pfl->Release();<\/font>\n<\/pre>\n\nAnd of course, all the errors we’ve been ignoring need to be taken care of.\nThis does create a big of a problem if we run into an error after we have\nalready made it through a few chunks. What should we do?\n<\/p>\n
\nI’m going to handle the error by drawing the string in the original font,\nugly boxes and all. We can’t erase the characters we already drew,\nand we can’t just draw half of the string (for our caller won’t know where\nto resume).\nSo we just draw with the original font and hope for the best.\nAt least it’s no worse than it was before font linking.\n<\/p>\n
\nPut all of these refinements together and you get this final function:\n<\/p>\n
\nHRESULT TextOutFL(HDC hdc, int x, int y, LPCWSTR psz, int cch)\n{\n HRESULT hr;\n IMLangFontLink2 *pfl;\n if (SUCCEEDED(hr = CoCreateInstance(CLSID_CMultiLanguage, NULL,\n CLSCTX_ALL, IID_IMLangFontLink2, (void**)&pfl))) {\n HFONT hfOrig = (HFONT)GetCurrentObject(hdc, OBJ_FONT);\n POINT ptOrig;\n DWORD dwAlignOrig = GetTextAlign(hdc);\n if (!(dwAlignOrig & TA_UPDATECP)) {\n SetTextAlign(hdc, dwAlignOrig | TA_UPDATECP);\n }\n MoveToEx(hdc, x, y, &ptOrig);\n DWORD dwFontCodePages = 0;\n hr = pfl->GetFontCodePages(hdc, hfOrig, &dwFontCodePages);\n if (SUCCEEDED(hr)) {\n while (cch > 0) {\n DWORD dwActualCodePages;\n long cchActual;\n hr = pfl->GetStrCodePages(psz, cch, dwFontCodePages, &dwActualCodePages, &cchActual);\n if (FAILED(hr)) {\n break;\n }\n if (dwActualCodePages & dwFontCodePages) {\n TextOut(hdc, 0, 0, psz, cchActual);\n } else {\n HFONT hfLinked;\n if (FAILED(hr = pfl->MapFont(hdc, dwActualCodePages, 0, &hfLinked))) {\n break;\n }\n SelectFont(hdc, hfLinked);\n TextOut(hdc, 0, 0, psz, cchActual);\n SelectFont(hdc, hfOrig);\n pfl->ReleaseFont(hfLinked);\n }\n psz += cchActual;\n cch -= cchActual;\n }\n if (FAILED(hr)) {\n \/\/ We started outputting characters so we have to finish.\n \/\/ Do the rest without font linking since we have no choice.\n TextOut(hdc, 0, 0, psz, cch);\n hr = S_FALSE;\n }\n }\n pfl->Release();\n if (!(dwAlignOrig & TA_UPDATECP)) {\n SetTextAlign(hdc, dwAlignOrig);\n MoveToEx(hdc, ptOrig.x, ptOrig.y, NULL);\n }\n }\n return hr;\n}\n<\/pre>\n\nFinally, we can wrap the entire operation inside a helper function\nthat first tries with font linking and if that fails, then just draws\nthe text the old-fashioned way.\n<\/p>\n
\nvoid TextOutTryFL(HDC hdc, int x, int y, LPCWSTR psz, int cch)\n{\n if (FAILED(TextOutFL(hdc, x, y, psz, cch)) {\n TextOut(hdc, x, y, psz, cch);\n }\n}\n<\/pre>\n\nOkay, now that we have our font-linked TextOut with fallback,\nwe can go ahead and adjust our PaintContent<\/code> function to use it.\n<\/p>\n\nvoid\nPaintContent(HWND hwnd, PAINTSTRUCT *pps)\n{\n TextOutTryFL(pps->hdc, 0, 0,\n TEXT(\"ABC\\x0410\\x0411\\x0412\\x0E01\\x0E02\\x0E03\"), 9);\n}\n<\/pre>\n\nObserve that the string is now displayed with no black boxes.\n<\/p>\n
\nOne refinement I did not do was to avoid creating the\nIMlangFontLink2 pointer each time we want to draw text.\nIn a “real program” you would probably create the multilanguage\nobject once per drawing context (per window, perhaps) and re-use it\nto avoid going through the whole object creation codepath each time\nyou want to draw a string.\n<\/p>\n
\n[Raymond is currently on vacation; this message was pre-recorded.]<\/p>\n","protected":false},"excerpt":{"rendered":"
You’ve all seen those ugly boxes. When you try to display a string and the font you have doesn’t support all of the characters in it, you get an ugly box for the characters that aren’t available in the font. Start with our scratch program and add this to the PaintContent function: void PaintContent(HWND hwnd, […]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[25],"class_list":["post-38413","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-code"],"acf":[],"blog_post_summary":"
You’ve all seen those ugly boxes. When you try to display a string and the font you have doesn’t support all of the characters in it, you get an ugly box for the characters that aren’t available in the font. Start with our scratch program and add this to the PaintContent function: void PaintContent(HWND hwnd, […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/38413","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=38413"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/38413\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=38413"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=38413"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=38413"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}