font: full mixed-case + punctuation glyph set (not uppercase-only)

Replace the small-caps placeholder font with a real baseline-aligned
4x8 set covering all 96 printable ASCII: distinct lowercase with true
ascenders (b d f h k l t) and descenders (g j p q y), digits, and
punctuation. Metrics: caps/ascenders rows 1-5, x-height rows 2-5,
baseline row 5, descenders into rows 6-7. Glyphs are ~3px wide in the
4px cell -- cramped but legible; the tile mechanism itself imposes no
character-set limit.

genfont.py now takes per-glyph (top, rows) so glyphs sit on the baseline.
Demo strings in term_test updated to show mixed case + punctuation.
Verified by screenshot: descenders visibly drop below the baseline.

1 files changed, 106 insertions, 95 deletions

diff --git a/tools/genfont.py b/tools/genfont.py
index 7fe7689..2f94881 100644
--- a/tools/genfont.py
+++ b/tools/genfont.py
@@ -1,105 +1,116 @@
 #!/usr/bin/env python3
-# Generate a 4x8 font (3x5 glyphs, left-aligned in a 4px cell) as RGBDS asm.
+# Generate a 4x8 font as RGBDS asm. Glyphs are up to 3px wide (in a 4px cell,
+# 1px right gap) and use the full 8px height with a real baseline at row 5:
+#   caps/ascenders  rows 1..5     x-height (lowercase)  rows 2..5
+#   descenders reach rows 6..7    row 0 = top gap / line spacing
 # Output: 96 glyphs (ASCII 32..127), 8 bytes each; each byte = one 4-px row,
-# bit3=leftmost pixel of the cell, bits 3..1 = the 3px glyph, bit0 = gap.
+# bit3 = leftmost pixel of the cell, bits 3..1 = the glyph, bit0 = gap.
 G = {}
-def d(ch, rows):  # rows: 5 strings of width 3 ('#'/' ')
-    G[ch] = rows
-# space
-d(' ', ["   ","   ","   ","   ","   "])
-# letters (uppercase; lowercase mapped to these)
-d('A',["## ","# #","###","# #","# #"])
-d('B',["## ","# #","## ","# #","## "])
-d('C',[" ##","#  ","#  ","#  "," ##"])
-d('D',["## ","# #","# #","# #","## "])
-d('E',["###","#  ","## ","#  ","###"])
-d('F',["###","#  ","## ","#  ","#  "])
-d('G',[" ##","#  ","# #","# #"," ##"])
-d('H',["# #","# #","###","# #","# #"])
-d('I',["###"," # "," # "," # ","###"])
-d('J',["  #","  #","  #","# #"," # "])
-d('K',["# #","# #","## ","# #","# #"])
-d('L',["#  ","#  ","#  ","#  ","###"])
-d('M',["# #","###","###","# #","# #"])
-d('N',["# #","###","###","###","# #"])
-d('O',[" # ","# #","# #","# #"," # "])
-d('P',["## ","# #","## ","#  ","#  "])
-d('Q',[" # ","# #","# #"," # ","  #"])
-d('R',["## ","# #","## ","# #","# #"])
-d('S',[" ##","#  "," # ","  #","## "])
-d('T',["###"," # "," # "," # "," # "])
-d('U',["# #","# #","# #","# #"," ##"])
-d('V',["# #","# #","# #"," # "," # "])
-d('W',["# #","# #","###","###","# #"])
-d('X',["# #","# #"," # ","# #","# #"])
-d('Y',["# #","# #"," # "," # "," # "])
-d('Z',["###","  #"," # ","#  ","###"])
-# digits
-d('0',[" # ","# #","# #","# #"," # "])
-d('1',[" # ","## "," # "," # ","###"])
-d('2',["## ","  #"," # ","#  ","###"])
-d('3',["## ","  #"," # ","  #","## "])
-d('4',["# #","# #","###","  #","  #"])
-d('5',["###","#  ","## ","  #","## "])
-d('6',[" ##","#  ","## ","# #"," # "])
-d('7',["###","  #"," # "," # "," # "])
-d('8',[" # ","# #"," # ","# #"," # "])
-d('9',[" # ","# #"," ##","  #","## "])
-# punctuation
-d('.',["   ","   ","   ","   "," # "])
-d(',',["   ","   ","   "," # ","#  "])
-d(':',["   "," # ","   "," # ","   "])
-d(';',["   "," # ","   "," # ","#  "])
-d('!',[" # "," # "," # ","   "," # "])
-d('?',["## ","  #"," # ","   "," # "])
-d('-',["   ","   ","###","   ","   "])
-d('+',["   "," # ","###"," # ","   "])
-d('=',["   ","###","   ","###","   "])
-d('*',["# #"," # ","###"," # ","# #"])
-d('/',["  #","  #"," # ","#  ","#  "])
-d('\\',["#  ","#  "," # ","  #","  #"])
-d('(',["  #"," # "," # "," # ","  #"])
-d(')',["#  "," # "," # "," # ","#  "])
-d('[',["## ","#  ","#  ","#  ","## "])
-d(']',[" ##","  #","  #","  #"," ##"])
-d('<',["  #"," # ","#  "," # ","  #"])
-d('>',["#  "," # ","  #"," # ","#  "])
-d('#',["# #","###","# #","###","# #"])
-d('$',[" # "," ##","## "," ##","## "])  # rough
-d('%',["# #","  #"," # ","#  ","# #"])
-d('&',[" # ","# #"," # ","# #"," ##"])
-d("'",[" # "," # ","   ","   ","   "])
-d('"',["# #","# #","   ","   ","   "])
-d('@',[" # ","# #","###","#  "," ##"])
-d('_',["   ","   ","   ","   ","###"])
-d('~',["   "," ##","## ","   ","   "])
-d('^',[" # ","# #","   ","   ","   "])
-d('|',[" # "," # "," # "," # "," # "])
-d('{',["  #"," # ","## "," # ","  #"])
-d('}',["#  "," # "," ##"," # ","#  "])
-d('`',["#  "," # ","   ","   ","   "])
+def d(ch, top, rows):        # rows: list of 3-char strings ('#'=on)
+    G[ch] = (top, rows)
 
