ref: f42e6595e61b9e65946f9a8b36eecbf8b9a3e26c
parent: a6c747d2b5c45ba08be27547065c343ba95472e3
author: Werner Lemberg <[email protected]>
date: Wed Nov 8 15:21:38 EST 2000
Minor fixes.
--- a/docs/ft2faq.html
+++ b/docs/ft2faq.html
@@ -104,19 +104,19 @@
<ul><p>
<li>
<a href="#other-color">How can I set the color of text rendered
- by FreeType ?</a>
+ by FreeType?</a>
</li>
<li>
<a href="#other-depth">Can I use FreeType to draw text on a pixmap
- with arbitrary depth ?</a>
+ with arbitrary depth?</a>
</li>
<li>
- <a href="#other-size">I set the pixel size to 8x8, but the resulting
- glyphs are larger than that. Why ?</a>
+ <a href="#other-size">I set the pixel size to 8x8, but the
+ resulting glyphs are larger than that. Why?</a>
</li>
<li>
<a href="#other-bbox">How can I compute the bounding box of a text
- string without loading its glyphs ?</a>
+ string without loading its glyphs?</a>
</li>
<li>
<a href="#other-antialias">Which anti-aliasing algorithm is
@@ -567,112 +567,111 @@
<a name="other-depth">
<h3>
- IV.1 Can I use FreeType to draw text on a pixmap with arbitratry depth ?
+ IV.1 Can I use FreeType to draw text on a pixmap with arbitratry depth?
</h3>
- <p>No directly, as FreeType is a font library, not a general purpose
- graphics library or text rendering service. However, note that the
+ <p>Not directly, as FreeType is a font library, not a general purpose
+ graphics library or text rendering service. However, note that the
anti-aliased renderer allows you to convert a vectorial glyph outline
- into a list of "spans" (i.e. horizontal pixel segments with same coverage)
- that can be rendered through user-provided callbacks.</p>
+ into a list of "spans" (i.e. horizontal pixel segments with same
+ coverage) that can be rendered through user-provided callbacks.</p>
- <p>By providing the appropriate span callback, you can render anti-aliased
- text to any kind of surface. You can also use any color or fill
- pattern/image if you want to. This process is called
- <em>direct rendering</em>. For more information, please read the
- documentation contained in the following files:</p>
+ <p>By providing the appropriate span callback, you can render
+ anti-aliased text to any kind of surface. You can also use any color or
+ fill pattern/image if you want to. This process is called <em>direct
+ rendering</em>. For more information, please read the documentation
+ contained in the following files:</p>
- <ul>
- <li><p>
- <b><tt><freetype/ftimage.h></tt></b> contains the definition
- of the <tt>FT_Raster_Params</tt> type used with direct rendering.
- </p></li>
-
- <li><p>
- <b><tt><freetype/ftoutln.h></tt></b> contains the definition
- of the <tt>FT_Outline_Render</tt> function that can be used to
- convert vectorial outlines to span lists.
- </p></li>
- </ul>
+ <ul>
+ <li>
+ <p><tt><freetype/ftimage.h></tt> contains the definition of
+ the <tt>FT_Raster_Params</tt> type used with direct rendering.</p>
+ </li>
+ <li>
+ <p><tt><freetype/ftoutln.h></tt> contains the definition of
+ the <tt>FT_Outline_Render()</tt> function that can be used to
+ convert vectorial outlines to span lists.</p>
+ </li>
+ </ul>
- <p>Here's some code that uses them:</p>
- <font color="blue"><pre>
-
- FT_Raster_Params params;
- FT_Outline outline;
+ <p>Here's some code that uses them:</p>
+
+ <font color="blue"><pre>
+ FT_Raster_Params params;
+ FT_Outline outline;
- .. load vectorial glyph in "outline"
+
+ ... load vectorial glyph in "outline" ...
- params.flags = ft_raster_flag_aa | ft_raster_flag_direct;
- params.gray_spans = (FT_Raster_Span_Func)your_own_span_function_here;
- params.user = your_own_data_pointer;
+ params.flags = ft_raster_flag_aa | ft_raster_flag_direct;
+ params.gray_spans = (FT_Raster_Span_Func)your_own_span_function_here;
+ params.user = your_own_data_pointer;
- error = FT_Outline_Render( library, &outline, &params );
- </pre></font>
+ error = FT_Outline_Render( library, &outline, &params );</pre>
+ </font>
- <p>Note that direct rendering is <em>not</em> available with monochrome
- output, as the current renderer uses a two-pass algorithm to generate
- glyphs with correct drop-out control.</p>
+ <p>Note that direct rendering is <em>not</em> available with monochrome
+ output, as the current renderer uses a two-pass algorithm to generate
+ glyphs with correct drop-out control.</p>
<hr>
<a name="other-color">
<h3>
- IV.2 How can I set the color of text rendered by FreeType ?
