vcl: Implement drawing of transformed bitmaps in OpenGL backend

Change-Id: I79717a608f33050b84244e378a6e51bd3be29232

1 files changed, 24 insertions, 0 deletions

diff --git a/vcl/opengl/transformedTextureVertexShader.glsl b/vcl/opengl/transformedTextureVertexShader.glsl
new file mode 100644
index 000000000000..51485a068871
--- /dev/null
+++ b/vcl/opengl/transformedTextureVertexShader.glsl
@@ -0,0 +1,24 @@
+/* -*- 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 vec4 position;
+attribute vec2 tex_coord_in;
+uniform vec2 viewport;
+uniform mat4 transform;
+varying vec2 tex_coord;
+
+void main() {
+    vec4 pos = transform * position;
+    pos.x = (2.0 * pos.x) / viewport.x - 1.0;
+    pos.y = 1.0 - (2.0 * pos.y / viewport.y);
+    gl_Position = pos;
+    tex_coord = tex_coord_in;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */