Move imgui's stb truetype to render_core, and make it the only available implementation.

sfw/render_core/3rd_stb_truetype.h

@@ -1,3 +1,8 @@
+// [DEAR IMGUI]
+// This is a slightly modified version of stb_truetype.h 1.26.
+// Mostly fixing for compiler and static analyzer warnings.
+// Grep for [DEAR IMGUI] to find the changes.
+
 // stb_truetype.h - v1.26 - public domain
 // authored from 2009-2021 by Sean Barrett / RAD Game Tools
 //
@@ -651,7 +656,7 @@ STBTT_DEF void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h
 STBTT_DEF void stbtt_PackSetSkipMissingCodepoints(stbtt_pack_context *spc, int skip);
 // If skip != 0, this tells stb_truetype to skip any codepoints for which
 // there is no corresponding glyph. If skip=0, which is the default, then
-// codepoints without a glyph recived the font's "missing character" glyph,
+// codepoints without a glyph received the font's "missing character" glyph,
 // typically an empty box by convention.
 
 STBTT_DEF void stbtt_GetPackedQuad(const stbtt_packedchar *chardata, int pw, int ph,  // same data as above
@@ -2003,7 +2008,7 @@ static stbtt__buf stbtt__cid_get_glyph_subrs(const stbtt_fontinfo *info, int gly
          start = end;
       }
    }
-   if (fdselector == -1) stbtt__new_buf(NULL, 0);
+   if (fdselector == -1) return stbtt__new_buf(NULL, 0); // [DEAR IMGUI] fixed, see #6007 and nothings/stb#1422
    return stbtt__get_subrs(info->cff, stbtt__cff_index_get(info->fontdicts, fdselector));
 }
 
@@ -3195,8 +3200,11 @@ static void stbtt__fill_active_edges_new(float *scanline, float *scanline_fill,
 
                // check if final y_crossing is blown up; no test case for this
                if (y_final > y_bottom) {
+                  int denom = (x2 - (x1+1));
                   y_final = y_bottom;
-                  dy = (y_final - y_crossing ) / (x2 - (x1+1)); // if denom=0, y_final = y_crossing, so y_final <= y_bottom
+                  if (denom != 0) { // [DEAR IMGUI] Avoid div by zero (https://github.com/nothings/stb/issues/1316)
+                     dy = (y_final - y_crossing ) / denom; // if denom=0, y_final = y_crossing, so y_final <= y_bottom
+                  }
                }
 
                // in second pixel, area covered by line segment found in first pixel
@@ -4302,7 +4310,7 @@ STBTT_DEF void stbtt_PackFontRangesPackRects(stbtt_pack_context *spc, stbrp_rect
 STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index, stbtt_pack_range *ranges, int num_ranges)
 {
    stbtt_fontinfo info;
-   int i,j,n, return_value = 1;
+   int i, j, n, return_value; // [DEAR IMGUI] removed = 1;
    //stbrp_context *context = (stbrp_context *) spc->pack_info;
    stbrp_rect    *rects;
 

sfw/render_gui/imconfig.h

@@ -12,7 +12,9 @@
 // Call IMGUI_CHECKVERSION() from your .cpp file to verify that the data structures your files are using are matching the ones imgui.cpp is using.
 //-----------------------------------------------------------------------------
 
+//--STRIP
 #pragma once
+//--STRIP
 
 //---- Define assertion handler. Defaults to calling assert().
 // If your macro uses multiple statements, make sure is enclosed in a 'do { .. } while (0)' block so it can be used as a single statement.
@@ -68,6 +70,7 @@
 //---- Avoid multiple STB libraries implementations, or redefine path/filenames to prioritize another version
 // By default the embedded implementations are declared static and not available outside of Dear ImGui sources files.
 //#define IMGUI_STB_TRUETYPE_FILENAME   "my_folder/stb_truetype.h"
+#define IMGUI_STB_TRUETYPE_FILENAME   "render_core/3rd_stb_truetype.h"
 //#define IMGUI_STB_RECT_PACK_FILENAME  "my_folder/stb_rect_pack.h"
 //#define IMGUI_STB_SPRINTF_FILENAME    "my_folder/stb_sprintf.h"    // only used if IMGUI_USE_STB_SPRINTF is defined.
 //#define IMGUI_DISABLE_STB_TRUETYPE_IMPLEMENTATION