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+
- <li class="md-nav__item">
- <a href="ft2-winfnt_fonts.html" title="Window FNT Files" class="md-nav__link">
- Window FNT Files
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item md-nav__item--nested">
+
+
+ <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_6" type="checkbox" id="__nav_6" >
+
+ <label class="md-nav__link" for="__nav_6">
+ Format-Specific API
+ <span class="md-nav__icon md-icon"></span>
+ </label>
+ <nav class="md-nav" aria-label="Format-Specific API" data-md-level="1">
+ <label class="md-nav__title" for="__nav_6">
+ <span class="md-nav__icon md-icon"></span>
+ Format-Specific API
+ </label>
+ <ul class="md-nav__list" data-md-scrollfix>
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-multiple_masters.html" class="md-nav__link">
+ Multiple Masters
+ </a>
+ </li>
+
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-truetype_tables.html" class="md-nav__link">
+ TrueType Tables
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-type1_tables.html" class="md-nav__link">
+ Type 1 Tables
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-sfnt_names.html" class="md-nav__link">
+ SFNT Names
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-bdf_fonts.html" class="md-nav__link">
+ BDF and PCF Files
+ </a>
+ </li>
+
- <li class="md-nav__item">
- <a href="ft2-font_formats.html" title="Font Formats" class="md-nav__link">
- Font Formats
- </a>
- </li>
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-cid_fonts.html" class="md-nav__link">
+ CID Fonts
+ </a>
+ </li>
+
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-pfr_fonts.html" class="md-nav__link">
+ PFR Fonts
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-winfnt_fonts.html" class="md-nav__link">
+ Window FNT Files
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-svg_fonts.html" class="md-nav__link">
+ OpenType SVG Fonts
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-font_formats.html" class="md-nav__link">
+ Font Formats
+ </a>
+ </li>
+
- <li class="md-nav__item">
- <a href="ft2-gasp_table.html" title="Gasp Table" class="md-nav__link">
- Gasp Table
- </a>
- </li>
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-gasp_table.html" class="md-nav__link">
+ Gasp Table
+ </a>
+ </li>
+
-
- </ul>
- </nav>
- </li>
+
+ </ul>
+ </nav>
+ </li>
+
-
-
- <li class="md-nav__item md-nav__item--active md-nav__item--nested">
+
- <input class="md-toggle md-nav__toggle" data-md-toggle="nav-6" type="checkbox" id="nav-6" checked>
+
+
- <label class="md-nav__link" for="nav-6">
- Controlling FreeType Modules
- </label>
- <nav class="md-nav" data-md-component="collapsible" data-md-level="1">
- <label class="md-nav__title" for="nav-6">
+ <li class="md-nav__item md-nav__item--active md-nav__item--nested">
+
+
+ <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_7" type="checkbox" id="__nav_7" checked>
+
+ <label class="md-nav__link" for="__nav_7">
Controlling FreeType Modules
+ <span class="md-nav__icon md-icon"></span>
</label>
- <ul class="md-nav__list" data-md-scrollfix>
-
-
-
+ <nav class="md-nav" aria-label="Controlling FreeType Modules" data-md-level="1">
+ <label class="md-nav__title" for="__nav_7">
+ <span class="md-nav__icon md-icon"></span>
+ Controlling FreeType Modules
+ </label>
+ <ul class="md-nav__list" data-md-scrollfix>
-
-
-
- <li class="md-nav__item">
- <a href="ft2-auto_hinter.html" title="The auto-hinter" class="md-nav__link">
- The auto-hinter
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-auto_hinter.html" class="md-nav__link">
+ The auto-hinter
+ </a>
+ </li>
+
-
-
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-cff_driver.html" class="md-nav__link">
+ The CFF driver
+ </a>
+ </li>
+
-
- <li class="md-nav__item">
