Add a built-in Bitstream Vera Sans Roman font.

Before this commit, the default font chosen for TTF text is Arial
(chosen by the basename of arial.ttf), which isn't present on most
Linux systems, and cannot be redistributed. After this commit, it is
replaced with Bitstream Vera Sans, which can be. Existing files
are not affected.

The font name in the TTF file was artificially modified to add
the (built-in) suffix, which will need to be done if more built-in
fonts are added.

CHANGELOG.md

@@ -69,6 +69,8 @@ Other new features:
     the entity from a request is selected. For example, dragging a point on
     a face of an extrusion coincident with the source sketch plane will
     drag the point from the source sketch.
+  * The default font for TTF text is now Bitstream Vera Sans, which is
+    included in the resources such that it is available on any OS.
   * In expressions, numbers can contain the digit group separator, "_".
   * The "=" key is bound to "Zoom In", like "+" key.
   * The numpad decimal separator key is bound to "." regardless of locale.

THIRD_PARTIES.txt

@@ -0,0 +1,50 @@
+This file outlines third party licenses that apply to the files and resources
+listed with them. All file paths are relative to the SolveSpace project root.
+
+When redistributing SolveSpace, make sure to also reproduce this file such that
+the paths indicating the scope of each license remain intact.
+================================================================================
+
+        Bitstream Vera, ./res/fonts/BitstreamVeraSans-Roman-builtin.ttf
+                                       ~
+Copyright (c) 2003 by Bitstream, Inc. All Rights Reserved. Bitstream Vera is a
+trademark of Bitstream, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+the fonts accompanying this license (“Fonts”) and associated documentation files
+(the “Font Software”), to reproduce and distribute the Font Software, including
+without limitation the rights to use, copy, merge, publish, distribute, and/or
+sell copies of the Font Software, and to permit persons to whom the Font
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright and trademark notices and this permission notice shall be
+included in all copies of one or more of the Font Software typefaces.
+
+The Font Software may be modified, altered, or added to, and in particular the
+designs of glyphs or characters in the Fonts may be modified and additional
+glyphs or characters may be added to the Fonts, only if the fonts are renamed to
+names not containing either the words “Bitstream” or the word “Vera”.
+
+This License becomes null and void to the extent applicable to Fonts or Font
+Software that has been modified and is distributed under the “Bitstream Vera”
+names.
+
+The Font Software may be sold as part of a larger software package but no copy
+of one or more of the Font Software typefaces may be sold by itself.
+
+THE FONT SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF COPYRIGHT, PATENT, TRADEMARK, OR
+OTHER RIGHT. IN NO EVENT SHALL BITSTREAM OR THE GNOME FOUNDATION BE LIABLE FOR
+ANY CLAIM, DAMAGES OR OTHER LIABILITY, INCLUDING ANY GENERAL, SPECIAL, INDIRECT,
+INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+OTHERWISE, ARISING FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR
+FROM OTHER DEALINGS IN THE FONT SOFTWARE.
+
+Except as contained in this notice, the names of GNOME, the GNOME Foundation,
+and Bitstream Inc., shall not be used in advertising or otherwise to promote the
+sale, use or other dealings in this Font Software without prior written
+authorization from the GNOME Foundation or Bitstream Inc., respectively. For
+further information, contact: fonts at gnome dot org.
+
+                                  -----------

res/CMakeLists.txt

@@ -212,6 +212,7 @@ add_resources(
     fonts/private/6-stipple-dash.png
     fonts/private/7-stipple-zigzag.png
     fonts/unicode.lff.gz
+    fonts/BitstreamVeraSans-Roman-builtin.ttf
     shaders/imesh.frag
     shaders/imesh.vert
     shaders/imesh_point.frag

src/mouse.cpp

@@ -1107,7 +1107,7 @@ void GraphicsWindow::MouseLeftDown(double mx, double my) {
                     AddToPending(hr);
                     Request *r = SK.GetRequest(hr);
                     r->str = "Abc";
-                    r->font = "arial.ttf";
+                    r->font = "BitstreamVeraSans-Roman-builtin.ttf";
 
                     SK.GetEntity(hr.entity(1))->PointForceTo(v);
                     SK.GetEntity(hr.entity(2))->PointForceTo(v);

src/ttf.cpp

@@ -63,6 +63,14 @@ void TtfFontList::LoadAll() {
             l.Add(&tf);
     }
 
+    // Add builtin font to end of font list so it is displayed first in the UI
+    {
+        TtfFont tf = {};
+        tf.SetResourceID("fonts/BitstreamVeraSans-Roman-builtin.ttf");
+        if(tf.LoadFromResource(fontLibrary))
+            l.Add(&tf);
+    }
+
     // Sort fonts according to their actual name, not filename.
     std::sort(&l.elem[0], &l.elem[l.n],
         [](const TtfFont &a, const TtfFont &b) { return a.name < b.name; });
@@ -84,11 +92,14 @@ TtfFont *TtfFontList::LoadFont(const std::string &font)
     LoadAll();
 
