From 487d7f9a296cec2af496b64f6eb9d939fc8fae33 Mon Sep 17 00:00:00 2001 From: ocornut Date: Thu, 16 Jan 2025 22:30:43 +0100 Subject: [PATCH] Font: Internals: make used page maps smaller. Since it's extremely rarely used and for iterations only. ~34->16 bytes with ImWchar32. --- imgui.cpp | 4 ++-- imgui.h | 2 +- imgui_draw.cpp | 20 ++++++++++---------- 3 files changed, 13 insertions(+), 13 deletions(-) diff --git a/imgui.cpp b/imgui.cpp index 7c08e6e87..b326c444d 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -16177,9 +16177,9 @@ void ImGui::DebugNodeFont(ImFont* font) // Skip ahead if a large bunch of glyphs are not present in the font (test in chunks of 4k) // This is only a small optimization to reduce the number of iterations when IM_UNICODE_MAX_CODEPOINT // is large // (if ImWchar==ImWchar32 we will do at least about 272 queries here) - if (!(base & 4095) && font->IsGlyphRangeUnused(base, base + 4095)) + if (!(base & 8191) && font->IsGlyphRangeUnused(base, base + 8191)) { - base += 4096 - 256; + base += 8192 - 256; continue; } diff --git a/imgui.h b/imgui.h index b111407e2..bcf0ac403 100644 --- a/imgui.h +++ b/imgui.h @@ -3461,7 +3461,7 @@ struct ImFont float Scale; // 4 // in // = 1.f // Base font scale, multiplied by the per-window font scale which you can adjust with SetWindowFontScale() float Ascent, Descent; // 4+4 // out // // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize] (unscaled) int MetricsTotalSurface;// 4 // out // // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs) - ImU8 Used4kPagesMap[(IM_UNICODE_CODEPOINT_MAX+1)/4096/8]; // 2 bytes if ImWchar=ImWchar16, 34 bytes if ImWchar==ImWchar32. Store 1-bit for each block of 4K codepoints that has one active glyph. This is mainly used to facilitate iterations across all used codepoints. + ImU8 Used8kPagesMap[(IM_UNICODE_CODEPOINT_MAX+1)/8192/8]; // 1 bytes if ImWchar=ImWchar16, 16 bytes if ImWchar==ImWchar32. Store 1-bit for each block of 4K codepoints that has one active glyph. This is mainly used to facilitate iterations across all used codepoints. // Methods IMGUI_API ImFont(); diff --git a/imgui_draw.cpp b/imgui_draw.cpp index e8c445dd3..67a993de5 100644 --- a/imgui_draw.cpp +++ b/imgui_draw.cpp @@ -3689,7 +3689,7 @@ ImFont::ImFont() Scale = 1.0f; Ascent = Descent = 0.0f; MetricsTotalSurface = 0; - memset(Used4kPagesMap, 0, sizeof(Used4kPagesMap)); + memset(Used8kPagesMap, 0, sizeof(Used8kPagesMap)); } ImFont::~ImFont() @@ -3709,7 +3709,7 @@ void ImFont::ClearOutputData() DirtyLookupTables = true; Ascent = Descent = 0.0f; MetricsTotalSurface = 0; - memset(Used4kPagesMap, 0, sizeof(Used4kPagesMap)); + memset(Used8kPagesMap, 0, sizeof(Used8kPagesMap)); } static ImWchar FindFirstExistingGlyph(ImFont* font, const ImWchar* candidate_chars, int candidate_chars_count) @@ -3732,7 +3732,7 @@ void ImFont::BuildLookupTable() IndexAdvanceX.clear(); IndexLookup.clear(); DirtyLookupTables = false; - memset(Used4kPagesMap, 0, sizeof(Used4kPagesMap)); + memset(Used8kPagesMap, 0, sizeof(Used8kPagesMap)); GrowIndex(max_codepoint + 1); for (int i = 0; i < Glyphs.Size; i++) { @@ -3741,8 +3741,8 @@ void ImFont::BuildLookupTable() IndexLookup[codepoint] = (ImWchar)i; // Mark 4K page as used - const int page_n = codepoint / 4096; - Used4kPagesMap[page_n >> 3] |= 1 << (page_n & 7); + const int page_n = codepoint / 8192; + Used8kPagesMap[page_n >> 3] |= 1 << (page_n & 7); } // Create a glyph to handle TAB @@ -3804,15 +3804,15 @@ void ImFont::BuildLookupTable() } } -// API is designed this way to avoid exposing the 4K page size +// API is designed this way to avoid exposing the 8K page size // e.g. use with IsGlyphRangeUnused(0, 255) bool ImFont::IsGlyphRangeUnused(unsigned int c_begin, unsigned int c_last) { - unsigned int page_begin = (c_begin / 4096); - unsigned int page_last = (c_last / 4096); + unsigned int page_begin = (c_begin / 8192); + unsigned int page_last = (c_last / 8192); for (unsigned int page_n = page_begin; page_n <= page_last; page_n++) - if ((page_n >> 3) < sizeof(Used4kPagesMap)) - if (Used4kPagesMap[page_n >> 3] & (1 << (page_n & 7))) + if ((page_n >> 3) < sizeof(Used8kPagesMap)) + if (Used8kPagesMap[page_n >> 3] & (1 << (page_n & 7))) return false; return true; }