Create/Update assets for version 1.19-pre1

assets/minecraft/shaders/program/overlay.fsh

@@ -0,0 +1,29 @@
+#version 150
+
+uniform sampler2D DiffuseSampler;
+uniform sampler2D OverlaySampler;
+
+uniform vec2 InSize;
+
+in vec2 texCoord;
+
+uniform float MosaicSize;
+uniform vec3 RedMatrix;
+uniform vec3 GreenMatrix;
+uniform vec3 BlueMatrix;
+
+out vec4 fragColor;
+
+void main(){
+    vec2 mosaicInSize = InSize / MosaicSize;
+    vec2 fractPix = fract(texCoord * mosaicInSize) / mosaicInSize;
+
+    vec4 baseTexel = texture(DiffuseSampler, texCoord - fractPix);
+    float red = dot(baseTexel.rgb, RedMatrix);
+    float green = dot(baseTexel.rgb, GreenMatrix);
+    float blue = dot(baseTexel.rgb, BlueMatrix);
+
+    vec4 overlayTexel = texture(OverlaySampler, vec2(texCoord.x, 1.0 - texCoord.y));
+    overlayTexel.a = 1.0;
+    fragColor = mix(vec4(red, green, blue, 1.0), overlayTexel, overlayTexel.a);
+}