devdraw: correct mouse event buffering on OS X
diff --git a/src/cmd/devdraw/osx-srv.c b/src/cmd/devdraw/osx-srv.c
index 32450cd..9329bc2 100644
--- a/src/cmd/devdraw/osx-srv.c
+++ b/src/cmd/devdraw/osx-srv.c
@@ -45,6 +45,7 @@
struct Mousebuf
{
Mouse m[32];
+ Mouse last;
int ri;
int wi;
int stall;
@@ -201,7 +202,6 @@
mousetags.wi = 0;
if(mousetags.wi == mousetags.ri)
sysfatal("too many queued mouse reads");
- /* fprint(2, "mouse unstall\n"); */
mouse.stall = 0;
matchmouse();
zunlock();
@@ -379,21 +379,28 @@
y = mouserect.max.y;
zlock();
- m = &mouse.m[mouse.wi];
- m->xy.x = x;
- m->xy.y = y;
- m->buttons = b;
- m->msec = ms;
- mouse.wi++;
- if(mouse.wi == nelem(mouse.m))
- mouse.wi = 0;
- if(mouse.wi == mouse.ri){
- mouse.stall = 1;
- mouse.ri = 0;
- mouse.wi = 1;
- mouse.m[0] = *m;
+ // If reader has stopped reading, don't bother.
+ // If reader is completely caught up, definitely queue.
+ // Otherwise, queue only button change events.
+ if(!mouse.stall)
+ if(mouse.wi == mouse.ri || mouse.last.buttons != b){
+ m = &mouse.last;
+ m->xy.x = x;
+ m->xy.y = y;
+ m->buttons = b;
+ m->msec = ms;
+
+ mouse.m[mouse.wi] = *m;
+ if(++mouse.wi == nelem(mouse.m))
+ mouse.wi = 0;
+ if(mouse.wi == mouse.ri){
+ mouse.stall = 1;
+ mouse.ri = 0;
+ mouse.wi = 1;
+ mouse.m[0] = *m;
+ }
+ matchmouse();
}
- matchmouse();
zunlock();
}
