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mirror of https://github.com/ocornut/imgui.git synced 2025-02-08 23:19:40 +01:00

Font: Internals: make used page maps smaller. Since it's extremely rarely used and for iterations only. ~34->16 bytes with ImWchar32.

This commit is contained in:
ocornut 2025-01-16 22:30:43 +01:00
parent f2262eb81a
commit 487d7f9a29
3 changed files with 13 additions and 13 deletions

View File

@ -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;
}

View File

@ -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();

View File

@ -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;
}