dot/config/picom/shaders/sdf_mask.glsl
2025-12-01 10:08:43 +00:00

131 lines
4.3 KiB
GLSL

#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);
}