- <a href="ft2-cff_driver.html" title="The CFF driver" class="md-nav__link">
- The CFF driver
- </a>
- </li>
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-t1_cid_driver.html" title="The Type 1 and CID drivers" class="md-nav__link">
- The Type 1 and CID drivers
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-t1_cid_driver.html" class="md-nav__link">
+ The Type 1 and CID drivers
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-tt_driver.html" title="The TrueType driver" class="md-nav__link">
- The TrueType driver
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-tt_driver.html" class="md-nav__link">
+ The TrueType driver
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-pcf_driver.html" title="The PCF driver" class="md-nav__link">
- The PCF driver
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-pcf_driver.html" class="md-nav__link">
+ The PCF driver
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-properties.html" title="Driver properties" class="md-nav__link">
- Driver properties
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-ot_svg_driver.html" class="md-nav__link">
+ The SVG driver
+ </a>
+ </li>
+
-
-
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-properties.html" class="md-nav__link">
+ Driver properties
+ </a>
+ </li>
+
-
- <li class="md-nav__item">
- <a href="ft2-parameter_tags.html" title="Parameter Tags" class="md-nav__link">
- Parameter Tags
- </a>
- </li>
-
-
-
-
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-parameter_tags.html" class="md-nav__link">
+ Parameter Tags
+ </a>
+ </li>
-
- <li class="md-nav__item md-nav__item--active">
-
- <input class="md-toggle md-nav__toggle" data-md-toggle="toc" type="checkbox" id="__toc">
+
+
+
+
+
+
+ <li class="md-nav__item md-nav__item--active">
-
-
- <label class="md-nav__link md-nav__link--active" for="__toc">
+ <input class="md-nav__toggle md-toggle" data-md-toggle="toc" type="checkbox" id="__toc">
+
+
+
+
+
+ <label class="md-nav__link md-nav__link--active" for="__toc">
+ Subpixel Rendering
+ <span class="md-nav__icon md-icon"></span>
+ </label>
+
+ <a href="ft2-lcd_rendering.html" class="md-nav__link md-nav__link--active">
Subpixel Rendering
- </label>
-
- <a href="ft2-lcd_rendering.html" title="Subpixel Rendering" class="md-nav__link md-nav__link--active">
- Subpixel Rendering
- </a>
-
+ </a>
-<nav class="md-nav md-nav--secondary">
+
+<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
+
- <label class="md-nav__title" for="__toc">Table of contents</label>
- <ul class="md-nav__list" data-md-scrollfix>
+ <label class="md-nav__title" for="__toc">
+ <span class="md-nav__icon md-icon"></span>
+ Table of contents
+ </label>
+ <ul class="md-nav__list" data-md-component="toc" data-md-scrollfix>
<li class="md-nav__item">
<a href="#synopsis" class="md-nav__link">
</li>
-
-
-
-
</ul>
</nav>
-
- </li>
+
+ </li>
+
-
- </ul>
- </nav>
- </li>
+
+ </ul>
+ </nav>
+ </li>
+
-
- <li class="md-nav__item md-nav__item--nested">
-
- <input class="md-toggle md-nav__toggle" data-md-toggle="nav-7" type="checkbox" id="nav-7">
-
- <label class="md-nav__link" for="nav-7">
- Cache Sub-System
- </label>
- <nav class="md-nav" data-md-component="collapsible" data-md-level="1">
- <label class="md-nav__title" for="nav-7">
- Cache Sub-System
- </label>
- <ul class="md-nav__list" data-md-scrollfix>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-cache_subsystem.html" title="Cache Sub-System" class="md-nav__link">
- Cache Sub-System
- </a>
- </li>
-
-
- </ul>
- </nav>
- </li>
-
+
+
+
+ <li class="md-nav__item md-nav__item--nested">
+ <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_8" type="checkbox" id="__nav_8" >
-
-
- <li class="md-nav__item md-nav__item--nested">
-
