1 files changed, 42 insertions, 0 deletions
diff --git a/advanced_opengl/8.geometry_shader/shaders/normals.geom b/advanced_opengl/8.geometry_shader/shaders/normals.geom
new file mode 100644
index 0000000..f0e1a75
--- /dev/null
+++ b/advanced_opengl/8.geometry_shader/shaders/normals.geom
@@ -0,0 +1,42 @@
+#version 330 core
+layout(triangles) in;
+layout(line_strip, max_vertices = 6) out;
+
+in VS_OUT {
+    vec3 normal;
+} gs_in[];
+
+uniform mat4 proj;
+
+const float MAGNITUDE = 0.4;
+
+void generate_line(int index)
+{
+    gl_Position = proj*gl_in[index].gl_Position;
+    EmitVertex();
+    gl_Position = proj*(gl_in[index].gl_Position+
+                              vec4(gs_in[index].normal, 0.0)*MAGNITUDE);
+    EmitVertex();
+    EndPrimitive();
+}
+
+void main(void)
+{
+    /*
+    vec4 center = (gl_in[0].gl_Position+
+                   gl_in[1].gl_Position+
+                   gl_in[2].gl_Position)/3.0;
+    vec4 end = center+vec4(((gs_in[0].normal+
+                             gs_in[1].normal+
+                             gs_in[2].normal)/3.0),
+                           0.0)*MAGNITUDE;
+    gl_Position = proj*center;
+    EmitVertex();
+    gl_Position = proj*end;
+    EmitVertex();
+    EndPrimitive();
+    */
+    generate_line(0);
+    generate_line(1);
+    generate_line(2);
+}