1 files changed, 75 insertions, 0 deletions
diff --git a/shaders/gst-gl-sin.frag b/shaders/gst-gl-sin.frag
new file mode 100644
index 0000000..4141e82
--- /dev/null
+++ b/shaders/gst-gl-sin.frag
@@ -0,0 +1,75 @@
+// [config]
+// expect_result: pass
+// glsl_version: 1.10
+//
+// # NOTE: Config section was auto-generated from file
+// # NOTE: 'glslparser.tests' at git revision
+// # NOTE: 6cc17ae70b70d150aa1751f8e28db7b2a9bd50f0
+// [end config]
+
+/*
+ * GStreamer
+ * Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library 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.
+ */
+
+#extension GL_ARB_texture_rectangle : enable
+uniform sampler2DRect tex;
+vec3 rgb2hsl (vec3 v)
+{
+/* TODO: check this algorythm */
+  float MIN, MAX;
+  float r, g, b;
+  float h, l, s;
+  float delta;
+  h = 0.0; l = 0.0; s = 0.0;
+  r = v.r; g = v.g; b = v.b;
+  MIN = min (r, min (g, b));
+  MAX = max (r, max (g, b));
+  delta = MAX - MIN;
+  l = (MAX + MIN) / 2.0;
+  if ((MAX - MIN) < 0.0001) { h = 0.0; s = 0.0; }
+  else {
+    if (l <= 0.5) s = (MAX - MIN) / (MAX + MIN);
+    else s = (MAX - MIN) / (2.0 - MAX - MIN);
+    if (r == MAX) h = (g - b) / delta;
+    else if (g == MAX) h = 2.0 + (b - r) / delta;
+    else h = 4.0 + (r - g) / delta;
+    h *= 60.0;
+    if (h < 0.0) h += 360.0;
+  }
+  return vec3 (h, l, s);
+}
+
+void main () {
+  vec3 HSL, RGB;
+  vec4 color = texture2DRect (tex, vec2(gl_TexCoord[0].st));
+  float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));
+  HSL = rgb2hsl (color.rgb);
+/* move hls discontinuity away from the desired red zone so we can use
+ * smoothstep.. to try: convert degrees in radiants, divide by 2 and
+ * smoothstep cosine */
+  HSL.x += 180.0;
+  if ((HSL.x) > 360.0) HSL.x -= 360.0;
+/* damn, it is extremely hard to get rid of human face reds! */
+/* picked hue is slightly shifted towards violet to prevent this but
+ * still fails.. maybe hsl is not well suited for this */
+  float a = smoothstep (110.0, 150.0, HSL.x);
+  float b = smoothstep (170.0, 210.0, HSL.x);
+  float alpha = a - b;
+  gl_FragColor = color * alpha + luma * (1.0 - alpha);
+}