3 files changed, 33 insertions(+), 16 deletions(-)

M app/Main.hs
M src/Typograffiti/Store.hs
M src/Typograffiti/Text.hs

@@ 28,7 28,21 @@ main = do
     _ <- glCreateContext w
 
     let ttfName = "assets/Lora-Regular.ttf"
-    text <- pack <$> unwords <$> getArgs
+    args <- getArgs
+    let text = pack $ case args of
+          [] -> unlines [
+            "Decoder Ring Theatre brings you the continuing adventures",
+            "of Canada's greatest superhero, that scourage of the underworld,",
+            "hunter of those who pray upon the innocent,",
+            "that marvelous masked mystery man",
+            "known only as The Red Panda!",
+            "",
+            "The Red Panda, masked crucader for justice, hides his secret identity",
+            "as one of the city's wealthiest men in his neverending battle",
+            "against crime & corruption. Only his trust driver, Kit Baxter",
+            "who joins him in the guise of The Flying Squirrel,",
+            "knows who wears the mask of The Red Panda!"]
+          _ -> unwords args
     drawText <- makeDrawText' ttfName 0 (PixelSize 15 15) $ defaultSample { sampleText = text }
     runExceptT $ do
         drawText0 <- liftEither drawText


@@ 42,10 56,8 @@ main = do
             sz@(V2 dw dh) <- liftIO $ glGetDrawableSize w
             liftIO $ glViewport 0 0 (fromIntegral dw) (fromIntegral dh)
 
-            let offset = V2 0 $ fromIntegral dy
-                V2 _ dy = arSize drawText'
             liftIO $ arDraw drawText' [
-                TextTransformSpatial $ SpatialTransformTranslate $ fromIntegral dy
+                TextTransformSpatial $ SpatialTransformTranslate $ fromIntegral 10
               ] (fromIntegral <$> sz)
 
             liftIO $ glSwapWindow w

@@ 87,8 87,9 @@ makeDrawTextCached store filepath index fontsize SampleText {..} = do
         (atlas:_) -> return atlas
         _ -> allocAtlas' (atlases font) (freetype font) glyphset
 
-    return $ drawLinesWrapper tabwidth $ \RichText {..} -> drawGlyphs store atlas $
-        shape (harfbuzz font) defaultBuffer { HB.text = text } []
+    return $ drawLinesWrapper tabwidth minLineHeight $
+        \RichText {..} -> drawGlyphs store atlas $
+            shape (harfbuzz font) defaultBuffer { HB.text = text } []
 
 -- | Opens & sizes the given font using both FreeType & Harfbuzz,
 -- loading it into the `FontStore` before returning.

@@ 52,14 52,17 @@ data SampleText = SampleText {
     -- Defaults to ASCII, no ligatures.
     tabwidth :: Int,
     -- ^ How many spaces wide should a tab be rendered?
-    -- Defaults to 4.
-    fontOptions :: FontOptions
+    -- Defaults to 4 spaces.
+    fontOptions :: FontOptions,
     -- ^ Additional font options offered by Harfbuzz.
+    minLineHeight :: Float
+    -- ^ Number of pixels tall each line should be at minimum.
+    -- Defaults to 10px.
 }
 
 -- | Constructs a `SampleText` with default values.
 defaultSample :: SampleText
-defaultSample = SampleText [] (pack $ map toEnum [32..126]) 4 defaultFontOptions
+defaultSample = SampleText [] (pack $ map toEnum [32..126]) 4 defaultFontOptions 10
 -- | Appends an OpenType feature callers may use to the `Sample` ensuring its
 -- glyphs are available. Call after setting `sampleText`.
 addSampleFeature :: String -> Word32 -> SampleText -> SampleText


@@ 145,8 148,9 @@ makeDrawText lib filepath index fontsize SampleText {..} = do
     liftFreetype $ ft_Done_Face font
 
     drawGlyphs <- makeDrawGlyphs
-    return $ freeAtlasWrapper atlas $ drawLinesWrapper tabwidth $ \RichText {..} ->
-        drawGlyphs atlas $ shape font' defaultBuffer { HB.text = text } features
+    return $ freeAtlasWrapper atlas $ drawLinesWrapper tabwidth minLineHeight
+        $ \RichText {..} ->
+            drawGlyphs atlas $ shape font' defaultBuffer { HB.text = text } features
   where
     x2 = (*2)
     float2fixed :: Float -> FT_Fixed


@@ 158,16 162,15 @@ makeDrawText' a b c d =
 
 -- | Internal utility for rendering multiple lines of text & expanding tabs as configured.
 type TextRenderer m = RichText -> m (AllocatedRendering [TextTransform])
-drawLinesWrapper :: (MonadIO m, MonadFail m) => Int -> TextRenderer m -> TextRenderer m
-drawLinesWrapper indent cb RichText {..} = do
+drawLinesWrapper :: (MonadIO m, MonadFail m) => Int -> Float -> TextRenderer m -> TextRenderer m
+drawLinesWrapper indent lineheight cb RichText {..} = do
     let features' = splitFeatures 0 features (Txt.lines text) ++ repeat []
     let cb' (a, b) = cb $ RichText a b
-    liftIO $ print $ Txt.lines text
     renderers <- mapM cb' $ flip zip features' $ map processLine $ Txt.lines text
     let drawLine ts wsz y renderer = do
             arDraw renderer (move 0 y:ts) wsz
             let V2 _ height = arSize renderer
-            return (y + toEnum height)
+            return (y + max lineheight (toEnum height))
     let draw ts wsz = do
             foldM (drawLine ts wsz) 0 renderers
             return ()


@@ 195,7 198,8 @@ drawLinesWrapper indent cb RichText {..} = do
             splitFeatures (offset + toEnum n) features' lines'
 
     processLine :: Text -> Text
-    processLine = expandTabs 0
+    processLine "" = " " -- Prevent Harfbuzz from throwing errors.
+    processLine cs = expandTabs 0 cs
     -- monospace tabshaping, good enough outside full line-layout.
     expandTabs n cs = case Txt.break (== '\t') cs of
         (tail, "") -> tail