Add existing to tracked

node_modules/@cesium/engine/Source/Shaders/Materials/CheckerboardMaterial.js

@@ -0,0 +1,31 @@
+//This file is automatically rebuilt by the Cesium build process.
+export default "uniform vec4 lightColor;\n\
+uniform vec4 darkColor;\n\
+uniform vec2 repeat;\n\
+\n\
+czm_material czm_getMaterial(czm_materialInput materialInput)\n\
+{\n\
+    czm_material material = czm_getDefaultMaterial(materialInput);\n\
+\n\
+    vec2 st = materialInput.st;\n\
+\n\
+    // From Stefan Gustavson's Procedural Textures in GLSL in OpenGL Insights\n\
+    float b = mod(floor(repeat.s * st.s) + floor(repeat.t * st.t), 2.0);  // 0.0 or 1.0\n\
+\n\
+    // Find the distance from the closest separator (region between two colors)\n\
+    float scaledWidth = fract(repeat.s * st.s);\n\
+    scaledWidth = abs(scaledWidth - floor(scaledWidth + 0.5));\n\
+    float scaledHeight = fract(repeat.t * st.t);\n\
+    scaledHeight = abs(scaledHeight - floor(scaledHeight + 0.5));\n\
+    float value = min(scaledWidth, scaledHeight);\n\
+\n\
+    vec4 currentColor = mix(lightColor, darkColor, b);\n\
+    vec4 color = czm_antialias(lightColor, darkColor, currentColor, value, 0.03);\n\
+\n\
+    color = czm_gammaCorrect(color);\n\
+    material.diffuse = color.rgb;\n\
+    material.alpha = color.a;\n\
+\n\
+    return material;\n\
+}\n\
+";