Merge branch 'main' into ac/editor

1 files changed, 34 insertions, 0 deletions

diff --git a/virtual-programs/display/stroke.folk b/virtual-programs/display/stroke.folk
new file mode 100644
index 00000000..f212f471
--- /dev/null
+++ b/virtual-programs/display/stroke.folk
@@ -0,0 +1,34 @@
+Wish the GPU compiles pipeline "line" {
+    {vec2 from vec2 to float thickness vec4 color} {
+        vec2 vertices[4] = vec2[4](
+             min(from, to) - thickness,
+             vec2(max(from.x, to.x) + thickness, min(from.y, to.y) - thickness),
+             vec2(min(from.x, to.x) - thickness, max(from.y, to.y) + thickness),
+             max(from, to) + thickness
+        );
+        return vertices[gl_VertexIndex];
+    } {
+        float l = length(to - from);
+        vec2 d = (to - from) / l;
+        vec2 q = (gl_FragCoord.xy - (from + to)*0.5);
+        q = mat2(d.x, -d.y, d.y, d.x) * q;
+        q = abs(q) - vec2(l, thickness)*0.5;
+        float dist = length(max(q, 0.0)) + min(max(q.x, q.y), 0.0);
+
+        return dist < 0.0 ? color : vec4(0, 0, 0, 0);
+    }
+}
+
+When /someone/ wishes to draw a stroke with /...options/ {
+    set points [dict get $options points]
+    set width [dict get $options width]
+    set color [getColor [dict get $options color]]
+
+    set instances [list]
+    for {set i 0} {$i < [expr {[llength $points] - 1}]} {incr i} {
+        set from [lindex $points $i]
+        set to [lindex $points [expr $i+1]]
+        lappend instances [list $from $to $width $color]
+    }
+    Wish the GPU draws pipeline "line" with instances $instances
+}