replace 'circle' with Mu implementation

shell/data.limg

@@ -140,24 +140,6 @@
     (fill_rect . [def (fill_rect screen x1 y1 x2 y2 color)
   for y y1 (y < y2) ++y
     (hline screen y x1 x2 color)])
-    (circle . [def (circle scr cx cy r clr)
-  with (x (0 - r)
-        y 0
-        err (2 - 2*r)
-        continue? 1)
-    while continue?
-      (pixel scr cx-x cy+y clr)
-      (pixel scr cx-y cy-x clr)
-      (pixel scr cx+x cy-y clr)
-      (pixel scr cx+y cy+x clr)
-      (set r err)
-      when (r <= y)
-        ++y
-        err += (2*y + 1)
-      when (or (r > x) (err > y))
-        ++x
-        err += (2*x + 1)
-      set continue? (x < 0)])
     (ring . [def (ring screen cx cy r0 w clr)
   for r r0 (r < r0+w) ++r
     (circle screen cx cy r clr)])

shell/primitives.mu

@@ -41,6 +41,7 @@ fn initialize-primitives _self: (addr global-table) {
   append-primitive self, "line"
   append-primitive self, "hline"
   append-primitive self, "vline"
+  append-primitive self, "circle"
   append-primitive self, "width"
   append-primitive self, "height"
   # for keyboards
@@ -128,7 +129,7 @@ fn render-primitives screen: (addr screen), xmin: int, xmax: int, ymax: int {
   tmpx <- draw-text-rightward screen, "pixel graphics", tmpx, left-max, y, 7/fg=grey, 0xdc/bg=green-bg
   y <- increment
   var tmpx/eax: int <- copy xmin
-  tmpx <- draw-text-rightward screen, "  line hline vline pixel", tmpx, left-max, y, 0x2a/fg=orange, 0xdc/bg=green-bg
+  tmpx <- draw-text-rightward screen, "  circle line hline vline pixel", tmpx, left-max, y, 0x2a/fg=orange, 0xdc/bg=green-bg
   y <- increment
   var tmpx/eax: int <- copy xmin
   tmpx <- draw-text-rightward screen, "  width height", tmpx, left-max, y, 0x2a/fg=orange, 0xdc/bg=green-bg
@@ -456,6 +457,13 @@ fn apply-primitive _f: (addr cell), args-ah: (addr handle cell), out: (addr hand
     apply-vline args-ah, out, trace
     return
   }
+  {
+    var circle?/eax: boolean <- string-equal? f-name, "circle"
+    compare circle?, 0/false
+    break-if-=
+    apply-circle args-ah, out, trace
+    return
+  }
   {
     var width?/eax: boolean <- string-equal? f-name, "width"
     compare width?, 0/false
@@ -2439,6 +2447,158 @@ fn apply-vline _args-ah: (addr handle cell), out: (addr handle cell), trace: (ad
   # return nothing
 }
 
