1 files changed, 35 insertions, 0 deletions
diff --git a/slideshow/opengl/fadeBlackFragmentShader.glsl b/slideshow/opengl/fadeBlackFragmentShader.glsl
new file mode 100644
index 0000000000..3d618a3b4b
--- /dev/null
+++ b/slideshow/opengl/fadeBlackFragmentShader.glsl
@@ -0,0 +1,35 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#version 120
+
+uniform sampler2D leavingSlideTexture;
+uniform sampler2D enteringSlideTexture;
+uniform float time;
+varying vec2 v_texturePosition;
+
+void main() {
+#ifdef use_white
+    vec4 color = vec4(1.0, 1.0, 1.0, 1.0);
+#else
+    vec4 color = vec4(0.0, 0.0, 0.0, 1.0);
+#endif
+    vec4 texel;
+    float amount;
+    if (time < 0.5) {
+        texel = texture2D(leavingSlideTexture, v_texturePosition);
+        amount = time * 2;
+    } else {
+        texel = texture2D(enteringSlideTexture, v_texturePosition);
+        amount = (1.0 - time) * 2;
+    }
+    gl_FragColor = mix(texel, color, amount);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */