cb96812dad082e9c (patch) | |
| tree | 0fba6e85aff3b120a0b65fbdd76ccd3a3c821afd /Source/Core | |
| parent | 6c58ba353caced302f1e4e23eee0de6d59a527a2 (diff) | |
IndexGenerator: Fix off-by-one in GetRemainingIndices
Fixes https://bugs.dolphin-emu.org/issues/13136.
Diffstat (limited to 'Source/Core')
| -rw-r--r-- | Source/Core/VideoCommon/IndexGenerator.cpp | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/Source/Core/VideoCommon/IndexGenerator.cpp b/Source/Core/VideoCommon/IndexGenerator.cpp index 04068e88ec..03d0815a13 100644 --- a/Source/Core/VideoCommon/IndexGenerator.cpp +++ b/Source/Core/VideoCommon/IndexGenerator.cpp @@ -328,13 +328,21 @@ void IndexGenerator::AddExternalIndices(const u16* indices, u32 num_indices, u32 u32 IndexGenerator::GetRemainingIndices(OpcodeDecoder::Primitive primitive) const { - u32 max_index = USHRT_MAX; + u32 max_index = UINT16_MAX; if (g_Config.UseVSForLinePointExpand() && primitive >= OpcodeDecoder::Primitive::GX_DRAW_LINES) max_index >>= 2; - // -1 is reserved for primitive restart - max_index = max_index - 1; + // Although we reserve UINT16_MAX for primitive restart, we aren't allowed to use that as an + // actual index. But, the maximum number of vertices a game can send is UINT16_MAX, so up to + // 0xffff indices will be used by the game. These indices would be 0x0000 through 0xfffe, + // and since m_base_index gets incremented for each index used, after that m_base_index + // would be 0xffff and no indices remain. If a game uses 0xfffe vertices, assuming m_base_index + // started at 0 it would end at 0xfffe and one more index could be used. So, we do not need to + // subtract 1 from max_index to correctly reserve one index for primitive restart. + // + // Pocoyo Racing uses a draw command with 0xffff vertices, which previously caused issues; see + // https://bugs.dolphin-emu.org/issues/13136 for details. if (m_base_index > max_index) [[unlikely]] { |