misskey/packages/frontend/src/utility/image-effector/fxs/blur.glsl

79 lines
2.5 KiB
GLSL

#version 300 es
precision mediump float;
/*
* SPDX-FileCopyrightText: syuilo and misskey-project
* SPDX-License-Identifier: AGPL-3.0-only
*/
const float PI = 3.141592653589793;
const float TWO_PI = 6.283185307179586;
const float HALF_PI = 1.5707963267948966;
in vec2 in_uv;
uniform sampler2D in_texture;
uniform vec2 in_resolution;
uniform vec2 u_offset;
uniform vec2 u_scale;
uniform bool u_ellipse;
uniform float u_angle;
uniform float u_radius;
uniform int u_samples;
out vec4 out_color;
void main() {
float angle = -(u_angle * PI);
vec2 centeredUv = in_uv - vec2(0.5, 0.5) - u_offset;
vec2 rotatedUV = vec2(
centeredUv.x * cos(angle) - centeredUv.y * sin(angle),
centeredUv.x * sin(angle) + centeredUv.y * cos(angle)
) + u_offset;
bool isInside = false;
if (u_ellipse) {
vec2 norm = (rotatedUV - u_offset) / u_scale;
isInside = dot(norm, norm) <= 1.0;
} else {
isInside = rotatedUV.x > u_offset.x - u_scale.x && rotatedUV.x < u_offset.x + u_scale.x && rotatedUV.y > u_offset.y - u_scale.y && rotatedUV.y < u_offset.y + u_scale.y;
}
if (!isInside) {
out_color = texture(in_texture, in_uv);
return;
}
vec4 result = vec4(0.0);
float totalSamples = 0.0;
// Make blur radius resolution-independent by using a percentage of image size
// This ensures consistent visual blur regardless of image resolution
float referenceSize = min(in_resolution.x, in_resolution.y);
float normalizedRadius = u_radius / 100.0; // Convert radius to percentage (0-15 -> 0-0.15)
vec2 blurOffset = vec2(normalizedRadius) / in_resolution * referenceSize;
// Calculate how many samples to take in each direction
// This determines the grid density, not the blur extent
int sampleRadius = int(sqrt(float(u_samples)) / 2.0);
// Sample in a grid pattern within the specified radius
for (int x = -sampleRadius; x <= sampleRadius; x++) {
for (int y = -sampleRadius; y <= sampleRadius; y++) {
// Normalize the grid position to [-1, 1] range
float normalizedX = float(x) / float(sampleRadius);
float normalizedY = float(y) / float(sampleRadius);
// Scale by radius to get the actual sampling offset
vec2 offset = vec2(normalizedX, normalizedY) * blurOffset;
vec2 sampleUV = in_uv + offset;
// Only sample if within texture bounds
if (sampleUV.x >= 0.0 && sampleUV.x <= 1.0 && sampleUV.y >= 0.0 && sampleUV.y <= 1.0) {
result += texture(in_texture, sampleUV);
totalSamples += 1.0;
}
}
}
out_color = totalSamples > 0.0 ? result / totalSamples : texture(in_texture, in_uv);
}