freetype/tests/README

Test-Framework for FreeType's Rendering output.

INSTRUCTIONS

NOTE: One version of FreeType is referred as "base" version and the
      other as the "test" version.

  1. Get the two versions ready
  -------------------------------------

  Download an older version of FreeType (For example : 2.6.5)
  ( This being the "base" version of the two)
  Go to 'include/freetype/ftoption.h' and uncomment this line

      #define FT_CONFIG_OPTION_SUBPIXEL_RENDERING
  
  2. Compile the two versions 
  -------------------------------------     
  Go to the "base" version's folder and compile the library.

      ./configure --enable-shared --disable-static
      make

  Repeat step 2. for the "test" version as well.

 3. Compile the code
  -------------------------------------     
  Return to this folder and make the binary

      make tests

 4. Run the executable
  ------------------------------------- 

  => Set resolution in DPI by passing argument to variable FT_TEST_DPI.

  => Set the Rendering mode by passing FT_TEST_RENDER_MODE.
     FT_TEST_RENDER_MODE can take values 1. MONO
                           2. AA
                           3. RGB
                           4. BGR
                           5. VRGB
                           6. VBGR

  => Set the variables FT_TEST_BASE_DLL and FT_TEST_TEST_DLL to
     point to the libfreetype.so file of the base and the test
     versions respectively.

     By default, the folders '$(HOME)/base/' and '$(HOME)/test/'
     folders are set for FT_TEST_BASE_DIR and FT_TEST_TEST_DIR
     respectively. If FT_TEST_XXX_DLL isn't defined, these values
     are taken to search for DLL files.

  => Set FT_TEST_FONT_FILE to the path to font files needed.

  => set FT_TEST_PT_SIZE as a number to denote the font size.

	EXAMPLE:  FT_TEST_BASE_DIR=$(HOME)/base \
		  FT_TEST_TEST_DIR=$(HOME)/test \
		  FT_TEST_DPI="72 96" \
		  FT_TEST_FONT_FILE="test.ttf" \
		  FT_TEST_RENDER_MODE="AA RGB" \
		  FT_TEST_PT_SIZE="16 20" \
		  ./runme.sh
  ( The values in the above example denote the default values
  for the variables. )

  Open ./html/top.html for the web interface.

 5. Run the executable
  -------------------------------------
  To clean the html folder / to remove all the generated files,
      make clean

---------------------------------------------------------------------

FEATURES

  An interactive web interface to visualize glyphs.(html/top.html)

  View lists of glyphs in tables in the left iFrame accessed by
  selecting values from the drop-box.
  ( The list consists of all the glyphs whose images rendered on
  the two versions of the FreeType library are different. )

  NOTE: If there is no visual difference in the two images, this
        means that the dimensions of the images rendered aren't
        the same for both the versions.
        This is because the smaller images are aligned and padded
        and then compared.

  Subimages in the sprite sheet.
    1.  'Base' version's rendering of the glyph.
    2.  'Test' version's rendering of the glyph.
    3.  'Base' version glyph as Gray

  By clicking on the Headers of the respective columns,they can be
  arranged (in increasing/decreasing order) based on
    ->  Glyph-Index
    ->  Name
    ->  Difference Metric

  When clicked on any image in the table, a detailed visualization
  page for the glyph is shown in the right iFrame.

  Click on the Buttons below the iframe for the animations.

  To pause the animation, click and hold on the image.