Glyph advances from generateAdvance do not always match generateMetrics results.
http://codereview.appspot.com/5841071/
git-svn-id: http://skia.googlecode.com/svn/trunk@3480 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index b2e3b42..55845dc 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -767,7 +767,7 @@
// compute the flags we send to Load_Glyph
{
FT_Int32 loadFlags = FT_LOAD_DEFAULT;
- bool linearMetrics = false;
+ bool linearMetrics = SkToBool(fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag);
if (SkMask::kBW_Format == fRec.fMaskFormat) {
// See http://code.google.com/p/chromium/issues/detail?id=43252#c24
@@ -784,7 +784,6 @@
break;
case SkPaint::kSlight_Hinting:
loadFlags = FT_LOAD_TARGET_LIGHT; // This implies FORCE_AUTOHINT
- linearMetrics = true;
break;
case SkPaint::kNormal_Hinting:
if (fRec.fFlags & SkScalerContext::kAutohinting_Flag)
@@ -1076,16 +1075,17 @@
goto ERROR;
}
- if ((fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) == 0) {
+ if (fDoLinearMetrics) {
+ glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance);
+ glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance);
+ } else {
glyph->fAdvanceX = SkFDot6ToFixed(fFace->glyph->advance.x);
glyph->fAdvanceY = -SkFDot6ToFixed(fFace->glyph->advance.y);
+
if (fRec.fFlags & kDevKernText_Flag) {
glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta);
glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta);
}
- } else {
- glyph->fAdvanceX = SkFixedMul(fMatrix22.xx, fFace->glyph->linearHoriAdvance);
- glyph->fAdvanceY = -SkFixedMul(fMatrix22.yx, fFace->glyph->linearHoriAdvance);
}
if ((fRec.fFlags & SkScalerContext::kVertical_Flag)
diff --git a/tests/FontHostTest.cpp b/tests/FontHostTest.cpp
index 8ab7ad3..eab7bc4 100644
--- a/tests/FontHostTest.cpp
+++ b/tests/FontHostTest.cpp
@@ -85,8 +85,64 @@
}
}
+/*
+ * Verifies that the advance values returned by generateAdvance and
+ * generateMetrics match.
+ */
+static void test_advances(skiatest::Reporter* reporter) {
+ static const char* const faces[] = {
+ NULL, // default font
+ "Arial", "Times", "Times New Roman", "Helvetica", "Courier",
+ "Courier New", "Verdana", "monospace",
+ };
+
+ static const struct {
+ SkPaint::Hinting hinting;
+ unsigned flags;
+ } settings[] = {
+ { SkPaint::kNo_Hinting, 0 },
+ { SkPaint::kNo_Hinting, SkPaint::kLinearText_Flag },
+ { SkPaint::kNo_Hinting, SkPaint::kSubpixelText_Flag },
+ { SkPaint::kSlight_Hinting, 0 },
+ { SkPaint::kSlight_Hinting, SkPaint::kLinearText_Flag },
+ { SkPaint::kSlight_Hinting, SkPaint::kSubpixelText_Flag },
+ { SkPaint::kNormal_Hinting, 0 },
+ { SkPaint::kNormal_Hinting, SkPaint::kLinearText_Flag },
+ { SkPaint::kNormal_Hinting, SkPaint::kSubpixelText_Flag },
+ };
+
+ SkPaint paint;
+ char txt[] = "long.text.with.lots.of.dots.";
+
+ for (size_t i = 0; i < SK_ARRAY_COUNT(faces); i++) {
+ SkTypeface* face = SkTypeface::CreateFromName(faces[i], SkTypeface::kNormal);
+ paint.setTypeface(face);
+
+ for (size_t j = 0; j < SK_ARRAY_COUNT(settings); j++) {
+ paint.setHinting(settings[j].hinting);
+ paint.setLinearText((settings[j].flags & SkPaint::kLinearText_Flag) != 0);
+ paint.setSubpixelText((settings[j].flags & SkPaint::kSubpixelText_Flag) != 0);
+
+ SkRect bounds;
+
+ // For no hinting and light hinting this should take the
+ // optimized generateAdvance path.
+ SkScalar width1 = paint.measureText(txt, strlen(txt));
+
+ // Requesting the bounds forces a generateMetrics call.
+ SkScalar width2 = paint.measureText(txt, strlen(txt), &bounds);
+
+ // SkDebugf("Font: %s, generateAdvance: %f, generateMetrics: %f\n",
+ // faces[i], SkScalarToFloat(width1), SkScalarToFloat(width2));
+
+ REPORTER_ASSERT(reporter, width1 == width2);
+ }
+ }
+}
+
static void TestFontHost(skiatest::Reporter* reporter) {
test_tables(reporter);
+ test_advances(reporter);
}
// need tests for SkStrSearch