[PATCH v3 1/3] gdi32: Specify the hinting algorithms to apply explicitly.

[Byeongsik Jeon]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=41639
Signed-off-by: Byeongsik Jeon <bsjeon at hanmail.net>
---

As a result of analyzing the native Tahoma font in the ftview, I realized 
that the bug #41639 is a result of not specifying the appropriate hinting 
algorithm.

https://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_LOAD_XXX
---
.. values to select a specific hinting algorithm for the hinter.
..
You can use a hinting algorithm that doesn't correspond to the same 
rendering mode. As an example, it is possible to use the ‘light’ 
hinting algorithm and have the results rendered in horizontal LCD pixel 
mode, with code like

FT_Load_Glyph( face, glyph_index, load_flags | FT_LOAD_TARGET_LIGHT );
FT_Render_Glyph( face->glyph, FT_RENDER_MODE_LCD );
---

FT_LOAD_TARGET_NORMAL is 0.
So, we have been applying FT_LOAD_TARGET_NORMAL to all load_flags.

---
FT_LOAD_TARGET_NORMAL :
Default render mode; it corresponds to 8-bit anti-aliased bitmaps.
FT_LOAD_TARGET_MONO :
Strong hinting algorithm that should only be used for monochrome output.
---

We usually do not see this problem because we use the Wine's Tahoma with 
the embeded bitmap.

MacOS XQuartz 2.7.11, Freetype 2.7:
 - subpixel rendering disabled Freetype.
 - MacOS builtined Tahoma.
This bug appears because of the combination of two situations.

This is about the Freetype interpreter version 40.
Version 40 is the default.

 dlls/gdi32/freetype.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/dlls/gdi32/freetype.c b/dlls/gdi32/freetype.c
index 07de6f2f6c..56d1e99873 100644
--- a/dlls/gdi32/freetype.c
+++ b/dlls/gdi32/freetype.c
@@ -7001,6 +7001,30 @@ static DWORD get_glyph_outline(GdiFont *incoming_font, UINT glyph, UINT format,
     if (needsTransform || format != GGO_BITMAP) load_flags |= FT_LOAD_NO_BITMAP;
     if (vertical_metrics) load_flags |= FT_LOAD_VERTICAL_LAYOUT;
 
+    if (!(load_flags & FT_LOAD_NO_HINTING))
+    {
+        switch (format)
+        {
+        case GGO_BITMAP:
+            load_flags |= FT_LOAD_TARGET_MONO;
+            break;
+        case GGO_GRAY2_BITMAP:
+        case GGO_GRAY4_BITMAP:
+        case GGO_GRAY8_BITMAP:
+        case WINE_GGO_GRAY16_BITMAP:
+            load_flags |= FT_LOAD_TARGET_NORMAL;
+            break;
+        case WINE_GGO_HRGB_BITMAP:
+        case WINE_GGO_HBGR_BITMAP:
+            load_flags |= FT_LOAD_TARGET_LCD;
+            break;
+        case WINE_GGO_VRGB_BITMAP:
+        case WINE_GGO_VBGR_BITMAP:
+            load_flags |= FT_LOAD_TARGET_LCD_V;
+            break;
+        }
+    }
+
     err = pFT_Load_Glyph(ft_face, glyph_index, load_flags);
 
     if(err) {
-- 
2.19.1