- <input class="md-toggle md-nav__toggle" data-md-toggle="nav-8" type="checkbox" id="nav-8">
-
- <label class="md-nav__link" for="nav-8">
- Support API
- </label>
- <nav class="md-nav" data-md-component="collapsible" data-md-level="1">
- <label class="md-nav__title" for="nav-8">
- Support API
+ <label class="md-nav__link" for="__nav_8">
+ Cache Sub-System
+ <span class="md-nav__icon md-icon"></span>
</label>
- <ul class="md-nav__list" data-md-scrollfix>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-computations.html" title="Computations" class="md-nav__link">
- Computations
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-list_processing.html" title="List Processing" class="md-nav__link">
- List Processing
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-outline_processing.html" title="Outline Processing" class="md-nav__link">
- Outline Processing
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-quick_advance.html" title="Quick retrieval of advance values" class="md-nav__link">
- Quick retrieval of advance values
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-bitmap_handling.html" title="Bitmap Handling" class="md-nav__link">
- Bitmap Handling
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-raster.html" title="Scanline Converter" class="md-nav__link">
- Scanline Converter
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-glyph_stroker.html" title="Glyph Stroker" class="md-nav__link">
- Glyph Stroker
- </a>
- </li>
-
-
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-system_interface.html" title="System Interface" class="md-nav__link">
- System Interface
- </a>
- </li>
-
-
-
-
+ <nav class="md-nav" aria-label="Cache Sub-System" data-md-level="1">
+ <label class="md-nav__title" for="__nav_8">
+ <span class="md-nav__icon md-icon"></span>
+ Cache Sub-System
+ </label>
+ <ul class="md-nav__list" data-md-scrollfix>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-cache_subsystem.html" class="md-nav__link">
+ Cache Sub-System
+ </a>
+ </li>
+
+
+ </ul>
+ </nav>
+ </li>
+
- <li class="md-nav__item">
- <a href="ft2-module_management.html" title="Module Management" class="md-nav__link">
- Module Management
- </a>
- </li>
+
+
+
+
-
-
-
+
+
+
+
+ <li class="md-nav__item md-nav__item--nested">
+
+
+ <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_9" type="checkbox" id="__nav_9" >
+
+ <label class="md-nav__link" for="__nav_9">
+ Support API
+ <span class="md-nav__icon md-icon"></span>
+ </label>
+ <nav class="md-nav" aria-label="Support API" data-md-level="1">
+ <label class="md-nav__title" for="__nav_9">
+ <span class="md-nav__icon md-icon"></span>
+ Support API
+ </label>
+ <ul class="md-nav__list" data-md-scrollfix>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-computations.html" class="md-nav__link">
+ Computations
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-list_processing.html" class="md-nav__link">
+ List Processing
+ </a>
+ </li>
+
- <li class="md-nav__item">
- <a href="ft2-gzip.html" title="GZIP Streams" class="md-nav__link">
- GZIP Streams
- </a>
- </li>
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-outline_processing.html" class="md-nav__link">
+ Outline Processing
+ </a>
+ </li>
+
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-quick_advance.html" class="md-nav__link">
+ Quick retrieval of advance values
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-bitmap_handling.html" class="md-nav__link">
+ Bitmap Handling
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-raster.html" class="md-nav__link">
+ Scanline Converter
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-glyph_stroker.html" class="md-nav__link">
+ Glyph Stroker
+ </a>
+ </li>
+
- <li class="md-nav__item">
- <a href="ft2-lzw.html" title="LZW Streams" class="md-nav__link">
