fixed line drawing routines

git-svn-id: svn://svn.cc65.org/cc65/trunk@2282 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/c128/c128-640-200-2.s b/libsrc/c128/c128-640-200-2.s
index 10a7b21e58ad595acfafa4f5aa1e60e1fcd0a357..c43601fbc0b6f47f6da0221d27c1413e2a09b052 100644 (file)
--- a/libsrc/c128/c128-640-200-2.s
+++ b/libsrc/c128/c128-640-200-2.s
@@ -696,63 +696,70 @@ HORLINE:
 ;
 
 LINE:
-       ; if (x2>x1) {
-       ldx     #X1
-       lda     X2
-       ldy     X2+1
-       jsr     icmp
-       bcc     @L0137
-       beq     @L0137
-       ;  x2<->x1 }
-       lda     X1
-       ldx     X2
-       sta     X2
-       stx     X1
-       lda     X1+1
-       ldx     X2+1
-       sta     X2+1
-       stx     X1+1
-@L0137:        ; if (y2>y1) {
-       ldx     #Y1
-       lda     Y2
-       ldy     Y2+1
-       jsr     icmp
-       bcc     @L013F
-       bne     @nequal
-       jmp     HORLINE         ; x1/x2 are sorted, y1==y2 - do faster horizontal line draw
-@nequal:
-       ; y2<->y1 }
-       lda     Y1
-       ldx     Y2
-       sta     Y2
-       stx     Y1
-       lda     Y1+1
-       ldx     Y2+1
-       sta     Y2+1
-       stx     Y1+1
-@L013F:
-       ; nx = x2 - x1
+       ; nx = abs(x2 - x1)
        lda     X2
        sec
        sbc     X1
        sta     NX
        lda     X2+1
        sbc     X1+1
-       sta     NX+1
-       ; ny = y2 - y1
+       tay
+       lda     NX
+       jsr     abs
+       sta     NX
+       sty     NX+1
+       ; ny = abs(y2 - y1)
        lda     Y2
        sec
        sbc     Y1
        sta     NY
        lda     Y2+1
        sbc     Y1+1
-       sta     NY+1
+       tay
+       lda     NY
+       jsr     abs
+       sta     NY
+       sty     NY+1
+       ; if (x2>x1)
+       ldx     #X2
+       lda     X1
+       ldy     X1+1
+       jsr     icmp
+       bcc     @L0243
+       beq     @L0243
+       ; dx = 1;
+       lda     #1
+       bne     @L0244
+       ; else
+       ; dx = -1;
+@L0243:        lda     #$ff
+@L0244:        sta     DX
+       ; if (y2>y1)
+       ldx     #Y2
+       lda     Y1
+       ldy     Y1+1
+       jsr     icmp
+       bcc     @L024A
+       beq     @L024A
+       ; dy = 1;
+       lda     #1
+       bne     @L024B
+       ; else
+       ; dy = -1;
+@L024A:        lda     #$ff
+@L024B:        sta     DY
+       ; err = ay = 0;
+       lda     #0
+       sta     ERR
+       sta     ERR+1
+       sta     AY
+
        ; if (nx<ny) {
        ldx     #NX
        lda     NY
        ldy     NY+1
        jsr     icmp
-       bcs     @L041B
+       bcs     @L0255
        ;  nx <-> ny
        lda     NX
        ldx     NY
@@ -762,21 +769,19 @@ LINE:
        ldx     NY+1
        sta     NY+1
        stx     NX+1
-       ; dx = dy = 0; ax = ay = 1 }
-       ldy     #1
-       sty     AY
-       dey
-       beq     @L025A
-       ; else { dx = dy = 1; ax = ay = 0 }
-@L041B:        ldy     #0
-       sty     AY
-       iny
-@L025A:        sty     DX
-       sty     DY
-       ; err = 0
+       ; ay = dx
+       lda     DX
+       sta     AY
+       ; dx = dy = 0;
        lda     #0
-       sta     ERR
-       sta     ERR+1
+       sta     DX
+       sta     DY
+       ; ny = - ny;
+@L0255:        lda     NY
+       ldy     NY+1
+       jsr     neg
+       sta     NY
+       sty     NY+1
        ; for (count=nx;count>0;--count) {
        lda     NX
        ldx     NX+1
@@ -788,13 +793,13 @@ LINE:
        rts
        ;    setpixel(X1,Y1)
 @L0167:        jsr     SETPIXELCLIP
-       ;    pb = err - ny
+       ;    pb = err + ny
        lda     ERR
-       sec
-       sbc     NY
+       clc
+       adc     NY
        sta     PB
        lda     ERR+1
-       sbc     NY+1
+       adc     NY+1
        sta     PB+1
        tax
        ;    ub = pb + nx
@@ -806,21 +811,27 @@ LINE:
        adc     NX+1
        sta     UB+1
        ;    x1 = x1 + dx
-       lda     X1
-       clc
-       adc     DX
+       ldx     #0
+       lda     DX
+       bpl     @L027B
+       dex
+@L027B:        clc
+       adc     X1
        sta     X1
-       bcc     @L0254
-       inc     X1+1
+       txa
+       adc     X1+1
+       sta     X1+1
        ;   y1 = y1 + ay
-@L0254:
-       lda     Y1
-       clc
-       adc     AY
+       ldx     #0
+       lda     AY
+       bpl     @L027E
+       dex
+@L027E:        clc
+       adc     Y1
        sta     Y1
-       bcc     @L0255
-       inc     Y1+1
-@L0255:
+       txa
+       adc     Y1+1
+       sta     Y1+1
        ; if (abs(pb)<abs(ub)) {
        lda     PB
        ldy     PB+1
@@ -832,32 +843,38 @@ LINE:
        jsr     abs
        ldx     #TEMP3
        jsr     icmp
-       bpl     @L017B
+       bpl     @L027F
        ;   err = pb
        lda     PB
        ldx     PB+1
-       jmp     @L025B
+       jmp     @L0312
        ; } else { x1 = x1 + ay
-@L017B:
-       lda     X1
-       clc
-       adc     AY
+@L027F:
+       ldx     #0
+       lda     AY
+       bpl     @L0288
+       dex
+@L0288:        clc
+       adc     X1
        sta     X1
-       bcc     @L0256
-       inc     X1+1
+       txa
+       adc     X1+1
+       sta     X1+1
        ;       y1 = y1 + dy
-@L0256:
-       lda     Y1
-       clc
-       adc     DY
+       ldx     #0
+       lda     DY
+       bpl     @L028B
+       dex
+@L028B:        clc
+       adc     Y1
        sta     Y1
-       bcc     @L0257
-       inc     Y1+1
+       txa
+       adc     Y1+1
+       sta     Y1+1
        ;       err = ub }
-@L0257:
        lda     UB
        ldx     UB+1
-@L025B:
+@L0312:
        sta     ERR
        stx     ERR+1
        ; } (--count)
@@ -1194,9 +1211,9 @@ abs:
        ; a/y := abs(a/y)
        dey
        iny
-       bpl     @L1
+       bpl     absend
        ; negay
-       clc
+neg:   clc
        eor     #$ff
        adc     #1
        pha
@@ -1205,7 +1222,7 @@ abs:
        adc     #0
        tay
        pla
-@L1:   rts
+absend:        rts
 
