[freetype2-demos] gsoc-2022-chariri-3 2261646 20/36: [ftinspect] Fix Singular Grid View.

[Werner Lemberg]

branch: gsoc-2022-chariri-3
commit 226164633cedcdb8455b70152499596b7423fdd9
Author: Charlie Jiang <w@chariri.moe>
Commit: Charlie Jiang <w@chariri.moe>

    [ftinspect] Fix Singular Grid View.
    
    When drawing a `FT_BitmapGlyph`, sometimes the `bitmap->top` need to be
    negated while sometimes not, so add a argument to control this behavior.
    
    * src/ftinspect/engine/engine.cpp, src/ftinspect/engine/engine.hpp:
      Add `inverseRectY` arg to `Engine::convertGlyphToQImage`.
    
    * src/ftinspect/rendering/glyphbitmap.cpp: Negate Y coord.
    
    * src/ftinspect/rendering/glyphcontinuous.cpp: Don't negate Y coord.
---
 src/ftinspect/engine/engine.cpp             | 17 +++++++++++++----
 src/ftinspect/engine/engine.hpp             |  6 ++++--
 src/ftinspect/rendering/glyphbitmap.cpp     |  2 +-
 src/ftinspect/rendering/glyphcontinuous.cpp |  2 +-
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/ftinspect/engine/engine.cpp b/src/ftinspect/engine/engine.cpp
index 32794de..da0573b 100644
--- a/src/ftinspect/engine/engine.cpp
+++ b/src/ftinspect/engine/engine.cpp
@@ -882,7 +882,9 @@ cleanup:
 
 
 QImage*
-Engine::convertGlyphToQImage(FT_Glyph src, QRect* outRect)
+Engine::convertGlyphToQImage(FT_Glyph src,
+                             QRect* outRect,
+                             bool inverseRectY)
 {
   FT_BitmapGlyph bitmapGlyph;
   bool ownBitmapGlyph
@@ -895,7 +897,10 @@ Engine::convertGlyphToQImage(FT_Glyph src, QRect* outRect)
   if (result && outRect)
   {
     outRect->setLeft(bitmapGlyph->left);
-    outRect->setTop(bitmapGlyph->top);
+    if (inverseRectY)
+      outRect->setTop(-bitmapGlyph->top);
+    else
+      outRect->setTop(bitmapGlyph->top);
     outRect->setWidth(bitmapGlyph->bitmap.width);
     outRect->setHeight(bitmapGlyph->bitmap.rows);
   }
@@ -908,7 +913,7 @@ Engine::convertGlyphToQImage(FT_Glyph src, QRect* outRect)
 
 
 QPoint
-Engine::computeGlyphOffset(FT_Glyph glyph)
+Engine::computeGlyphOffset(FT_Glyph glyph, bool inverseY)
 {
   if (glyph->format == FT_GLYPH_FORMAT_OUTLINE)
   {
@@ -919,13 +924,17 @@ Engine::computeGlyphOffset(FT_Glyph glyph)
     cbox.yMin &= ~63;
     cbox.xMax = (cbox.xMax + 63) & ~63;
     cbox.yMax = (cbox.yMax + 63) & ~63;
+    if (inverseY)
+      cbox.yMax = -cbox.yMax;
     return { static_cast<int>(cbox.xMin) / 64,
                static_cast<int>(cbox.yMax / 64) };
   }
   if (glyph->format == FT_GLYPH_FORMAT_BITMAP)
   {
     auto bg = reinterpret_cast<FT_BitmapGlyph>(glyph);
-    return { bg->left, -bg->top };
+    if (inverseY)
+      return { bg->left, -bg->top };
+    return { bg->left, bg->top };
   }
 
   return {};
diff --git a/src/ftinspect/engine/engine.hpp b/src/ftinspect/engine/engine.hpp
index 47001b7..eb345a8 100644
--- a/src/ftinspect/engine/engine.hpp
+++ b/src/ftinspect/engine/engine.hpp
@@ -89,8 +89,10 @@ public:
   bool convertGlyphToBitmapGlyph(FT_Glyph src, FT_Glyph* out);
   FT_Bitmap convertBitmapTo8Bpp(FT_Bitmap* bitmap);
   QImage* convertBitmapToQImage(FT_Bitmap* src);
-  QImage* convertGlyphToQImage(FT_Glyph src, QRect* outRect);
-  QPoint computeGlyphOffset(FT_Glyph glyph);
+  QImage* convertGlyphToQImage(FT_Glyph src, 
+                               QRect* outRect,
+                               bool inverseRectY);
+  QPoint computeGlyphOffset(FT_Glyph glyph, bool inverseY);
 
   // reload current triplet, but with updated settings, useful for updating
   // `ftSize_` only
diff --git a/src/ftinspect/rendering/glyphbitmap.cpp 
b/src/ftinspect/rendering/glyphbitmap.cpp
index aab7776..a3a35db 100644
--- a/src/ftinspect/rendering/glyphbitmap.cpp
+++ b/src/ftinspect/rendering/glyphbitmap.cpp
@@ -18,7 +18,7 @@ GlyphBitmap::GlyphBitmap(FT_Glyph glyph,
                          Engine* engine)
 {
   QRect bRect;
-  image_ = engine->convertGlyphToQImage(glyph, &bRect);
+  image_ = engine->convertGlyphToQImage(glyph, &bRect, true);
   boundingRect_ = bRect; // QRectF to QRect
 }
 
diff --git a/src/ftinspect/rendering/glyphcontinuous.cpp 
b/src/ftinspect/rendering/glyphcontinuous.cpp
index 3eb61c6..f30ea51 100644
--- a/src/ftinspect/rendering/glyphcontinuous.cpp
+++ b/src/ftinspect/rendering/glyphcontinuous.cpp
@@ -244,7 +244,7 @@ GlyphContinuous::drawSingleGlyph(QPainter* painter, 
FT_Glyph glyph)
   }
 
   QRect rect;
-  QImage* image = engine_->convertGlyphToQImage(glyph, &rect);
+  QImage* image = engine_->convertGlyphToQImage(glyph, &rect, false);
   rect.setTop(height() - rect.top());
 
   painter->drawImage(rect.topLeft(), *image);