- LZW Streams
- </a>
- </li>
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-system_interface.html" class="md-nav__link">
+ System Interface
+ </a>
+ </li>
+
-
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-module_management.html" class="md-nav__link">
+ Module Management
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-gzip.html" class="md-nav__link">
+ GZIP Streams
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-lzw.html" class="md-nav__link">
+ LZW Streams
+ </a>
+ </li>
+
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-bzip2.html" class="md-nav__link">
+ BZIP2 Streams
+ </a>
+ </li>
+
- <li class="md-nav__item">
- <a href="ft2-bzip2.html" title="BZIP2 Streams" class="md-nav__link">
- BZIP2 Streams
- </a>
- </li>
+
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-debugging_apis.html" class="md-nav__link">
+ External Debugging APIs
+ </a>
+ </li>
+
-
- </ul>
- </nav>
- </li>
+
+ </ul>
+ </nav>
+ </li>
+
-
- <li class="md-nav__item md-nav__item--nested">
-
- <input class="md-toggle md-nav__toggle" data-md-toggle="nav-9" type="checkbox" id="nav-9">
+
+
+
- <label class="md-nav__link" for="nav-9">
- Error Codes
- </label>
- <nav class="md-nav" data-md-component="collapsible" data-md-level="1">
- <label class="md-nav__title" for="nav-9">
+ <li class="md-nav__item md-nav__item--nested">
+
+
+ <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_10" type="checkbox" id="__nav_10" >
+
+ <label class="md-nav__link" for="__nav_10">
Error Codes
+ <span class="md-nav__icon md-icon"></span>
</label>
- <ul class="md-nav__list" data-md-scrollfix>
-
-
-
+ <nav class="md-nav" aria-label="Error Codes" data-md-level="1">
+ <label class="md-nav__title" for="__nav_10">
+ <span class="md-nav__icon md-icon"></span>
+ Error Codes
+ </label>
+ <ul class="md-nav__list" data-md-scrollfix>
-
-
-
- <li class="md-nav__item">
- <a href="ft2-error_enumerations.html" title="Error Enumerations" class="md-nav__link">
- Error Enumerations
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-error_enumerations.html" class="md-nav__link">
+ Error Enumerations
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-error_code_values.html" title="Error Code Values" class="md-nav__link">
- Error Code Values
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-error_code_values.html" class="md-nav__link">
+ Error Code Values
+ </a>
+ </li>
+
-
- </ul>
- </nav>
- </li>
+
+ </ul>
+ </nav>
+ </li>
+
-
- <li class="md-nav__item md-nav__item--nested">
-
- <input class="md-toggle md-nav__toggle" data-md-toggle="nav-10" type="checkbox" id="nav-10">
+
+
+
- <label class="md-nav__link" for="nav-10">
- Miscellaneous
- </label>
- <nav class="md-nav" data-md-component="collapsible" data-md-level="1">
- <label class="md-nav__title" for="nav-10">
+ <li class="md-nav__item md-nav__item--nested">
+
+
+ <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_11" type="checkbox" id="__nav_11" >
+
+ <label class="md-nav__link" for="__nav_11">
Miscellaneous
+ <span class="md-nav__icon md-icon"></span>
</label>
- <ul class="md-nav__list" data-md-scrollfix>
-
-
+ <nav class="md-nav" aria-label="Miscellaneous" data-md-level="1">
+ <label class="md-nav__title" for="__nav_11">
+ <span class="md-nav__icon md-icon"></span>
+ Miscellaneous
+ </label>
+ <ul class="md-nav__list" data-md-scrollfix>
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-gx_validation.html" title="TrueTypeGX/AAT Validation" class="md-nav__link">
- TrueTypeGX/AAT Validation
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-gx_validation.html" class="md-nav__link">
+ TrueTypeGX/AAT Validation
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-incremental.html" title="Incremental Loading" class="md-nav__link">
- Incremental Loading
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-incremental.html" class="md-nav__link">
+ Incremental Loading
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-truetype_engine.html" title="The TrueType Engine" class="md-nav__link">
- The TrueType Engine
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-truetype_engine.html" class="md-nav__link">
+ The TrueType Engine
+ </a>
+ </li>
+
-
-
-
-
-
- <li class="md-nav__item">
- <a href="ft2-ot_validation.html" title="OpenType Validation" class="md-nav__link">
- OpenType Validation
- </a>
- </li>
+
+
+
+
+ <li class="md-nav__item">
+ <a href="ft2-ot_validation.html" class="md-nav__link">
+ OpenType Validation
+ </a>
+ </li>
+
-
- </ul>
- </nav>
- </li>
+
+ </ul>
+ </nav>
+ </li>
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<h1 id="subpixel-rendering">Subpixel Rendering<a class="headerlink" href="#subpixel-rendering" title="Permanent link">¶</a></h1>
<h2 id="synopsis">Synopsis<a class="headerlink" href="#synopsis" title="Permanent link">¶</a></h2>
<p>FreeType provides two alternative subpixel rendering technologies. Should you define <code>FT_CONFIG_OPTION_SUBPIXEL_RENDERING</code> in your <code>ftoption.h</code> file, this enables ClearType-style rendering. Otherwise, Harmony LCD rendering is enabled. These technologies are controlled differently and API described below, although always available, performs its function when appropriate method is enabled and does nothing otherwise.</p>
-<p>ClearType-style LCD rendering exploits the color-striped structure of LCD pixels, increasing the available resolution in the direction of the stripe (usually horizontal RGB) by a factor of 3. Using the subpixels coverages unfiltered can create severe color fringes especially when rendering thin features. Indeed, to produce black-on-white text, the nearby color subpixels must be dimmed equally.</p>
-<p>A good 5-tap FIR filter should be applied to subpixel coverages regardless of pixel boundaries and should have these properties:</p>
+<p>ClearType-style LCD rendering exploits the color-striped structure of LCD pixels, increasing the available resolution in the direction of the stripe (usually horizontal RGB) by a factor of 3. Using the subpixel coverages unfiltered can create severe color fringes especially when rendering thin features. Indeed, to produce black-on-white text, the nearby color subpixels must be dimmed evenly. Therefore, an equalizing 5-tap FIR filter should be applied to subpixel coverages regardless of pixel boundaries and should have these properties:</p>
<ol>
<li>
<p>It should be symmetrical, like { a, b, c, b, a }, to avoid any shifts in appearance.</p>
</li>
</ol>
<p>Boxy 3-tap filter {0, ⅓, ⅓, ⅓, 0} is sharper but is less forgiving of non-ideal gamma curves of a screen (and viewing angles), beveled filters are fuzzier but more tolerant.</p>
-<p>Use the <code><a href="ft2-lcd_rendering.html#ft_library_setlcdfilter">FT_Library_SetLcdFilter</a></code> or <code><a href="ft2-lcd_rendering.html#ft_library_setlcdfilterweights">FT_Library_SetLcdFilterWeights</a></code> API to specify a low-pass filter, which is then applied to subpixel-rendered bitmaps generated through <code><a href="ft2-base_interface.html#ft_render_glyph">FT_Render_Glyph</a></code>.</p>
-<p>Harmony LCD rendering is suitable to panels with any regular subpixel structure, not just monitors with 3 color striped subpixels, as long as the color subpixels have fixed positions relative to the pixel center. In this case, each color channel is then rendered separately after shifting the outline opposite to the subpixel shift so that the coverage maps are aligned. This method is immune to color fringes because the shifts do not change integral coverage.</p>
+<p>Use the <code><a href="ft2-lcd_rendering.html#ft_library_setlcdfilter">FT_Library_SetLcdFilter</a></code> or <code><a href="ft2-lcd_rendering.html#ft_library_setlcdfilterweights">FT_Library_SetLcdFilterWeights</a></code> API to specify a low-pass filter, which is then applied to subpixel-rendered bitmaps generated through <code><a href="ft2-glyph_retrieval.html#ft_render_glyph">FT_Render_Glyph</a></code>.</p>
+<p>Harmony LCD rendering is suitable to panels with any regular subpixel structure, not just monitors with 3 color striped subpixels, as long as the color subpixels have fixed positions relative to the pixel center. In this case, each color channel can be rendered separately after shifting the outline opposite to the subpixel shift so that the coverage maps are aligned. This method is immune to color fringes because the shifts do not change integral coverage.</p>
<p>The subpixel geometry must be specified by xy-coordinates for each subpixel. By convention they may come in the RGB order: {{-⅓, 0}, {0, 0}, {⅓, 0}} for standard RGB striped panel or {{-⅙, ¼}, {-⅙, -¼}, {⅓, 0}} for a certain PenTile panel.</p>
<p>Use the <code><a href="ft2-lcd_rendering.html#ft_library_setlcdgeometry">FT_Library_SetLcdGeometry</a></code> API to specify subpixel positions. If one follows the RGB order convention, the same order applies to the resulting <code><a href="ft2-basic_types.html#ft_pixel_mode">FT_PIXEL_MODE_LCD</a></code> and <code><a href="ft2-basic_types.html#ft_pixel_mode">FT_PIXEL_MODE_LCD_V</a></code> bitmaps. Note, however, that the coordinate frame for the latter must be rotated clockwise. Harmony with default LCD geometry is equivalent to ClearType with light filter.</p>
-<p>As a result of ClearType filtering or Harmony rendering, the dimensions of LCD bitmaps can be either wider or taller than the dimensions of the corresponding outline with regard to the pixel grid. For example, for <code><a href="ft2-base_interface.html#ft_render_mode">FT_RENDER_MODE_LCD</a></code>, the filter adds 2 subpixels to the left, and 2 subpixels to the right. The bitmap offset values are adjusted accordingly, so clients shouldn't need to modify their layout and glyph positioning code when enabling the filter.</p>
-<p>The ClearType and Harmony rendering is applicable to glyph bitmaps rendered through <code><a href="ft2-
base_interface.html#ft_render_glyph">FT_Render_Glyph</a></code>, <code><a href="ft2-base_interface.html#ft_load_glyph">FT_Load_Glyph</a></code>, <code><a href="ft2-base_interface.html#ft_load_char">FT_Load_Char</a></code>, and <code><a href="ft2-glyph_management.html#ft_glyph_to_bitmap">FT_Glyph_To_Bitmap</a></code>, when <code><a href="ft2-base_interface.html#ft_render_mode">FT_RENDER_MODE_LCD</a></code> or <code><a href="ft2-base_interface.html#ft_render_mode">FT_RENDER_MODE_LCD_V</a></code> is specified. This API does not control <code><a href="ft2-outline_processing.html#ft_outline_render">FT_Outline_Render</a></code> and <code><a href="ft2-outline_processing.html#ft_outline_get_bitmap">FT_Outline_Get_Bitmap</a></code>.</p>
+<p>As a result of ClearType filtering or Harmony shifts, the resulting dimensions of LCD bitmaps can be slightly wider or taller than the dimensions the original outline with regard to the pixel grid. For example, for <code><a href="ft2-glyph_retrieval.html#ft_render_mode">FT_RENDER_MODE_LCD</a></code>, the filter adds 2 subpixels to the left, and 2 subpixels to the right. The bitmap offset values are adjusted accordingly, so clients shouldn't need to modify their layout and glyph positioning code when enabling the filter.</p>
+<p>The ClearType and Harmony rendering is applicable to glyph bitmaps rendered through <code><a href="ft2-
