Create/Update assets for version 18w45a

assets/minecraft/shaders/program/overlay.fsh

@@ -0,0 +1,27 @@
+#version 120
+
+uniform sampler2D DiffuseSampler;
+uniform sampler2D OverlaySampler;
+
+uniform vec2 InSize;
+
+varying vec2 texCoord;
+
+uniform float MosaicSize = 1.0;
+uniform vec3 RedMatrix   = vec3(1.0, 0.0, 0.0);
+uniform vec3 GreenMatrix = vec3(0.0, 1.0, 0.0);
+uniform vec3 BlueMatrix  = vec3(0.0, 0.0, 1.0);
+
+void main(){
+    vec2 mosaicInSize = InSize / MosaicSize;
+    vec2 fractPix = fract(texCoord * mosaicInSize) / mosaicInSize;
+
+    vec4 baseTexel = texture2D(DiffuseSampler, texCoord - fractPix);
+    float red = dot(baseTexel.rgb, RedMatrix);
+    float green = dot(baseTexel.rgb, GreenMatrix);
+    float blue = dot(baseTexel.rgb, BlueMatrix);
+
+    vec4 overlayTexel = texture2D(OverlaySampler, vec2(texCoord.x, 1.0 - texCoord.y));
+    overlayTexel.a = 1.0;
+    gl_FragColor = mix(vec4(red, green, blue, 1.0), overlayTexel, overlayTexel.a);
+}