Add more bitmap fonts.

Currently three variants. Each font is embedded into the binary and
costs about 4KB of ram.

Worth considering making them loadable.

1 files changed, 59 insertions, 20 deletions

diff --git a/tools/make-font.janet b/tools/make-font.janet
index 2938632..bcd7905 100644
--- a/tools/make-font.janet
+++ b/tools/make-font.janet
@@ -1,5 +1,13 @@
 (use spork/cjanet)
 
+###
+### Generate bitmaps for the built-in retro console fonts encoded in TTFs.
+### We seek to minimize memory usage for these fonts. Technically, this should be
+### similar to how these fonts were stored in BIOS roms but it is much easier to find
+### TTF extractions/reproductions of these fonts and build an internal representation
+### ourselves.
+###
+
 (begin-jit
   :module-name "make-font"
   :cflags @["-Ideps/stb" "-Ideps"])
@@ -15,15 +23,18 @@
 
 (include "stb_truetype.h")
 (include "stb_image_write.h")
+(include <string.h>)
 
 (cfunction load-font
   "Load a font from disk and create compressed font"
-  [path:cstring gw:int gh:int] -> int
+  [header-dest:cstring cname:cstring path:cstring gw:int gh:int] -> int
 
   (def fnt:stbtt-fontinfo)
-  (def font-buffer (malloc (<< 1 23)))
+  (def font-buffer (malloc (<< 1 24)))
   (def f (fopen path "rb"))
-  (assert (fread font-buffer 1 (<< 1 23) f))
+  (unless f
+    (janet-panic "no font file found"))
+  (assert (fread font-buffer 1 (<< 1 24) f))
   (fclose f)
 
   # Raster pixel data from stb truetype
@@ -35,36 +46,59 @@
   (def scale:float (stbtt-ScaleForPixelHeight ;fnt gh))
   (printf "scale: %f\n" scale)
 
+  # Iterate glyphs to find the overall offset for characters
+  (var x0min:int 10000)
+  (var y0min:int 10000)
+  (var x1max:int -10000)
+  (var y1max:int -10000)
+  (for [(var glyph:int 1) (<= glyph 0x100) (++ glyph)]
+    (var x0:int 0)
+    (var y0:int 0)
+    (var x1:int 0)
+    (var y1:int 0)
+    (stbtt-GetGlyphBitmapBox ;fnt glyph scale scale ;x0 ;y0 ;x1 ;y1)
+    # (printf "glyph %d (x0, y0, x1, y1) = (%d, %d, %d, %d)\n" glyph x0 y0 x1 y1)
+    (set x0min (? (< x0 x0min) x0 x0min))
+    (set y0min (? (< y0 y0min) y0 y0min))
+    (set x1max (? (> x1 x1max) x1 x1max))
+    (set y1max (? (> y1 y1max) y1 y1max)))
+
+  (assert (>= gw (- x1max x0min)))
+  (assert (>= gh (- y1max y0min)))
+  (assert (< 0 (- x1max x0min)))
+  (assert (< 0 (- y1max y0min)))
+  (def xoff:int (- x0min))
+  (def yoff:int (- y0min))
+  (printf "xoff, yoff = %d, %d\n" xoff yoff)
+
   # Iterate glyphs
   (for [(var glyph:int 1) (<= glyph 0x100) (++ glyph)]
-    #(def glyph:int (stbtt-FindGlyphIndex ;fnt codepoint))
-    #(if (= 0 glyph) (continue))
-    (var lsb:int 0)
-    (var advance:int 0)
-    (var ascent:int 0)
-    (var descent 0)
     (var x0:int 0)
     (var y0:int 0)
     (var x1:int 0)
     (var y1:int 0)
-    (stbtt-GetGlyphHMetrics ;fnt glyph ;advance ;lsb)
     (stbtt-GetGlyphBitmapBox ;fnt glyph scale scale ;x0 ;y0 ;x1 ;y1)
-    (printf "glyph %d (x0, y0, x1, y1, advance, lsb) = (%d, %d, %d, %d, %d, %d)\n" glyph x0 y0 x1 y1 advance lsb)
     (def pw:int (* 16 gw))
-    #(def x:int (* gw (% codepoint 16)))
-    #(def y:int (* gh (/ codepoint 16)))
-    (def x:int (+ x0 (* gw (% (- glyph 1) 16))))
-    (def y:int (+ y0 -1 gh (* gh (/ (- glyph 1) 16))))
+    (def x:int (+ x0 xoff (* gw (% (- glyph 1) 16))))
+    (def y:int (+ y0 yoff (* gh (/ (- glyph 1) 16))))
+    # (printf "rendering at (x, y) = (%d, %d)\n" x y)
     (stbtt-MakeGlyphBitmap ;fnt (+ img-data x (* pw y)) gw gh pw scale scale glyph))
+
+  # Clean up font data
   (free font-buffer)
 
   # Write image for debugging
-  (stbi-write-png "deps/cp437_font.png" (* 16 gw) (* 16 gh) 1 img-data (* 16 gw))
+  (def pngname (malloc 1000))
+  (memset pngname 0 1000)
+  (strcat pngname header-dest)
+  (strcat pngname ".png")
+  (stbi-write-png pngname (* 16 gw) (* 16 gh) 1 img-data (* 16 gw))
+  (free pngname)
 
   # Now extract pixels into 1 bit per pixel buffer.
   # Print the buffer as a C array
-  (def fp (fopen "deps/cp437_font.h" "wb"))
-  (fprintf fp "unsigned char cp437_font_data[] = {\n")
+  (def fp (fopen header-dest "wb"))
+  (fprintf fp "unsigned char %s_data[] = {\n" cname)
   (for [(var y:int 0) (< y (* 16 gh)) (set y (+ y gh))]
     (for [(var x:int 0) (< x (* 16 gw)) (set x (+ x gw))]
       (fprintf fp "\n")
@@ -77,6 +111,10 @@
             (set next-byte (<< next-byte 1))))
         (fprintf fp "0x%.2X, " next-byte))))
   (fprintf fp "\n\n};\n")
+  (fprintf fp "const BitmapFont %s = {\n" cname)
+  (fprintf fp " .gw = %d,\n" gw)
+  (fprintf fp " .gh = %d,\n" gh)
+  (fprintf fp " .data = %s_data\n};\n" cname)
   (fclose fp)
 
   (printf "Made font %s\n" path)
@@ -86,5 +124,6 @@
 (end-jit)
 
 ### Save the font to a file so we can look at it
-(load-font "deps/fonts/Px437_DG_One.ttf" 8 8)
-#(load-font "deps/fonts/Px437_Nix8810_M16.ttf" 8 16)
+(load-font "deps/default_font.h" "default_font" "deps/fonts/Px437_DG_One.ttf" 8 8)
+(load-font "deps/tall_font.h" "tall_font" "deps/fonts/Px437_Nix8810_M16.ttf" 8 16)
+(load-font "deps/olive_font.h" "olive_font" "deps/fonts/Px437_OlivettiThin_8x16.ttf" 8 16)