Clean up line-metrics code

basis/core-text/core-text.factor

@@ -46,7 +46,7 @@ TUPLE: line font line metrics dim bitmap age refs disposed ;
 : compute-line-metrics ( line -- line-metrics )
     0 <CGFloat> 0 <CGFloat> 0 <CGFloat>
     [ CTLineGetTypographicBounds ] 3keep [ *CGFloat ] tri@
-    line-metrics boa ;
+    metrics boa ;
 
 : bounds>dim ( bounds -- dim )
     [ width>> ] [ [ ascent>> ] [ descent>> ] bi + ] bi
@@ -58,16 +58,16 @@ TUPLE: line font line metrics dim bitmap age refs disposed ;
         [let* | open-font [ font cache-font CFRetain |CFRelease ]
                 line [ string open-font font foreground>> <CTLine> |CFRelease ]
                 metrics [ line compute-line-metrics ]
-                dim [ bounds bounds>dim ] |
+                dim [ metrics bounds>dim ] |
             dim [
                 {
                     [ font background>> >rgba-components CGContextSetRGBFillColor ]
                     [ 0 0 dim first2 <CGRect> CGContextFillRect ]
-                    [ 0 metrics descent>> CGContextSetTextPosition ]
+                    [ 0 metrics descent>> ceiling CGContextSetTextPosition ]
                     [ line swap CTLineDraw ]
                 } cleave
             ] with-bitmap-context
-            [ open-font line bounds dim ] dip 0 0 f
+            [ open-font line metrics dim ] dip 0 0 f
         ]
         line boa
     ] with-destructors ;

basis/fonts/fonts-docs.factor

@@ -34,6 +34,8 @@ ARTICLE: "fonts" "Fonts"
 "Useful constants:"
 { $subsection monospace-font }
 { $subsection sans-serif-font }
-{ $subsection serif-font } ;
+{ $subsection serif-font }
+"A data type for font metrics. The " { $vocab-link "fonts" } " vocabulary does not provide any means of computing font metrics, it simply defines a common data type that other vocabularies, such as " { $vocab-link "ui.text" } " may use:"
+{ $subsection metrics } ;
 
 ABOUT: "fonts"

basis/fonts/fonts.factor

@@ -16,6 +16,9 @@ TUPLE: font name size bold? italic? foreground background ;
 : font-with-background ( font color -- font' )
     [ clone ] dip >>background ; inline
 
+: font-with-size ( font size -- font' )
+    [ clone ] dip >>size ; inline
+
 : reverse-video-font ( font -- font )
     clone dup
     [ foreground>> ] [ background>> ] bi
@@ -46,4 +49,4 @@ TUPLE: font name size bold? italic? foreground background ;
         "monospace" >>name
         12 >>size ;
 
-TUPLE: line-metrics width ascent descent leading ;
+TUPLE: metrics width ascent descent leading ;

basis/ui/text/core-text/core-text.factor

@@ -72,7 +72,9 @@ M: core-text-renderer offset>x ( n font string -- x )
     CTLineGetOffsetForStringIndex ;
 
 M: core-text-renderer line-metrics ( font string -- metrics )
-    cached-line metrics>> ;
+    [ " " line-metrics clone 0 >>width ]
+    [ cached-line metrics>> ]
+    if-empty ;
 
 M: core-text-renderer free-fonts ( fonts -- )
     values dispose-each ;

basis/ui/text/freetype/freetype.factor

@@ -86,10 +86,10 @@ SYMBOL: dpi
     face-size face-size-y-scale FT_MulFix ;
 
 : init-ascent ( font face -- font )
-    dup face-y-max swap font-units>pixels >>ascent ; inline
+    [ face-y-max ] keep font-units>pixels >>ascent ; inline
 
 : init-descent ( font face -- font )
-    dup face-y-min swap font-units>pixels >>descent ; inline
+    [ face-y-min ] keep font-units>pixels >>descent ; inline
 
 : init-font ( font -- font )
     dup handle>> init-ascent

basis/ui/text/text-docs.factor

@@ -55,6 +55,7 @@ ARTICLE: "text-rendering" "Rendering text"
 { $subsection text-dim }
 { $subsection text-width }
 { $subsection text-height }
+{ $subsection line-metrics }
 "Converting screen locations to string offsets, and vice versa:"
 { $subsection x>offset }
 { $subsection offset>x }

basis/ui/text/text.factor

@@ -50,7 +50,7 @@ M: sequence text-dim
 
 : text-height ( font text -- h ) text-dim second ;
 
-HOOK: text-metrics font-renderer ( font string -- metrics )
+HOOK: line-metrics font-renderer ( font string -- metrics )
 
 GENERIC# draw-text 1 ( font text loc -- )