1 files changed, 44 insertions, 0 deletions
diff --git a/src/graphics/shaders/horizshadow.frag b/src/graphics/shaders/horizshadow.frag
new file mode 100644
index 0000000..c9e512d
--- /dev/null
+++ b/src/graphics/shaders/horizshadow.frag
@@ -0,0 +1,44 @@
+//
+//  libavg - Media Playback Engine. 
+//  Copyright (C) 2003-2011 Ulrich von Zadow
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+//  Current versions can be found at www.libavg.de
+//
+
+uniform float u_Width;
+uniform int u_Radius;
+uniform sampler2D u_KernelTex;
+uniform sampler2D u_Texture;
+uniform vec2 u_Offset;
+
+#ifndef FRAGMENT_ONLY
+varying vec2 v_TexCoord;
+varying vec4 v_Color;
+#endif
+
+void main(void)
+{
+    float sum = 0.;
+    float dx = dFdx(v_TexCoord.x);
+    for (int i=-u_Radius; i<=u_Radius; ++i) {
+        float a = texture2D(u_Texture,
+                v_TexCoord-u_Offset+vec2(float(i)*dx,0)).a;
+        float coeff = texture2D(u_KernelTex, vec2((float(i+u_Radius)+0.5)/u_Width,0)).r;
+        sum += a*coeff;
+    }
+    gl_FragColor = vec4(sum, sum, sum, sum);
+}