crash with Font

[sonoro1234]

Hello Omar,

If I use:

imgui.ImGui_ImplGlfwGL3_Init(self.window, false);
imgui.ImFontAtlas_AddFontFromFileTTF(imgui.igGetIO().Fonts, [[C:\luaGL\ProggyTiny.ttf]], 10, nil, nil)

I am getting crashes so I did gdb with Debug and RelWithDebInfo:

--Debug version

Program: C:\luaGL\luajit.exe
File: C:\luaGL\gitsources\cimgui\imgui\imgui_draw.cpp, Line 1278

Expression: font_offset >= 0

This application has requested the Runtime to terminate it in an unusual way.

--RelWithDebInfo

Program received signal SIGSEGV, Segmentation fault.
SetCurrentFont (font=0x3be170) at C:\luaGL\gitsources\cimgui\imgui\imgui.cpp:4636
4636        g.FontTexUvWhitePixel = g.Font->ContainerAtlas->TexUvWhitePixel;


Thread 1 (Thread 4812.0xa24):
#0  SetCurrentFont (font=0x3be170) at C:\luaGL\gitsources\cimgui\imgui\imgui.cpp:4636
#1  0x6bd13a66 in ImGui::NewFrame () at C:\luaGL\gitsources\cimgui\imgui\imgui.cpp:2142
#2  0x6bd4066b in ImGui_ImplGlfwGL3_NewFrame ()
    at C:\luaGL\gitsources\cimgui\extras\impl_glfw3\imgui_impl_glfw_gl3.cpp:401
#3  0x66d84bb2 in ?? () from C:\luaGL\lua51.dll

but I am not able to make conclusions.
1278 is ImFontAtlas::Build()

Thanks

[ocornut]

Is your filename correct? I am not sure what \ means in your language but in c++ it would escape the next character. Do you have asserts enabled? It looks like you are missing some diagnostics checks.

…

On 24 Dec 2016, at 12:32, Victor Bombi ***@***.***> wrote: Hello Omar, If I use: imgui.ImGui_ImplGlfwGL3_Init(self.window, false); imgui.ImFontAtlas_AddFontFromFileTTF(imgui.igGetIO().Fonts, [[C:\luaGL\ProggyTiny.ttf]], 10, nil, nil) I am getting crashes so I did gdb with Debug and RelWithDebInfo: --Debug version Program: C:\luaGL\luajit.exe File: C:\luaGL\gitsources\cimgui\imgui\imgui_draw.cpp, Line 1278 Expression: font_offset >= 0 This application has requested the Runtime to terminate it in an unusual way. --RelWithDebInfo Program received signal SIGSEGV, Segmentation fault. SetCurrentFont (font=0x3be170) at C:\luaGL\gitsources\cimgui\imgui\imgui.cpp:4636 4636 g.FontTexUvWhitePixel = g.Font->ContainerAtlas->TexUvWhitePixel; Thread 1 (Thread 4812.0xa24): #0 SetCurrentFont (font=0x3be170) at C:\luaGL\gitsources\cimgui\imgui\imgui.cpp:4636 #1 0x6bd13a66 in ImGui::NewFrame () at C:\luaGL\gitsources\cimgui\imgui\imgui.cpp:2142 #2 0x6bd4066b in ImGui_ImplGlfwGL3_NewFrame () at C:\luaGL\gitsources\cimgui\extras\impl_glfw3\imgui_impl_glfw_gl3.cpp:401 #3 0x66d84bb2 in ?? () from C:\luaGL\lua51.dll but I am not able to make conclusions. 1278 is ImFontAtlas::Build() Thanks ― You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute the thread.

[sonoro1234]

Filename is ok in Lua and ImFontAtlas_AddFontFromFileTTF returns not null.
Are asserts enabled building for Debug?

[ocornut]

Assert being enabled or not is up your building configuration and where it goes when calling assert(), unless you have redefined IM_ASSERT in imconfig.h From your log your should have stopped/crashed on the IM_ASSERT(font_offset >= 0); line and not gone any further than that. We are calling stbtt_GetFontOffsetForIndex() and it returns an error so either the font data is invalid, either the FontNo is invalid, either there is a bug/issue in stb_truetype.h. Maybe first try with one of the ttf file provided in extra_fonts/ because those definitively works.

…

Sent from my fax machine

[sonoro1234]

I could check that the pointer in SetCurrentFont is the same returned from ImFontAtlas_AddFontFromFileTTF

[sonoro1234]

ProggyTiny.ttf is from extra_fonts

[sonoro1234]

Also : there are two gdb traces, one for Debug the other for Release with debug information

[ocornut]

Use a debugger to trace thru the code!

[sonoro1234]

(gdb) print cfg
$1 = (ImFontConfig &) @0x5fe4b8: {FontData = 0x3ac0048, FontDataSize = 68677, FontDataOwnedByAtlas = true,
  FontNo = 0, SizePixels = 10, OversampleH = 3, OversampleV = 1, PixelSnapH = false, GlyphExtraSpacing = {
    x = 0, y = 0}, GlyphRanges = 0x0, MergeMode = false, MergeGlyphCenterV = false,
  Name = "ProggyTiny.ttf, 10px", '\000' <repeats 11 times>, DstFont = 0x5fe170}

[sonoro1234]

A lot of noise for: Fake ProggyTiny.ttf
It was an html file saved with that name!!
(inspecting the data in the debugger revealed it)
Everything works now
Sorry

[ocornut]

Your assert should really crash/halt your application, this is what asserts are for.
I can silently fail or keep returning error codes but it'll have to fail at some point (main loop needs at least one valid font).