     TtfFont *tf = std::find_if(l.begin(), l.end(),
-        [&](const TtfFont &tf) { return tf.FontFileBaseName() == font; });
+        [&font](const TtfFont &tf) { return tf.FontFileBaseName() == font; });
 
     if(tf != l.end()) {
         if(tf->fontFace == NULL) {
-            tf->LoadFromFile(fontLibrary, /*nameOnly=*/false);
+            if(tf->IsResource())
+                tf->LoadFromResource(fontLibrary, /*nameOnly=*/false);
+            else
+                tf->LoadFromFile(fontLibrary, /*nameOnly=*/false);
         }
         return tf;
     } else {
@@ -131,11 +142,22 @@ std::string TtfFont::FontFileBaseName() const {
 }
 
 //-----------------------------------------------------------------------------
-// Load a TrueType font into memory. We care about the curves that define
+// Convenience method to set fontFile for resource-loaded fonts as res://<path>
-// the letter shapes, and about the mappings that determine which glyph goes
+//-----------------------------------------------------------------------------
-// with which character.
+void TtfFont::SetResourceID(const std::string &resource) {
+    fontFile = { "res://" + resource };
+}
+
+bool TtfFont::IsResource() const {
+    return fontFile.raw.compare(0, 6, "res://") == 0;
+}
+
+//-----------------------------------------------------------------------------
+// Load a TrueType font into memory.
 //-----------------------------------------------------------------------------
 bool TtfFont::LoadFromFile(FT_Library fontLibrary, bool nameOnly) {
+    ssassert(!IsResource(), "Cannot load a font provided by a resource as a file.");
+
     FT_Open_Args args = {};
     args.flags    = FT_OPEN_PATHNAME;
     args.pathname = &fontFile.raw[0]; // FT_String is char* for historical reasons
@@ -149,6 +171,38 @@ bool TtfFont::LoadFromFile(FT_Library fontLibrary, bool nameOnly) {
         return false;
     }
 
+    return ExtractTTFData(nameOnly);
+}
+
+//-----------------------------------------------------------------------------
+// Load a TrueType from resource in memory. Implemented to load bundled fonts
+// through theresource system.
+//-----------------------------------------------------------------------------
+bool TtfFont::LoadFromResource(FT_Library fontLibrary, bool nameOnly) {
+    ssassert(IsResource(), "Font to be loaded as resource is not provided by a resource "
+             "or does not have the 'res://' prefix.");
+
+    size_t _size;
+    // substr to cut off 'res://' (length: 6)
+    const void *_buffer = Platform::LoadResource(fontFile.raw.substr(6, fontFile.raw.size()),
+                                                 &_size);
+
+    FT_Long size = static_cast<FT_Long>(_size);
+    const FT_Byte *buffer = reinterpret_cast<const FT_Byte*>(_buffer);
+
+    if(int fterr = FT_New_Memory_Face(fontLibrary, buffer, size, 0, &fontFace)) {
+            dbp("freetype: loading font '%s' from memory failed: %s",
+                fontFile.raw.c_str(), ft_error_string(fterr));
+            return false;
+    }
+
+    return ExtractTTFData(nameOnly);
+}
+
+//-----------------------------------------------------------------------------
+// Extract font information. We care about the font name and unit size.
+//-----------------------------------------------------------------------------
+bool TtfFont::ExtractTTFData(bool nameOnly) {
     if(int fterr = FT_Select_Charmap(fontFace, FT_ENCODING_UNICODE)) {
         dbp("freetype: loading unicode CMap for file '%s' failed: %s",
             fontFile.raw.c_str(), ft_error_string(fterr));

src/ttf.h

@@ -11,17 +11,23 @@
 
 class TtfFont {
 public:
-    Platform::Path  fontFile;
+    Platform::Path  fontFile; // or resource path/name as res://<path>
     std::string     name;
     FT_FaceRec_    *fontFace;
     double          capHeight;
 
+    void SetResourceID(const std::string &resource);
+    bool IsResource() const;
+
     std::string FontFileBaseName() const;
     bool LoadFromFile(FT_LibraryRec_ *fontLibrary, bool nameOnly = true);
+    bool LoadFromResource(FT_LibraryRec_ *fontLibrary, bool nameOnly = true);
 
     void PlotString(const std::string &str,
                     SBezierList *sbl, Vector origin, Vector u, Vector v);
     double AspectRatio(const std::string &str);
+
+    bool ExtractTTFData(bool nameOnly);
 };
 
 class TtfFontList {