-def glyph_bytes(rows):
-    out=[]
-    # 5 glyph rows in the top; cell is 4px wide, glyph 3px left-aligned (bit3..1)
-    for r in range(8):
-        if r < 5:
-            s = rows[r]
-            v = 0
-            for i,px in enumerate(s):          # i=0 leftmost -> bit3
-                if px=='#': v |= (1 << (3-i))
-            out.append(v)
-        else:
-            out.append(0)
+# ---- uppercase (top=1, 5 tall) ----
+CAPS = {
+ 'A':["##.","#.#","###","#.#","#.#"], 'B':["##.","#.#","##.","#.#","##."],
+ 'C':[".##","#..","#..","#..",".##"], 'D':["##.","#.#","#.#","#.#","##."],
+ 'E':["###","#..","##.","#..","###"], 'F':["###","#..","##.","#..","#.."],
+ 'G':[".##","#..","#.#","#.#",".##"], 'H':["#.#","#.#","###","#.#","#.#"],
+ 'I':["###",".#.",".#.",".#.","###"], 'J':["..#","..#","..#","#.#",".#."],
+ 'K':["#.#","#.#","##.","#.#","#.#"], 'L':["#..","#..","#..","#..","###"],
+ 'M':["#.#","###","###","#.#","#.#"], 'N':["#.#","###","###","###","#.#"],
+ 'O':[".#.","#.#","#.#","#.#",".#."], 'P':["##.","#.#","##.","#..","#.."],
+ 'Q':[".#.","#.#","#.#",".#.","..#"], 'R':["##.","#.#","##.","#.#","#.#"],
+ 'S':[".##","#..",".#.","..#","##."], 'T':["###",".#.",".#.",".#.",".#."],
+ 'U':["#.#","#.#","#.#","#.#",".##"], 'V':["#.#","#.#","#.#",".#.",".#."],
+ 'W':["#.#","#.#","###","###","#.#"], 'X':["#.#","#.#",".#.","#.#","#.#"],
+ 'Y':["#.#","#.#",".#.",".#.",".#."], 'Z':["###","..#",".#.","#..","###"],
+}
+for c,r in CAPS.items(): d(c,1,r)
+
+# ---- digits (top=1, 5 tall) ----
+DIG = {
+ '0':[".#.","#.#","#.#","#.#",".#."], '1':[".#.","##.",".#.",".#.","###"],
+ '2':["##.","..#",".#.","#..","###"], '3':["##.","..#",".#.","..#","##."],
+ '4':["#.#","#.#","###","..#","..#"], '5':["###","#..","##.","..#","##."],
+ '6':[".##","#..","##.","#.#",".#."], '7':["###","..#",".#.",".#.",".#."],
+ '8':[".#.","#.#",".#.","#.#",".#."], '9':[".#.","#.#",".##","..#","##."],
+}
+for c,r in DIG.items(): d(c,1,r)
+
+# ---- lowercase: x-height rows 2..5, baseline row 5 ----
+# plain x-height (top=2, 4 tall)
+XH = {
+ 'a':["##.",".##","#.#",".##"], 'c':[".##","#..","#..",".##"],
+ 'e':[".#.","#.#","##.",".##"], 'm':["#.#","###","###","#.#"],
+ 'n':["##.","#.#","#.#","#.#"], 'o':[".#.","#.#","#.#",".#."],
+ 'r':["#.#","##.","#..","#.."], 's':[".##","##.",".##","##."],
+ 'u':["#.#","#.#","#.#",".##"], 'v':["#.#","#.#","#.#",".#."],
+ 'w':["#.#","###","###","#.#"], 'x':["#.#",".#.",".#.","#.#"],
+ 'z':["###","..#",".#.","###"],
+}
+for c,r in XH.items(): d(c,2,r)
+# ascenders (top=1, 5 tall)
+ASC = {
+ 'b':["#..","#..","##.","#.#","##."], 'd':["..#","..#",".##","#.#",".##"],
+ 'f':[".##",".#.","###",".#.",".#."], 'h':["#..","#..","##.","#.#","#.#"],
+ 'k':["#..","#.#","##.","#.#","#.#"], 'l':["##.",".#.",".#.",".#.",".##"],
+ 't':[".#.","###",".#.",".#.",".##"], 'i':[".#.","...",".#.",".#.",".#."],
+}
+for c,r in ASC.items(): d(c,1,r)
+# descenders (top=2, body 4 + descender -> rows 2..7)
+DESC = {
+ 'g':[".##","#.#",".##","..#","##."], 'p':["##.","#.#","##.","#..","#.."],
+ 'q':[".##","#.#",".##","..#","..#"], 'y':["#.#","#.#",".##","..#","##."],
+ 'j':["..#","...","..#","..#","##."],
+}
+for c,r in DESC.items(): d(c,2,r)
+
+# ---- punctuation ----
+P = {
+ '.':(4,[".#."]), ',':(4,[".#.","#.."]), ':':(2,[".#.","...",".#."]),
+ ';':(2,[".#.","...",".#.","#.."]), '!':(1,[".#.",".#.",".#.","...",".#."]),
+ '?':(1,["##.","..#",".#.","...",".#."]), '-':(3,["###"]),
+ '+':(2,[".#.","###",".#."]), '=':(2,["###","...","###"]),
+ '*':(1,["#.#",".#.","###",".#.","#.#"]), '/':(1,["..#","..#",".#.","#..","#.."]),
+ '\\':(1,["#..","#..",".#.","..#","..#"]), '(':(1,["..#",".#.",".#.",".#.","..#"]),
+ ')':(1,["#..",".#.",".#.",".#.","#.."]), '[':(1,["##.","#..","#..","#..","##."]),
+ ']':(1,[".##","..#","..#","..#",".##"]), '<':(1,["..#",".#.","#..",".#.","..#"]),
+ '>':(1,["#..",".#.","..#",".#.","#.."]), '#':(1,["#.#","###","#.#","###","#.#"]),
+ '$':(1,[".##","#.#",".#.","#.#","##."]), '%':(1,["#.#","..#",".#.","#..","#.#"]),
+ '&':(1,[".#.","#.#",".#.","#.#",".##"]), "'":(1,[".#.",".#."]),
+ '"':(1,["#.#","#.#"]), '@':(1,[".#.","#.#","###","#..",".##"]),
+ '_':(7,["###"]), '~':(3,[".##","##."]), '^':(1,[".#.","#.#"]),
+ '|':(1,[".#.",".#.",".#.",".#.",".#."]), '`':(1,["#..",".#."]),
+ '{':(1,["..#",".#.","##.",".#.","..#"]), '}':(1,["#..",".#.",".##",".#.","#.."]),
+ ' ':(0,[]),
+}
+for c,(t,r) in P.items(): d(c,t,r)
+
+def bits(s):
+    v=0
+    for i,px in enumerate(s[:3]):
+        if px=='#': v |= (1 << (3-i))
+    return v
+
+def glyph_bytes(top, rows):
+    out=[0]*8
+    for k,s in enumerate(rows):
+        r = top + k
+        if 0 <= r < 8: out[r] = bits(s)
     return out
 
