Share font file memory usage? #2234

New issue

Closed

opened 2018-12-11 04:00:21 +00:00 by leozzyzheng · 1 comment

leozzyzheng commented

2018-12-11 04:00:21 +00:00

(Migrated from github.com)

Version/Branch of Dear ImGui:

Version: 1.65
Branch: release version

Back-end/Renderer/Compiler/OS

Back-ends: imgui_impl_win32.cpp + imgui_impl_dx9.cpp
Compiler: VS2015 with update 3, version 14.0.25420.1
Operating System: Windows 7 x64

My Issue/Question:

When I need to set different font size for different text, I need load font for each size, and each AddFontFromFileTTF will read the TTF file into memory. In my case, I use 3 times so I see the three times memory usage for the same TTF file, so is it possible to share only one TTF file to save the memory usage?

Standalone, minimal, complete and verifiable example: (see CONTRIBUTING.md)
See the line 5

ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels, const ImFontConfig* font_cfg_template, const ImWchar* glyph_ranges)
{
    IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!");
    size_t data_size = 0;
    void* data = ImFileLoadToMemory(filename, "rb", &data_size, 0);  <- Here load file no matter whether it is loaded before
    if (!data)
    {
        IM_ASSERT(0); // Could not load file.
        return NULL;
    }
    ImFontConfig font_cfg = font_cfg_template ? *font_cfg_template : ImFontConfig();
    if (font_cfg.Name[0] == '\0')
    {
        // Store a short copy of filename into into the font name for convenience
        const char* p;
        for (p = filename + strlen(filename); p > filename && p[-1] != '/' && p[-1] != '\\'; p--) {}
        ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "%s, %.0fpx", p, size_pixels);
    }
    return AddFontFromMemoryTTF(data, (int)data_size, size_pixels, &font_cfg, glyph_ranges);
}

Screenshots/Video (you can drag files here)

**Version/Branch of Dear ImGui:** Version: 1.65 Branch: release version **Back-end/Renderer/Compiler/OS** Back-ends: imgui_impl_win32.cpp + imgui_impl_dx9.cpp Compiler: VS2015 with update 3, version 14.0.25420.1 Operating System: Windows 7 x64 **My Issue/Question:** When I need to set different font size for different text, I need load font for each size, and each `AddFontFromFileTTF` will read the TTF file into memory. In my case, I use 3 times so I see the three times memory usage for the same TTF file, so is it possible to share only one TTF file to save the memory usage? **Standalone, minimal, complete and verifiable example:** _(see CONTRIBUTING.md)_ See the line 5 ``` ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels, const ImFontConfig* font_cfg_template, const ImWchar* glyph_ranges) { IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!"); size_t data_size = 0; void* data = ImFileLoadToMemory(filename, "rb", &data_size, 0); <- Here load file no matter whether it is loaded before if (!data) { IM_ASSERT(0); // Could not load file. return NULL; } ImFontConfig font_cfg = font_cfg_template ? *font_cfg_template : ImFontConfig(); if (font_cfg.Name[0] == '\0') { // Store a short copy of filename into into the font name for convenience const char* p; for (p = filename + strlen(filename); p > filename && p[-1] != '/' && p[-1] != '\\'; p--) {} ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "%s, %.0fpx", p, size_pixels); } return AddFontFromMemoryTTF(data, (int)data_size, size_pixels, &font_cfg, glyph_ranges); } ``` **Screenshots/Video** _(you can drag files here)_ ![image](https://user-images.githubusercontent.com/6134295/49777604-30990580-fd3c-11e8-9d91-2cdb9b615045.png)

leozzyzheng commented

2018-12-11 06:48:41 +00:00

(Migrated from github.com)

I think I could manually read the TTF file and use AddFontFromMemoryTTF to load font and also set FontDataOwnedByAtlas to true.

I think I could manually read the TTF file and use `AddFontFromMemoryTTF` to load font and also set `FontDataOwnedByAtlas` to true.

👍 1