From c7fb068ae5b51256a2ca0bd5fe44147443c62ccc Mon Sep 17 00:00:00 2001
From: hyzboy <hyzboy@gmail.com>
Date: Tue, 14 Jul 2020 19:51:15 +0800
Subject: [PATCH] add XorColor.frag

---
 shader/XorColor.frag | 49 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 shader/XorColor.frag

diff --git a/shader/XorColor.frag b/shader/XorColor.frag
new file mode 100644
index 0000000..0ebdfa7
--- /dev/null
+++ b/shader/XorColor.frag
@@ -0,0 +1,49 @@
+#version 450 core
+
+layout(location=0) out vec4 FragColor;
+
+layout(binding=1) uniform ColorMaterial
+{
+    vec4 color;
+} color_material;
+
+layout(binding=10) uniform WorldMatrix     // hgl/math/Math.h
+{
+    mat4 ortho;
+
+    mat4 projection;
+    mat4 inverse_projection;
+
+    mat4 modelview;
+    mat4 inverse_modelview;
+
+    mat4 mvp;
+    mat4 inverse_mvp;
+
+    vec4 view_pos;
+    vec2 canvas_resolution;
+    vec2 viewport_resolution;
+}fs_world;
+
+void main()
+{
+    vec2 p = 256.0 * gl_FragCoord.xy/fs_world.canvas_resolution.x;
+
+    float x = 0.0;
+
+    for( int i=0; i<7; i++ )
+    {
+        vec2 a = floor(p);
+        vec2 b = fract(p);
+
+        x += mod( a.x + a.y, 2.0 ) *
+
+            // the following line implements the smooth xor
+            mix( 1.0, 1.5*pow(4.0*(1.0-b.x)*b.x*(1.0-b.y)*b.y,0.25), 0.0 );
+
+        p /= 2.0;
+        x /= 2.0;
+    }
+
+    FragColor=vec4(color_material.color.rgb*x,1.0);
+}