Added fast font routine using unrolled loops

HiSprite.py

@@ -921,6 +921,65 @@ class BackingStoreDriver(Listing):
         self.out()
 
 
+class FastFont(Listing):
+    def __init__(self, assembler, screen, font, double_buffer):
+        Listing.__init__(self, assembler)
+        self.slug = "fastfont"
+        self.generate_table(screen, "H1", 0x2000)
+        if double_buffer:
+            self.generate_table(screen, "H2", 0x4000)
+        self.generate_transposed_font(screen, font)
+
+    def generate_table(self, screen, suffix, hgrbase):
+        label = "FASTFONT_%s" % suffix
+        self.label(label)
+
+        # Have to use self-modifying code because assembler may not allow
+        # taking the hi/lo bytes of an address - 1
+        self.comment("A = character, X = column, Y = row; A is clobbered, X&Y are not")
+        self.asm("pha")
+        self.asm("lda %s_JMP_HI,y" % label)
+        self.asm("sta %s_JMP+2" % label)
+        self.asm("lda %s_JMP_LO,y" % label)
+        self.asm("sta %s_JMP+1" % label)
+        self.asm("sty FASTFONT_SCRATCH0")
+        self.asm("pla")
+        self.asm("tay")
+        self.label("%s_JMP" % label)
+        self.asm("jmp $ffff\n")
+
+        # Bit-shift jump table for generic 6502
+        self.out()
+        self.label("%s_JMP_HI" % label)
+        for r in range(24):
+            self.asm(".byte >%s_%d" % (label, r))
+        self.label("%s_JMP_LO" % label)
+        for r in range(24):
+            self.asm(".byte <%s_%d" % (label, r))
+
+        self.out()
+        hgr1 = screen.generate_row_addresses(hgrbase)
+        for r in range(24):
+            self.label("%s_%d" % (label, r))
+            for i in range(8):
+                self.asm("lda TRANSPOSED_FONT_ROW%d,y" % i)
+                self.asm("sta $%04x,x" % (hgr1[r*8 + i]))
+            self.asm("ldy FASTFONT_SCRATCH0")
+            self.asm("rts")
+        self.out()
+
+    def generate_transposed_font(self, screen, font):
+        with open(font, 'rb') as fh:
+            data = fh.read()
+        num_bytes = len(data)
+        num_chars = num_bytes / 8
+        for r in range(8):
+            self.label("TRANSPOSED_FONT_ROW%d" % r)
+            for i in range(num_chars):
+                index = i * 8 + r
+                self.byte("$%02x" % ord(data[index]), 16)
+
+
 if __name__ == "__main__":
     disclaimer = '''
 ; This file was generated by HiSprite.py, a sprite compiler by Quinn Dunki.
@@ -941,6 +1000,7 @@ if __name__ == "__main__":
     parser.add_argument("-k", "--clobber", action="store_true", default=False, help="don't save the registers on the stack")
     parser.add_argument("-d", "--double-buffer", action="store_true", default=False, help="add code blit to either page (default: page 1 only)")
     parser.add_argument("-g", "--damage", action="store_true", default=False, help="add code to report size of sprite upon return. Can be used in a damage list to restore an area from a pristine source.")
+    parser.add_argument("-f", "--font", action="store", default="", help="generate a fast font blitter for text on the hgr screen using the specified binary font file")
     parser.add_argument("-o", "--output-prefix", default="", help="Base name to create a set of output files. If not supplied, all code will be sent to stdout.")
     parser.add_argument("files", metavar="IMAGE", nargs="*", help="a PNG image [or a list of them]. PNG files must not have an alpha channel!")
     options, extra_args = parser.parse_known_args()
@@ -990,6 +1050,9 @@ if __name__ == "__main__":
     if options.cols:
         listings.append(ColLookup(assembler, screen))
 
+    if options.font:
+        listings.append(FastFont(assembler, screen, options.font, options.double_buffer))
+
     if listings:
         if options.output_prefix:
             if Sprite.backing_store_sizes: