1 files changed, 89 insertions, 0 deletions
diff --git a/.config/hypr/shaders/05_sketch.glsl b/.config/hypr/shaders/05_sketch.glsl
new file mode 100755
index 0000000..29ffff9
--- /dev/null
+++ b/.config/hypr/shaders/05_sketch.glsl
@@ -0,0 +1,89 @@
+#version 300 es
+precision highp float;
+
+in vec2 v_texcoord;
+uniform sampler2D tex;
+out vec4 fragColor;
+
+// --- CONFIGURATION ---
+const float edge_threshold = 0.15;      // Sensitivity (0.05-0.5) - lower = more edges
+const float edge_softness = 0.08;       // Anti-aliasing amount
+const float line_thickness = 1.0;       // 1.0 = normal, 2.0 = thicker
+const float line_darkness = 0.05;       // 0.0 = pure black, higher = lighter
+const float paper_brightness = 0.98;    // Paper color
+const float paper_grain = 0.03;         // Paper texture intensity
+const float noise_reduction = 0.5;      // Reduces speckles in smooth areas
+// ---------------------
+
+float luminance(vec3 color) {
+    return dot(color, vec3(0.2126, 0.7152, 0.0722));
+}
+
+float hash12(vec2 p) {
+    vec3 p3 = fract(vec3(p.xyx) * 0.1031);
+    p3 += dot(p3, p3.yzx + 33.33);
+    return fract((p3.x + p3.y) * p3.z);
+}
+
+// Sample luminance with bounds checking
+float sampleLum(vec2 uv) {
+    vec2 safe_uv = clamp(uv, 0.0, 1.0);
+    return luminance(texture(tex, safe_uv).rgb);
+}
+
+void main() {
+    vec2 screen_res = vec2(textureSize(tex, 0));
+    vec2 pixel_size = line_thickness / screen_res;
+    vec2 pixel_coords = v_texcoord * screen_res;
+    
+    // Sobel kernel sampling with proper edge clamping
+    float tl = sampleLum(v_texcoord + vec2(-pixel_size.x, -pixel_size.y));
+    float t  = sampleLum(v_texcoord + vec2( 0.0,          -pixel_size.y));
+    float tr = sampleLum(v_texcoord + vec2( pixel_size.x, -pixel_size.y));
+    float l  = sampleLum(v_texcoord + vec2(-pixel_size.x,  0.0));
+    float c  = sampleLum(v_texcoord);  // Center pixel
+    float r  = sampleLum(v_texcoord + vec2( pixel_size.x,  0.0));
+    float bl = sampleLum(v_texcoord + vec2(-pixel_size.x,  pixel_size.y));
+    float b  = sampleLum(v_texcoord + vec2( 0.0,           pixel_size.y));
+    float br = sampleLum(v_texcoord + vec2( pixel_size.x,  pixel_size.y));
+    
+    // Sobel operators
+    float Gx = (tr + 2.0 * r + br) - (tl + 2.0 * l + bl);
+    float Gy = (bl + 2.0 * b + br) - (tl + 2.0 * t + tr);
+    float gradient = sqrt(Gx * Gx + Gy * Gy);
+    
+    // Calculate local variance for noise reduction
+    // (reduces speckles in smooth areas while preserving real edges)
+    float mean = (tl + t + tr + l + c + r + bl + b + br) / 9.0;
+    float variance = 0.0;
+    variance += (tl - mean) * (tl - mean);
+    variance += (t - mean) * (t - mean);
+    variance += (tr - mean) * (tr - mean);
+    variance += (l - mean) * (l - mean);
+    variance += (c - mean) * (c - mean);
+    variance += (r - mean) * (r - mean);
+    variance += (bl - mean) * (bl - mean);
+    variance += (b - mean) * (b - mean);
+    variance += (br - mean) * (br - mean);
+    variance = sqrt(variance / 9.0);
+    
+    // Adaptive threshold: require stronger edges in noisy areas
+    float adaptive_threshold = edge_threshold + variance * noise_reduction;
+    
+    // Smooth edge detection (anti-aliased)
+    float edge = smoothstep(
+        adaptive_threshold - edge_softness,
+        adaptive_threshold + edge_softness,
+        gradient
+    );
+    
+    // Paper texture
+    float paper = paper_brightness;
+    paper -= hash12(pixel_coords * 0.4) * paper_grain;
+    paper -= hash12(pixel_coords * 2.1) * paper_grain * 0.4;
+    
+    // Final blend
+    float final_value = mix(paper, line_darkness, edge);
+    
+    fragColor = vec4(vec3(final_value), 1.0);
+}