another size optimization, make bgcolor() much more robust

libsrc/c64/soft80_color.s

@@ -7,6 +7,8 @@
 
         .export         soft80_textcolor, soft80_bgcolor
         .import         soft80_internal_textcolor, soft80_internal_bgcolor
+        .import         soft80_internal_cursorxlsb
+        .import         soft80_kplot, soft80_checkchar
 
         .importzp       tmp1, tmp2
 
@@ -17,74 +19,6 @@ soft80_textcolor:
         ldx     soft80_internal_textcolor       ; get old value
         sta     soft80_internal_textcolor       ; set new value
 
-        jsr     mkcharcolor
-
-        txa                                     ; get old value
-        rts
-
-soft80_bgcolor:
-        ldx     soft80_internal_bgcolor         ; get old value
-        sta     soft80_internal_bgcolor         ; set new value
-
-        jsr     mkcharcolor
-
-        stx     tmp2                            ; save old value
-
-.if SOFT80COLORVOODOO = 1
-        ; if the old bg color is equal to color ram of that cell, then also
-        ; update the color ram to the new value.
-        ; FIXME: perhaps we must also check if the non visible character is not
-        ;        a space, and NOT update the color ram in that case.
-        ldx     #$00
-lp1:
-        .repeat $4,page
-        .scope
-        lda     soft80_colram+(page*250),x
-        and     #$0f
-        cmp     tmp2                            ; old bg color
-        bne     @sk1
-        lda     soft80_internal_bgcolor         ; new bg color
-        sta     soft80_colram+(page*250),x
-@sk1:
-        .endscope
-        .endrepeat
-
-        inx
-        bne     lp1
-.endif
-
-        sei
-        ldy     $01
-        lda     #$34                            ; disable I/O
-        sta     $01
-
-        ; if the old bg color is equal to text color in this cell, then also
-        ; update the text color to the new value.
-        ; FIXME: perhaps we need to check for space, see note above
-        ldx     #$00
-lp2:
-        .repeat $4,page
-        .scope
-        lda     soft80_vram+(page*250),x
-        and     #$0f
-        cmp     tmp2                            ; old bg color
-        bne     @sk2
-        lda     soft80_internal_bgcolor         ; new bg color
-@sk2:
-        ora     tmp1                            ; new bg color (high nibble)
-        sta     soft80_vram+(page*250),x
-        .endscope
-        .endrepeat
-
-        inx
-        bne     lp2
-
-        sty     $01                             ; enable I/O
-        cli
-
-        lda     tmp2                            ; get old value
-        rts
-
 mkcharcolor:
         lda     soft80_internal_bgcolor
         asl     a
@@ -94,6 +28,126 @@ mkcharcolor:
         sta     tmp1                            ; remember new bg color (high nibble)
         ora     soft80_internal_textcolor
         sta     CHARCOLOR                       ; text/bg combo for new chars
+
+        txa                                     ; get old value
+        rts
+
+soft80_bgcolor:
+        ldx     soft80_internal_bgcolor         ; get old value
+        stx     tmp2                            ; save old value
+        sta     soft80_internal_bgcolor         ; set new value
+
+        jsr     mkcharcolor
+
+        lda     CURS_X
+        pha
+        lda     CURS_Y
+        pha
+
+        ldy     #0
+        ldx     #0
+        clc
+        jsr     soft80_kplot
+
+        sei
+        lda     $01
+        pha
+        ldx     #$34
+        stx     $01                             ; $34
+
+        ;ldy     #0                              ; is still 0
+
+        lda     #24
+        sta     CURS_Y
+lpy:
+        lda     #39
+        sta     CURS_X
+lpx:
+
+.if SOFT80COLORVOODOO = 1
+        ; if the old bg color is equal to color ram of that cell, then also
+        ; update the color ram to the new value.
+
+        inc     $01                             ; $35
+        lda     (CRAM_PTR),y                    ; colram
+        stx     $01                             ; $34
+
+        and     #$0f
+        cmp     tmp2                            ; old bg color
+        bne     @sk1
+
+        ; if the left character in the cell is not a space, then dont update
+        ; the color ram
+        lda     #1
+        sta     soft80_internal_cursorxlsb
+        jsr     soft80_checkchar
+        bcc     @sk1
+        lda     soft80_internal_bgcolor         ; new bg color
+
+        inc     $01                             ; $35
+        sta     (CRAM_PTR),y                    ; colram
+        stx     $01                             ; $34
+@sk1:
+.endif
+        ; if the old bg color is equal to text color in this cell, then also
+        ; update the text color to the new value.
+
+        lda     (CRAM_PTR),y                    ; vram
+        and     #$0f
+        cmp     tmp2                            ; old bg color
+        bne     @sk2
+
+        ; if there are non space characters in the cell, do not update the
+        ; color ram
+        pha
+        lda     #0
+        sta     soft80_internal_cursorxlsb
+        jsr     soft80_checkchar
+        pla
+        bcc     @sk2
+
+        pha
+        inc     soft80_internal_cursorxlsb
+        jsr     soft80_checkchar
+        pla
+        bcc     @sk2
+
+        lda     soft80_internal_bgcolor         ; new bg color
+@sk2:
+        ora     tmp1                            ; new bg color (high nibble)
+        sta     (CRAM_PTR),y                    ; vram
+
+        inc     CRAM_PTR
+        bne     @sk3
+        inc     CRAM_PTR+1
+@sk3:
+
+        lda     SCREEN_PTR
+        clc
+        adc     #8
+        sta     SCREEN_PTR
+        bcc     @sk4
+        inc     SCREEN_PTR+1
+@sk4:
+
+        dec     CURS_X
+        bpl     lpx
+
+        dec     CURS_Y
+        bpl     lpy
+
+        pla
+        sta     $01                             ; enable I/O
+        cli
+
+        pla     ; CURS_Y
+        tax
+        pla     ; CURS_X
+        tay
+        clc
+        jsr     soft80_kplot
+
+        lda     tmp2                            ; get old value
         rts
 
 ;-------------------------------------------------------------------------------

libsrc/c64/soft80_cputc.s

@@ -8,6 +8,7 @@
         .export         soft80_cputcxy, soft80_cputc
         .export         soft80_cputdirect, soft80_putchar
         .export         soft80_newline, soft80_plot
+        .export         soft80_checkchar
 
         .import         popa, _gotoxy
 
@@ -470,15 +471,14 @@ soft80_putcolor:
 ; test if there is a space or a character at current position
 ;
 ; in:  x = $34
-;      y must be $00
+;      $01 must be $34
+;
 ; out: SEC: space
 ;      CLC: character
 ;      x = $34
 ;      y = $00
 soft80_checkchar:
 
-        ;ldy     #$00                            ; is still $00
-
         lda     soft80_internal_cursorxlsb
         bne     @l1a