Repo created

libs/shaders/GL/route_dash.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 vec3 v_length;
+layout (location = 1) in vec4 v_color;
+
+layout (location = 0) out vec4 v_FragColor;
+
+layout (binding = 0) uniform UBO
+{
+  mat4 u_modelView;
+  mat4 u_projection;
+  mat4 u_pivotTransform;
+  vec4 u_routeParams;
+  vec4 u_color;
+  vec4 u_maskColor;
+  vec4 u_outlineColor;
+  vec4 u_fakeColor;
+  vec4 u_fakeOutlineColor;
+  vec2 u_fakeBorders;
+  vec2 u_pattern;
+  vec2 u_angleCosSin;
+  float u_arrowHalfWidth;
+  float u_opacity;
+};
+
+const float kAntialiasingThreshold = 0.92;
+
+float alphaFromPattern(float curLen, float dashLen, float gapLen)
+{
+  float len = dashLen + gapLen;
+  float offset = fract(curLen / len) * len;
+  return step(offset, dashLen);
+}
+
+void main()
+{
+  if (v_length.x < v_length.z)
+    discard;
+  vec2 coefs = step(v_length.xx, u_fakeBorders);
+  coefs.y = 1.0 - coefs.y;
+  vec4 mainColor = mix(u_color, u_fakeColor, coefs.x);
+  mainColor = mix(mainColor, u_fakeColor, coefs.y);
+  vec4 color = mainColor + v_color;
+  color.a *= (1.0 - smoothstep(kAntialiasingThreshold, 1.0, abs(v_length.y))) *
+              alphaFromPattern(v_length.x, u_pattern.x, u_pattern.y);
+  color = vec4(mix(color.rgb, u_maskColor.rgb, u_maskColor.a), color.a);
+  v_FragColor = color;
+}