From 7f7ef85aea3911cbe350ec0f313623908d3053fe Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <alcinnz@lavabit.com>
Date: Thu, 10 Feb 2022 18:36:15 +1300
Subject: [PATCH] Integrate glyph-mutating callback into atlas preparation.

---
 src/Typograffiti/Atlas.hs | 10 +++++-----
 src/Typograffiti/Utils.hs |  4 ++++
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/Typograffiti/Atlas.hs b/src/Typograffiti/Atlas.hs
index edccf71..127b327 100644
--- a/src/Typograffiti/Atlas.hs
+++ b/src/Typograffiti/Atlas.hs
@@ -25,8 +25,6 @@ import           Graphics.GL.Types
 import           FreeType.Core.Types                               as BM
 import           FreeType.Support.Bitmap                           as BM
 import           FreeType.Support.Bitmap.Internal                  as BM
---import           Graphics.Rendering.FreeType.Internal.Bitmap       as BM
---import           Graphics.Rendering.FreeType.Internal.GlyphMetrics as GM
 import           Linear
 
 import           Typograffiti.GL
@@ -85,10 +83,11 @@ spacing = 1
 measure
   :: FT_Face
   -> Int
+  -> (FT_GlyphSlot -> FreeTypeIO ())
   -> (IntMap AtlasMeasure, AtlasMeasure)
   -> Char
   -> FreeTypeIO (IntMap AtlasMeasure, AtlasMeasure)
-measure fce maxw (prev, am@AM{..}) char
+measure fce maxw glyphCb (prev, am@AM{..}) char
   -- Skip chars that have already been measured
   | fromEnum char `IM.member` prev = return (prev, am)
   | otherwise = do
@@ -96,10 +95,11 @@ measure fce maxw (prev, am@AM{..}) char
         V2 w h = amWH
     -- Load the char, replacing the glyph according to
     -- https://www.freetype.org/freetype2/docs/tutorial/step1.html
-    loadChar fce (fromIntegral $ fromEnum char) ft_LOAD_RENDER
+    loadChar fce (fromIntegral $ fromEnum char) ft_LOAD_DEFAULT
     -- Get the glyph slot
     fce' <- liftIO $ peek fce
     let slot = frGlyph fce'
+    glyphCb slot
     -- Get the bitmap
     slot' <- liftIO $ peek slot
     let bmp =  gsrBitmap slot'
@@ -183,7 +183,7 @@ allocAtlas fontFilePath gs str = do
       GlyphSizeInPixels w h -> setPixelSizes fce w h
       GlyphSizeByChar (CharSize w h dpix dpiy) -> setCharSize fce w h dpix dpiy
 
-    (amMap, am) <- foldM (measure fce 512) (mempty, emptyAM) str
+    (amMap, am) <- foldM (measure fce 512 renderGlyph) (mempty, emptyAM) str
 
     let V2 w h = amWH am
         xymap :: IntMap (V2 Int)
diff --git a/src/Typograffiti/Utils.hs b/src/Typograffiti/Utils.hs
index 316b853..6f2eb67 100644
--- a/src/Typograffiti/Utils.hs
+++ b/src/Typograffiti/Utils.hs
@@ -12,6 +12,7 @@ module Typograffiti.Utils (
 -- , hasKerning
  , loadChar
  , loadGlyph
+ , renderGlyph
  , newFace
  , setCharSize
  , setPixelSizes
@@ -112,6 +113,9 @@ loadGlyph ff fg flags = runIOErr "ft_Load_Glyph" $ ft_Load_Glyph' ff fg flags
 loadChar :: MonadIO m => FT_Face -> FT_ULong -> FT_Int32 -> FreeTypeT m ()
 loadChar ff char flags = runIOErr "ft_Load_Char" $ ft_Load_Char' ff char flags
 
+renderGlyph :: MonadIO m => FT_GlyphSlot -> FreeTypeT m ()
+renderGlyph glyph = runIOErr "ft_Render_Glyph" $ ft_Render_Glyph' glyph 0
+
 --hasKerning :: MonadIO m => FT_Face -> FreeTypeT m Bool
 --hasKerning = liftIO . ft_HAS_KERNING
 --ft_HAS_KERNING FT_HAS_KERNING = return True
-- 
2.30.2