-lines=["; auto-generated by tools/genfont.py - 4x8 font (3x5 glyphs), 96 glyphs",
+lines=["; auto-generated by tools/genfont.py - 4x8 mixed-case font, 96 glyphs",
        "SECTION \"font\", ROM0", "FontData::"]
+missing=[]
 for code in range(32,128):
     ch = chr(code)
-    key = ch.upper() if ch.isalpha() else ch
-    rows = G.get(key, G.get(ch, ["###","# #","# #","# #","###"]))  # box for unknown
-    b = glyph_bytes(rows)
-    lines.append("    db " + ",".join("$%02X"%x for x in b) + "    ; '%s'"%(ch if ch!='\\' and code!=127 else '?'))
+    if ch in G:
+        top,rows = G[ch]
+    else:
+        top,rows = 1,["###","#.#","#.#","#.#","###"]   # box for undefined
+        if code!=127: missing.append(ch)
+    b = glyph_bytes(top,rows)
+    label = ch if ch not in '\\' else '\\\\'
+    lines.append("    db " + ",".join("$%02X"%x for x in b) + "    ; '%s'"%(label if 32<code<127 else ('SP' if code==32 else 'DEL')))
 open("/home/user/dev/gbos/src/font.asm","w").write("\n".join(lines)+"\n")
-print("wrote src/font.inc:", (128-32), "glyphs")
+print("wrote src/font.asm; missing glyphs:", "".join(missing) or "(none)")