optimize downsample shader. readd noise for blur. fix max blur pass panic.

Author: busyoGG

src/render_helpers/blur/element.rs

@@ -280,7 +280,7 @@ fn draw_true_blur(
             ],
         ),
         // Uniform::new("alpha", alpha),
-        // Uniform::new("noise", config.noise.0 as f32),
+        Uniform::new("noise", config.noise.0 as f32),
         Uniform::new("corner_radius", corner_radius),
         // Uniform::new(
         //     "output_size",
@@ -362,7 +362,7 @@ impl RenderElement<GlesRenderer> for BlurRenderElement {
                                 ],
                             ),
                             Uniform::new("corner_radius", *corner_radius),
-                            // Uniform::new("noise", *noise),
+                            Uniform::new("noise", *noise),
                             // Uniform::new("alpha", self.alpha()),
                             Uniform::new("ignore_alpha", 0.),
                         ],

src/render_helpers/blur/mod.rs

@@ -130,10 +130,10 @@ impl EffectsFramebuffers {
                 size.to_logical(1).to_buffer(1, Transform::Normal),
             )
         }
- 
+
         let mut sample_effects: Vec<GlesTexture> = Vec::new();
         let mut sample_fbos: Vec<u32> = Vec::new();
-        for i in 0..8 {
+        for i in 0..9 {
             let size = if i == 0 {
                 texture_size
             } else {
@@ -210,7 +210,7 @@ impl EffectsFramebuffers {
 
         let mut sample_effects: Vec<GlesTexture> = Vec::new();
         let mut sample_fbos: Vec<u32> = Vec::new();
-        for i in 0..8 {
+        for i in 0..9 {
             let size = if i == 0 {
                 texture_size
             } else {
@@ -441,10 +441,10 @@ pub(super) unsafe fn get_main_buffer_blur(
 
     let dst_expanded = {
         let mut dst = dst;
-        // let size =
-        //     (2f32.powi(blur_config.passes as i32 + 1) * blur_config.radius.0 as f32).ceil() as i32;
+        let p = blur_config.passes.saturating_sub(1);
+        let size = (1 << p) * blur_config.radius.0 as i32;
         // let size= blur_config.radius.0 as i32;
-        let size = blur_config.radius.0 as i32 * blur_config.passes as i32;
+        // let size = blur_config.radius.0 as i32 * blur_config.passes as i32;
         dst.loc -= Point::from((size, size));
         dst.size += Size::from((size, size)).upscale(2);
         dst
@@ -909,10 +909,7 @@ unsafe fn render_blur_pass_with_gl(
             if i == 0 { 0.0 } else { config.radius.0 as f32 },
         );
         gl.Uniform2f(program.uniform_half_pixel, half_pixel[0], half_pixel[1]);
-        gl.Uniform1f(
-            program.uniform_scale,
-            scale as f32,
-        );
+        gl.Uniform1f(program.uniform_scale, scale as f32);
 
         gl.EnableVertexAttribArray(program.attrib_vert as u32);
         gl.BindBuffer(ffi::ARRAY_BUFFER, vbos[0]);

src/render_helpers/shaders/blur_down.frag

@@ -21,13 +21,14 @@ void main() {
         gl_FragColor = texture2D(tex, uv);
         return;
     }
-    vec2 offset = half_pixel * radius; 
-    vec4 sum = texture2D(tex, uv) * 4.0
-        + texture2D(tex, uv + vec2(offset.x, 0.0))
-        + texture2D(tex, uv - vec2(offset.x, 0.0))
-        + texture2D(tex, uv + vec2(0.0, offset.y))
-        + texture2D(tex, uv - vec2(0.0, offset.y));
+    // Kawase风格：对角线采样
+    vec2 offset = half_pixel * (radius * 0.707 + 0.5); // 调整到对角线
 
-    gl_FragColor = sum * 0.125;
+    vec4 sum = texture2D(tex, uv + vec2(-offset.x, -offset.y))
+            + texture2D(tex, uv + vec2( offset.x, -offset.y))
+            + texture2D(tex, uv + vec2(-offset.x,  offset.y))
+            + texture2D(tex, uv + vec2( offset.x,  offset.y));
+
+    gl_FragColor = sum * 0.25;
     // gl_FragColor = texture2D(tex, uv);
 }

src/render_helpers/shaders/blur_finish.frag

@@ -29,7 +29,7 @@ varying vec2 v_coords;
 uniform vec4 geo;
 // uniform vec2 output_size;
 uniform float corner_radius;
-// uniform float noise;
+uniform float noise;
 uniform float ignore_alpha;
 
 // float rounding_alpha(vec2 coords, vec2 size, float radius) {
@@ -58,13 +58,22 @@ float fast_rounding_alpha(vec2 coords, vec2 size, float radius) {
     return 1.0 - smoothstep(radius - 0.5, radius + 0.5, sdf);
 }
 
-// // Noise function copied from hyprland.
-// // I like the effect it gave, can be tweaked further
-// float hash(vec2 p) {
-//     vec3 p3 = fract(vec3(p.xyx) * 727.727); // wysi :wink: :wink:
-//     p3 += dot(p3, p3.xyz + 33.33);
-//     return fract((p3.x + p3.y) * p3.z);
-// }
+// 优化3：蓝噪声（Blue Noise）近似
+float blue_noise(vec2 uv) {
+    // 使用旋转的三角波
+    float x = uv.x * 1.61803398875; // 黄金比例
+    float y = uv.y * 1.61803398875;
+
+    float noise = sin(x * 12.9898 + y * 78.233) * 43758.5453;
+    noise = fract(noise);
+
+    // 添加高频分量
+    noise += sin(x * 26.9898 + y * 92.233) * 43758.5453;
+    noise = fract(noise) * 0.5 + 0.25; // 限制在[0.25, 0.75]
+
+    return noise - 0.5; // 居中在0
+}
+
 
 void main() {
     vec4 color = texture2D(tex, v_coords);
@@ -86,10 +95,9 @@ void main() {
     vec2 size = geo.zw;
     vec2 loc = gl_FragCoord.xy - geo.xy;
 
-    // // 噪声（只在alpha测试通过时添加）
-    // float noiseHash = hash(loc / size);
-    // float noise_contrib = (noiseHash - 0.5) * noise;
-    // color.rgb += noise_contrib * alphaMask;  // 用alphaMask控制
+    // 噪声（只在alpha测试通过时添加）
+    float noise_contrib = blue_noise(loc / size) * noise * 0.08;
+    color.rgb = mix(color.rgb, color.rgb + noise_contrib, alphaMask);
 
     float round_alpha = fast_rounding_alpha(loc, size, corner_radius);
 

src/render_helpers/shaders/mod.rs

@@ -111,7 +111,7 @@ impl Shaders {
                     // UniformName::new("output_size", UniformType::_2f),
                     UniformName::new("corner_radius", UniformType::_1f),
                     // UniformName::new("alpha", UniformType::_1f),
-                    // UniformName::new("noise", UniformType::_1f),
+                    UniformName::new("noise", UniformType::_1f),
                     UniformName::new("geo", UniformType::_4f),
                     UniformName::new("ignore_alpha", UniformType::_1f),
                     UniformName::new("alpha_tex", UniformType::_1i),