1 files changed, 47 insertions, 0 deletions
diff --git a/vcl/opengl/combinedVertexShader.glsl b/vcl/opengl/combinedVertexShader.glsl
new file mode 100644
index 000000000000..9272544c33ef
--- /dev/null
+++ b/vcl/opengl/combinedVertexShader.glsl
@@ -0,0 +1,47 @@
+/* -*- 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/.
+ */
+
+attribute vec2 position;
+attribute vec4 extrusion_vectors;
+
+varying float fade_factor; // fade factor for anti-aliasing
+
+uniform float line_width;
+uniform float feather; // width where we fade the line
+
+uniform mat4 mvp;
+
+#define TYPE_NORMAL 0
+#define TYPE_LINE   1
+
+uniform int type;
+
+void main()
+{
+   vec4 final_position = vec4(position, 0.0, 1.0);
+
+   if (type == TYPE_LINE)
+   {
+      vec2 extrusion_vector = extrusion_vectors.xy;
+      // miter factor to additionaly lenghten the distance of vertex (needed for miter)
+      // if 1.0 - miter_factor has no effect
+      float miter_factor = 1.0f / abs(extrusion_vectors.z);
+      // fade factor is always -1.0 or 1.0 -> we transport that info together with length
+      fade_factor = sign(extrusion_vectors.z);
+
+      float rendered_thickness = (line_width + feather * 2.0) * miter_factor;
+
+      // lengthen the vertex in directon of the extrusion vector by line width.
+      final_position = vec4(position + (extrusion_vector * (rendered_thickness / 2.0) ), 0.0, 1.0);
+   }
+
+   gl_Position = mvp * final_position;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */