more control codes for MEGA65 screen editor

src/kernal/screen_m65/mega65_chrout_screen_control.s

@@ -73,6 +73,81 @@ m65_chrout_try_color_loop:
 
 
 
+
+// XXX: consider moving to separate files
+
+m65_chrout_screen_RETURN:
+
+	// RETURN clears quote and insert modes, it also clears reverse flag
+	
+	lda #$00
+	sta QTSW
+	sta INSRT
+	sta RVS
+
+	// XXX should we clear special colour attributes too?
+
+	// Move cursor to the beginning of the next line
+
+	sta M65__TXTCOL
+	inc M65__TXTROW
+
+	// Correct the column/row values
+
+	jmp m65_chrout_fix_column_row
+
+
+
+
+m65_chrout_screen_RVS_ON:
+
+	lda #$80
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+m65_chrout_screen_RVS_OFF:
+
+	lda #$00
+
+	sta RVS
+	jmp m65_chrout_screen_done
+
+
+
+m65_chrout_screen_CRSR_RIGHT:
+
+	inc M65__TXTCOL
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+m65_chrout_screen_CRSR_LEFT:
+	
+	dec M65__TXTCOL
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+m65_chrout_screen_CRSR_DOWN:
+
+	inc M65__TXTROW
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+m65_chrout_screen_CRSR_UP:
+
+	dec M65__TXTROW
+
+	// Correct the column/row values
+
+	jmp m65_chrout_fix_column_row
+
+
+
+
+
 // XXX: implement screen routines below:
 
 m65_chrout_screen_quote:
@@ -89,18 +164,6 @@ m65_chrout_screen_TXT:
 	nop
 m65_chrout_screen_GFX:
 	nop
-m65_chrout_screen_RVS_OFF:
-	nop
-m65_chrout_screen_RVS_ON:
-	nop
-m65_chrout_screen_CRSR_RIGHT:
-	nop
-m65_chrout_screen_CRSR_LEFT:
-	nop
-m65_chrout_screen_CRSR_DOWN:
-	nop
-m65_chrout_screen_CRSR_UP:
-	nop
 m65_chrout_screen_INS:
 	nop
 m65_chrout_screen_TAB:
@@ -125,5 +188,5 @@ m65_chrout_screen_STOP:
 	nop
 m65_chrout_screen_DEL:
 	nop
-m65_chrout_screen_RETURN:
+
 	jmp m65_chrout_screen_done