Repo created

libs/shaders/GL/traffic_circle.fsh.glsl

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+// Warning! Beware to use this shader. "discard" command may significally reduce performance.
+// Unfortunately some CG algorithms cannot be implemented without discarding fragments from depth buffer.
+
+layout (location = 0) in vec2 v_colorTexCoord;
+layout (location = 1) in vec3 v_radius;
+
+layout (location = 0) out vec4 v_FragColor;
+
+layout (binding = 0) uniform UBO
+{
+  mat4 u_modelView;
+  mat4 u_projection;
+  mat4 u_pivotTransform;
+  vec4 u_trafficParams;
+  vec4 u_outlineColor;
+  vec4 u_lightArrowColor;
+  vec4 u_darkArrowColor;
+  float u_outline;
+  float u_opacity;
+};
+
+layout (binding = 1) uniform sampler2D u_colorTex;
+
+const float kAntialiasingThreshold = 0.92;
+
+void main()
+{
+  vec4 color = texture(u_colorTex, v_colorTexCoord);
+  float smallRadius = v_radius.z * kAntialiasingThreshold;
+  float stepValue = smoothstep(smallRadius * smallRadius, v_radius.z * v_radius.z,
+                               v_radius.x * v_radius.x + v_radius.y * v_radius.y);
+  color.a = u_opacity * (1.0 - stepValue);
+  if (color.a < 0.01)
+    discard;
+  v_FragColor = color;
+}