Optimizations to font compiler

CompileFont.py

@@ -43,7 +43,7 @@ def main(argv):
 			charOriginY = charY*CHAR_HEIGHT
 			
 			for charRow in reversed(range(0,CHAR_HEIGHT)):
-				print ("\t; Line %d, Pixel values: %x,%x,%x,%x,%x,%x,%x,%x" % (charRow,
+				print ("\t; Line %d, Pixel values: %x%x%x%x %x%x%x%x" % (charRow,
 					pixels[charOriginY+charRow][charOriginX+0],
 					pixels[charOriginY+charRow][charOriginX+1],
 					pixels[charOriginY+charRow][charOriginX+2],
@@ -52,7 +52,11 @@ def main(argv):
 					pixels[charOriginY+charRow][charOriginX+5],
 					pixels[charOriginY+charRow][charOriginX+6],
 					pixels[charOriginY+charRow][charOriginX+7]))
+					
 				nextRowDelta = 160
+				localStackList = []
+				rowPushTotal = 0	# Row-right relative
+				
 				for charCol in reversed(range(0,CHAR_WIDTH,4)):
 					nibbles = [pixels[charOriginY+charRow][charOriginX+charCol],
 								pixels[charOriginY+charRow][charOriginX+charCol+1],
@@ -60,6 +64,7 @@ def main(argv):
 								pixels[charOriginY+charRow][charOriginX+charCol+3]]
 					
 					word = nibbles[2]<<12 | nibbles[3]<<8 | nibbles[0]<<4 | nibbles[1]
+					requiredStackIndex = charCol/2
 					
 					if (nibbles[0]==CHROMA and nibbles[1]==CHROMA and nibbles[2]==CHROMA and nibbles[3]==CHROMA):
 						print ("\ttsc")					# Case 1 : All chroma, so let stack advance with no work
@@ -67,12 +72,17 @@ def main(argv):
 						print ("\tdec")
 						print ("\ttcs")
 						nextRowDelta-=2
+						rowPushTotal +=2
 					elif (nibbles[0]!=CHROMA and nibbles[1]!=CHROMA and nibbles[2]!=CHROMA and nibbles[3]!=CHROMA):
-						print ("\ttsc")					# Advance stack 1 for two byte push
+						offsetNeeded = (CHAR_WIDTH/2-requiredStackIndex) - rowPushTotal - 2
-						print ("\tdec")
+						if (offsetNeeded>0):
+							print ("\ttsc")					# Advance stack to position needed for our two byte push
+							print ("\tsec")					# Note that PEA needs a little +1 to put bytes in the place we expect
+							print ("\tsbc #%d" % (offsetNeeded+1))
 							print ("\ttcs")
 						print ("\tpea $%04x" % word)	# Case 2 : No chroma, so fast push
 						nextRowDelta -= 3
+						rowPushTotal += (3+offsetNeeded)
 					else:
 						mask = 0xFFFF					# Case 3 : Mixed chroma, so mask and or
 						if (nibbles[0]!=CHROMA):
@@ -94,16 +104,26 @@ def main(argv):
 						if (nibbles[3]==CHROMA):
 							sprite = sprite & 0xF0FF
 						
-						print ("\ttsc")					# Keep stack moving, even though we didn't use it
+						localStackEntry = [requiredStackIndex,mask,sprite]
-						print ("\tdec")
+						localStackList.append(localStackEntry)
-						print ("\tdec")
-						print ("\ttcs")
-						print ("\tlda 0,S")				# Blend mask, sprite, and background
-						print ("\tand #$%04x" % mask)
-						print ("\tora #$%04x" % sprite)
-						print ("\tsta 0,S")
 						nextRowDelta -= 2
 						
+				# Process any local stack work we accumulated
+				if len(localStackList) > 0:
+					if (rowPushTotal < CHAR_WIDTH/2):			# Get stack pointer to end of row if needed
+						print ("\ttsc")
+						print ("\tsec")
+						print ("\tsbc #%d" % (CHAR_WIDTH/2-rowPushTotal))
+						print ("\ttcs")
+						rowPushTotal = CHAR_WIDTH/2
+					
+					extraReach = rowPushTotal - CHAR_WIDTH/2
+					for stackEntry in localStackList:
+						print ("\tlda %d,S" % (stackEntry[0] + extraReach))				# Blend mask, sprite, and background
+						print ("\tand #$%04x" % stackEntry[1])
+						print ("\tora #$%04x" % stackEntry[2])
+						print ("\tsta %d,S" % (stackEntry[0] + extraReach))
+						
 				# Advance stack pointer to next row
 				print ("\ttsc")
 				print ("\tsec")