Add minimap. Some perforarmance tweaks especially around bread crumbs.

minimapshader.glsl

@@ -0,0 +1,10 @@
+#version 460 core
+// Vertex shader for minimap overlay geometry (lines/quads) in screen space.
+layout (location = 0) in vec2 aPos;
+
+uniform mat4 projection;
+
+void main()
+{
+    gl_Position = projection * vec4(aPos, 0.0, 1.0);
+}