New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/shaders/GL/circle.fsh.glsl

@@ -0,0 +1,26 @@
+uniform float u_opacity;
+#ifdef ENABLE_VTF
+varying LOW_P vec4 v_color;
+#else
+uniform sampler2D u_colorTex;
+varying vec2 v_colorTexCoords;
+#endif
+
+varying vec3 v_radius;
+
+const float aaPixelsCount = 2.5;
+
+void main()
+{
+#ifdef ENABLE_VTF
+  LOW_P vec4 finalColor = v_color;
+#else
+  LOW_P vec4 finalColor = texture2D(u_colorTex, v_colorTexCoords);
+#endif
+
+  float smallRadius = v_radius.z - aaPixelsCount;
+  float stepValue = smoothstep(smallRadius * smallRadius, v_radius.z * v_radius.z,
+                               v_radius.x * v_radius.x + v_radius.y * v_radius.y);
+  finalColor.a = finalColor.a * u_opacity * (1.0 - stepValue);
+  gl_FragColor = finalColor;
+}