1 files changed, 30 insertions, 0 deletions
diff --git a/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl b/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl
index f07bd7f1d6f..55d5d941290 100644
--- a/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_2D_nodelink_frag.glsl
@@ -1,11 +1,41 @@
 
 in float colorGradient;
 in vec4 finalColor;
+in float lineU;
+flat in float lineLength;
+flat in float dashFactor;
+flat in int isMainLine;
 
 out vec4 fragColor;
 
+#define DASH_WIDTH 20.0
+#define ANTIALIAS 1.0
+
 void main()
 {
   fragColor = finalColor;
+
+  if ((isMainLine != 0) && (dashFactor < 1.0)) {
+    float distance_along_line = lineLength * lineU;
+    float normalized_distance = fract(distance_along_line / DASH_WIDTH);
+
+    /* Checking if `normalized_distance <= dashFactor` is already enough for a basic
+     * dash, however we want to handle a nice antialias. */
+
+    float dash_center = DASH_WIDTH * dashFactor * 0.5;
+    float normalized_distance_triangle =
+        1.0 - abs((fract((distance_along_line - dash_center) / DASH_WIDTH)) * 2.0 - 1.0);
+    float t = ANTIALIAS / DASH_WIDTH;
+    float slope = 1.0 / (2.0 * t);
+
+    float alpha = min(1.0, max(0.0, slope * (normalized_distance_triangle - dashFactor + t)));
+
+    if (alpha < 0.0) {
+      discard;
+    }
+
+    fragColor.a *= 1.0 - alpha;
+  }
+
   fragColor.a *= smoothstep(1.0, 0.1, abs(colorGradient));
 }