Package: libftgl2 Version: 2.1.3~rc5-3 Severity: normal Tags: patch *** Please type your report below this line ***
Most of this report corresponds to Debian bug #531489, with my patches updated to the current FTGL version in Debian testing. 1. FTPolygonGlyph and FTOutlineGlyph segfault when given a font of a wrong type, e.g. a bitmap type. This is because vectorizer is uninitialized, and the constructor in this case returns before setting it. My patch (FTPolygonGlyph.cpp, FTOutlineGlyph.cpp) adds the initialization (copied from FTExtrudeGlyph) and prevents the crashing. 2. FTPixmapGlyph also doesn't check whether its impl is valid, which it would not be, again, in case of a bitmap type. In this case, it doesn't crash (in my tests), but draws garbage. The patch (FTBitmapGlyphImpl.h, FTPixmapGlyph.h, FTPixmapGlyph.cpp) adds this check, and in this case just creates an FTBitmapGlyphImpl and delegates the work to it. Also I add a check in FTPixmapGlyphImpl for the case of "num_grays == 1" which is valid according to the specification, though it might occur rarely. In this case, the font is effectively a bitmap, and is treated as such. 3. FTBitmapFontImpl disables GL_BLEND. While, of course, it does not need to enable it, unlike e.g. pixmap fonts, I don't think it's useful to disable it unconditionally, instead of leaving the choice to the caller. The patch (FTBitmapFont.cpp) removes the disabling. If the caller doesn't explicitly set GL_BLEND, nothing changes, but if they set it, and set a color with alpha < 1, bitmap fonts can now be drawn with transparency. 4. Bitmap fonts cannot be used as FTGLTextureFont, which is a serious disadvantage, since unlike textures, bitmaps cannot be rotated, scaled, etc. in OpenGL. This in particular affects X11 .pcf fonts. It might also apply to TrueType fonts with embedded bitmaps: When googling for the problem, I found this message on the FreeType list: http://osdir.com/ml/fonts.freetype.devel/2005-03/msg00091.html It might refer to the same problem, so the diagnosis offered in the reply might apply to FTGL which was used there as well. The patch (FTTextureGlyph.cpp) converts bitmaps to pixmaps in FTTextureGlyphImpl, so they can be used now. 5. (New issue, not in #531489) FTContour::ComputeOutsetPoint computes an invalid point (-nan, -nan), when two edges form an angle of nearly 180°. (I'm not sure if this is somehow invalid according to the spec, but it actually occurs, e.g., with the "F" character in the font "El Abogado Loco" as installed in squeeze.) This is because norm + tmp.X() goes to 0, and therefore the fraction to infinity, when the angle approaches 180°. It is not merely a numeric problem, but the intersection point actually goes to infinity. The visible effect is that drawing such glyphs creates some spurious lines to the edge of the visual (even if Outset is not used, because 0 * inf is nan, so it's a regression compared to previous versions that didn't have Outset). Since it's an actual geometric problem, there is no obvious numeric solution. In my patch (FTContour.cpp), I just limit the outset point's distance (which also avoids ugly results, when the angle is just somewhat close to 180°, where there is no numeric problem yet, but the outset point would be very far away from A, B and C). Another solution might be to insert two outset points instead of one, say when the angle is > 90° (or < -90°), but that would be a bigger change. -- System Information: Debian Release: squeeze/sid APT prefers testing APT policy: (500, 'testing') Architecture: i386 (i686) Kernel: Linux 2.6.34 (SMP w/1 CPU core) Locale: LANG=de_DE, LC_CTYPE=de_DE (charmap=ISO-8859-1) Shell: /bin/sh linked to /bin/dash Versions of packages libftgl2 depends on: ii libc6 2.11.2-2 Embedded GNU C Library: Shared lib ii libfreetype6 2.4.0-1 FreeType 2 font engine, shared lib ii libgcc1 1:4.4.4-6 GCC support library ii libgl1-mesa-glx [libgl1 7.7.1-3 A free implementation of the OpenG ii libglu1-mesa [libglu1] 7.7.1-3 The OpenGL utility library (GLU) ii libstdc++6 4.4.4-6 The GNU Standard C++ Library v3 ii zlib1g 1:1.2.3.4.dfsg-3 compression library - runtime libftgl2 recommends no packages. libftgl2 suggests no packages. -- no debconf information
ftgl.patch
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