1 files changed, 76 insertions, 0 deletions
diff --git a/vcl/opengl/shaders/combinedVertexShader.glsl b/vcl/opengl/shaders/combinedVertexShader.glsl
new file mode 100644
index 000000000..16fc4a942
--- /dev/null
+++ b/vcl/opengl/shaders/combinedVertexShader.glsl
@@ -0,0 +1,76 @@
+/* -*- 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 130
+
+attribute vec2 position;
+attribute vec4 extrusion_vectors;
+#ifdef USE_VERTEX_COLORS
+attribute vec4 vertex_color_in;
+#endif
+
+varying float fade_factor; // fade factor for anti-aliasing
+varying float multiply;
+
+#ifdef USE_VERTEX_COLORS
+varying vec4 vertex_color;
+#endif
+
+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()
+{
+   vec2 extrusion_vector = extrusion_vectors.xy;
+
+   float render_thickness = 0.0;
+
+   if (type == TYPE_LINE)
+   {
+      // miter factor to additionally lengthen the distance of vertex (needed for miter)
+      // if 1.0 - miter_factor has no effect
+      float miter_factor = 1.0 / 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);
+#ifdef USE_VERTEX_COLORS
+      float the_feather = (1.0 + sign(extrusion_vectors.w)) / 4.0;
+      float the_line_width = abs(extrusion_vectors.w);
+#else
+      float the_feather = feather;
+      float the_line_width = line_width;
+#endif
+      render_thickness = (the_line_width * miter_factor + the_feather * 2.0 * miter_factor);
+
+      // Calculate the multiplier so we can transform the 0->1 fade factor
+      // to take feather and line width into account.
+
+      float start = mix(0.0, (the_line_width / 2.0) - the_feather, the_feather * 2.0);
+      float end   = mix(1.0, (the_line_width / 2.0) + the_feather, the_feather * 2.0);
+
+      multiply = 1.0 / (1.0 - (start / end));
+   }
+
+   // lengthen the vertex in direction of the extrusion vector by line width.
+   vec4 final_position = vec4(position + (extrusion_vector * (render_thickness / 2.0) ), 0.0, 1.0);
+
+   gl_Position = mvp * final_position;
+
+#ifdef USE_VERTEX_COLORS
+   vertex_color = vertex_color_in / 255.0;
+#endif
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */