<div dir="ltr">PSB with comment [UvarajaP]. <div class="gmail_extra"> <div class="gmail_quote">On Thu, Sep 11, 2014 at 3:24 PM, Rajeesh K Nambiar <<a href="mailto:rajeeshknambiar@gmail.com" target="_blank">rajeeshknambiar@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"> <div class="gmail_extra"> <div class="gmail_quote">On Thu, Sep 11, 2014 at 11:06 AM, Uvaraja Pandian <<a href="mailto:p.uvaraja@gmail.com" target="_blank">p.uvaraja@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Hi Team, We are using the Harfbuzz 0.9.34 version. While rendering the Malayalam string using the Harfbuzz and Freetype engine, we see some issues. String used: ക്കേUnicode value: 0x0d15, 0x0d4d, 0x0d15, 0x0d47, 0x0000 Harfbuzz Output:<img width="123" height="64" src="cid:image001.jpg@01CFCDC3.FEC4C960"> Proper Output :<img width="69" height="45" src="cid:image002.png@01CFCDC3.FEC4C960"> Font File used: Akruti Family, Since this is a licensed font file, we are not able to share it. Issue in Detail: In the font file,script mlym { # Malayalam feature Akhands; feature BelowBaseSubstitutions; feature HalfForms; feature PostBaseForms; feature PostBaseSubstitutions; feature PreBaseSubstitutions;} As per the Harfbuzz implementation, below substitution is happening as part of the HalfForms ,0x0d15 & 0x0d4d è XYZ character, so the output is XYZ, 0x0d15, 0x0d47 Final re-ordering happens and rearranges as below,XYZ, 0x0d15, 0x0d47 è XYZ, 0x0d47, 0x0d15</div></blockquote><div> </div><div>Does final_reordering happen before applying 'pres' lookup?</div></div></div></div></blockquote><div>[UvarajaP] Yes, as per the HARFBUZZ logic in indic_features[] list, PRES is applied after the final_reordering.</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"> As per the PreBaseSubstitutions,XYZ & 0x0d15 is not matched and the output is not proper.</div></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"> </div></blockquote><div> </div><div>If the font has a 'pres' rule for XYZ, 0x0D15, the conjunct should form correctly. </div></div></div></div></blockquote><div>[UvarajaP] Font file has a substitution rule for XYZ and 0xOD15 combination. However in final_reordering() it has changed the order, so it is not able to match the substitution rule. </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">In-Order to solve this issue, below changes has been done, Final Re-ordering,PSB for the code changes As per the PreBaseSubstitutions,XYZ & 0x0d15 forms the final character. Code Modifications:In the file hb-ot-shape-complex-indic.cc, if we modify the lines as below in the function final_reordering_syllable() it is working, if (start + 1 < end && start < base) /* Otherwise there can't be any pre-base matra characters. */ { /* If we lost track of base, alas, position before last thingy. */ unsigned int new_pos = base == end ? base - 2 : base - 1; /* Malayalam / Tamil do not have "half" forms or explicit virama forms. * The glyphs formed by 'half' are Chillus or ligated explicit viramas. * We want to position matra after them. */ if (buffer->props.script != HB_SCRIPT_MALAYALAM && buffer->props.script != HB_SCRIPT_TAMIL) { …<s> }</s> if (start < new_pos && info[new_pos].indic_position () != POS_PRE_M) { … } else { … } } } Please comment, will it have any side effect. Best Regards,Uvaraja P.Sindhura P.</div> </blockquote></div> <div> </div>-- <div dir="ltr">Rajeesh </div> </div></div> </blockquote></div> </div></div>