Added new directory of GL shading language demos: glsl

1 files changed, 36 insertions, 0 deletions

diff --git a/progs/glsl/CH06-brick.frag.txt b/progs/glsl/CH06-brick.frag.txt
new file mode 100644
index 00000000000..06ef04e3afb
--- /dev/null
+++ b/progs/glsl/CH06-brick.frag.txt
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+//
+// Fragment shader for procedural bricks
+//
+// Authors: Dave Baldwin, Steve Koren, Randi Rost
+//          based on a shader by Darwyn Peachey
+//
+// Copyright (c) 2002-2006 3Dlabs Inc. Ltd. 
+//
+// See 3Dlabs-License.txt for license information
+//
+
+uniform vec3  BrickColor, MortarColor;
+uniform vec2  BrickSize;
+uniform vec2  BrickPct;
+
+varying vec2  MCposition;
+varying float LightIntensity;
+
+void main()
+{
+    vec3  color;
+    vec2  position, useBrick;
+    
+    position = MCposition / BrickSize;
+
+    if (fract(position.y * 0.5) > 0.5)
+        position.x += 0.5;
+
+    position = fract(position);
+
+    useBrick = step(position, BrickPct);
+
+    color  = mix(MortarColor, BrickColor, useBrick.x * useBrick.y);
+    color *= LightIntensity;
+    gl_FragColor = vec4(color, 1.0);
+}