basic checkerboard shader

src/kiss_flixel/shaders/CheckerBoard.frag

@@ -0,0 +1,20 @@
+#pragma header
+
+uniform vec4 color1 = vec4(1.0, 1.0, 1.0, 1.0);
+uniform vec4 color2 = vec4(0.0, 0.0, 0.0, 1.0);
+uniform float checkSize = 64;
+
+void main()
+{
+    vec2 position = openfl_TextureCoordv * iResolution;
+    float row = floor(position.y / checkSize);
+    float col = floor(position.x / checkSize);
+
+    bool oddRow = mod(row, 2) == 1;
+    bool oddCol = mod(col, 2) == 1;
+
+    vec4 oddColor = oddRow ? color1 : color2;
+    vec4 evenColor = oddRow ? color2 : color1;
+
+    gl_FragColor = oddCol ? oddColor: evenColor;
+}