diff --git a/Assets/test/QRCode.mat b/Assets/test/QRCode.mat
index c9b6cac..86e7e76 100644
--- a/Assets/test/QRCode.mat
+++ b/Assets/test/QRCode.mat
@@ -61,6 +61,7 @@ Material:
         m_Scale: {x: 1, y: 1}
         m_Offset: {x: 0, y: 0}
     m_Ints:
+    - _DisableMask: 0
     - _Version: 15
     m_Floats:
     - _BumpScale: 1
@@ -70,6 +71,7 @@ Material:
     - _GlossMapScale: 1
     - _Glossiness: 0.5
     - _GlossyReflections: 1
+    - _Mask: 1
     - _Metallic: 0
     - _Mode: 0
     - _OcclusionStrength: 1
diff --git a/Assets/test/QRCode.shader b/Assets/test/QRCode.shader
index 3645021..388c93f 100644
--- a/Assets/test/QRCode.shader
+++ b/Assets/test/QRCode.shader
@@ -3,6 +3,9 @@ Properties {
 	[HideInInspector]
 	_("",2D)=""{}
 	_Version("Version", Range(1, 40)) = 1
+	_Mask("Mask type", Range(0, 7)) = 1
+	[Toggle]
+	_DisableMask("Hide mask", Integer) = 0
 	_TimeSlider("Time", Range(0, 250)) = 0
 }
 SubShader {
@@ -12,6 +15,8 @@ CGPROGRAM
 	#pragma surface s Standard
 	struct Input{float2 uv_;};
 	uint _Version;
+	uint _Mask;
+	bool _DisableMask;
 	float _TimeSlider;
 
 	#define VERSION _Version
@@ -32,7 +37,9 @@ CGPROGRAM
 	#define EC_LEVEL_H 2
 
 	#define EC_LEVEL EC_LEVEL_L
-	#define MASK_TYPE 1
+	#define MASK_TYPE _Mask
+	// ECI_MODE 0100 = byte
+	#define ECI_MODE 4
 
 	static const uint FORMAT_BIT_SETS[32] = {0x5412, 0x5125, 0x5e7c, 0x5b4b, 0x45f9, 0x40ce, 0x4f97, 0x4aa0, 0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976, 0x1689, 0x13be, 0x1ce7, 0x19d0, 0x0762, 0x0255, 0x0d0c, 0x083b, 0x355f, 0x3068, 0x3f31, 0x3a06, 0x24b4, 0x2183, 0x2eda, 0x2bed};
 	#define FORMAT_BITS_RAW ((EC_LEVEL << 3) | MASK_TYPE)
@@ -49,7 +56,6 @@ CGPROGRAM
 	#define BLACK 0
 	#define PINK float3(1, .3, .5)
 	#define BLUE float3(0, .4, .7)
-	#define CYAN float3(0,1,1)
 
 	float3 finder_pattern(uint x, uint y) {
 		if (x < 6 && x > 0 && y < 6 && y > 0) return !(x < 5 && x > 1 && y < 5 && y > 1);
@@ -57,11 +63,13 @@ CGPROGRAM
 	}
 
 	float3 main (float2 uv){
+		// hell_o wo_rld!
 		const uint data[] = {0x68656c6c,0x6f20776f,0x726c6421};
+		const uint data_len = 12;
 		uv.y = 1 - uv.y;
 		uv = uv * 1.5 - 0.25;
 		// Quiet zone
-		if (uv.x < 0 || uv.x > 1 || uv.y < 0 || uv.y > 1) return 1;
+		if (uv.x < 0 || uv.x > 1 || uv.y < 0 || uv.y > 1) return 2;
 
 		uint px = uv.x * PIXEL_WIDTH;
 		uint py = uv.y * PIXEL_WIDTH;
@@ -129,18 +137,56 @@ CGPROGRAM
 		}
 		if (px < 9)	bit_index -= 16; // rightmost tiny column
 
-		// debugging worm
-		uint worm = abs(TIME % BIT_COUNT - bit_index);
-		const uint length = 4;
-		if (worm < length) return CYAN * (worm/(float)length);
-		return (float)(bit_index%BIT_COUNT)/(float)BIT_COUNT;
+		// data
+		uint bit = 0;
+		if (bit_index < 4){
+			bit = (ECI_MODE >> (3-bit_index))&1;
+		} else if (bit_index < 12) {
+			bit = (data_len >> (7 - (bit_index - 4))) & 1;
+		} else if (bit_index < data_len*8 + 12){
+			uint data_bit_index = bit_index - 12;
+			bit = ((data[data_bit_index/32] >> (31-(data_bit_index % 32))) & 1);
+		}
 
-		// return lerp(BLUE, PINK, column / (WIDTH/2.));
-		return lerp(BLUE, PINK, (px+py)&1);
-		// return float3((px%5)/5., (px/10+py/10)&1, (py%5)/5.);
-		// return float3((px/8 + py/8) & 1, (px/2 + py/2) & 1, (px/4 + py/4) & 1, 1);
-		// return direction_up;
-		return 0.5;
+		// mask
+		uint mask;
+		switch (_Mask){
+			case 0:
+				mask = (px+py) % 2 == 0;
+				break;
+			case 1:
+				mask = py % 2 == 0;
+				break;
+			case 2:
+				mask = px % 3 == 0;
+				break;
+			case 3:
+				mask = (px+py) % 3 == 0;
+				break;
+			case 4:
+				mask = (py/2 + px/3) % 2 == 0;
+				break;
+			case 5:
+				mask = (py*px)%2 + (px*py)%3 == 0;
+				break;
+			case 6:
+				mask = ((py*px)%2 + (px*py)%3) % 2 == 0;
+				break;
+			case 7:
+				mask = ((py+px)%2 + (px*py)%3) % 2 == 0;
+				break;
+		}
+		if (!_DisableMask) {
+			bit ^= mask;
+		}
+
+		return !bit;
+
+		// // bit index debugging worm
+		// uint worm = abs(TIME % BIT_COUNT - bit_index);
+		// const uint length = 4;
+		// if (worm < length) return BLUE * (worm/(float)length);
+		// return (float)(bit_index%BIT_COUNT)/(float)BIT_COUNT;
 	}
 
 	void s (Input IN, inout SurfaceOutputStandard o) { o.Albedo = main(IN.uv_); }