Vulcan Nightmare

Experimentally bringing up vulcan support

assets/shaders/selection_circle.frag.glsl

@@ -0,0 +1,19 @@
+#version 450
+
+layout(push_constant) uniform Push {
+    mat4 mvp;
+    vec4 color;
+} push;
+
+layout(location = 0) in vec2 vLocalPos;
+
+layout(location = 0) out vec4 outColor;
+
+void main() {
+    float r = length(vLocalPos);
+    float ring = smoothstep(0.93, 0.97, r) * smoothstep(1.0, 0.97, r);
+    float inward = (1.0 - smoothstep(0.0, 0.93, r)) * 0.15;
+    float alpha = max(ring, inward);
+    if (alpha < 0.01) discard;
+    outColor = vec4(push.color.rgb, alpha);
+}