Upload spectral-font/src/msdf.rs

spectral-font/src/msdf.rs

@@ -0,0 +1,57 @@
+pub fn dilate(bitmap: &[u8], width: usize, height: usize, radius: u8) -> Vec<u8> {
+    if radius == 0 || bitmap.is_empty() { return bitmap.to_vec(); }
+    let r = radius as isize;
+    let mut out = vec![0u8; width * height];
+    for y in 0..height {
+        for x in 0..width {
+            let mut max_val = bitmap[y * width + x];
+            for dy in -r..=r {
+                for dx in -r..=r {
+                    let ny = (y as isize + dy).clamp(0, height as isize - 1) as usize;
+                    let nx = (x as isize + dx).clamp(0, width as isize - 1) as usize;
+                    max_val = max_val.max(bitmap[ny * width + nx]);
+                }
+            }
+            out[y * width + x] = max_val;
+        }
+    }
+    out
+}
+
+pub fn thicken_light(bitmap: &[u8], width: usize, height: usize, strength: f32) -> Vec<u8> {
+    if strength <= 0.0 || bitmap.is_empty() { return bitmap.to_vec(); }
+    let mut out = bitmap.to_vec();
+    let threshold = 64u8;
+    let strength_byte = (strength * 255.0).clamp(0.0, 255.0) as u8;
+    for y in 0..height {
+        for x in 0..width {
+            let idx = y * width + x;
+            if bitmap[idx] >= threshold { continue; }
+            let mut neighbor_max = 0u8;
+            for dy in -1..=1isize {
+                for dx in -1..=1isize {
+                    if dy == 0 && dx == 0 { continue; }
+                    let ny = (y as isize + dy).clamp(0, height as isize - 1) as usize;
+                    let nx = (x as isize + dx).clamp(0, width as isize - 1) as usize;
+                    neighbor_max = neighbor_max.max(bitmap[ny * width + nx]);
+                }
+            }
+            if neighbor_max > threshold {
+                out[idx] = out[idx].saturating_add(strength_byte);
+            }
+        }
+    }
+    out
+}
+
+pub fn r8_to_rgb(r8: &[u8]) -> Vec<u8> {
+    let mut rgb = Vec::with_capacity(r8.len() * 3);
+    for &v in r8 { rgb.push(v); rgb.push(v); rgb.push(v); }
+    rgb
+}
+
+pub fn r8_to_rgba(r8: &[u8]) -> Vec<u8> {
+    let mut rgba = Vec::with_capacity(r8.len() * 4);
+    for &v in r8 { rgba.push(v); rgba.push(v); rgba.push(v); rgba.push(v); }
+    rgba
+}