Generalized font engine entry points

fontEngine.s

@@ -10,28 +10,46 @@ FIRST_CHAR = 32
 ;
 ; Draws a Pascal string
 ;
-; PARAM0L = Pointer to string
+; PARAML0 = Pointer to string
+; PARAML1 = Width of one character in pixels (you can tweak kerning if you like)
+; X = Font index
 ; Y = VRAM position of lower right corner of string at which to draw
 ;
 ; Trashes SCRATCHL, X, Y, A
 ;
 renderString:
 	NATIVE
-	sty SCRATCHL
+	SAVE_DBR
 
+	sty SCRATCHL	; Cache VRAM position
+
+	txa				; Cache font character table
+	asl
+	tay
+	lda fontJumpTable,y
+	sta renderCharBounce+1
+
+	lda PARAML1		; Convert pixel width to bytes
+	lsr
+	sta PARAML1
+
+	plb				; Temporarily revert to caller's DBR to access their pointer
 	BITS8
 	lda (PARAML0)
 	tax
 	BITS16
+	phb
 
 renderStringLoop:
 
 	; Fetch and render next character in string
 	txy
 	lda #0
+	plb				; Temporarily revert to caller's DBR to access their pointer
 	BITS8A
 	lda (PARAML0),y
 	BITS16
+	phb
 	ldy SCRATCHL
 	jsr renderChar
 
@@ -41,11 +59,12 @@ renderStringLoop:
 	; Calculate VRAM pointer for position of next character
 	lda SCRATCHL
 	sec
-	sbc #8
+	sbc PARAML1
 	sta SCRATCHL
 	bra renderStringLoop
 
 renderStringDone:
+	RESTORE_DBR
 	rtl
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -64,13 +83,21 @@ renderChar:
 	asl
 	tax
 	FASTGRAPHICS
+
+renderCharBounce:		; Self modifying code. Don't panic
 	jmp (font16characterJumpTable,x)
 
 renderCharJumpReturn:	; Compiled glyphs jump back here. Can't rts because stack is turboborked
 	SLOWGRAPHICS
-RESTORE_AXY
+
+	RESTORE_AXY
 	rts
 
+fontJumpTable:
+	.addr font8characterJumpTable
+	.addr font16characterJumpTable
+
+
 .include "font8x8.s"
 .include "font16x16.s"
 

gamemanager.s

@@ -71,7 +71,10 @@ beginGameplay:
 	; Test font renderer
 	lda #testString
 	sta PARAML0
+	lda #8
+	sta PARAML1
 	ldy #$4430			; Correct start of line address for 16 wide: $4bc7
+	ldx #0
 	jsl $050000
 	bra gameplayLoop
 testString: