mirror of https://github.com/freetype/freetype
grammatical fixes
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@ -151,12 +151,12 @@
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3. Character and font metrics
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</h3>
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<p>Each glyph image is associated to various metrics which are used to
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describe how must be placed and managed when rendering text. Though
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they are described in more details in section III, they relate to
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glyph placement, cursor advances as well as text layout. They are
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extremely important to compute the flow of text when rendering a string
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of text.</p>
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<p>Each glyph image is associated with various metrics which are used to
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describe how it must be placed and managed when rendering text. These
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are described in more details in section III; they relate to glyph
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placement, cursor advances as well as text layout. They are extremely
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important to compute the flow of text when rendering a string of
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text.</p>
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<p>Each scalable format also contains some global metrics, expressed in
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notional units, to describe some properties of all glyphs in the same
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@ -164,8 +164,8 @@
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the ascender, descender and text height for the font.</p>
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<p>Though these metrics also exist for non-scalable formats, they only
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apply for a set of given character dimensions and resolutions, and
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they are usually expressed in pixels then.</p>
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apply for a set of given character dimensions and resolutions, and are
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usually expressed in pixels.</p>
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<p><hr></p>
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@ -62,13 +62,14 @@
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<tr bgcolor="#CCCCFF"
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valign=center><td>
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<h2>
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II. Glyph mutlines
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II. Glyph outlines
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</h2>
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</td></tr>
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</table>
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<p>This section describes the way scalable representation of glyph images,
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called outlines, are used by FreeType as well as client applications.</p>
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<p>This section describes the way scalable representations of glyph
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images, called outlines, are used by FreeType as well as client
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applications.</p>
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<a name="section-1">
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<h3>
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@ -94,7 +95,7 @@
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<em>points</em>, rather than device-specific pixels. Points are a
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simple <em>physical</em> unit, where 1 point = 1/72th of
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an inch, in digital typography. As an example, most Roman books are
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printed with a body text which size is chosen between 10 and
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printed with a body text whose size is somewhere between 10 and
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14 points.</p>
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<p>It is thus possible to compute the size of text in pixels from the
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@ -148,7 +149,7 @@
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<p>In creating the glyph outlines, a type designer uses an imaginary
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square called the <em>EM square</em>. Typically, the EM square can be
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thought of as a tablet on which the character are drawn. The square's
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thought of as a tablet on which the characters are drawn. The square's
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size, i.e., the number of grid units on its sides, is very important for
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two reasons:</p>
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@ -218,7 +219,7 @@
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<p>As a consequence, proper glyph rendering needs the scaled points to
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be aligned along the target device pixel grid, through an operation
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called <em>grid-fitting</em>, and often <em>hinting</em>. One of its
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called <em>grid-fitting</em> (often called<em>hinting</em>). One of its
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main purposes is to ensure that important widths and heights are
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respected throughout the whole font (for example, it is very often
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desirable that the "I" and the "T" have their central vertical line of
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@ -255,9 +256,10 @@
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<p><em>automatic grid-fitting</em></p>
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<p>Some formats simply include no control information with each
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glyph outline, apart metrics like the advance width and height. It
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is then up to the renderer to "guess" the more interesting features
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of the outline in order to perform some decent grid-fitting.</p>
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glyph outline, apart from metrics like the advance width and height.
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It is then up to the renderer to "guess" the more interesting
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features of the outline in order to perform some decent
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grid-fitting.</p>
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</li>
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</ul>
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@ -306,7 +308,7 @@
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<p><b>Size.</b> Glyph programs can be long.</p>
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<p><b>Technicity.</b>
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<p><b>Technical difficulty.</b>
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It is extremely difficult to write good hinting
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programs. Very few tools available.</p>
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</td>
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@ -212,7 +212,7 @@
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<p>The horizontal distance from the current pen position to the
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glyph's left bbox edge. It is positive for horizontal layouts, and
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in most cases negative for vertical one.</p>
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in most cases negative for vertical ones.</p>
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</li>
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<li>
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@ -220,7 +220,7 @@
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<p>The vertical distance from the baseline to the top of the glyph's
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bbox. It is usually positive for horizontal layouts, and negative
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for vertical ones</p>
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for vertical ones.</p>
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</li>
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<li>
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<ul>
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<li>
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Because of hinting, simply scaling the font ascent or descent might
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not give correct results. A possible solution is to keepthe ceiling
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of the scaled ascent, and floor of the scaled descent.
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not give correct results. A possible solution is to keep the
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ceiling of the scaled ascent, and floor of the scaled descent.
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</li>
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<li>
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@ -78,7 +78,7 @@
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1. Kerning pairs
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</h3>
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<p>Kerning consists in modifying the spacing between two successive
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<p>Kerning consists of modifying the spacing between two successive
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glyphs according to their outlines. For example, a "T" and a "y" can be
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easily moved closer, as the top of the "y" fits nicely under the upper
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right bar of the "T".</p>
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@ -331,8 +331,8 @@
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</h3>
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<p>An outline point's vectorial coordinates are expressed in the
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26.6 format, i.e. in 1/64th of a pixel, hence coordinates
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(1.0,-2.5) is stored as the integer pair (x:64,y:-192).</p>
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26.6 format, i.e. in 1/64th of a pixel, hence the coordinates
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(1.0,-2.5) are stored as the integer pair (x:64,y:-192).</p>
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<p>After a master glyph outline is scaled from the EM grid to the
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current character dimensions, the hinter or grid-fitter is in charge of
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@ -182,9 +182,9 @@
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<tt>num_grays</tt>
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</td>
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<td valign=top>
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this is only used for "gray" pixel modes, it gives the number of
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this is only used for "gray" pixel modes; it gives the number of
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gray levels used to describe the anti-aliased gray levels --
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256 by default with FreeType 2
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FreeType 2 defaults to 256 grays.
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</td>
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</tr>
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</table>
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