optimized text screen clear/fill and scrolling on c64

compiler/res/prog8lib/c64/textio.p8

@@ -38,13 +38,13 @@ asmsub  clear_screenchars (ubyte char @ A) clobbers(Y)  {
 	; ---- clear the character screen with the given fill character (leaves colors)
 	;      (assumes screen matrix is at the default address)
 	%asm {{
-		ldy  #0
+		ldy  #250
-_loop		sta  c64.Screen,y
+-		sta  c64.Screen+250*0-1,y
-		sta  c64.Screen+$0100,y
+		sta  c64.Screen+250*1-1,y
-		sta  c64.Screen+$0200,y
+		sta  c64.Screen+250*2-1,y
-		sta  c64.Screen+$02e8,y
+		sta  c64.Screen+250*3-1,y
-		iny
+		dey
-		bne  _loop
+		bne  -
 		rts
         }}
 }
@@ -53,13 +53,13 @@ asmsub  clear_screencolors (ubyte color @ A) clobbers(Y)  {
 	; ---- clear the character screen colors with the given color (leaves characters).
 	;      (assumes color matrix is at the default address)
 	%asm {{
-		ldy  #0
+		ldy  #250
-_loop		sta  c64.Colors,y
+-		sta  c64.Colors+250*0-1,y
-		sta  c64.Colors+$0100,y
+		sta  c64.Colors+250*1-1,y
-		sta  c64.Colors+$0200,y
+		sta  c64.Colors+250*2-1,y
-		sta  c64.Colors+$02e8,y
+		sta  c64.Colors+250*3-1,y
-		iny
+		dey
-		bne  _loop
+		bne  -
 		rts
         }}
 }
@@ -83,28 +83,30 @@ asmsub  scroll_left  (ubyte alsocolors @ Pc) clobbers(A, Y)  {
 
 	%asm {{
 		stx  P8ZP_SCRATCH_REG
-		bcs  +
+		bcc _scroll_screen
-		jmp  _scroll_screen
 
-+               ; scroll the color memory
++               ; scroll the screen and the color memory
-		ldx  #0
-		ldy  #38
--
-	.for row=0, row<=24, row+=1
-		lda  c64.Colors + 40*row + 1,x
-		sta  c64.Colors + 40*row,x
-	.next
-		inx
-		dey
-		bpl  -
-
-_scroll_screen  ; scroll the screen memory
 		ldx  #0
 		ldy  #38
 -
         .for row=0, row<=24, row+=1
             lda  c64.Screen + 40*row + 1,x
-		sta  c64.Screen + 40*row,x
+            sta  c64.Screen + 40*row + 0,x
+            lda  c64.Colors + 40*row + 1,x
+            sta  c64.Colors + 40*row + 0,x
+        .next
+		inx
+		dey
+		bpl  -
+		rts
+
+_scroll_screen  ; scroll only the screen memory
+		ldx  #0
+		ldy  #38
+-
+        .for row=0, row<=24, row+=1
+            lda  c64.Screen + 40*row + 1,x
+            sta  c64.Screen + 40*row + 0,x
         .next
 		inx
 		dey
@@ -121,20 +123,22 @@ asmsub  scroll_right  (ubyte alsocolors @ Pc) clobbers(A)  {
 	;      Carry flag determines if screen color data must be scrolled too
 	%asm {{
 		stx  P8ZP_SCRATCH_REG
-		bcs  +
+		bcc  _scroll_screen
-		jmp  _scroll_screen
 
-+               ; scroll the color memory
++               ; scroll the screen and the color memory
 		ldx  #38
 -
         .for row=0, row<=24, row+=1
+            lda  c64.Screen + 40*row + 0,x
+            sta  c64.Screen + 40*row + 1,x
             lda  c64.Colors + 40*row + 0,x
             sta  c64.Colors + 40*row + 1,x
         .next
 		dex
 		bpl  -
+		rts
 
-_scroll_screen  ; scroll the screen memory
+_scroll_screen  ; scroll only the screen memory
 		ldx  #38
 -
         .for row=0, row<=24, row+=1
@@ -155,20 +159,22 @@ asmsub  scroll_up  (ubyte alsocolors @ Pc) clobbers(A)  {
 	;      Carry flag determines if screen color data must be scrolled too
 	%asm {{
 		stx  P8ZP_SCRATCH_REG
-		bcs  +
+		bcc  _scroll_screen
-		jmp  _scroll_screen
 
