1 files changed, 131 insertions, 0 deletions
diff --git a/config/picom/shaders/sdf_mask.glsl b/config/picom/shaders/sdf_mask.glsl
new file mode 100644
index 0000000..3e73770
--- /dev/null
+++ b/config/picom/shaders/sdf_mask.glsl
@@ -0,0 +1,131 @@
+#version 330
+
+in vec2 texcoord;             // texture coordinate of the fragment
+
+uniform sampler2D tex;        // texture of the window
+
+
+ivec2 window_size = textureSize(tex, 0); // Size of the window
+ivec2 window_center = ivec2(window_size.x/2, window_size.y/2);
+
+/*
+These shaders use a sorta hacky way to use the changing
+window opacity you might set on picom.conf animation rules
+to perform animations.
+
+Basically, when a window get's mapped, we make it's alpha 
+go from 0 to 1, so, using the default_post_processing to get that alpha
+we can get a variable going from 0 (start of mapping animation)
+to 1 (end of mapping animation)
+
+You can also set up your alpha value to go from 1 to 0 in picom when
+a window is closed, effectively reversing the animations described here
+*/
+
+// Default window post-processing:
+// 1) invert color
+// 2) opacity / transparency
+// 3) max-brightness clamping
+// 4) rounded corners
+vec4 default_post_processing(vec4 c);
+
+//  If you have semitransparent windows (like a terminal)
+// You can use the below function to add an opacity threshold where the
+// animation won't apply. For example, if you had your terminal
+// configured to have 0.8 opacity, you'd set the below variable to 0.8
+float max_opacity = 0.8;
+float opacity_threshold(float opacity)
+{
+  // if statement jic?
+  if (opacity >= max_opacity)
+  {
+    return 1.0;
+  }
+  else 
+  {
+    return min(1, opacity/max_opacity);
+  }
+
+}
+
+// NEW anim function: Morphing Distance-Field Mask (Wobbly Circle)
+vec4 anim(float progress) {
+
+    vec4 c = texelFetch(tex, ivec2(texcoord), 0);
+
+    // Early exit for fully transparent or fully opaque states
+    if (progress <= 0.001) { // Beginning of reveal / End of conceal
+        c.a = 0.0;
+        return c;
+    }
+    if (progress >= 0.999) { // End of reveal / Beginning of conceal
+        return c; // Original alpha, effect is complete
+    }
+
+    vec2 p_centered = texcoord - vec2(window_center); // Pixel coords relative to center
+
+    // --- SDF Parameters ---
+    // Max radius needed to cover the window from the center to a corner
+    float max_coverage_radius = length(vec2(window_size) * 0.5) * 1.05; // 5% margin
+
+    // Easing for progress (e.g., ease-in: starts slow, speeds up)
+    float eased_progress = progress * progress;
+    // float eased_progress = sqrt(progress); // Alternative: ease-out
+    // float eased_progress = progress; // Alternative: linear
+
+    float base_radius = eased_progress * max_coverage_radius;
+
+    // --- Wobble Parameters ---
+    float angle = atan(p_centered.y, p_centered.x); // Angle of pixel from center
+
+    float spatial_freq = 7.0; // Number of wobbles around circumference
+    float wobble_anim_speed = 10.0; // How fast wobbles change with progress
+    // Wobble amplitude (as a factor of base_radius), decreases as reveal completes
+    float wobble_amplitude_factor = 0.15 * (1.0 - eased_progress * 0.7);
+
+    // Wobble animation phase based on progress
+    float wobble_phase = progress * wobble_anim_speed;
+    
+    float radius_offset = sin(angle * spatial_freq + wobble_phase) *
+                          base_radius * wobble_amplitude_factor;
+    
+    float effective_radius = base_radius + radius_offset;
+
+    // --- SDF Calculation (Circle) ---
+    // Distance from current pixel to the center of the coordinate system (p_centered)
+    float dist_from_center = length(p_centered);
+    // SDF value: negative inside the shape, positive outside
+    float sdf_value = dist_from_center - effective_radius;
+
+    // --- Alpha Masking ---
+    float edge_softness = 15.0; // Softness of the mask edge in pixels
+
+    // Create mask: 1.0 inside (visible), 0.0 outside (transparent)
+    // smoothstep transitions from 0 to 1 as sdf_value goes from 0 to edge_softness
+    // So, for sdf_value < 0 (inside), mask is 1.0.
+    // For sdf_value > edge_softness (far outside), mask is 0.0.
+    float mask = 1.0 - smoothstep(0.0, edge_softness, sdf_value);
+
+    c.a *= mask; // Apply the mask to the original alpha
+
+    return c;
+}
+
+// Default window shader:
+// 1) fetch the specified pixel
+// 2) apply default post-processing
+vec4 window_shader() {
+  vec4 c = texelFetch(tex, ivec2(texcoord), 0);
+  c = default_post_processing(c);
+  float opacity = opacity_threshold(c.w);
+  if (opacity == 0.0)
+  {
+    return c;
+  }
+  vec4 anim_c = anim(opacity);
+  if (anim_c.w < max_opacity)
+  {
+    return vec4(0);
+  }
+  return default_post_processing(anim_c);
+}