glyph_retrieval.html#ft_render_glyph">FT_Render_Glyph</a></code>, <code><a href="ft2-glyph_retrieval.html#ft_load_glyph">FT_Load_Glyph</a></code>, <code><a href="ft2-character_mapping.html#ft_load_char">FT_Load_Char</a></code>, and <code><a href="ft2-glyph_management.html#ft_glyph_to_bitmap">FT_Glyph_To_Bitmap</a></code>, when <code><a href="ft2-glyph_retrieval.html#ft_render_mode">FT_RENDER_MODE_LCD</a></code> or <code><a href="ft2-glyph_retrieval.html#ft_render_mode">FT_RENDER_MODE_LCD_V</a></code> is specified. This API does not control <code><a href="ft2-outline_processing.html#ft_outline_render">FT_Outline_Render</a></code> and <code><a href="ft2-outline_processing.html#ft_outline_get_bitmap">FT_Outline_Get_Bitmap</a></code>.</p>
<p>The described algorithms can completely remove color artefacts when combined with gamma-corrected alpha blending in linear space. Each of the 3 alpha values (subpixels) must by independently used to blend one color channel. That is, red alpha blends the red channel of the text color with the red channel of the background pixel.</p>
<h2 id="ft_lcdfilter">FT_LcdFilter<a class="headerlink" href="#ft_lcdfilter" title="Permanent link">¶</a></h2>
<p>Defined in FT_LCD_FILTER_H (freetype/ftlcdfil.h).</p>
<p>A list of values to identify various types of LCD filters.</p>
<h4>values</h4>
-
<table class="fields">
<tr><td class="val" id="ft_lcd_filter_none">FT_LCD_FILTER_NONE</td><td class="desc">
<p>Do not perform filtering. When used with subpixel rendering, this results in sometimes severe color fringes.</p>
</td></tr>
<tr><td class="val" id="ft_lcd_filter_default">FT_LCD_FILTER_DEFAULT</td><td class="desc">
-<p>This is a beveled, normalized, and color-balanced five-tap filter with weights of [0x08 0x4D 0x56 0x4D 0x08] in 1/256th units.</p>
+<p>This is a beveled, normalized, and color-balanced five-tap filter with weights of [0x08 0x4D 0x56 0x4D 0x08] in 1/256 units.</p>
</td></tr>
<tr><td class="val" id="ft_lcd_filter_light">FT_LCD_FILTER_LIGHT</td><td class="desc">
-<p>this is a boxy, normalized, and color-balanced three-tap filter with weights of [0x00 0x55 0x56 0x55 0x00] in 1/256th units.</p>
+<p>this is a boxy, normalized, and color-balanced three-tap filter with weights of [0x00 0x55 0x56 0x55 0x00] in 1/256 units.</p>
</td></tr>
<tr><td class="val" id="ft_lcd_filter_legacy">FT_LCD_FILTER_LEGACY</td><td class="desc">
<h2 id="ft_library_setlcdfilter">FT_Library_SetLcdFilter<a class="headerlink" href="#ft_library_setlcdfilter" title="Permanent link">¶</a></h2>
<p>Defined in FT_LCD_FILTER_H (freetype/ftlcdfil.h).</p>
<div class = "codehilite"><pre><code> FT_EXPORT( <a href="ft2-basic_types.html#ft_error">FT_Error</a> )
- <b>FT_Library_SetLcdFilter</b>( <a href="ft2-base_interface.html#ft_library">FT_Library</a> library,
+ <b>FT_Library_SetLcdFilter</b>( <a href="ft2-library_setup.html#ft_library">FT_Library</a> library,
<a href="ft2-lcd_rendering.html#ft_lcdfilter">FT_LcdFilter</a> filter );
</code></pre></div>
-<p>This function is used to change filter applied to LCD decimated bitmaps, like the ones used when calling <code><a href="ft2-base_interface.html#ft_render_glyph">FT_Render_Glyph</a></code> with <code><a href="ft2-base_interface.html#ft_render_mode">FT_RENDER_MODE_LCD</a></code> or <code><a href="ft2-base_interface.html#ft_render_mode">FT_RENDER_MODE_LCD_V</a></code>.</p>
+<p>This function is used to change filter applied to LCD decimated bitmaps, like the ones used when calling <code><a href="ft2-glyph_retrieval.html#ft_render_glyph">FT_Render_Glyph</a></code> with <code><a href="ft2-glyph_retrieval.html#ft_render_mode">FT_RENDER_MODE_LCD</a></code> or <code><a href="ft2-glyph_retrieval.html#ft_render_mode">FT_RENDER_MODE_LCD_V</a></code>.</p>
<h4>input</h4>
-
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the target library instance.</p>
