ref: c61a6b9909e6a2b16ac76a137bfb29c9a919c339
parent: 52965c9a8366b1b30742215543032ef863f0b217
author: spew <spew@palas>
date: Wed Feb 19 21:52:20 EST 2025
implement the actual scrolling
--- a/scroll.c
+++ b/scroll.c
@@ -31,10 +31,13 @@
q = s->r;
h = Dy(q);
+ s->tot = tot;
+ s->p₀ = p₀;
+ s->p₁ = p₁;
if(tot > 1024*1024){- tot>>=10;
- p₀>>=10;
- p₁>>=10;
+ tot >>= 10;
+ p₀ >>= 10;
+ p₁ >>= 10;
}
if(tot > 0){q.min.y += h*p₀/tot;
@@ -45,7 +48,45 @@
}
int
-scrollscr(Scroll *s, Mouse *m, uint *p₀)
+scrollactive(Scroll *s, Mouse *m)
{- return -1;
+ return ptinrect(m->xy, s->r) && m->buttons;
+}
+
+uint
+scrollscr(Scroll *s, Mouse *m)
+{+ int y, h;
+ uint p₀;
+
+ p₀ = 0;
+ h = Dy(s->r);
+ y = m->xy.y;
+ if(y < s->r.min.y)
+ y = s->r.min.y;
+ if(y > s->r.max.y)
+ y = s->r.max.y;
+ switch(m->buttons){+ case 2:
+ if(y > s->r.max.y-2)
+ y = s->r.max.y-2;
+ if(s->tot > 1024*1024)
+ p₀ = ((s->tot>>10)*(y-s->r.min.y)/h)<<10;
+ else
+ p₀ = s->tot*(y-s->r.min.y)/h;
+ break;
+ case 1:
+ case 8:
+ p₀ = (s->p₁-s->p₀)*(y-s->r.min.y)/h+s->p₀;
+ if(2*s->p₀ > p₀)
+ p₀ = 2*s->p₀-p₀;
+ else
+ p₀ = 0;
+ break;
+ case 4:
+ case 16:
+ p₀ = (s->p₁-s->p₀)*(y-s->r.min.y)/h+s->p₀;
+ break;
+ }
+ return p₀;
}
--- a/scroll.h
+++ b/scroll.h
@@ -2,10 +2,11 @@
struct Scroll {Rectangle r;
+ uint p₀, p₁, tot;
Image *image, *cols[NCOL];
- vlong pos, part, tot;
};
Rectangle scrollinit(Scroll *s, Rectangle r, Image *b, Image **cols);
void scrollpos(Scroll *s, uint p₀, uint p₁, uint tot);
-int scrollscr(Scroll *s, Mouse *m, uint *p₀);
+int scrollactive(Scroll *s, Mouse *m);
+uint scrollscr(Scroll *s, Mouse *m);