Use geometry shader for widgets.

data/shaders/menu.geom

@@ -0,0 +1,41 @@
+#version 330 core
+
+layout(points) in;
+layout(triangle_strip, max_vertices = 4) out;
+
+struct WidgetData
+{
+    vec2 position;
+    vec2 dimensions;
+};
+uniform WidgetData u_widgetData;
+
+out vec2 v_texCoord;
+
+void main()
+{
+    float glWidth = u_widgetData.dimensions.x * 2.0f;
+    float glHeight = u_widgetData.dimensions.y * 2.0f;
+
+    vec4 offset = vec4(0.0, 0.0, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(0.0, 0.0);
+    EmitVertex();
+
+    offset = vec4(glWidth, 0.0, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(1.0, 0.0);
+    EmitVertex();
+
+    offset = vec4(0.0, glHeight, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(0.0, 1.0);
+    EmitVertex();
+
+    offset = vec4(glWidth, glHeight, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(1.0, 1.0);
+    EmitVertex();
+
+    EndPrimitive();
+}