+ IV.2 How can I set the color of text rendered by FreeType?
</h3>
-
+
<p>Basically, you can't do that, because FreeType is simply a font
- library. In general, you'll need to use your favorite graphics library
- to draw the FreeType glyphs with the appropriate color.</p>
+ library. In general, you will need to use your favorite graphics
+ library to draw the FreeType glyphs with the appropriate color.</p>
<p>Note that for anti-aliased glyphs, you can "set the color" by using
<em>direct rendering</em> as described in <a href="#other-depth">this
- answer</a></p>
+ answer</a>.</p>
-
<hr>
<a name="other-size">
<h3>
IV.3 I set the pixel size to 8x8, but the resulting glyphs are larger
- (or smaller) than that. Why ??
+ (or smaller) than that. Why?
</h3>
- <p>A lot of people have a hard time understanding this topic, because
- they think of glyphs as fixed-width/height "cells", like those of
- fonts used in terminals/consoles. This assumption is simply not valid
- with most "modern" font formats, even bitmapped-based ones like
- PCF or BDF.</p>
+ <p>A lot of people have difficulties to understand this topic, because
+ they think of glyphs as fixed-width resp. fixed-height "cells", like
+ those of fonts used in terminals/consoles. This assumption is simply
+ not valid with most "modern" font formats, even bitmapped-based ones
+ like <tt>PCF</tt> or <tt>BDF</tt>.</p>
<p>Be aware that the <em>character size</em> that is set either through
- <tt>FT_Set_Char_Size</tt> or <tt>FT_Set_Pixel_Sizes</tt> isn't directly
- related to the dimension of the glyph bitmaps generated.</p>
+ <tt>FT_Set_Char_Size()</tt> or <tt>FT_Set_Pixel_Sizes()</tt> isn't
+ directly related to the dimension of the glyph bitmaps generated.</p>
- <p>Rather, the character size is indeed the size of
- <em>an abstract square</em>, called the <em>EM</em>, used by typographers
- to design fonts. Scaling two distinct fonts to the same character size, be
- it expressed in points or pixels, will generally result in bitmaps with
- <em>distinct dimensions</em> !</p>
+ <p>Rather, the character size is indeed the size of <em>an abstract
+ square</em>, called the <em>EM</em>, used by typographers to design
+ fonts. Scaling two distinct fonts to the same character size, be it
+ expressed in points or pixels, will generally result in bitmaps with
+ <em>distinct dimensions</em>!</p>
<p>Note that historically, the EM corresponded to the width of a capital
- "M" in Latin typefaces. However, later improvements in typography led to
- the designs that greatly detract from this rule. Today, it is not possible
- to connect the EM size to a specific font "feature" in a reliable way.</p>
+ "M" in Latin typefaces. However, later improvements in typography led
+ to designs that greatly detract from this rule. Today, it is not
+ possible to connect the EM size to a specific font "feature" in a
+ reliable way.</p>
<hr>
-
<a name="other-bbox">
<h3>
- IV.4 How can I compute the bounding box of a given string of text without
- loading its glyphs before ?
+ IV.4 How can I compute the bounding box of a given string of text
+ without loading its glyphs before?
</h3>
- <p>A lot of people want to be able to compute the size in pixels of a simple
- string of text with minimal overhead. For example, that can be useful to
- draw centered text within a button.</p>
-
-
+ <p>A lot of people want to be able to compute the size in pixels of a
+ simple string of text with minimal overhead. For example, that can be
+ useful to draw centered text within a button. (to be continued...)</p>
+
+ <hr>
<a name="other-antialias">
<h3>
- IV.1 Which anti-aliasing algorithm is used by FreeType 2?</h3>
+ IV.5 Which anti-aliasing algorithm is used by FreeType 2?</h3>
<p>The algorithm has been specifically designed for FreeType. It is
based on ideas that were originally found in the implementation of the
@@ -699,7 +698,7 @@
<hr>
<a name="other-opentype">
<h3>
- IV.2 When will FreeType 2 support OpenType?
+ IV.6 When will FreeType 2 support OpenType?
</h3>
<p>Well, the engine already reads OpenType/CFF files perfectly. What it
@@ -707,7 +706,7 @@
<p>FreeType 1 comes with a set of extensions that are used to load
and manage OpenType Layout tables. It even has a demonstration program
- named "<tt>ftstrtto</tt>" to show its capabilities.</p>
+ named <tt>ftstrtto</tt> to show its capabilities.</p>
<p>For FreeType 2, we have decided that the layout operations
provided through these tables are better placed in a specific