[orx-fx] Add Lenses Filter

orx-fx/src/shaders/glsl/distort/lenses.frag

@@ -0,0 +1,30 @@
+in vec2 v_texCoord0;
+uniform sampler2D tex0;// input
+uniform float scale;
+uniform float rotation;
+
+out vec4 o_color;
+void main() {
+    vec2 uv = v_texCoord0;
+    vec2 blockSize = vec2(1.0/8.0, 1.0/6.0);
+
+    vec2 blockIndex = floor(uv / blockSize);
+    vec2 blockCenter = (blockIndex+0.5) * blockSize;
+
+    float ca = cos(radians(rotation));
+    float sa = sin(radians(rotation));
+
+    vec2 ts = textureSize(tex0, 0);
+
+    mat2 rm =mat2(1.0, 0.0, 0.0, ts.x/ts.y) * mat2(vec2(ca, sa), vec2(-sa, ca)) * mat2(1.0, 0.0, 0.0, ts.y/ts.x);
+    vec2 cuv = (rm * (uv - blockCenter)
+    * scale + blockCenter);
+
+
+
+    float sx = step(0.0, cuv.x) * (1.0 - step(1.0, cuv.x));
+    float sy = step(0.0, cuv.y) * (1.0 - step(1.0, cuv.y));
+    vec4 c = texture(tex0, cuv) * sx * sy;
+
+    o_color = c;
+}