fix shaders format

data/shaders/stroke-preview.glsl

@@ -1,20 +1,27 @@
 [[vertex]]
+
 uniform mat4 mvp;
+
 in vec4 pos;
 in vec2 uvs;
 out vec2 uv;
+
 void main()
 {
     uv = uvs;
     gl_Position = mvp * vec4(pos.xyz, 1.0);
-};
+}
 
 [[fragment]]
+
 uniform sampler2D tex;
 uniform mediump vec4 col;
+
 in mediump vec2 uv;
 out mediump vec4 frag;
-void main() {
+
+void main()
+{
     mediump float stroke = 1.0 - texture(tex, uv).r;
     int zero_count = 0;
     if (textureOffset(tex, uv, ivec2(-1, -1)).r > 0.99) zero_count++;
@@ -28,4 +35,4 @@ void main() {
     if (textureOffset(tex, uv, ivec2(+1, +1)).r > 0.99) zero_count++;
     mediump float edge = (zero_count > 1 && zero_count < 9) ? 0.75 : 0.0;
     frag = vec4(col.rgb, edge * (1.0 - float(zero_count) / 9.f));
-};
+}