-+               ; scroll the color memory
++               ; scroll the screen and the color memory
 		ldx #39
 -
         .for row=1, row<=24, row+=1
+            lda  c64.Screen + 40*row,x
+            sta  c64.Screen + 40*(row-1),x
             lda  c64.Colors + 40*row,x
             sta  c64.Colors + 40*(row-1),x
         .next
 		dex
 		bpl  -
+		rts
 
-_scroll_screen  ; scroll the screen memory
+_scroll_screen  ; scroll only the screen memory
 		ldx #39
 -
         .for row=1, row<=24, row+=1
@@ -189,20 +195,22 @@ asmsub  scroll_down  (ubyte alsocolors @ Pc) clobbers(A)  {
 	;      Carry flag determines if screen color data must be scrolled too
 	%asm {{
 		stx  P8ZP_SCRATCH_REG
-		bcs  +
+		bcc  _scroll_screen
-		jmp  _scroll_screen
 
-+               ; scroll the color memory
++               ; scroll the screen and the color memory
 		ldx #39
 -
         .for row=23, row>=0, row-=1
             lda  c64.Colors + 40*row,x
             sta  c64.Colors + 40*(row+1),x
+            lda  c64.Screen + 40*row,x
+            sta  c64.Screen + 40*(row+1),x
         .next
 		dex
 		bpl  -
+		rts
 
-_scroll_screen  ; scroll the screen memory
+_scroll_screen  ; scroll only the screen memory
 		ldx #39
 -
         .for row=23, row>=0, row-=1

examples/balloonflight.p8

@@ -17,7 +17,7 @@ main {
 
         c64.SCROLX &= %11110111     ; 38 column mode
 
-        c64.set_rasterirq(1)     ; enable animation
+        c64.set_rasterirq(40)     ; enable animation
 
         ubyte target_height = 10
         ubyte active_height = 24

examples/line-circle-txt.p8

@@ -41,7 +41,7 @@ main {
         rect(10, 10, 10, 10, false)
         rect(6, 0, 16, 20, true)
 
-        ; test_stack.test()
+        test_stack.test()
 
 
         sub rect(ubyte x1, ubyte y1, ubyte x2, ubyte y2, ubyte fill) {
@@ -140,21 +140,17 @@ main {
             ubyte xx
 
             while x>=y {
-                for xx in cx to cx+x {
+                xx = cx-x
-                    txt.setcc(xx, cy + y as ubyte, 81, 1)
+                repeat 2*x+1 {
-                    txt.setcc(xx, cy - y as ubyte, 81, 2)
+                    txt.setcc(xx, cy + y as ubyte, 81, 11)
+                    txt.setcc(xx, cy - y as ubyte, 81, 12)
+                    xx++
                 }
-                for xx in cx-x to cx-1 {
+                xx = cx-y
-                    txt.setcc(xx, cy + y as ubyte, 81, 3)
+                repeat 2*y+1 {
-                    txt.setcc(xx, cy - y as ubyte, 81, 4)
+                    txt.setcc(xx, cy + x as ubyte, 81, 13)
-                }
+                    txt.setcc(xx, cy - x as ubyte, 81, 14)
-                for xx in cx to cx+y {
+                    xx++
-                    txt.setcc(xx, cy + x as ubyte, 81, 5)
-                    txt.setcc(xx, cy - x as ubyte, 81, 6)
-                }
-                for xx in cx-y to cx {
-                    txt.setcc(xx, cy + x as ubyte, 81, 7)
-                    txt.setcc(xx, cy - x as ubyte, 81, 8)
                 }
                 y++
                 if decisionOver2<=0

examples/test.p8

@@ -7,27 +7,13 @@ main {
     sub start() {
         txt.fill_screen('.',2)
 
-        ubyte xx
-        ubyte yy = 0
-        for xx in 0 to txt.DEFAULT_WIDTH-1 {
-            txt.setcc(xx, 0, xx, 1)
-            txt.setcc(xx, txt.DEFAULT_HEIGHT-1, xx, 1)
-        }
-        for yy in 0 to txt.DEFAULT_HEIGHT-1 {
-            txt.setcc(0, yy, yy,1)
-            txt.setcc(txt.DEFAULT_WIDTH-1, yy, yy, 1)
-        }
-
         repeat {
-            delay()
-            txt.scroll_left(false)
         }
     }
 
-
     sub delay () {
         ubyte tt
-        repeat 255 {
+        repeat 55 {
             repeat 255 {
                 tt++
             }