 icmp:
        ; compare a/y to zp,x

diff --git a/libsrc/c128/c128-640-480-2.s b/libsrc/c128/c128-640-480-2.s
index 6e314035bf24e69bd72725ea3645d4a5fe8f35ee..1c45e8673fc7f70495dfde237e58d93b2b68758e 100644 (file)
--- a/libsrc/c128/c128-640-480-2.s
+++ b/libsrc/c128/c128-640-480-2.s
@@ -694,63 +694,70 @@ HORLINE:
 ;
 
 LINE:
-       ; if (x2>x1) {
-       ldx     #X1
-       lda     X2
-       ldy     X2+1
-       jsr     icmp
-       bcc     @L0137
-       beq     @L0137
-       ;  x2<->x1 }
-       lda     X1
-       ldx     X2
-       sta     X2
-       stx     X1
-       lda     X1+1
-       ldx     X2+1
-       sta     X2+1
-       stx     X1+1
-@L0137:        ; if (y2>y1) {
-       ldx     #Y1
-       lda     Y2
-       ldy     Y2+1
-       jsr     icmp
-       bcc     @L013F
-       bne     @nequal
-       jmp     HORLINE         ; x1/x2 are sorted, y1==y2 - do faster horizontal line draw
-@nequal:
-       ; y2<->y1 }
-       lda     Y1
-       ldx     Y2
-       sta     Y2
-       stx     Y1
-       lda     Y1+1
-       ldx     Y2+1
-       sta     Y2+1
-       stx     Y1+1
-@L013F:
-       ; nx = x2 - x1
+       ; nx = abs(x2 - x1)
        lda     X2
        sec
        sbc     X1
        sta     NX
        lda     X2+1
        sbc     X1+1
-       sta     NX+1
-       ; ny = y2 - y1
+       tay
+       lda     NX
+       jsr     abs
+       sta     NX
+       sty     NX+1
+       ; ny = abs(y2 - y1)
        lda     Y2
        sec
        sbc     Y1
        sta     NY
        lda     Y2+1
        sbc     Y1+1
-       sta     NY+1
+       tay
+       lda     NY
+       jsr     abs
+       sta     NY
+       sty     NY+1
+       ; if (x2>x1)
+       ldx     #X2
+       lda     X1
+       ldy     X1+1
+       jsr     icmp
+       bcc     @L0243
+       beq     @L0243
+       ; dx = 1;
+       lda     #1
+       bne     @L0244
+       ; else
+       ; dx = -1;
+@L0243:        lda     #$ff
+@L0244:        sta     DX
+       ; if (y2>y1)
+       ldx     #Y2
+       lda     Y1
+       ldy     Y1+1
+       jsr     icmp
+       bcc     @L024A
+       beq     @L024A
+       ; dy = 1;
+       lda     #1
+       bne     @L024B
+       ; else
+       ; dy = -1;
+@L024A:        lda     #$ff
+@L024B:        sta     DY
+       ; err = ay = 0;
+       lda     #0
+       sta     ERR
+       sta     ERR+1
+       sta     AY
+
        ; if (nx<ny) {
        ldx     #NX
        lda     NY
        ldy     NY+1
        jsr     icmp
-       bcs     @L041B
+       bcs     @L0255
        ;  nx <-> ny
        lda     NX
        ldx     NY
@@ -760,21 +767,19 @@ LINE:
        ldx     NY+1
        sta     NY+1
        stx     NX+1
-       ; dx = dy = 0; ax = ay = 1 }
-       ldy     #1
-       sty     AY
-       dey
-       beq     @L025A
-       ; else { dx = dy = 1; ax = ay = 0 }
-@L041B:        ldy     #0
-       sty     AY
-       iny
-@L025A:        sty     DX
-       sty     DY
-       ; err = 0
