From b8bffe3cf3596239a569284043174164d2785475 Mon Sep 17 00:00:00 2001
From: Naveen Michaud-Agrawal <naveen.michaudagrawal@gmail.com>
Date: Sat, 7 Oct 2023 01:10:18 +0000
Subject: Implement arc primitive

The arc is specified as start angle (from positive x axis) plus arc length
(both in the range [0, 2*pi))
---
 virtual-programs/display.folk | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'virtual-programs')

diff --git a/virtual-programs/display.folk b/virtual-programs/display.folk
index f92afb67..546e1861 100644
--- a/virtual-programs/display.folk
+++ b/virtual-programs/display.folk
@@ -190,6 +190,38 @@ On process {
             }
         }
 
+        variable arc [Gpu::pipeline {vec2 center float start float arclen float radius float thickness vec4 color int filled} {
+            float r = radius + thickness;
+            vec2 vertices[4] = vec2[4](
+                 center - r,
+                 vec2(center.x + r, center.y - r),
+                 vec2(center.x - r, center.y + r),
+                 center + r
+            );
+            return vertices[gl_VertexIndex];
+        } {
+            #define M_TWO_PI 6.283185307179586
+            start = clamp(start, 0, M_TWO_PI);
+            arclen = clamp(arclen, 0, M_TWO_PI);
+
+            float dist = length(gl_FragCoord.xy - center) - radius;
+            float angle = atan(-(gl_FragCoord.y - center.y), gl_FragCoord.x - center.x);
+
+            // Shift angle from [-pi, pi) to [0, 2*pi]
+            angle = (angle < 0) ? (angle + M_TWO_PI) : angle;
+            float end = start + arclen;
+
+            return ((dist < thickness && dist > 0.0) &&
+                    ((end < M_TWO_PI && angle > start && angle < end) || 
+                    (end >= M_TWO_PI && (angle > start || angle < end-M_TWO_PI)))) ? color : vec4(0, 0, 0, 0);
+
+        }]
+
+        proc arc {x y start arclen radius thickness color {filled false}} {
+            variable arc
+            Gpu::draw $arc [list $x $y] $start $arclen $radius $thickness [getColor $color] [ne $filled "false"]
+        }
+
         # TODO: Fix bool support.
         variable circle [Gpu::pipeline {vec2 center float radius float thickness vec4 color int filled} {
             float r = radius + thickness;
-- 
cgit v1.2.3


From b2b4768a73458ca214198c9d9e751aceb036ef80 Mon Sep 17 00:00:00 2001
From: Naveen Michaud-Agrawal <naveen.michaudagrawal@gmail.com>
Date: Sat, 7 Oct 2023 21:49:11 +0000
Subject: Add claim for display size

---
 virtual-programs/display.folk | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'virtual-programs')

diff --git a/virtual-programs/display.folk b/virtual-programs/display.folk
index f92afb67..36a370e7 100644
--- a/virtual-programs/display.folk
+++ b/virtual-programs/display.folk
@@ -23,6 +23,8 @@ namespace eval ::Display {
             uplevel [list Wish display runs [list $func {*}$args] on layer $::Display::LAYER]
         }
     }
+
+    Claim the display Display has width $::Display::WIDTH height $::Display::HEIGHT
 }
 
 On process {
-- 
cgit v1.2.3


From f77cbd902cf1d352661261cd0fbf53d2b6bc1dba Mon Sep 17 00:00:00 2001
From: Omar Rizwan <omar@omar.website>
Date: Mon, 9 Oct 2023 13:36:11 -0400
Subject: display: Remove filled arg from arc

---
 virtual-programs/display.folk | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

(limited to 'virtual-programs')

diff --git a/virtual-programs/display.folk b/virtual-programs/display.folk
index 546e1861..bae5951f 100644
--- a/virtual-programs/display.folk
+++ b/virtual-programs/display.folk
@@ -190,7 +190,7 @@ On process {
             }
         }
 
-        variable arc [Gpu::pipeline {vec2 center float start float arclen float radius float thickness vec4 color int filled} {
+        variable arc [Gpu::pipeline {vec2 center float start float arclen float radius float thickness vec4 color} {
             float r = radius + thickness;
             vec2 vertices[4] = vec2[4](
                  center - r,
@@ -217,9 +217,9 @@ On process {
 
         }]
 
-        proc arc {x y start arclen radius thickness color {filled false}} {
+        proc arc {x y start arclen radius thickness color} {
             variable arc
-            Gpu::draw $arc [list $x $y] $start $arclen $radius $thickness [getColor $color] [ne $filled "false"]
+            Gpu::draw $arc [list $x $y] $start $arclen $radius $thickness [getColor $color]
         }
 
         # TODO: Fix bool support.
-- 
cgit v1.2.3