<h2 id="ft_library_setlcdfilterweights">FT_Library_SetLcdFilterWeights<a class="headerlink" href="#ft_library_setlcdfilterweights" title="Permanent link">¶</a></h2>
<p>Defined in FT_LCD_FILTER_H (freetype/ftlcdfil.h).</p>
<div class = "codehilite"><pre><code> FT_EXPORT( <a href="ft2-basic_types.html#ft_error">FT_Error</a> )
- <b>FT_Library_SetLcdFilterWeights</b>( <a href="ft2-base_interface.html#ft_library">FT_Library</a> library,
+ <b>FT_Library_SetLcdFilterWeights</b>( <a href="ft2-library_setup.html#ft_library">FT_Library</a> library,
<span class="keyword">unsigned</span> <span class="keyword">char</span> *weights );
</code></pre></div>
<p>This function can be used to enable LCD filter with custom weights, instead of using presets in <code><a href="ft2-lcd_rendering.html#ft_library_setlcdfilter">FT_Library_SetLcdFilter</a></code>.</p>
<h4>input</h4>
-
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the target library instance.</p>
</td></tr>
<tr><td class="val" id="weights">weights</td><td class="desc">
-<p>A pointer to an array; the function copies the first five bytes and uses them to specify the filter weights in 1/256th units.</p>
+<p>A pointer to an array; the function copies the first five bytes and uses them to specify the filter weights in 1/256 units.</p>
</td></tr>
</table>
<h4>note</h4>
<p>This function does nothing but returns <code>FT_Err_Unimplemented_Feature</code> if the configuration macro <code>FT_CONFIG_OPTION_SUBPIXEL_RENDERING</code> is not defined in your build of the library.</p>
-<p>LCD filter weights can also be set per face using <code><a href="ft2-
base_interface.html#ft_face_properties">FT_Face_Properties</a></code> with <code><a href="ft2-parameter_tags.html#ft_param_tag_lcd_filter_weights">FT_PARAM_TAG_LCD_FILTER_WEIGHTS</a></code>.</p>
+<p>LCD filter weights can also be set per face using <code><a href="ft2-
face_creation.html#ft_face_properties">FT_Face_Properties</a></code> with <code><a href="ft2-parameter_tags.html#ft_param_tag_lcd_filter_weights">FT_PARAM_TAG_LCD_FILTER_WEIGHTS</a></code>.</p>
<h4>since</h4>
<p>2.4.0</p>
<span class="keyword">typedef</span> <a href="ft2-basic_types.html#ft_byte">FT_Byte</a> <b>FT_LcdFiveTapFilter</b>[FT_LCD_FILTER_FIVE_TAPS];
</code></pre></div>
-<p>A typedef for passing the five LCD filter weights to <code><a href="ft2-base_interface.html#ft_face_properties">FT_Face_Properties</a></code> within an <code><a href="ft2-base_interface.html#ft_parameter">FT_Parameter</a></code> structure.</p>
+<p>A typedef for passing the five LCD filter weights to <code><a href="ft2-face_creation.html#ft_face_properties">FT_Face_Properties</a></code> within an <code><a href="ft2-face_creation.html#ft_parameter">FT_Parameter</a></code> structure.</p>
<h4>since</h4>
<p>2.8</p>
<h2 id="ft_library_setlcdgeometry">FT_Library_SetLcdGeometry<a class="headerlink" href="#ft_library_setlcdgeometry" title="Permanent link">¶</a></h2>
<p>Defined in FT_LCD_FILTER_H (freetype/ftlcdfil.h).</p>
<div class = "codehilite"><pre><code> FT_EXPORT( <a href="ft2-basic_types.html#ft_error">FT_Error</a> )
- <b>FT_Library_SetLcdGeometry</b>( <a href="ft2-base_interface.html#ft_library">FT_Library</a> library,
+ <b>FT_Library_SetLcdGeometry</b>( <a href="ft2-library_setup.html#ft_library">FT_Library</a> library,
<a href="ft2-basic_types.html#ft_vector">FT_Vector</a> sub[3] );
</code></pre></div>
<p>This function can be used to modify default positions of color subpixels, which controls Harmony LCD rendering.</p>
<h4>input</h4>
-
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the target library instance.</p>
<p>2.10.0</p>
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projects / platform / upstream / freetype2.git / blobdiff