+       ; ay = dx
+       lda     DX
+       sta     AY
+       ; dx = dy = 0;
        lda     #0
-       sta     ERR
-       sta     ERR+1
+       sta     DX
+       sta     DY
+       ; ny = - ny;
+@L0255:        lda     NY
+       ldy     NY+1
+       jsr     neg
+       sta     NY
+       sty     NY+1
        ; for (count=nx;count>0;--count) {
        lda     NX
        ldx     NX+1
@@ -786,13 +791,13 @@ LINE:
        rts
        ;    setpixel(X1,Y1)
 @L0167:        jsr     SETPIXELCLIP
-       ;    pb = err - ny
+       ;    pb = err + ny
        lda     ERR
-       sec
-       sbc     NY
+       clc
+       adc     NY
        sta     PB
        lda     ERR+1
-       sbc     NY+1
+       adc     NY+1
        sta     PB+1
        tax
        ;    ub = pb + nx
@@ -804,21 +809,27 @@ LINE:
        adc     NX+1
        sta     UB+1
        ;    x1 = x1 + dx
-       lda     X1
-       clc
-       adc     DX
+       ldx     #0
+       lda     DX
+       bpl     @L027B
+       dex
+@L027B:        clc
+       adc     X1
        sta     X1
-       bcc     @L0254
-       inc     X1+1
+       txa
+       adc     X1+1
+       sta     X1+1
        ;   y1 = y1 + ay
-@L0254:
-       lda     Y1
-       clc
-       adc     AY
+       ldx     #0
+       lda     AY
+       bpl     @L027E
+       dex
+@L027E:        clc
+       adc     Y1
        sta     Y1
-       bcc     @L0255
-       inc     Y1+1
-@L0255:
+       txa
+       adc     Y1+1
+       sta     Y1+1
        ; if (abs(pb)<abs(ub)) {
        lda     PB
        ldy     PB+1
@@ -830,32 +841,38 @@ LINE:
        jsr     abs
        ldx     #TEMP3
        jsr     icmp
-       bpl     @L017B
+       bpl     @L027F
        ;   err = pb
        lda     PB
        ldx     PB+1
-       jmp     @L025B
+       jmp     @L0312
        ; } else { x1 = x1 + ay
-@L017B:
-       lda     X1
-       clc
-       adc     AY
+@L027F:
+       ldx     #0
+       lda     AY
+       bpl     @L0288
+       dex
+@L0288:        clc
+       adc     X1
        sta     X1
-       bcc     @L0256
-       inc     X1+1
+       txa
+       adc     X1+1
+       sta     X1+1
        ;       y1 = y1 + dy
-@L0256:
-       lda     Y1
-       clc
-       adc     DY
+       ldx     #0
+       lda     DY
+       bpl     @L028B
+       dex
+@L028B:        clc
+       adc     Y1
        sta     Y1
-       bcc     @L0257
-       inc     Y1+1
+       txa
+       adc     Y1+1
+       sta     Y1+1
        ;       err = ub }
-@L0257:
        lda     UB
        ldx     UB+1
-@L025B:
+@L0312:
        sta     ERR
        stx     ERR+1
        ; } (--count)
@@ -1208,9 +1225,9 @@ abs:
        ; a/y := abs(a/y)
        dey
        iny
-       bpl     @L1
+       bpl     absend
        ; negay
-       clc
+neg:   clc
        eor     #$ff
        adc     #1
        pha
@@ -1219,7 +1236,7 @@ abs:
        adc     #0
        tay
        pla
-@L1:   rts
+absend:        rts
 
 icmp:
        ; compare a/y to zp,x