From d8c88bd94392eddc4d39d861abe0df648db0bfe6 Mon Sep 17 00:00:00 2001 From: ocornut Date: Thu, 4 Mar 2021 09:52:00 +0100 Subject: [PATCH] Tables: Fixed unaligned accesses when using TableSetBgColor(ImGuiTableBgTarget_CellBg). (#3872) ImSpanAllocator: Support for alignment. --- docs/CHANGELOG.txt | 1 + imgui_internal.h | 19 +++++++++++-------- imgui_tables.cpp | 6 +++--- 3 files changed, 15 insertions(+), 11 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index 0594222fa482..27c68342a07b 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -51,6 +51,7 @@ Other Changes: - Window: Shrink close button hit-testing region when it covers an abnormally high portion of the window visible area (e.g. when window is collapsed + moved in a corner) to facilitate moving the window away. (#3825) - Window, Nav: Fixed crash when calling SetWindowFocus(NULL) as the time a new window appears. (#3865) [@nem0] +- Tables: Fixed unaligned accesses when using TableSetBgColor(ImGuiTableBgTarget_CellBg). (#3872) - Added GetAllocatorFunctions() to facilitate sharing allocators accross DLL boundaries. (#3836) - ImFontAtlas: Added 'bool TexPixelsUseColors' output to help backend decide of underlying texture format. (#3369) This can currently only ever be set by the Freetype renderer. diff --git a/imgui_internal.h b/imgui_internal.h index 1292a7cdc547..9157a9d8e132 100644 --- a/imgui_internal.h +++ b/imgui_internal.h @@ -214,6 +214,7 @@ namespace ImStb #define IM_NEWLINE "\n" #endif #define IM_TABSIZE (4) +#define IM_MEMALIGN(_OFF,_ALIGN) (((_OFF) + (_ALIGN - 1)) & ~(_ALIGN - 1)) // Memory align e.g. IM_ALIGN(0,4)=0, IM_ALIGN(1,4)=4, IM_ALIGN(4,4)=4, IM_ALIGN(5,4)=8 #define IM_F32_TO_INT8_UNBOUND(_VAL) ((int)((_VAL) * 255.0f + ((_VAL)>=0 ? 0.5f : -0.5f))) // Unsaturated, for display purpose #define IM_F32_TO_INT8_SAT(_VAL) ((int)(ImSaturate(_VAL) * 255.0f + 0.5f)) // Saturated, always output 0..255 #define IM_FLOOR(_VAL) ((float)(int)(_VAL)) // ImFloor() is not inlined in MSVC debug builds @@ -545,20 +546,22 @@ struct ImSpan // Helper: ImSpanAllocator<> // Facilitate storing multiple chunks into a single large block (the "arena") +// - Usage: call Reserve() N times, allocate GetArenaSizeInBytes() worth, pass it to SetArenaBasePtr(), call GetSpan() N times to retrieve the aligned ranges. template struct ImSpanAllocator { char* BasePtr; - int TotalSize; - int CurrSpan; + int CurrOff; + int CurrIdx; int Offsets[CHUNKS]; + int Sizes[CHUNKS]; ImSpanAllocator() { memset(this, 0, sizeof(*this)); } - inline void ReserveBytes(int n, size_t sz) { IM_ASSERT(n == CurrSpan && n < CHUNKS); IM_UNUSED(n); Offsets[CurrSpan++] = TotalSize; TotalSize += (int)sz; } - inline int GetArenaSizeInBytes() { return TotalSize; } + inline void Reserve(int n, size_t sz, int a=4) { IM_ASSERT(n == CurrIdx && n < CHUNKS); CurrOff = IM_MEMALIGN(CurrOff, a); Offsets[n] = CurrOff; Sizes[n] = (int)sz; CurrIdx++; CurrOff += (int)sz; } + inline int GetArenaSizeInBytes() { return CurrOff; } inline void SetArenaBasePtr(void* base_ptr) { BasePtr = (char*)base_ptr; } - inline void* GetSpanPtrBegin(int n) { IM_ASSERT(n >= 0 && n < CHUNKS && CurrSpan == CHUNKS); return (void*)(BasePtr + Offsets[n]); } - inline void* GetSpanPtrEnd(int n) { IM_ASSERT(n >= 0 && n < CHUNKS && CurrSpan == CHUNKS); return (n + 1 < CHUNKS) ? BasePtr + Offsets[n + 1] : (void*)(BasePtr + TotalSize); } + inline void* GetSpanPtrBegin(int n) { IM_ASSERT(n >= 0 && n < CHUNKS && CurrIdx == CHUNKS); return (void*)(BasePtr + Offsets[n]); } + inline void* GetSpanPtrEnd(int n) { IM_ASSERT(n >= 0 && n < CHUNKS && CurrIdx == CHUNKS); return (void*)(BasePtr + Offsets[n] + Sizes[n]); } template inline void GetSpan(int n, ImSpan* span) { span->set((T*)GetSpanPtrBegin(n), (T*)GetSpanPtrEnd(n)); } }; @@ -592,7 +595,7 @@ struct IMGUI_API ImPool // Helper: ImChunkStream<> // Build and iterate a contiguous stream of variable-sized structures. // This is used by Settings to store persistent data while reducing allocation count. -// We store the chunk size first, and align the final size on 4 bytes boundaries (this what the '(X + 3) & ~3' statement is for) +// We store the chunk size first, and align the final size on 4 bytes boundaries. // The tedious/zealous amount of casting is to avoid -Wcast-align warnings. template struct IMGUI_API ImChunkStream @@ -602,7 +605,7 @@ struct IMGUI_API ImChunkStream void clear() { Buf.clear(); } bool empty() const { return Buf.Size == 0; } int size() const { return Buf.Size; } - T* alloc_chunk(size_t sz) { size_t HDR_SZ = 4; sz = ((HDR_SZ + sz) + 3u) & ~3u; int off = Buf.Size; Buf.resize(off + (int)sz); ((int*)(void*)(Buf.Data + off))[0] = (int)sz; return (T*)(void*)(Buf.Data + off + (int)HDR_SZ); } + T* alloc_chunk(size_t sz) { size_t HDR_SZ = 4; sz = IM_MEMALIGN(HDR_SZ + sz, 4u); int off = Buf.Size; Buf.resize(off + (int)sz); ((int*)(void*)(Buf.Data + off))[0] = (int)sz; return (T*)(void*)(Buf.Data + off + (int)HDR_SZ); } T* begin() { size_t HDR_SZ = 4; if (!Buf.Data) return NULL; return (T*)(void*)(Buf.Data + HDR_SZ); } T* next_chunk(T* p) { size_t HDR_SZ = 4; IM_ASSERT(p >= begin() && p < end()); p = (T*)(void*)((char*)(void*)p + chunk_size(p)); if (p == (T*)(void*)((char*)end() + HDR_SZ)) return (T*)0; IM_ASSERT(p < end()); return p; } int chunk_size(const T* p) { return ((const int*)p)[-1]; } diff --git a/imgui_tables.cpp b/imgui_tables.cpp index a34ab42f33ef..8c7f0682a44f 100644 --- a/imgui_tables.cpp +++ b/imgui_tables.cpp @@ -538,9 +538,9 @@ void ImGui::TableBeginInitMemory(ImGuiTable* table, int columns_count) { // Allocate single buffer for our arrays ImSpanAllocator<3> span_allocator; - span_allocator.ReserveBytes(0, columns_count * sizeof(ImGuiTableColumn)); - span_allocator.ReserveBytes(1, columns_count * sizeof(ImGuiTableColumnIdx)); - span_allocator.ReserveBytes(2, columns_count * sizeof(ImGuiTableCellData)); + span_allocator.Reserve(0, columns_count * sizeof(ImGuiTableColumn)); + span_allocator.Reserve(1, columns_count * sizeof(ImGuiTableColumnIdx)); + span_allocator.Reserve(2, columns_count * sizeof(ImGuiTableCellData), 4); table->RawData = IM_ALLOC(span_allocator.GetArenaSizeInBytes()); memset(table->RawData, 0, span_allocator.GetArenaSizeInBytes()); span_allocator.SetArenaBasePtr(table->RawData);