opengl: add flipping vertex shader

Add vertex shader which flips the texture upside down while blitting it.
Add argument to qemu_gl_run_texture_blit() to enable flipping.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20171010135453.6704-4-kraxel@redhat.com

1 files changed, 10 insertions, 0 deletions

diff --git a/ui/shader/texture-blit-flip.vert b/ui/shader/texture-blit-flip.vert
new file mode 100644
index 0000000..ba081fa
--- /dev/null
+++ b/ui/shader/texture-blit-flip.vert
@@ -0,0 +1,10 @@
+
+#version 300 es
+
+in vec2  in_position;
+out vec2 ex_tex_coord;
+
+void main(void) {
+    gl_Position = vec4(in_position, 0.0, 1.0);
+    ex_tex_coord = vec2(1.0 + in_position.x, 1.0 + in_position.y) * 0.5;
+}