42 lines
No EOL
1.6 KiB
GLSL
42 lines
No EOL
1.6 KiB
GLSL
// Created by Paul Robello
|
|
|
|
|
|
// Smooth oscillating function that varies over time
|
|
float smoothOscillation(float t, float frequency, float phase) {
|
|
return sin(t * frequency + phase);
|
|
}
|
|
|
|
void mainImage(out vec4 fragColor, in vec2 fragCoord) {
|
|
// Resolution and UV coordinates
|
|
vec2 uv = fragCoord.xy / iResolution.xy;
|
|
|
|
// Used to fix distortion when calculating distance to circle center
|
|
vec2 ratio = vec2(iResolution.x / iResolution.y, 1.0);
|
|
|
|
// Get the texture from iChannel0
|
|
vec4 texColor = texture(iChannel0, uv);
|
|
|
|
// Spotlight center moving based on a smooth random pattern
|
|
float time = iTime * 1.0; // Control speed of motion
|
|
vec2 spotlightCenter = vec2(
|
|
0.5 + 0.4 * smoothOscillation(time, 1.0, 0.0), // Smooth X motion
|
|
0.5 + 0.4 * smoothOscillation(time, 1.3, 3.14159) // Smooth Y motion with different frequency and phase
|
|
);
|
|
|
|
// Distance from the spotlight center
|
|
float distanceToCenter = distance(uv * ratio, spotlightCenter);
|
|
|
|
// Spotlight intensity based on distance
|
|
float spotlightRadius = 0.25; // Spotlight radius
|
|
float softness = 20.0; // Spotlight edge softness. Higher values have sharper edge
|
|
float spotlightIntensity = smoothstep(spotlightRadius, spotlightRadius - (1.0 / softness), distanceToCenter);
|
|
|
|
// Ambient light level
|
|
float ambientLight = 0.5; // Controls the minimum brightness across the texture
|
|
|
|
// Combine the spotlight effect with the texture
|
|
vec3 spotlightEffect = texColor.rgb * mix(vec3(ambientLight), vec3(1.0), spotlightIntensity);
|
|
|
|
// Final color output
|
|
fragColor = vec4(spotlightEffect, texColor.a);
|
|
} |