Add menu and some cleanup

shaders/dash_shader.frag

@@ -0,0 +1,19 @@
+
+flat in vec2 startPos;
+in vec2 vertPos;
+
+out vec4 fragColor;
+
+uniform vec4 color;
+uniform float dashSize;
+uniform float gapSize;
+
+void main()
+{
+    vec2  dir  = (vertPos.xy - startPos.xy);
+    float dist = length(dir);
+
+    if (fract(dist / (dashSize + gapSize)) > dashSize/(dashSize + gapSize))
+        discard; 
+    fragColor = color;
+}

shaders/dash_shader.vert

@@ -0,0 +1,15 @@
+
+layout (location = 0) in vec2 pos;
+
+flat out vec2 startPos;
+out vec2 vertPos;
+
+uniform mat4 viewMatrix;
+
+void main()
+{
+    vec4 outPos = viewMatrix * vec4(pos.x, pos.y, 0.0, 1.0);
+    gl_Position = outPos;
+    vertPos = pos.xy / outPos.w;
+    startPos = vertPos;
+}