+fn apply-circle _args-ah: (addr handle cell), out: (addr handle cell), trace: (addr trace) {
+  trace-text trace, "eval", "apply 'circle'"
+  var args-ah/eax: (addr handle cell) <- copy _args-ah
+  var _args/eax: (addr cell) <- lookup *args-ah
+  var args/esi: (addr cell) <- copy _args
+  {
+    var args-type/eax: (addr int) <- get args, type
+    compare *args-type, 0/pair
+    break-if-=
+    error trace, "args to 'circle' are not a list"
+    return
+  }
+  var empty-args?/eax: boolean <- nil? args
+  compare empty-args?, 0/false
+  {
+    break-if-=
+    error trace, "'circle' needs 5 args but got 0"
+    return
+  }
+  # screen = args->left
+  var first-ah/eax: (addr handle cell) <- get args, left
+  var first/eax: (addr cell) <- lookup *first-ah
+  {
+    var first-type/eax: (addr int) <- get first, type
+    compare *first-type, 5/screen
+    break-if-=
+    error trace, "first arg for 'circle' is not a screen"
+    return
+  }
+  var screen-ah/eax: (addr handle screen) <- get first, screen-data
+  var _screen/eax: (addr screen) <- lookup *screen-ah
+  var screen/edi: (addr screen) <- copy _screen
+  # cx = args->right->left->value
+  var rest-ah/eax: (addr handle cell) <- get args, right
+  var _rest/eax: (addr cell) <- lookup *rest-ah
+  var rest/esi: (addr cell) <- copy _rest
+  {
+    var rest-type/eax: (addr int) <- get rest, type
+    compare *rest-type, 0/pair
+    break-if-=
+    error trace, "'circle' encountered non-pair"
+    return
+  }
+  {
+    var rest-nil?/eax: boolean <- nil? rest
+    compare rest-nil?, 0/false
+    break-if-=
+    error trace, "'circle' needs 5 args but got 1"
+    return
+  }
+  var second-ah/eax: (addr handle cell) <- get rest, left
+  var second/eax: (addr cell) <- lookup *second-ah
+  {
+    var second-type/eax: (addr int) <- get second, type
+    compare *second-type, 1/number
+    break-if-=
+    error trace, "second arg for 'circle' is not a number (screen x coordinate of center)"
+    return
+  }
+  var second-value/eax: (addr float) <- get second, number-data
+  var cx/edx: int <- convert *second-value
+  # cy = rest->right->left->value
+  var rest-ah/eax: (addr handle cell) <- get rest, right
+  var _rest/eax: (addr cell) <- lookup *rest-ah
+  rest <- copy _rest
+  {
+    var rest-type/eax: (addr int) <- get rest, type
+    compare *rest-type, 0/pair
+    break-if-=
+    error trace, "'circle' encountered non-pair"
+    return
+  }
+  {
+    var rest-nil?/eax: boolean <- nil? rest
+    compare rest-nil?, 0/false
+    break-if-=
+    error trace, "'circle' needs 5 args but got 2"
+    return
+  }
+  var third-ah/eax: (addr handle cell) <- get rest, left
+  var third/eax: (addr cell) <- lookup *third-ah
+  {
+    var third-type/eax: (addr int) <- get third, type
+    compare *third-type, 1/number
+    break-if-=
+    error trace, "third arg for 'circle' is not a number (screen y coordinate of center)"
+    return
+  }
+  var third-value/eax: (addr float) <- get third, number-data
+  var cy/ebx: int <- convert *third-value
+  # r = rest->right->left->value
+  var rest-ah/eax: (addr handle cell) <- get rest, right
+  var _rest/eax: (addr cell) <- lookup *rest-ah
+  var rest/esi: (addr cell) <- copy _rest
+  {
+    var rest-type/eax: (addr int) <- get rest, type
+    compare *rest-type, 0/pair
+    break-if-=
+    error trace, "'circle' encountered non-pair"
+    return
+  }
+  {
+    var rest-nil?/eax: boolean <- nil? rest
+    compare rest-nil?, 0/false
+    break-if-=
+    error trace, "'circle' needs 5 args but got 3"
+    return
+  }
+  var fourth-ah/eax: (addr handle cell) <- get rest, left
+  var fourth/eax: (addr cell) <- lookup *fourth-ah
+  {
+    var fourth-type/eax: (addr int) <- get fourth, type
+    compare *fourth-type, 1/number
+    break-if-=
+    error trace, "fourth arg for 'circle' is not a number (screen radius)"
+    return
+  }
+  var fourth-value/eax: (addr float) <- get fourth, number-data
+  var r/ecx: int <- convert *fourth-value
+  # color = rest->right->left->value
+  var rest-ah/eax: (addr handle cell) <- get rest, right
+  var _rest/eax: (addr cell) <- lookup *rest-ah
+  rest <- copy _rest
+  {
+    var rest-type/eax: (addr int) <- get rest, type
+    compare *rest-type, 0/pair
+    break-if-=
+    error trace, "'circle' encountered non-pair"
+    return
+  }
+  {
+    var rest-nil?/eax: boolean <- nil? rest
+    compare rest-nil?, 0/false
+    break-if-=
+    error trace, "'circle' needs 5 args but got 5"
+    return
+  }
+  var fifth-ah/eax: (addr handle cell) <- get rest, left
+  var fifth/eax: (addr cell) <- lookup *fifth-ah
+  {
+    var fifth-type/eax: (addr int) <- get fifth, type
+    compare *fifth-type, 1/number
+    break-if-=
+    error trace, "fifth arg for 'circle' is not an int (color; 0..0xff)"
+    return
+  }
+  var fifth-value/eax: (addr float) <- get fifth, number-data
+  var color/eax: int <- convert *fifth-value
+  draw-circle screen, cx, cy, r, color
+  # return nothing
+}
+
 fn apply-wait-for-key _args-ah: (addr handle cell), out: (addr handle cell), trace: (addr trace) {
   trace-text trace, "eval", "apply 'key'"
   var args-ah/eax: (addr handle cell) <- copy _args-ah