Added new directory of GL shading language demos: glsl

1 files changed, 41 insertions, 0 deletions

diff --git a/progs/glsl/CH06-brick.vert.txt b/progs/glsl/CH06-brick.vert.txt
new file mode 100644
index 00000000000..e95e6f42f0b
--- /dev/null
+++ b/progs/glsl/CH06-brick.vert.txt
@@ -0,0 +1,41 @@
+//
+// Vertex 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 LightPosition;
+
+const float SpecularContribution = 0.3;
+const float DiffuseContribution  = 1.0 - SpecularContribution;
+
+varying float LightIntensity;
+varying vec2  MCposition;
+
+void main()
+{
+    vec3 ecPosition = vec3(gl_ModelViewMatrix * gl_Vertex);
+    vec3 tnorm      = normalize(gl_NormalMatrix * gl_Normal);
+    vec3 lightVec   = normalize(LightPosition - ecPosition);
+    vec3 reflectVec = reflect(-lightVec, tnorm);
+    vec3 viewVec    = normalize(-ecPosition);
+    float diffuse   = max(dot(lightVec, tnorm), 0.0);
+    float spec      = 0.0;
+
+    if (diffuse > 0.0)
+    {
+        spec = max(dot(reflectVec, viewVec), 0.0);
+        spec = pow(spec, 16.0);
+    }
+
+    LightIntensity  = DiffuseContribution * diffuse +
+                      SpecularContribution * spec;
+
+    MCposition      = gl_Vertex.xy;
+    gl_Position     = ftransform();
+}