On Fri, Feb 14, 2020 at 01:12:59AM +0100, Philippe Mathieu-Daudé wrote:
> We are initializating incy inconditionally:
>
> if (y1 <= y2) {
> incy = 1;
> } else {
> incy = -1;
> }
>
> Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> ---
> hw/display/artist.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/hw/display/artist.c b/hw/display/artist.c
> index abacb0e27d..47f0e9f0bc 100644
> --- a/hw/display/artist.c
> +++ b/hw/display/artist.c
> @@ -557,91 +557,90 @@ static void fill_window(ARTISTState *s, int startx, int
> starty,
> static void draw_line(ARTISTState *s, int x1, int y1, int x2, int y2,
> bool update_start, int skip_pix, int max_pix)
> {
> struct vram_buffer *buf;
> uint8_t color = artist_get_color(s);
> int dx, dy, t, e, x, y, incy, diago, horiz;
> bool c1;
> uint8_t *p;
>
> trace_artist_draw_line(x1, y1, x2, y2);
>
> if (update_start) {
> s->vram_start = (x2 << 16) | y2;
> }
>
> buf = &s->vram_buffer[ARTIST_BUFFER_AP];
>
> c1 = false;
> - incy = 1;
>
> if (x2 > x1) {
> dx = x2 - x1;
> } else {
> dx = x1 - x2;
> }
> if (y2 > y1) {
> dy = y2 - y1;
> } else {
> dy = y1 - y2;
> }
> if (dy > dx) {
> t = y2;
> y2 = x2;
> x2 = t;
>
> t = y1;
> y1 = x1;
> x1 = t;
>
> t = dx;
> dx = dy;
> dy = t;
>
> c1 = true;
> }
>
> if (x1 > x2) {
> t = y2;
> y2 = y1;
> y1 = t;
>
> t = x1;
> x1 = x2;
> x2 = t;
> }
>
> horiz = dy << 1;
> diago = (dy - dx) << 1;
> e = (dy << 1) - dx;
>
> if (y1 <= y2) {
> incy = 1;
> } else {
> incy = -1;
> }
> x = x1;
> y = y1;
>
> do {
> if (c1) {
> p = buf->data + x * s->width + y;
> } else {
> p = buf->data + y * s->width + x;
> }
>
> if (skip_pix > 0) {
> skip_pix--;
> } else {
> artist_rop8(s, p, color);
> }
>
> if (e > 0) {
> artist_invalidate_lines(buf, y, 1);
> y += incy;
> e += diago;
> } else {
> e += horiz;
> }
> x++;
> } while (x <= x2 && (max_pix == -1 || --max_pix > 0));
> }
> --
> 2.21.1
>
Acked-by: Sven Schnelle <sv...@stackframe.org>
